[all this code is from Kent, I'm helping him out because he's having
trouble with git send-email and OAUTH]
This should (hopefully) be the final iteration of this patch series.
Previous discussion:
https://lore.kernel.org/linux-mm/[email protected]/
Changes since v4:
- %pf(%p) format extension has been dropped for now, since it turned out to be
a bit controversial. I think we're going to want it, but I'm leaving it for a
future patch series.
- There was a small off by one error in the patch converting
trace_events_synth. The original code using seq_buf had to calculate the size
of the string to allocate; since printbufs have native support for heap
allocating strings, the version of the patch in this series just uses that
for a nice cleanup.
What are printbufs, and why?
============================
Printbufs are like the existing seq_buf, with some differences and new features:
- Heap allocation (optional)
Currently, we have no standard mechanism for printing to a heap-allocated
string: code that needs to do this must calculate the size of the buffer to
allocate, which is tedious and error prone. IOW, this is a major ergonomic
improvement.
- Indent level
Any time we're printing structured multi-line data, proper indenting makes
the output considerably more readable. Printbufs have state for the current
indent level, controlled by printbuf_indent_add() and printbuf_indent_sub()
and obeyed by prt_newline().
In the future this may work with just \n, pending work to do this without
performance regressions.
- Tab stops
Printing reports with nicely aligned columns is something we do a _lot_, and
printbufs make this a lot easier. After setting tabstops (byte offsets from
start of line), prt_tab() will output spaces up to the next tabstop, and
pr_tab_rjust() will right justify output since the previous output against
the next tabstap.
In the future this may work with just \t, pending work to do this without
performance regressions.
Why a new data structure, instead of extending seq_buf?
=======================================================
Some semantic changes were required. The main ones were:
- printbufs have different overflow semantics vs. seq_buf, to support
snprintf() which is required to return the number of characters that were
written even when an empty buffer is passed
- seq_buf has a readpos member which printbuf drops, since it's only for
tracing.
Also, a number of the existing seq_buf users were converted to printbuf's heap
allocation functionality, replacing open coded string size calculations and
allocations.
Given all this, adding the new thing and converting existing users one by one
felt like the more incremental/bisectable approach.
Goals of this patch series:
===========================
- A unified API for functions that output strings (i.e. pretty printers).
Currently, we've got a bit of a mess of different calling conventions for
functions that output strings. There's sprintf/snprintf style, seq_buf, and
various other variations of passing raw character pointers around.
- Low level helpers for building up strings (prt_char(), prt_str(), etc.).
This replaces a _lot_ of low level pointer arithmetic in vsprintf.c, and
elsewhere, with proper helpers.
- Cleanup of pretty-printers in vsprintf.c
Currently, we have a lot of pretty-printers in vsprintf.c invoked by various
%p extensions. However, arguments to those pretty printers are passed as
additional format string characters, instead of normal function arguments,
and we have the code that decodes format strings mixed with pretty-printer
code, which is not great for readability and makes those pretty-printers
unnecessarily tied to vsprintf.c internal details.
One of my goals is to give those pretty-printers normal function call
interfaces, and separate out the format-string parsing: this patch series
does some of the prep work. I've got more patches in progress in that vein,
but this patch series is big enough as is so I'm leaving them for later.
Kent Overstreet (32):
lib/printbuf: New data structure for printing strings
lib/string_helpers: Convert string_escape_mem() to printbuf
vsprintf: Convert to printbuf
lib/hexdump: Convert to printbuf
lib/string_helpers: string_get_size() now returns characters wrote
lib/printbuf: Heap allocation
lib/printbuf: Tabstops, indenting
lib/printbuf: Unit specifiers
vsprintf: Improve number()
vsprintf: prt_u64_minwidth(), prt_u64()
test_printf: Drop requirement that sprintf not write past nul
vsprintf: Start consolidating printf_spec handling
vsprintf: Refactor resource_string()
vsprintf: Refactor fourcc_string()
vsprintf: Refactor ip_addr_string()
vsprintf: Refactor mac_address_string()
vsprintf: time_and_date() no longer takes printf_spec
vsprintf: flags_string() no longer takes printf_spec
vsprintf: Refactor device_node_string, fwnode_string
vsprintf: Refactor hex_string, bitmap_string_list, bitmap_string
Input/joystick/analog: Convert from seq_buf -> printbuf
mm/memcontrol.c: Convert to printbuf
clk: tegra: bpmp: Convert to printbuf
tools/testing/nvdimm: Convert to printbuf
powerpc: Convert to printbuf
x86/resctrl: Convert to printbuf
PCI/P2PDMA: Convert to printbuf
tracing: trace_events_synth: Convert to printbuf
d_path: prt_path()
ACPI/APEI: Add missing include
tracing: Convert to printbuf
Delete seq_buf
arch/powerpc/kernel/process.c | 16 +-
arch/powerpc/kernel/security.c | 75 +-
arch/powerpc/platforms/pseries/papr_scm.c | 34 +-
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 +-
drivers/acpi/apei/erst-dbg.c | 1 +
drivers/clk/tegra/clk-bpmp.c | 21 +-
drivers/input/joystick/analog.c | 23 +-
drivers/pci/p2pdma.c | 21 +-
fs/d_path.c | 35 +
include/linux/dcache.h | 1 +
include/linux/kernel.h | 12 +
include/linux/printbuf.h | 257 ++++
include/linux/seq_buf.h | 162 --
include/linux/string.h | 5 +
include/linux/string_helpers.h | 8 +-
include/linux/trace_events.h | 2 +-
include/linux/trace_seq.h | 17 +-
kernel/trace/trace.c | 45 +-
kernel/trace/trace_dynevent.c | 34 +-
kernel/trace/trace_events_filter.c | 2 +-
kernel/trace/trace_events_synth.c | 53 +-
kernel/trace/trace_functions_graph.c | 6 +-
kernel/trace/trace_kprobe.c | 2 +-
kernel/trace/trace_seq.c | 111 +-
lib/Makefile | 4 +-
lib/hexdump.c | 246 ++--
lib/printbuf.c | 258 ++++
lib/seq_buf.c | 397 -----
lib/string_helpers.c | 224 +--
lib/test_hexdump.c | 30 +-
lib/test_printf.c | 6 -
lib/vsprintf.c | 1640 ++++++++++-----------
mm/memcontrol.c | 54 +-
tools/testing/nvdimm/test/ndtest.c | 22 +-
34 files changed, 1855 insertions(+), 1985 deletions(-)
create mode 100644 include/linux/printbuf.h
delete mode 100644 include/linux/seq_buf.h
create mode 100644 lib/printbuf.c
delete mode 100644 lib/seq_buf.c
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts vsnprintf() to printbufs: instead of passing around raw
char * pointers for current buf position and end of buf, we have a real
type!
This makes the calling convention for our existing pretty printers a lot
saner and less error prone, plus printbufs add some new helpers that
make the code smaller and more readable, with a lot less crazy pointer
arithmetic.
There are a lot more refactorings to be done: this patch tries to stick
to just converting the calling conventions, as that needs to be done all
at once in order to avoid introducing a ton of wrappers that will just
be deleted.
Thankfully we have good unit tests for printf, and they have been run
and are all passing with this patch.
We have two new exported functions with this patch:
- prt_printf(), which is like snprintf but outputs to a printbuf
- prt_vprintf, like vsnprintf
These are the actual core print routines now - vsnprintf() is a wrapper
around prt_vprintf().
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
include/linux/kernel.h | 4 +
include/linux/string.h | 5 +
lib/vsprintf.c | 1367 +++++++++++++++++++---------------------
3 files changed, 643 insertions(+), 733 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index fe6efb24d151..5c4f4b6d36ab 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -207,6 +207,10 @@ extern int num_to_str(char *buf, int size,
/* lib/printf utilities */
+struct printbuf;
+extern __printf(2, 3) void prt_printf(struct printbuf *out, const char *fmt, ...);
+extern __printf(2, 0) void prt_vprintf(struct printbuf *out, const char *fmt, va_list);
+
extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
extern __printf(3, 4)
diff --git a/include/linux/string.h b/include/linux/string.h
index 61ec7e4f6311..22a45d553fbc 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -195,7 +195,12 @@ int __sysfs_match_string(const char * const *array, size_t n, const char *s);
*/
#define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
+struct printbuf;
+
#ifdef CONFIG_BINARY_PRINTF
+void prt_vbinprintf(struct printbuf *out, const char *fmt, va_list args);
+void prt_bstrprintf(struct printbuf *out, const char *fmt, const u32 *bin_buf);
+void prt_bprintf(struct printbuf *out, const char *fmt, ...) __printf(2, 3);
int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf);
int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3c1853a9d1c0..52dac8519a0a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -44,6 +44,7 @@
#ifdef CONFIG_BLOCK
#include <linux/blkdev.h>
#endif
+#include <linux/printbuf.h>
#include "../mm/internal.h" /* For the trace_print_flags arrays */
@@ -451,8 +452,8 @@ static_assert(sizeof(struct printf_spec) == 8);
#define PRECISION_MAX ((1 << 15) - 1)
static noinline_for_stack
-char *number(char *buf, char *end, unsigned long long num,
- struct printf_spec spec)
+void number(struct printbuf *out, unsigned long long num,
+ struct printf_spec spec)
{
/* put_dec requires 2-byte alignment of the buffer. */
char tmp[3 * sizeof(num)] __aligned(2);
@@ -512,67 +513,43 @@ char *number(char *buf, char *end, unsigned long long num,
if (i > precision)
precision = i;
/* leading space padding */
- field_width -= precision;
- if (!(spec.flags & (ZEROPAD | LEFT))) {
- while (--field_width >= 0) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
+ field_width = max(0, field_width - precision);
+ if (!(spec.flags & (ZEROPAD | LEFT)) && field_width) {
+ __prt_chars(out, ' ', field_width);
+ field_width = 0;
}
/* sign */
- if (sign) {
- if (buf < end)
- *buf = sign;
- ++buf;
- }
+ if (sign)
+ __prt_char(out, sign);
/* "0x" / "0" prefix */
if (need_pfx) {
- if (spec.base == 16 || !is_zero) {
- if (buf < end)
- *buf = '0';
- ++buf;
- }
- if (spec.base == 16) {
- if (buf < end)
- *buf = ('X' | locase);
- ++buf;
- }
+ if (spec.base == 16 || !is_zero)
+ __prt_char(out, '0');
+ if (spec.base == 16)
+ __prt_char(out, 'X' | locase);
}
/* zero or space padding */
- if (!(spec.flags & LEFT)) {
+ if (!(spec.flags & LEFT) && field_width) {
char c = ' ' + (spec.flags & ZEROPAD);
- while (--field_width >= 0) {
- if (buf < end)
- *buf = c;
- ++buf;
- }
+ __prt_chars(out, c, field_width);
+ field_width = 0;
}
/* hmm even more zero padding? */
- while (i <= --precision) {
- if (buf < end)
- *buf = '0';
- ++buf;
- }
+ if (precision > i)
+ __prt_chars(out, '0', precision - i);
/* actual digits of result */
- while (--i >= 0) {
- if (buf < end)
- *buf = tmp[i];
- ++buf;
- }
+ while (--i >= 0)
+ __prt_char(out, tmp[i]);
/* trailing space padding */
- while (--field_width >= 0) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
+ if (field_width)
+ __prt_chars(out, ' ', field_width);
- return buf;
+ printbuf_nul_terminate(out);
}
static noinline_for_stack
-char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
+void special_hex_number(struct printbuf *out, unsigned long long num, int size)
{
struct printf_spec spec;
@@ -582,25 +559,28 @@ char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
spec.base = 16;
spec.precision = -1;
- return number(buf, end, num, spec);
+ number(out, num, spec);
}
-static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
+/*
+ * inserts @spaces spaces @len from the end of @out
+ */
+static void move_right(struct printbuf *out,
+ unsigned len, unsigned spaces)
{
- size_t size;
- if (buf >= end) /* nowhere to put anything */
- return;
- size = end - buf;
- if (size <= spaces) {
- memset(buf, ' ', size);
- return;
- }
- if (len) {
- if (len > size - spaces)
- len = size - spaces;
- memmove(buf + spaces, buf, len);
- }
- memset(buf, ' ', spaces);
+ unsigned move_src = out->pos - len;
+ unsigned move_dst = move_src + spaces;
+ unsigned remaining_from_dst = move_dst < out->size ? out->size - move_dst : 0;
+ unsigned remaining_from_src = move_src < out->size ? out->size - move_src : 0;
+
+ BUG_ON(len > out->pos);
+
+ memmove(out->buf + move_dst,
+ out->buf + move_src,
+ min(remaining_from_dst, len));
+ memset(out->buf + move_src, ' ',
+ min(remaining_from_src, spaces));
+ out->pos += spaces;
}
/*
@@ -612,67 +592,55 @@ static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
* Returns: new buffer position after padding.
*/
static noinline_for_stack
-char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
+void widen_string(struct printbuf *out, int n,
+ struct printf_spec spec)
{
unsigned spaces;
if (likely(n >= spec.field_width))
- return buf;
+ return;
/* we want to pad the sucker */
spaces = spec.field_width - n;
- if (!(spec.flags & LEFT)) {
- move_right(buf - n, end, n, spaces);
- return buf + spaces;
- }
- while (spaces--) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
- return buf;
+ if (!(spec.flags & LEFT))
+ move_right(out, n, spaces);
+ else
+ prt_chars(out, ' ', spaces);
}
/* Handle string from a well known address. */
-static char *string_nocheck(char *buf, char *end, const char *s,
- struct printf_spec spec)
+static void string_nocheck(struct printbuf *out,
+ const char *s,
+ struct printf_spec spec)
{
- int len = 0;
- int lim = spec.precision;
+ int len = strnlen(s, spec.precision);
- while (lim--) {
- char c = *s++;
- if (!c)
- break;
- if (buf < end)
- *buf = c;
- ++buf;
- ++len;
- }
- return widen_string(buf, len, end, spec);
+ prt_bytes(out, s, len);
+ widen_string(out, len, spec);
}
-static char *err_ptr(char *buf, char *end, void *ptr,
- struct printf_spec spec)
+static void err_ptr(struct printbuf *out, void *ptr,
+ struct printf_spec spec)
{
int err = PTR_ERR(ptr);
const char *sym = errname(err);
- if (sym)
- return string_nocheck(buf, end, sym, spec);
-
- /*
- * Somebody passed ERR_PTR(-1234) or some other non-existing
- * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
- * printing it as its decimal representation.
- */
- spec.flags |= SIGN;
- spec.base = 10;
- return number(buf, end, err, spec);
+ if (sym) {
+ string_nocheck(out, sym, spec);
+ } else {
+ /*
+ * Somebody passed ERR_PTR(-1234) or some other non-existing
+ * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
+ * printing it as its decimal representation.
+ */
+ spec.flags |= SIGN;
+ spec.base = 10;
+ number(out, err, spec);
+ }
}
/* Be careful: error messages must fit into the given buffer. */
-static char *error_string(char *buf, char *end, const char *s,
- struct printf_spec spec)
+static void error_string(struct printbuf *out, const char *s,
+ struct printf_spec spec)
{
/*
* Hard limit to avoid a completely insane messages. It actually
@@ -682,7 +650,7 @@ static char *error_string(char *buf, char *end, const char *s,
if (spec.precision == -1)
spec.precision = 2 * sizeof(void *);
- return string_nocheck(buf, end, s, spec);
+ string_nocheck(out, s, spec);
}
/*
@@ -701,14 +669,15 @@ static const char *check_pointer_msg(const void *ptr)
return NULL;
}
-static int check_pointer(char **buf, char *end, const void *ptr,
+static int check_pointer(struct printbuf *out,
+ const void *ptr,
struct printf_spec spec)
{
const char *err_msg;
err_msg = check_pointer_msg(ptr);
if (err_msg) {
- *buf = error_string(*buf, end, err_msg, spec);
+ error_string(out, err_msg, spec);
return -EFAULT;
}
@@ -716,18 +685,19 @@ static int check_pointer(char **buf, char *end, const void *ptr,
}
static noinline_for_stack
-char *string(char *buf, char *end, const char *s,
- struct printf_spec spec)
+void string(struct printbuf *out,
+ const char *s,
+ struct printf_spec spec)
{
- if (check_pointer(&buf, end, s, spec))
- return buf;
+ if (check_pointer(out, s, spec))
+ return;
- return string_nocheck(buf, end, s, spec);
+ string_nocheck(out, s, spec);
}
-static char *pointer_string(char *buf, char *end,
- const void *ptr,
- struct printf_spec spec)
+static void pointer_string(struct printbuf *out,
+ const void *ptr,
+ struct printf_spec spec)
{
spec.base = 16;
spec.flags |= SMALL;
@@ -736,7 +706,7 @@ static char *pointer_string(char *buf, char *end,
spec.flags |= ZEROPAD;
}
- return number(buf, end, (unsigned long int)ptr, spec);
+ number(out, (unsigned long int)ptr, spec);
}
/* Make pointers available for printing early in the boot sequence. */
@@ -801,8 +771,9 @@ int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
return __ptr_to_hashval(ptr, hashval_out);
}
-static char *ptr_to_id(char *buf, char *end, const void *ptr,
- struct printf_spec spec)
+static void ptr_to_id(struct printbuf *out,
+ const void *ptr,
+ struct printf_spec spec)
{
const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
unsigned long hashval;
@@ -813,47 +784,49 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
* as they are not actual addresses.
*/
if (IS_ERR_OR_NULL(ptr))
- return pointer_string(buf, end, ptr, spec);
+ return pointer_string(out, ptr, spec);
/* When debugging early boot use non-cryptographically secure hash. */
if (unlikely(debug_boot_weak_hash)) {
hashval = hash_long((unsigned long)ptr, 32);
- return pointer_string(buf, end, (const void *)hashval, spec);
+ return pointer_string(out, (const void *)hashval, spec);
}
ret = __ptr_to_hashval(ptr, &hashval);
if (ret) {
spec.field_width = 2 * sizeof(ptr);
/* string length must be less than default_width */
- return error_string(buf, end, str, spec);
+ return error_string(out, str, spec);
}
- return pointer_string(buf, end, (const void *)hashval, spec);
+ pointer_string(out, (const void *)hashval, spec);
}
-static char *default_pointer(char *buf, char *end, const void *ptr,
- struct printf_spec spec)
+static void default_pointer(struct printbuf *out,
+ const void *ptr,
+ struct printf_spec spec)
{
/*
* default is to _not_ leak addresses, so hash before printing,
* unless no_hash_pointers is specified on the command line.
*/
if (unlikely(no_hash_pointers))
- return pointer_string(buf, end, ptr, spec);
+ return pointer_string(out, ptr, spec);
- return ptr_to_id(buf, end, ptr, spec);
+ return ptr_to_id(out, ptr, spec);
}
int kptr_restrict __read_mostly;
static noinline_for_stack
-char *restricted_pointer(char *buf, char *end, const void *ptr,
- struct printf_spec spec)
+void restricted_pointer(struct printbuf *out,
+ const void *ptr,
+ struct printf_spec spec)
{
switch (kptr_restrict) {
case 0:
/* Handle as %p, hash and do _not_ leak addresses. */
- return default_pointer(buf, end, ptr, spec);
+ return default_pointer(out, ptr, spec);
case 1: {
const struct cred *cred;
@@ -864,7 +837,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
if (in_irq() || in_serving_softirq() || in_nmi()) {
if (spec.field_width == -1)
spec.field_width = 2 * sizeof(ptr);
- return error_string(buf, end, "pK-error", spec);
+ return error_string(out, "pK-error", spec);
}
/*
@@ -890,12 +863,13 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
break;
}
- return pointer_string(buf, end, ptr, spec);
+ return pointer_string(out, ptr, spec);
}
static noinline_for_stack
-char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
- const char *fmt)
+void dentry_name(struct printbuf *out,
+ const struct dentry *d, struct printf_spec spec,
+ const char *fmt)
{
const char *array[4], *s;
const struct dentry *p;
@@ -912,9 +886,9 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
rcu_read_lock();
for (i = 0; i < depth; i++, d = p) {
- if (check_pointer(&buf, end, d, spec)) {
+ if (check_pointer(out, d, spec)) {
rcu_read_unlock();
- return buf;
+ return;
}
p = READ_ONCE(d->d_parent);
@@ -927,7 +901,7 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
}
}
s = array[--i];
- for (n = 0; n != spec.precision; n++, buf++) {
+ for (n = 0; n != spec.precision; n++) {
char c = *s++;
if (!c) {
if (!i)
@@ -935,49 +909,47 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
c = '/';
s = array[--i];
}
- if (buf < end)
- *buf = c;
+ prt_char(out, c);
}
rcu_read_unlock();
- return widen_string(buf, n, end, spec);
+
+ widen_string(out, n, spec);
}
static noinline_for_stack
-char *file_dentry_name(char *buf, char *end, const struct file *f,
- struct printf_spec spec, const char *fmt)
+void file_dentry_name(struct printbuf *out,
+ const struct file *f,
+ struct printf_spec spec, const char *fmt)
{
- if (check_pointer(&buf, end, f, spec))
- return buf;
+ if (check_pointer(out, f, spec))
+ return;
- return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
+ return dentry_name(out, f->f_path.dentry, spec, fmt);
}
#ifdef CONFIG_BLOCK
static noinline_for_stack
-char *bdev_name(char *buf, char *end, struct block_device *bdev,
- struct printf_spec spec, const char *fmt)
+void bdev_name(struct printbuf *out,
+ struct block_device *bdev,
+ struct printf_spec spec, const char *fmt)
{
struct gendisk *hd;
- if (check_pointer(&buf, end, bdev, spec))
- return buf;
+ if (check_pointer(out, bdev, spec))
+ return;
hd = bdev->bd_disk;
- buf = string(buf, end, hd->disk_name, spec);
+ string(out, hd->disk_name, spec);
if (bdev->bd_partno) {
- if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
- if (buf < end)
- *buf = 'p';
- buf++;
- }
- buf = number(buf, end, bdev->bd_partno, spec);
+ if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
+ prt_char(out, 'p');
+ number(out, bdev->bd_partno, spec);
}
- return buf;
}
#endif
static noinline_for_stack
-char *symbol_string(char *buf, char *end, void *ptr,
- struct printf_spec spec, const char *fmt)
+void symbol_string(struct printbuf *out, void *ptr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long value;
#ifdef CONFIG_KALLSYMS
@@ -1000,9 +972,9 @@ char *symbol_string(char *buf, char *end, void *ptr,
else
sprint_symbol_no_offset(sym, value);
- return string_nocheck(buf, end, sym, spec);
+ string_nocheck(out, sym, spec);
#else
- return special_hex_number(buf, end, value, sizeof(void *));
+ special_hex_number(out, value, sizeof(void *));
#endif
}
@@ -1037,8 +1009,8 @@ static const struct printf_spec default_dec04_spec = {
};
static noinline_for_stack
-char *resource_string(char *buf, char *end, struct resource *res,
- struct printf_spec spec, const char *fmt)
+void resource_string(struct printbuf *out, struct resource *res,
+ struct printf_spec spec, const char *fmt)
{
#ifndef IO_RSRC_PRINTK_SIZE
#define IO_RSRC_PRINTK_SIZE 6
@@ -1077,69 +1049,67 @@ char *resource_string(char *buf, char *end, struct resource *res,
#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
- char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
+ char sym_buf[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
-
- char *p = sym, *pend = sym + sizeof(sym);
+ struct printbuf sym = PRINTBUF_EXTERN(sym_buf, sizeof(sym_buf));
int decode = (fmt[0] == 'R') ? 1 : 0;
const struct printf_spec *specp;
- if (check_pointer(&buf, end, res, spec))
- return buf;
+ if (check_pointer(out, res, spec))
+ return;
- *p++ = '[';
+ prt_char(&sym, '[');
if (res->flags & IORESOURCE_IO) {
- p = string_nocheck(p, pend, "io ", str_spec);
+ string_nocheck(&sym, "io ", str_spec);
specp = &io_spec;
} else if (res->flags & IORESOURCE_MEM) {
- p = string_nocheck(p, pend, "mem ", str_spec);
+ string_nocheck(&sym, "mem ", str_spec);
specp = &mem_spec;
} else if (res->flags & IORESOURCE_IRQ) {
- p = string_nocheck(p, pend, "irq ", str_spec);
+ string_nocheck(&sym, "irq ", str_spec);
specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_DMA) {
- p = string_nocheck(p, pend, "dma ", str_spec);
+ string_nocheck(&sym, "dma ", str_spec);
specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_BUS) {
- p = string_nocheck(p, pend, "bus ", str_spec);
+ string_nocheck(&sym, "bus ", str_spec);
specp = &bus_spec;
} else {
- p = string_nocheck(p, pend, "??? ", str_spec);
+ string_nocheck(&sym, "??? ", str_spec);
specp = &mem_spec;
decode = 0;
}
if (decode && res->flags & IORESOURCE_UNSET) {
- p = string_nocheck(p, pend, "size ", str_spec);
- p = number(p, pend, resource_size(res), *specp);
+ string_nocheck(&sym, "size ", str_spec);
+ number(&sym, resource_size(res), *specp);
} else {
- p = number(p, pend, res->start, *specp);
+ number(&sym, res->start, *specp);
if (res->start != res->end) {
- *p++ = '-';
- p = number(p, pend, res->end, *specp);
+ prt_char(&sym, '-');
+ number(&sym, res->end, *specp);
}
}
if (decode) {
if (res->flags & IORESOURCE_MEM_64)
- p = string_nocheck(p, pend, " 64bit", str_spec);
+ string_nocheck(&sym, " 64bit", str_spec);
if (res->flags & IORESOURCE_PREFETCH)
- p = string_nocheck(p, pend, " pref", str_spec);
+ string_nocheck(&sym, " pref", str_spec);
if (res->flags & IORESOURCE_WINDOW)
- p = string_nocheck(p, pend, " window", str_spec);
+ string_nocheck(&sym, " window", str_spec);
if (res->flags & IORESOURCE_DISABLED)
- p = string_nocheck(p, pend, " disabled", str_spec);
+ string_nocheck(&sym, " disabled", str_spec);
} else {
- p = string_nocheck(p, pend, " flags ", str_spec);
- p = number(p, pend, res->flags, default_flag_spec);
+ string_nocheck(&sym, " flags ", str_spec);
+ number(&sym, res->flags, default_flag_spec);
}
- *p++ = ']';
- *p = '\0';
+ prt_char(&sym, ']');
- return string_nocheck(buf, end, sym, spec);
+ string_nocheck(out, sym_buf, spec);
}
static noinline_for_stack
-char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
- const char *fmt)
+void hex_string(struct printbuf *out, u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
int i, len = 1; /* if we pass '%ph[CDN]', field width remains
negative value, fallback to the default */
@@ -1147,10 +1117,10 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
if (spec.field_width == 0)
/* nothing to print */
- return buf;
+ return;
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
switch (fmt[1]) {
case 'C':
@@ -1171,34 +1141,27 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
len = min_t(int, spec.field_width, 64);
for (i = 0; i < len; ++i) {
- if (buf < end)
- *buf = hex_asc_hi(addr[i]);
- ++buf;
- if (buf < end)
- *buf = hex_asc_lo(addr[i]);
- ++buf;
-
- if (separator && i != len - 1) {
- if (buf < end)
- *buf = separator;
- ++buf;
- }
+ __prt_char(out, hex_asc_hi(addr[i]));
+ __prt_char(out, hex_asc_lo(addr[i]));
+
+ if (separator && i != len - 1)
+ __prt_char(out, separator);
}
- return buf;
+ printbuf_nul_terminate(out);
}
static noinline_for_stack
-char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+void bitmap_string(struct printbuf *out, unsigned long *bitmap,
+ struct printf_spec spec, const char *fmt)
{
const int CHUNKSZ = 32;
int nr_bits = max_t(int, spec.field_width, 0);
int i, chunksz;
bool first = true;
- if (check_pointer(&buf, end, bitmap, spec))
- return buf;
+ if (check_pointer(out, bitmap, spec))
+ return;
/* reused to print numbers */
spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
@@ -1217,54 +1180,45 @@ char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
bit = i % BITS_PER_LONG;
val = (bitmap[word] >> bit) & chunkmask;
- if (!first) {
- if (buf < end)
- *buf = ',';
- buf++;
- }
+ if (!first)
+ prt_char(out, ',');
first = false;
spec.field_width = DIV_ROUND_UP(chunksz, 4);
- buf = number(buf, end, val, spec);
+ number(out, val, spec);
chunksz = CHUNKSZ;
}
- return buf;
}
static noinline_for_stack
-char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
+ struct printf_spec spec, const char *fmt)
{
int nr_bits = max_t(int, spec.field_width, 0);
bool first = true;
int rbot, rtop;
- if (check_pointer(&buf, end, bitmap, spec))
- return buf;
+ if (check_pointer(out, bitmap, spec))
+ return ;
for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
- if (!first) {
- if (buf < end)
- *buf = ',';
- buf++;
- }
+ if (!first)
+ prt_char(out, ',');
first = false;
- buf = number(buf, end, rbot, default_dec_spec);
+ number(out, rbot, default_dec_spec);
if (rtop == rbot + 1)
continue;
- if (buf < end)
- *buf = '-';
- buf = number(++buf, end, rtop - 1, default_dec_spec);
+ prt_char(out, '-');
+ number(out, rtop - 1, default_dec_spec);
}
- return buf;
}
static noinline_for_stack
-char *mac_address_string(char *buf, char *end, u8 *addr,
- struct printf_spec spec, const char *fmt)
+void mac_address_string(struct printbuf *out, u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
char *p = mac_addr;
@@ -1272,8 +1226,8 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
char separator;
bool reversed = false;
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
switch (fmt[1]) {
case 'F':
@@ -1300,11 +1254,12 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
}
*p = '\0';
- return string_nocheck(buf, end, mac_addr, spec);
+ string_nocheck(out, mac_addr, spec);
}
static noinline_for_stack
-char *ip4_string(char *p, const u8 *addr, const char *fmt)
+void ip4_string(struct printbuf *out,
+ const u8 *addr, const char *fmt)
{
int i;
bool leading_zeros = (fmt[0] == 'i');
@@ -1337,24 +1292,21 @@ char *ip4_string(char *p, const u8 *addr, const char *fmt)
int digits = put_dec_trunc8(temp, addr[index]) - temp;
if (leading_zeros) {
if (digits < 3)
- *p++ = '0';
+ prt_char(out, '0');
if (digits < 2)
- *p++ = '0';
+ prt_char(out, '0');
}
/* reverse the digits in the quad */
while (digits--)
- *p++ = temp[digits];
+ prt_char(out, temp[digits]);
if (i < 3)
- *p++ = '.';
+ prt_char(out, '.');
index += step;
}
- *p = '\0';
-
- return p;
}
static noinline_for_stack
-char *ip6_compressed_string(char *p, const char *addr)
+void ip6_compressed_string(struct printbuf *out, const char *addr)
{
int i, j, range;
unsigned char zerolength[8];
@@ -1398,14 +1350,14 @@ char *ip6_compressed_string(char *p, const char *addr)
for (i = 0; i < range; i++) {
if (i == colonpos) {
if (needcolon || i == 0)
- *p++ = ':';
- *p++ = ':';
+ __prt_char(out, ':');
+ __prt_char(out, ':');
needcolon = false;
i += longest - 1;
continue;
}
if (needcolon) {
- *p++ = ':';
+ __prt_char(out, ':');
needcolon = false;
}
/* hex u16 without leading 0s */
@@ -1414,81 +1366,79 @@ char *ip6_compressed_string(char *p, const char *addr)
lo = word & 0xff;
if (hi) {
if (hi > 0x0f)
- p = hex_byte_pack(p, hi);
+ prt_hex_byte(out, hi);
else
- *p++ = hex_asc_lo(hi);
- p = hex_byte_pack(p, lo);
+ __prt_char(out, hex_asc_lo(hi));
+ prt_hex_byte(out, lo);
}
else if (lo > 0x0f)
- p = hex_byte_pack(p, lo);
+ prt_hex_byte(out, lo);
else
- *p++ = hex_asc_lo(lo);
+ __prt_char(out, hex_asc_lo(lo));
needcolon = true;
}
if (useIPv4) {
if (needcolon)
- *p++ = ':';
- p = ip4_string(p, &in6.s6_addr[12], "I4");
+ __prt_char(out, ':');
+ ip4_string(out, &in6.s6_addr[12], "I4");
}
- *p = '\0';
- return p;
+ printbuf_nul_terminate(out);
}
static noinline_for_stack
-char *ip6_string(char *p, const char *addr, const char *fmt)
+void ip6_string(struct printbuf *out, const char *addr, const char *fmt)
{
int i;
for (i = 0; i < 8; i++) {
- p = hex_byte_pack(p, *addr++);
- p = hex_byte_pack(p, *addr++);
+ prt_hex_byte(out, *addr++);
+ prt_hex_byte(out, *addr++);
if (fmt[0] == 'I' && i != 7)
- *p++ = ':';
+ prt_char(out, ':');
}
- *p = '\0';
-
- return p;
}
static noinline_for_stack
-char *ip6_addr_string(char *buf, char *end, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+void ip6_addr_string(struct printbuf *out, const u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
- char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
+ char ip6_addr_buf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
+ struct printbuf ip6_addr = PRINTBUF_EXTERN(ip6_addr_buf, sizeof(ip6_addr_buf));
if (fmt[0] == 'I' && fmt[2] == 'c')
- ip6_compressed_string(ip6_addr, addr);
+ ip6_compressed_string(&ip6_addr, addr);
else
- ip6_string(ip6_addr, addr, fmt);
+ ip6_string(&ip6_addr, addr, fmt);
- return string_nocheck(buf, end, ip6_addr, spec);
+ string_nocheck(out, ip6_addr_buf, spec);
}
static noinline_for_stack
-char *ip4_addr_string(char *buf, char *end, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+void ip4_addr_string(struct printbuf *out, const u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
- char ip4_addr[sizeof("255.255.255.255")];
+ char ip4_addr_buf[sizeof("255.255.255.255")];
+ struct printbuf ip4_addr = PRINTBUF_EXTERN(ip4_addr_buf, sizeof(ip4_addr_buf));
- ip4_string(ip4_addr, addr, fmt);
+ ip4_string(&ip4_addr, addr, fmt);
- return string_nocheck(buf, end, ip4_addr, spec);
+ string_nocheck(out, ip4_addr_buf, spec);
}
static noinline_for_stack
-char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
- struct printf_spec spec, const char *fmt)
+void ip6_addr_string_sa(struct printbuf *out,
+ const struct sockaddr_in6 *sa,
+ struct printf_spec spec, const char *fmt)
{
bool have_p = false, have_s = false, have_f = false, have_c = false;
- char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
- sizeof(":12345") + sizeof("/123456789") +
- sizeof("%1234567890")];
- char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
+ char ip6_addr_buf[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
+ sizeof(":12345") + sizeof("/123456789") +
+ sizeof("%1234567890")];
+ struct printbuf ip6_addr = PRINTBUF_EXTERN(ip6_addr_buf, sizeof(ip6_addr_buf));
const u8 *addr = (const u8 *) &sa->sin6_addr;
char fmt6[2] = { fmt[0], '6' };
- u8 off = 0;
fmt++;
while (isalpha(*++fmt)) {
@@ -1508,44 +1458,42 @@ char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
}
}
- if (have_p || have_s || have_f) {
- *p = '[';
- off = 1;
- }
+ if (have_p || have_s || have_f)
+ prt_char(&ip6_addr, '[');
if (fmt6[0] == 'I' && have_c)
- p = ip6_compressed_string(ip6_addr + off, addr);
+ ip6_compressed_string(&ip6_addr, addr);
else
- p = ip6_string(ip6_addr + off, addr, fmt6);
+ ip6_string(&ip6_addr, addr, fmt6);
if (have_p || have_s || have_f)
- *p++ = ']';
+ prt_char(&ip6_addr, ']');
if (have_p) {
- *p++ = ':';
- p = number(p, pend, ntohs(sa->sin6_port), spec);
+ prt_char(&ip6_addr, ':');
+ number(&ip6_addr, ntohs(sa->sin6_port), spec);
}
if (have_f) {
- *p++ = '/';
- p = number(p, pend, ntohl(sa->sin6_flowinfo &
- IPV6_FLOWINFO_MASK), spec);
+ prt_char(&ip6_addr, '/');
+ number(&ip6_addr, ntohl(sa->sin6_flowinfo &
+ IPV6_FLOWINFO_MASK), spec);
}
if (have_s) {
- *p++ = '%';
- p = number(p, pend, sa->sin6_scope_id, spec);
+ prt_char(&ip6_addr, '%');
+ number(&ip6_addr, sa->sin6_scope_id, spec);
}
- *p = '\0';
- return string_nocheck(buf, end, ip6_addr, spec);
+ string_nocheck(out, ip6_addr_buf, spec);
}
static noinline_for_stack
-char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
- struct printf_spec spec, const char *fmt)
+void ip4_addr_string_sa(struct printbuf *out,
+ const struct sockaddr_in *sa,
+ struct printf_spec spec, const char *fmt)
{
bool have_p = false;
- char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
- char *pend = ip4_addr + sizeof(ip4_addr);
+ char ip4_addr_buf[sizeof("255.255.255.255") + sizeof(":12345")];
+ struct printbuf ip4_addr = PRINTBUF_EXTERN(ip4_addr_buf, sizeof(ip4_addr_buf));
const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
char fmt4[3] = { fmt[0], '4', 0 };
@@ -1564,30 +1512,29 @@ char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
}
}
- p = ip4_string(ip4_addr, addr, fmt4);
+ ip4_string(&ip4_addr, addr, fmt4);
if (have_p) {
- *p++ = ':';
- p = number(p, pend, ntohs(sa->sin_port), spec);
+ prt_char(&ip4_addr, ':');
+ number(&ip4_addr, ntohs(sa->sin_port), spec);
}
- *p = '\0';
- return string_nocheck(buf, end, ip4_addr, spec);
+ string_nocheck(out, ip4_addr_buf, spec);
}
static noinline_for_stack
-char *ip_addr_string(char *buf, char *end, const void *ptr,
- struct printf_spec spec, const char *fmt)
+void ip_addr_string(struct printbuf *out, const void *ptr,
+ struct printf_spec spec, const char *fmt)
{
char *err_fmt_msg;
- if (check_pointer(&buf, end, ptr, spec))
- return buf;
+ if (check_pointer(out, ptr, spec))
+ return;
switch (fmt[1]) {
case '6':
- return ip6_addr_string(buf, end, ptr, spec, fmt);
+ return ip6_addr_string(out, ptr, spec, fmt);
case '4':
- return ip4_addr_string(buf, end, ptr, spec, fmt);
+ return ip4_addr_string(out, ptr, spec, fmt);
case 'S': {
const union {
struct sockaddr raw;
@@ -1597,21 +1544,21 @@ char *ip_addr_string(char *buf, char *end, const void *ptr,
switch (sa->raw.sa_family) {
case AF_INET:
- return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
+ return ip4_addr_string_sa(out, &sa->v4, spec, fmt);
case AF_INET6:
- return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
+ return ip6_addr_string_sa(out, &sa->v6, spec, fmt);
default:
- return error_string(buf, end, "(einval)", spec);
+ return error_string(out, "(einval)", spec);
}}
}
err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
- return error_string(buf, end, err_fmt_msg, spec);
+ return error_string(out, err_fmt_msg, spec);
}
static noinline_for_stack
-char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
- const char *fmt)
+void escaped_string(struct printbuf *out, u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
bool found = true;
int count = 1;
@@ -1619,10 +1566,10 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
int len;
if (spec.field_width == 0)
- return buf; /* nothing to print */
+ return; /* nothing to print */
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
do {
switch (fmt[count++]) {
@@ -1657,44 +1604,35 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
flags = ESCAPE_ANY_NP;
len = spec.field_width < 0 ? 1 : spec.field_width;
-
- /*
- * string_escape_mem() writes as many characters as it can to
- * the given buffer, and returns the total size of the output
- * had the buffer been big enough.
- */
- buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
-
- return buf;
+ prt_escaped_string(out, addr, len, flags, NULL);
}
-static char *va_format(char *buf, char *end, struct va_format *va_fmt,
- struct printf_spec spec, const char *fmt)
+static void va_format(struct printbuf *out,
+ struct va_format *va_fmt,
+ struct printf_spec spec, const char *fmt)
{
va_list va;
- if (check_pointer(&buf, end, va_fmt, spec))
- return buf;
+ if (check_pointer(out, va_fmt, spec))
+ return;
va_copy(va, *va_fmt->va);
- buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
+ prt_vprintf(out, va_fmt->fmt, va);
va_end(va);
-
- return buf;
}
static noinline_for_stack
-char *uuid_string(char *buf, char *end, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+void uuid_string(struct printbuf *out, const u8 *addr,
+ struct printf_spec spec, const char *fmt)
{
- char uuid[UUID_STRING_LEN + 1];
- char *p = uuid;
+ char uuid_buf[UUID_STRING_LEN + 1];
+ struct printbuf uuid = PRINTBUF_EXTERN(uuid_buf, sizeof(uuid_buf));
int i;
const u8 *index = uuid_index;
bool uc = false;
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
switch (*(++fmt)) {
case 'L':
@@ -1710,60 +1648,58 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
for (i = 0; i < 16; i++) {
if (uc)
- p = hex_byte_pack_upper(p, addr[index[i]]);
+ prt_hex_byte_upper(&uuid, addr[index[i]]);
else
- p = hex_byte_pack(p, addr[index[i]]);
+ prt_hex_byte(&uuid, addr[index[i]]);
switch (i) {
case 3:
case 5:
case 7:
case 9:
- *p++ = '-';
+ prt_char(&uuid, '-');
break;
}
}
- *p = 0;
-
- return string_nocheck(buf, end, uuid, spec);
+ string_nocheck(out, uuid_buf, spec);
}
static noinline_for_stack
-char *netdev_bits(char *buf, char *end, const void *addr,
- struct printf_spec spec, const char *fmt)
+void netdev_bits(struct printbuf *out, const void *addr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long long num;
int size;
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
switch (fmt[1]) {
case 'F':
num = *(const netdev_features_t *)addr;
size = sizeof(netdev_features_t);
+ special_hex_number(out, num, size);
break;
default:
- return error_string(buf, end, "(%pN?)", spec);
+ error_string(out, "(%pN?)", spec);
+ break;
}
-
- return special_hex_number(buf, end, num, size);
}
static noinline_for_stack
-char *fourcc_string(char *buf, char *end, const u32 *fourcc,
- struct printf_spec spec, const char *fmt)
+void fourcc_string(struct printbuf *out, const u32 *fourcc,
+ struct printf_spec spec, const char *fmt)
{
- char output[sizeof("0123 little-endian (0x01234567)")];
- char *p = output;
+ char output_buf[sizeof("0123 little-endian (0x01234567)")];
+ struct printbuf output = PRINTBUF_EXTERN(output_buf, sizeof(output_buf));
unsigned int i;
u32 orig, val;
if (fmt[1] != 'c' || fmt[2] != 'c')
- return error_string(buf, end, "(%p4?)", spec);
+ return error_string(out, "(%p4?)", spec);
- if (check_pointer(&buf, end, fourcc, spec))
- return buf;
+ if (check_pointer(out, fourcc, spec))
+ return;
orig = get_unaligned(fourcc);
val = orig & ~BIT(31);
@@ -1772,31 +1708,29 @@ char *fourcc_string(char *buf, char *end, const u32 *fourcc,
unsigned char c = val >> (i * 8);
/* Print non-control ASCII characters as-is, dot otherwise */
- *p++ = isascii(c) && isprint(c) ? c : '.';
+ prt_char(&output, isascii(c) && isprint(c) ? c : '.');
}
- *p++ = ' ';
- strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
- p += strlen(p);
+ prt_char(&output, ' ');
+ prt_str(&output, orig & BIT(31) ? "big-endian" : "little-endian");
- *p++ = ' ';
- *p++ = '(';
- p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
- *p++ = ')';
- *p = '\0';
+ prt_char(&output, ' ');
+ prt_char(&output, '(');
+ special_hex_number(&output, orig, sizeof(u32));
+ prt_char(&output, ')');
- return string(buf, end, output, spec);
+ string(out, output_buf, spec);
}
static noinline_for_stack
-char *address_val(char *buf, char *end, const void *addr,
- struct printf_spec spec, const char *fmt)
+void address_val(struct printbuf *out, const void *addr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long long num;
int size;
- if (check_pointer(&buf, end, addr, spec))
- return buf;
+ if (check_pointer(out, addr, spec))
+ return;
switch (fmt[1]) {
case 'd':
@@ -1810,55 +1744,44 @@ char *address_val(char *buf, char *end, const void *addr,
break;
}
- return special_hex_number(buf, end, num, size);
+ special_hex_number(out, num, size);
}
static noinline_for_stack
-char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
+void date_str(struct printbuf *out,
+ const struct rtc_time *tm, bool r)
{
int year = tm->tm_year + (r ? 0 : 1900);
int mon = tm->tm_mon + (r ? 0 : 1);
- buf = number(buf, end, year, default_dec04_spec);
- if (buf < end)
- *buf = '-';
- buf++;
-
- buf = number(buf, end, mon, default_dec02_spec);
- if (buf < end)
- *buf = '-';
- buf++;
-
- return number(buf, end, tm->tm_mday, default_dec02_spec);
+ number(out, year, default_dec04_spec);
+ prt_char(out, '-');
+ number(out, mon, default_dec02_spec);
+ prt_char(out, '-');
+ number(out, tm->tm_mday, default_dec02_spec);
}
static noinline_for_stack
-char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
+void time_str(struct printbuf *out, const struct rtc_time *tm, bool r)
{
- buf = number(buf, end, tm->tm_hour, default_dec02_spec);
- if (buf < end)
- *buf = ':';
- buf++;
-
- buf = number(buf, end, tm->tm_min, default_dec02_spec);
- if (buf < end)
- *buf = ':';
- buf++;
-
- return number(buf, end, tm->tm_sec, default_dec02_spec);
+ number(out, tm->tm_hour, default_dec02_spec);
+ prt_char(out, ':');
+ number(out, tm->tm_min, default_dec02_spec);
+ prt_char(out, ':');
+ number(out, tm->tm_sec, default_dec02_spec);
}
static noinline_for_stack
-char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
- struct printf_spec spec, const char *fmt)
+void rtc_str(struct printbuf *out, const struct rtc_time *tm,
+ struct printf_spec spec, const char *fmt)
{
bool have_t = true, have_d = true;
bool raw = false, iso8601_separator = true;
bool found = true;
int count = 2;
- if (check_pointer(&buf, end, tm, spec))
- return buf;
+ if (check_pointer(out, tm, spec))
+ return;
switch (fmt[count]) {
case 'd':
@@ -1886,21 +1809,16 @@ char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
} while (found);
if (have_d)
- buf = date_str(buf, end, tm, raw);
- if (have_d && have_t) {
- if (buf < end)
- *buf = iso8601_separator ? 'T' : ' ';
- buf++;
- }
+ date_str(out, tm, raw);
+ if (have_d && have_t)
+ prt_char(out, iso8601_separator ? 'T' : ' ');
if (have_t)
- buf = time_str(buf, end, tm, raw);
-
- return buf;
+ time_str(out, tm, raw);
}
static noinline_for_stack
-char *time64_str(char *buf, char *end, const time64_t time,
- struct printf_spec spec, const char *fmt)
+void time64_str(struct printbuf *out, const time64_t time,
+ struct printf_spec spec, const char *fmt)
{
struct rtc_time rtc_time;
struct tm tm;
@@ -1918,47 +1836,48 @@ char *time64_str(char *buf, char *end, const time64_t time,
rtc_time.tm_isdst = 0;
- return rtc_str(buf, end, &rtc_time, spec, fmt);
+ rtc_str(out, &rtc_time, spec, fmt);
}
static noinline_for_stack
-char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
- const char *fmt)
+void time_and_date(struct printbuf *out,
+ void *ptr, struct printf_spec spec,
+ const char *fmt)
{
switch (fmt[1]) {
case 'R':
- return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
+ return rtc_str(out, (const struct rtc_time *)ptr, spec, fmt);
case 'T':
- return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
+ return time64_str(out, *(const time64_t *)ptr, spec, fmt);
default:
- return error_string(buf, end, "(%pt?)", spec);
+ return error_string(out, "(%pt?)", spec);
}
}
static noinline_for_stack
-char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
- const char *fmt)
+void clock(struct printbuf *out, struct clk *clk,
+ struct printf_spec spec, const char *fmt)
{
if (!IS_ENABLED(CONFIG_HAVE_CLK))
- return error_string(buf, end, "(%pC?)", spec);
+ return error_string(out, "(%pC?)", spec);
- if (check_pointer(&buf, end, clk, spec))
- return buf;
+ if (check_pointer(out, clk, spec))
+ return;
switch (fmt[1]) {
case 'n':
default:
#ifdef CONFIG_COMMON_CLK
- return string(buf, end, __clk_get_name(clk), spec);
+ return string(out, __clk_get_name(clk), spec);
#else
- return ptr_to_id(buf, end, clk, spec);
+ return ptr_to_id(out, clk, spec);
#endif
}
}
static
-char *format_flags(char *buf, char *end, unsigned long flags,
- const struct trace_print_flags *names)
+void format_flags(struct printbuf *out, unsigned long flags,
+ const struct trace_print_flags *names)
{
unsigned long mask;
@@ -1967,20 +1886,15 @@ char *format_flags(char *buf, char *end, unsigned long flags,
if ((flags & mask) != mask)
continue;
- buf = string(buf, end, names->name, default_str_spec);
+ string(out, names->name, default_str_spec);
flags &= ~mask;
- if (flags) {
- if (buf < end)
- *buf = '|';
- buf++;
- }
+ if (flags)
+ prt_char(out, '|');
}
if (flags)
- buf = number(buf, end, flags, default_flag_spec);
-
- return buf;
+ number(out, flags, default_flag_spec);
}
struct page_flags_fields {
@@ -2005,20 +1919,18 @@ static const struct page_flags_fields pff[] = {
};
static
-char *format_page_flags(char *buf, char *end, unsigned long flags)
+void format_page_flags(struct printbuf *out, unsigned long flags)
{
unsigned long main_flags = flags & PAGEFLAGS_MASK;
bool append = false;
int i;
- buf = number(buf, end, flags, default_flag_spec);
- if (buf < end)
- *buf = '(';
- buf++;
+ number(out, flags, default_flag_spec);
+ prt_char(out, '(');
/* Page flags from the main area. */
if (main_flags) {
- buf = format_flags(buf, end, main_flags, pageflag_names);
+ format_flags(out, main_flags, pageflag_names);
append = true;
}
@@ -2029,41 +1941,31 @@ char *format_page_flags(char *buf, char *end, unsigned long flags)
continue;
/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
- if (append) {
- if (buf < end)
- *buf = '|';
- buf++;
- }
+ if (append)
+ prt_char(out, '|');
- buf = string(buf, end, pff[i].name, default_str_spec);
- if (buf < end)
- *buf = '=';
- buf++;
- buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
- *pff[i].spec);
+ string(out, pff[i].name, default_str_spec);
+ prt_char(out, '=');
+ number(out, (flags >> pff[i].shift) & pff[i].mask, *pff[i].spec);
append = true;
}
- if (buf < end)
- *buf = ')';
- buf++;
-
- return buf;
+ prt_char(out, ')');
}
static noinline_for_stack
-char *flags_string(char *buf, char *end, void *flags_ptr,
- struct printf_spec spec, const char *fmt)
+void flags_string(struct printbuf *out, void *flags_ptr,
+ struct printf_spec spec, const char *fmt)
{
unsigned long flags;
const struct trace_print_flags *names;
- if (check_pointer(&buf, end, flags_ptr, spec))
- return buf;
+ if (check_pointer(out, flags_ptr, spec))
+ return;
switch (fmt[1]) {
case 'p':
- return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
+ return format_page_flags(out, *(unsigned long *)flags_ptr);
case 'v':
flags = *(unsigned long *)flags_ptr;
names = vmaflag_names;
@@ -2073,15 +1975,15 @@ char *flags_string(char *buf, char *end, void *flags_ptr,
names = gfpflag_names;
break;
default:
- return error_string(buf, end, "(%pG?)", spec);
+ return error_string(out, "(%pG?)", spec);
}
- return format_flags(buf, end, flags, names);
+ return format_flags(out, flags, names);
}
static noinline_for_stack
-char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
- char *end)
+void fwnode_full_name_string(struct printbuf *out,
+ struct fwnode_handle *fwnode)
{
int depth;
@@ -2090,25 +1992,23 @@ char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
struct fwnode_handle *__fwnode =
fwnode_get_nth_parent(fwnode, depth);
- buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
- default_str_spec);
- buf = string(buf, end, fwnode_get_name(__fwnode),
- default_str_spec);
+ string(out, fwnode_get_name_prefix(__fwnode),
+ default_str_spec);
+ string(out, fwnode_get_name(__fwnode),
+ default_str_spec);
fwnode_handle_put(__fwnode);
}
-
- return buf;
}
static noinline_for_stack
-char *device_node_string(char *buf, char *end, struct device_node *dn,
- struct printf_spec spec, const char *fmt)
+void device_node_string(struct printbuf *out, struct device_node *dn,
+ struct printf_spec spec, const char *fmt)
{
char tbuf[sizeof("xxxx") + 1];
const char *p;
int ret;
- char *buf_start = buf;
+ unsigned start = out->pos;
struct property *prop;
bool has_mult, pass;
@@ -2116,13 +2016,13 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
str_spec.field_width = -1;
if (fmt[0] != 'F')
- return error_string(buf, end, "(%pO?)", spec);
+ return error_string(out, "(%pO?)", spec);
if (!IS_ENABLED(CONFIG_OF))
- return error_string(buf, end, "(%pOF?)", spec);
+ return error_string(out, "(%pOF?)", spec);
- if (check_pointer(&buf, end, dn, spec))
- return buf;
+ if (check_pointer(out, dn, spec))
+ return;
/* simple case without anything any more format specifiers */
fmt++;
@@ -2131,32 +2031,28 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
int precision;
- if (pass) {
- if (buf < end)
- *buf = ':';
- buf++;
- }
+ if (pass)
+ prt_char(out, ':');
switch (*fmt) {
case 'f': /* full_name */
- buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
- end);
+ fwnode_full_name_string(out, of_fwnode_handle(dn));
break;
case 'n': /* name */
p = fwnode_get_name(of_fwnode_handle(dn));
precision = str_spec.precision;
str_spec.precision = strchrnul(p, '@') - p;
- buf = string(buf, end, p, str_spec);
+ string(out, p, str_spec);
str_spec.precision = precision;
break;
case 'p': /* phandle */
- buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
+ number(out, (unsigned int)dn->phandle, default_dec_spec);
break;
case 'P': /* path-spec */
p = fwnode_get_name(of_fwnode_handle(dn));
if (!p[1])
p = "/";
- buf = string(buf, end, p, str_spec);
+ string(out, p, str_spec);
break;
case 'F': /* flags */
tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
@@ -2164,21 +2060,21 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
tbuf[4] = 0;
- buf = string_nocheck(buf, end, tbuf, str_spec);
+ string_nocheck(out, tbuf, str_spec);
break;
case 'c': /* major compatible string */
ret = of_property_read_string(dn, "compatible", &p);
if (!ret)
- buf = string(buf, end, p, str_spec);
+ string(out, p, str_spec);
break;
case 'C': /* full compatible string */
has_mult = false;
of_property_for_each_string(dn, "compatible", prop, p) {
if (has_mult)
- buf = string_nocheck(buf, end, ",", str_spec);
- buf = string_nocheck(buf, end, "\"", str_spec);
- buf = string(buf, end, p, str_spec);
- buf = string_nocheck(buf, end, "\"", str_spec);
+ string_nocheck(out, ",", str_spec);
+ string_nocheck(out, "\"", str_spec);
+ string(out, p, str_spec);
+ string_nocheck(out, "\"", str_spec);
has_mult = true;
}
@@ -2188,37 +2084,38 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
}
}
- return widen_string(buf, buf - buf_start, end, spec);
+ widen_string(out, out->pos - start, spec);
}
static noinline_for_stack
-char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
- struct printf_spec spec, const char *fmt)
+void fwnode_string(struct printbuf *out,
+ struct fwnode_handle *fwnode,
+ struct printf_spec spec, const char *fmt)
{
struct printf_spec str_spec = spec;
- char *buf_start = buf;
+ unsigned start = out->pos;
str_spec.field_width = -1;
if (*fmt != 'w')
- return error_string(buf, end, "(%pf?)", spec);
+ return error_string(out, "(%pf?)", spec);
- if (check_pointer(&buf, end, fwnode, spec))
- return buf;
+ if (check_pointer(out, fwnode, spec))
+ return;
fmt++;
switch (*fmt) {
case 'P': /* name */
- buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
+ string(out, fwnode_get_name(fwnode), str_spec);
break;
case 'f': /* full_name */
default:
- buf = fwnode_full_name_string(fwnode, buf, end);
+ fwnode_full_name_string(out, fwnode);
break;
}
- return widen_string(buf, buf - buf_start, end, spec);
+ widen_string(out, out->pos - start, spec);
}
int __init no_hash_pointers_enable(char *str)
@@ -2374,8 +2271,8 @@ early_param("no_hash_pointers", no_hash_pointers_enable);
* rendering it useful as a unique identifier.
*/
static noinline_for_stack
-char *pointer(const char *fmt, char *buf, char *end, void *ptr,
- struct printf_spec spec)
+void pointer(struct printbuf *out, const char *fmt,
+ void *ptr, struct printf_spec spec)
{
switch (*fmt) {
case 'S':
@@ -2383,24 +2280,24 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
ptr = dereference_symbol_descriptor(ptr);
fallthrough;
case 'B':
- return symbol_string(buf, end, ptr, spec, fmt);
+ return symbol_string(out, ptr, spec, fmt);
case 'R':
case 'r':
- return resource_string(buf, end, ptr, spec, fmt);
+ return resource_string(out, ptr, spec, fmt);
case 'h':
- return hex_string(buf, end, ptr, spec, fmt);
+ return hex_string(out, ptr, spec, fmt);
case 'b':
switch (fmt[1]) {
case 'l':
- return bitmap_list_string(buf, end, ptr, spec, fmt);
+ return bitmap_list_string(out, ptr, spec, fmt);
default:
- return bitmap_string(buf, end, ptr, spec, fmt);
+ return bitmap_string(out, ptr, spec, fmt);
}
case 'M': /* Colon separated: 00:01:02:03:04:05 */
case 'm': /* Contiguous: 000102030405 */
/* [mM]F (FDDI) */
/* [mM]R (Reverse order; Bluetooth) */
- return mac_address_string(buf, end, ptr, spec, fmt);
+ return mac_address_string(out, ptr, spec, fmt);
case 'I': /* Formatted IP supported
* 4: 1.2.3.4
* 6: 0001:0203:...:0708
@@ -2410,57 +2307,57 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
* 4: 001.002.003.004
* 6: 000102...0f
*/
- return ip_addr_string(buf, end, ptr, spec, fmt);
+ return ip_addr_string(out, ptr, spec, fmt);
case 'E':
- return escaped_string(buf, end, ptr, spec, fmt);
+ return escaped_string(out, ptr, spec, fmt);
case 'U':
- return uuid_string(buf, end, ptr, spec, fmt);
+ return uuid_string(out, ptr, spec, fmt);
case 'V':
- return va_format(buf, end, ptr, spec, fmt);
+ return va_format(out, ptr, spec, fmt);
case 'K':
- return restricted_pointer(buf, end, ptr, spec);
+ return restricted_pointer(out, ptr, spec);
case 'N':
- return netdev_bits(buf, end, ptr, spec, fmt);
+ return netdev_bits(out, ptr, spec, fmt);
case '4':
- return fourcc_string(buf, end, ptr, spec, fmt);
+ return fourcc_string(out, ptr, spec, fmt);
case 'a':
- return address_val(buf, end, ptr, spec, fmt);
+ return address_val(out, ptr, spec, fmt);
case 'd':
- return dentry_name(buf, end, ptr, spec, fmt);
+ return dentry_name(out, ptr, spec, fmt);
case 't':
- return time_and_date(buf, end, ptr, spec, fmt);
+ return time_and_date(out, ptr, spec, fmt);
case 'C':
- return clock(buf, end, ptr, spec, fmt);
+ return clock(out, ptr, spec, fmt);
case 'D':
- return file_dentry_name(buf, end, ptr, spec, fmt);
+ return file_dentry_name(out, ptr, spec, fmt);
#ifdef CONFIG_BLOCK
case 'g':
- return bdev_name(buf, end, ptr, spec, fmt);
+ return bdev_name(out, ptr, spec, fmt);
#endif
case 'G':
- return flags_string(buf, end, ptr, spec, fmt);
+ return flags_string(out, ptr, spec, fmt);
case 'O':
- return device_node_string(buf, end, ptr, spec, fmt + 1);
+ return device_node_string(out, ptr, spec, fmt + 1);
case 'f':
- return fwnode_string(buf, end, ptr, spec, fmt + 1);
+ return fwnode_string(out, ptr, spec, fmt + 1);
case 'x':
- return pointer_string(buf, end, ptr, spec);
+ return pointer_string(out, ptr, spec);
case 'e':
/* %pe with a non-ERR_PTR gets treated as plain %p */
if (!IS_ERR(ptr))
- return default_pointer(buf, end, ptr, spec);
- return err_ptr(buf, end, ptr, spec);
+ return default_pointer(out, ptr, spec);
+ return err_ptr(out, ptr, spec);
case 'u':
case 'k':
switch (fmt[1]) {
case 's':
- return string(buf, end, ptr, spec);
+ return string(out, ptr, spec);
default:
- return error_string(buf, end, "(einval)", spec);
+ return error_string(out, "(einval)", spec);
}
default:
- return default_pointer(buf, end, ptr, spec);
+ return default_pointer(out, ptr, spec);
}
}
@@ -2682,52 +2579,27 @@ set_precision(struct printf_spec *spec, int prec)
}
/**
- * vsnprintf - Format a string and place it in a buffer
- * @buf: The buffer to place the result into
- * @size: The size of the buffer, including the trailing null space
+ * prt_vprintf - Format a string, outputting to a printbuf
+ * @out: The printbuf to output to
* @fmt: The format string to use
* @args: Arguments for the format string
*
- * This function generally follows C99 vsnprintf, but has some
- * extensions and a few limitations:
- *
- * - ``%n`` is unsupported
- * - ``%p*`` is handled by pointer()
- *
- * See pointer() or Documentation/core-api/printk-formats.rst for more
- * extensive description.
- *
- * **Please update the documentation in both places when making changes**
+ * prt_vprintf works much like the traditional vsnprintf(), but outputs to a
+ * printbuf instead of raw pointer/size.
*
- * The return value is the number of characters which would
- * be generated for the given input, excluding the trailing
- * '\0', as per ISO C99. If you want to have the exact
- * number of characters written into @buf as return value
- * (not including the trailing '\0'), use vscnprintf(). If the
- * return is greater than or equal to @size, the resulting
- * string is truncated.
+ * If you're not already dealing with a va_list consider using prt_printf().
*
- * If you're not already dealing with a va_list consider using snprintf().
+ * See the vsnprintf() documentation for format string extensions over C99.
*/
-int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+void prt_vprintf(struct printbuf *out, const char *fmt, va_list args)
{
unsigned long long num;
- char *str, *end;
struct printf_spec spec = {0};
/* Reject out-of-range values early. Large positive sizes are
used for unknown buffer sizes. */
- if (WARN_ON_ONCE(size > INT_MAX))
- return 0;
-
- str = buf;
- end = buf + size;
-
- /* Make sure end is always >= buf */
- if (end < buf) {
- end = ((void *)-1);
- size = end - buf;
- }
+ if (WARN_ON_ONCE(out->size > INT_MAX))
+ return;
while (*fmt) {
const char *old_fmt = fmt;
@@ -2736,16 +2608,9 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
fmt += read;
switch (spec.type) {
- case FORMAT_TYPE_NONE: {
- int copy = read;
- if (str < end) {
- if (copy > end - str)
- copy = end - str;
- memcpy(str, old_fmt, copy);
- }
- str += read;
+ case FORMAT_TYPE_NONE:
+ prt_bytes(out, old_fmt, read);
break;
- }
case FORMAT_TYPE_WIDTH:
set_field_width(&spec, va_arg(args, int));
@@ -2755,44 +2620,29 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
set_precision(&spec, va_arg(args, int));
break;
- case FORMAT_TYPE_CHAR: {
- char c;
+ case FORMAT_TYPE_CHAR:
+ if (spec.field_width > 0 && !(spec.flags & LEFT))
+ prt_chars(out, spec.field_width, ' ');
- if (!(spec.flags & LEFT)) {
- while (--spec.field_width > 0) {
- if (str < end)
- *str = ' ';
- ++str;
+ __prt_char(out, (unsigned char) va_arg(args, int));
- }
- }
- c = (unsigned char) va_arg(args, int);
- if (str < end)
- *str = c;
- ++str;
- while (--spec.field_width > 0) {
- if (str < end)
- *str = ' ';
- ++str;
- }
+ if (spec.field_width > 0 && (spec.flags & LEFT))
+ prt_chars(out, spec.field_width, ' ');
+ spec.field_width = 0;
break;
- }
case FORMAT_TYPE_STR:
- str = string(str, end, va_arg(args, char *), spec);
+ string(out, va_arg(args, char *), spec);
break;
case FORMAT_TYPE_PTR:
- str = pointer(fmt, str, end, va_arg(args, void *),
- spec);
+ pointer(out, fmt, va_arg(args, void *), spec);
while (isalnum(*fmt))
fmt++;
break;
case FORMAT_TYPE_PERCENT_CHAR:
- if (str < end)
- *str = '%';
- ++str;
+ __prt_char(out, '%');
break;
case FORMAT_TYPE_INVALID:
@@ -2845,21 +2695,70 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
num = va_arg(args, unsigned int);
}
- str = number(str, end, num, spec);
+ number(out, num, spec);
}
}
-
out:
- if (size > 0) {
- if (str < end)
- *str = '\0';
- else
- end[-1] = '\0';
- }
+ printbuf_nul_terminate(out);
+}
+EXPORT_SYMBOL(prt_vprintf);
- /* the trailing null byte doesn't count towards the total */
- return str-buf;
+/**
+ * prt_printf - Format a string, outputting to a printbuf
+ * @out: The printbuf to output to
+ * @fmt: The format string to use
+ * @args: Arguments for the format string
+ *
+ *
+ * prt_printf works much like the traditional sprintf(), but outputs to a
+ * printbuf instead of raw pointer/size.
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
+ */
+void prt_printf(struct printbuf *out, const char *fmt, ...)
+{
+ va_list args;
+ va_start(args, fmt);
+ prt_vprintf(out, fmt, args);
+ va_end(args);
+}
+EXPORT_SYMBOL(prt_printf);
+
+/**
+ * vsnprintf - Format a string and place it in a buffer
+ * @buf: The buffer to place the result into
+ * @size: The size of the buffer, including the trailing null space
+ * @fmt: The format string to use
+ * @args: Arguments for the format string
+ *
+ * This function generally follows C99 vsnprintf, but has some
+ * extensions and a few limitations:
+ *
+ * - ``%n`` is unsupported
+ * - ``%p*`` is handled by pointer()
+ *
+ * See pointer() or Documentation/core-api/printk-formats.rst for more
+ * extensive description.
+ *
+ * **Please update the documentation in both places when making changes**
+ *
+ * The return value is the number of characters which would
+ * be generated for the given input, excluding the trailing
+ * '\0', as per ISO C99. If you want to have the exact
+ * number of characters written into @buf as return value
+ * (not including the trailing '\0'), use vscnprintf(). If the
+ * return is greater than or equal to @size, the resulting
+ * string is truncated.
+ *
+ * If you're not already dealing with a va_list consider using snprintf().
+ */
+int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
+{
+ struct printbuf out = PRINTBUF_EXTERN(buf, size);
+
+ prt_vprintf(&out, fmt, args);
+ return out.pos;
}
EXPORT_SYMBOL(vsnprintf);
@@ -2997,53 +2896,46 @@ EXPORT_SYMBOL(sprintf);
* bstr_printf() - Binary data to text string
*/
+static inline void printbuf_align(struct printbuf *out, unsigned align)
+{
+ /* Assumes output buffer is correctly aligned: */
+ out->pos += align - 1;
+ out->pos &= ~(align - 1);
+}
+
/**
- * vbin_printf - Parse a format string and place args' binary value in a buffer
- * @bin_buf: The buffer to place args' binary value
- * @size: The size of the buffer(by words(32bits), not characters)
+ * prt_vbinprintf - Parse a format string and place args' binary value in a buffer
+ * @out: The buffer to place args' binary value
* @fmt: The format string to use
* @args: Arguments for the format string
*
* The format follows C99 vsnprintf, except %n is ignored, and its argument
* is skipped.
*
- * The return value is the number of words(32bits) which would be generated for
- * the given input.
- *
* NOTE:
* If the return value is greater than @size, the resulting bin_buf is NOT
* valid for bstr_printf().
*/
-int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
+void prt_vbinprintf(struct printbuf *out, const char *fmt, va_list args)
{
struct printf_spec spec = {0};
- char *str, *end;
int width;
- str = (char *)bin_buf;
- end = (char *)(bin_buf + size);
-
#define save_arg(type) \
({ \
unsigned long long value; \
if (sizeof(type) == 8) { \
- unsigned long long val8; \
- str = PTR_ALIGN(str, sizeof(u32)); \
- val8 = va_arg(args, unsigned long long); \
- if (str + sizeof(type) <= end) { \
- *(u32 *)str = *(u32 *)&val8; \
- *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
- } \
+ u64 val8 = va_arg(args, u64); \
+ printbuf_align(out, sizeof(u32)); \
+ prt_bytes(out, (u32 *) &val8, 4); \
+ prt_bytes(out, ((u32 *) &val8) + 1, 4); \
value = val8; \
} else { \
- unsigned int val4; \
- str = PTR_ALIGN(str, sizeof(type)); \
- val4 = va_arg(args, int); \
- if (str + sizeof(type) <= end) \
- *(typeof(type) *)str = (type)(long)val4; \
+ u32 val4 = va_arg(args, u32); \
+ printbuf_align(out, sizeof(type)); \
+ prt_bytes(out, &val4, sizeof(type)); \
value = (unsigned long long)val4; \
} \
- str += sizeof(type); \
value; \
})
@@ -3074,16 +2966,12 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
case FORMAT_TYPE_STR: {
const char *save_str = va_arg(args, char *);
const char *err_msg;
- size_t len;
err_msg = check_pointer_msg(save_str);
if (err_msg)
save_str = err_msg;
- len = strlen(save_str) + 1;
- if (str + len < end)
- memcpy(str, save_str, len);
- str += len;
+ prt_str(out, save_str);
break;
}
@@ -3103,12 +2991,7 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
save_arg(void *);
break;
}
- str = pointer(fmt, str, end, va_arg(args, void *),
- spec);
- if (str + 1 < end)
- *str++ = '\0';
- else
- end[-1] = '\0'; /* Must be nul terminated */
+ pointer(out, fmt, va_arg(args, void *), spec);
}
/* skip all alphanumeric pointer suffixes */
while (isalnum(*fmt))
@@ -3146,15 +3029,15 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
}
out:
- return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
+ printbuf_nul_terminate(out);
+ printbuf_align(out, 4);
#undef save_arg
}
-EXPORT_SYMBOL_GPL(vbin_printf);
+EXPORT_SYMBOL_GPL(prt_vbinprintf);
/**
- * bstr_printf - Format a string from binary arguments and place it in a buffer
+ * prt_bstrprintf - Format a string from binary arguments and place it in a buffer
* @buf: The buffer to place the result into
- * @size: The size of the buffer, including the trailing null space
* @fmt: The format string to use
* @bin_buf: Binary arguments for the format string
*
@@ -3164,26 +3047,14 @@ EXPORT_SYMBOL_GPL(vbin_printf);
*
* The format follows C99 vsnprintf, but has some extensions:
* see vsnprintf comment for details.
- *
- * The return value is the number of characters which would
- * be generated for the given input, excluding the trailing
- * '\0', as per ISO C99. If you want to have the exact
- * number of characters written into @buf as return value
- * (not including the trailing '\0'), use vscnprintf(). If the
- * return is greater than or equal to @size, the resulting
- * string is truncated.
*/
-int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
+void prt_bstrprintf(struct printbuf *out, const char *fmt, const u32 *bin_buf)
{
struct printf_spec spec = {0};
- char *str, *end;
const char *args = (const char *)bin_buf;
- if (WARN_ON_ONCE(size > INT_MAX))
- return 0;
-
- str = buf;
- end = buf + size;
+ if (WARN_ON_ONCE(out->size > INT_MAX))
+ return;
#define get_arg(type) \
({ \
@@ -3200,12 +3071,6 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
value; \
})
- /* Make sure end is always >= buf */
- if (end < buf) {
- end = ((void *)-1);
- size = end - buf;
- }
-
while (*fmt) {
const char *old_fmt = fmt;
int read = format_decode(fmt, &spec);
@@ -3213,16 +3078,9 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
fmt += read;
switch (spec.type) {
- case FORMAT_TYPE_NONE: {
- int copy = read;
- if (str < end) {
- if (copy > end - str)
- copy = end - str;
- memcpy(str, old_fmt, copy);
- }
- str += read;
+ case FORMAT_TYPE_NONE:
+ prt_bytes(out, old_fmt, read);
break;
- }
case FORMAT_TYPE_WIDTH:
set_field_width(&spec, get_arg(int));
@@ -3232,38 +3090,24 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
set_precision(&spec, get_arg(int));
break;
- case FORMAT_TYPE_CHAR: {
- char c;
-
- if (!(spec.flags & LEFT)) {
- while (--spec.field_width > 0) {
- if (str < end)
- *str = ' ';
- ++str;
- }
- }
- c = (unsigned char) get_arg(char);
- if (str < end)
- *str = c;
- ++str;
- while (--spec.field_width > 0) {
- if (str < end)
- *str = ' ';
- ++str;
- }
+ case FORMAT_TYPE_CHAR:
+ if (!(spec.flags & LEFT))
+ prt_chars(out, spec.field_width, ' ');
+ __prt_char(out, (unsigned char) get_arg(char));
+ if ((spec.flags & LEFT))
+ prt_chars(out, spec.field_width, ' ');
break;
- }
case FORMAT_TYPE_STR: {
const char *str_arg = args;
args += strlen(str_arg) + 1;
- str = string(str, end, (char *)str_arg, spec);
+ string(out, (char *)str_arg, spec);
break;
}
case FORMAT_TYPE_PTR: {
bool process = false;
- int copy, len;
+ int len;
/* Non function dereferences were already done */
switch (*fmt) {
case 'S':
@@ -3279,17 +3123,12 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
break;
}
/* Pointer dereference was already processed */
- if (str < end) {
- len = copy = strlen(args);
- if (copy > end - str)
- copy = end - str;
- memcpy(str, args, copy);
- str += len;
- args += len + 1;
- }
+ len = strlen(args);
+ prt_bytes(out, args, len);
+ args += len + 1;
}
if (process)
- str = pointer(fmt, str, end, get_arg(void *), spec);
+ pointer(out, fmt, get_arg(void *), spec);
while (isalnum(*fmt))
fmt++;
@@ -3297,9 +3136,7 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
}
case FORMAT_TYPE_PERCENT_CHAR:
- if (str < end)
- *str = '%';
- ++str;
+ __prt_char(out, '%');
break;
case FORMAT_TYPE_INVALID:
@@ -3342,23 +3179,87 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
num = get_arg(int);
}
- str = number(str, end, num, spec);
+ number(out, num, spec);
} /* default: */
} /* switch(spec.type) */
} /* while(*fmt) */
out:
- if (size > 0) {
- if (str < end)
- *str = '\0';
- else
- end[-1] = '\0';
- }
-
#undef get_arg
+ printbuf_nul_terminate(out);
+}
+EXPORT_SYMBOL_GPL(prt_bstrprintf);
+
+/**
+ * prt_bprintf - Parse a format string and place args' binary value in a buffer
+ * @out: The buffer to place args' binary value
+ * @fmt: The format string to use
+ * @...: Arguments for the format string
+ */
+void prt_bprintf(struct printbuf *out, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ prt_vbinprintf(out, fmt, args);
+ va_end(args);
+}
+EXPORT_SYMBOL_GPL(prt_bprintf);
+
+/**
+ * vbin_printf - Parse a format string and place args' binary value in a buffer
+ * @bin_buf: The buffer to place args' binary value
+ * @size: The size of the buffer(by words(32bits), not characters)
+ * @fmt: The format string to use
+ * @args: Arguments for the format string
+ *
+ * The format follows C99 vsnprintf, except %n is ignored, and its argument
+ * is skipped.
+ *
+ * The return value is the number of words(32bits) which would be generated for
+ * the given input.
+ *
+ * NOTE:
+ * If the return value is greater than @size, the resulting bin_buf is NOT
+ * valid for bstr_printf().
+ */
+int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
+{
+ struct printbuf out = PRINTBUF_EXTERN((char *) bin_buf, size);
+
+ prt_vbinprintf(&out, fmt, args);
+ return out.pos;
+}
+EXPORT_SYMBOL_GPL(vbin_printf);
+
+/**
+ * bstr_printf - Format a string from binary arguments and place it in a buffer
+ * @buf: The buffer to place the result into
+ * @size: The size of the buffer, including the trailing null space
+ * @fmt: The format string to use
+ * @bin_buf: Binary arguments for the format string
+ *
+ * This function like C99 vsnprintf, but the difference is that vsnprintf gets
+ * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
+ * a binary buffer that generated by vbin_printf.
+ *
+ * The format follows C99 vsnprintf, but has some extensions:
+ * see vsnprintf comment for details.
+ *
+ * The return value is the number of characters which would
+ * be generated for the given input, excluding the trailing
+ * '\0', as per ISO C99. If you want to have the exact
+ * number of characters written into @buf as return value
+ * (not including the trailing '\0'), use vscnprintf(). If the
+ * return is greater than or equal to @size, the resulting
+ * string is truncated.
+ */
+int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
+{
+ struct printbuf out = PRINTBUF_EXTERN(buf, size);
- /* the trailing null byte doesn't count towards the total */
- return str - buf;
+ prt_bstrprintf(&out, fmt, bin_buf);
+ return out.pos;
}
EXPORT_SYMBOL_GPL(bstr_printf);
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf, which is similar but heap
allocates the string buffer.
Previously in this code the string buffer was allocated on the stack;
this means we've added a new potential memory allocation failure. This
is fine though since it's only for a dev_printk() message.
Memory allocation context: printbuf doesn't take gfp flags, instead we
prefer the new memalloc_no*_(save|restore) interfaces to be used. Here
the surrounding code is already allocating with GFP_KERNEL, so
everything is fine.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: [email protected]
---
drivers/clk/tegra/clk-bpmp.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/drivers/clk/tegra/clk-bpmp.c b/drivers/clk/tegra/clk-bpmp.c
index 3748a39dae7c..7e3b48ed9d45 100644
--- a/drivers/clk/tegra/clk-bpmp.c
+++ b/drivers/clk/tegra/clk-bpmp.c
@@ -5,7 +5,7 @@
#include <linux/clk-provider.h>
#include <linux/device.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/slab.h>
#include <soc/tegra/bpmp.h>
@@ -365,39 +365,38 @@ static void tegra_bpmp_clk_info_dump(struct tegra_bpmp *bpmp,
const struct tegra_bpmp_clk_info *info)
{
const char *prefix = "";
- struct seq_buf buf;
+ struct printbuf buf = PRINTBUF;
unsigned int i;
- char flags[64];
-
- seq_buf_init(&buf, flags, sizeof(flags));
if (info->flags)
- seq_buf_printf(&buf, "(");
+ prt_printf(&buf, "(");
if (info->flags & TEGRA_BPMP_CLK_HAS_MUX) {
- seq_buf_printf(&buf, "%smux", prefix);
+ prt_printf(&buf, "%smux", prefix);
prefix = ", ";
}
if ((info->flags & TEGRA_BPMP_CLK_HAS_SET_RATE) == 0) {
- seq_buf_printf(&buf, "%sfixed", prefix);
+ prt_printf(&buf, "%sfixed", prefix);
prefix = ", ";
}
if (info->flags & TEGRA_BPMP_CLK_IS_ROOT) {
- seq_buf_printf(&buf, "%sroot", prefix);
+ prt_printf(&buf, "%sroot", prefix);
prefix = ", ";
}
if (info->flags)
- seq_buf_printf(&buf, ")");
+ prt_printf(&buf, ")");
dev_printk(level, bpmp->dev, "%03u: %s\n", info->id, info->name);
- dev_printk(level, bpmp->dev, " flags: %lx %s\n", info->flags, flags);
+ dev_printk(level, bpmp->dev, " flags: %lx %s\n", info->flags, printbuf_str(&buf));
dev_printk(level, bpmp->dev, " parents: %u\n", info->num_parents);
for (i = 0; i < info->num_parents; i++)
dev_printk(level, bpmp->dev, " %03u\n", info->parents[i]);
+
+ printbuf_exit(&buf);
}
static int tegra_bpmp_probe_clocks(struct tegra_bpmp *bpmp,
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf. We're using printbuf in external
buffer mode, so it's a direct conversion, aside from some trivial
refactoring in cpu_show_meltdown() to make the code more consistent.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: [email protected]
---
arch/powerpc/kernel/process.c | 16 +++--
arch/powerpc/kernel/security.c | 75 ++++++++++-------------
arch/powerpc/platforms/pseries/papr_scm.c | 34 +++++-----
3 files changed, 57 insertions(+), 68 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 0fbda89cd1bb..05654dbeb2c4 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -37,7 +37,7 @@
#include <linux/hw_breakpoint.h>
#include <linux/uaccess.h>
#include <linux/pkeys.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <asm/interrupt.h>
#include <asm/io.h>
@@ -1396,32 +1396,30 @@ void show_user_instructions(struct pt_regs *regs)
{
unsigned long pc;
int n = NR_INSN_TO_PRINT;
- struct seq_buf s;
char buf[96]; /* enough for 8 times 9 + 2 chars */
+ struct printbuf s = PRINTBUF_EXTERN(buf, sizeof(buf));
pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
- seq_buf_init(&s, buf, sizeof(buf));
-
while (n) {
int i;
- seq_buf_clear(&s);
+ printbuf_reset(&s);
for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
int instr;
if (copy_from_user_nofault(&instr, (void __user *)pc,
sizeof(instr))) {
- seq_buf_printf(&s, "XXXXXXXX ");
+ prt_printf(&s, "XXXXXXXX ");
continue;
}
- seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
+ prt_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
}
- if (!seq_buf_has_overflowed(&s))
+ if (printbuf_remaining(&s))
pr_info("%s[%d]: code: %s\n", current->comm,
- current->pid, s.buffer);
+ current->pid, s.buf);
}
}
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index d96fd14bd7c9..b34de62e65ce 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -10,7 +10,7 @@
#include <linux/memblock.h>
#include <linux/nospec.h>
#include <linux/prctl.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/debugfs.h>
#include <asm/asm-prototypes.h>
@@ -144,31 +144,28 @@ void __init setup_spectre_v2(void)
#ifdef CONFIG_PPC_BOOK3S_64
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
bool thread_priv;
thread_priv = security_ftr_enabled(SEC_FTR_L1D_THREAD_PRIV);
if (rfi_flush) {
- struct seq_buf s;
- seq_buf_init(&s, buf, PAGE_SIZE - 1);
- seq_buf_printf(&s, "Mitigation: RFI Flush");
+ prt_printf(&s, "Mitigation: RFI Flush");
if (thread_priv)
- seq_buf_printf(&s, ", L1D private per thread");
-
- seq_buf_printf(&s, "\n");
-
- return s.len;
+ prt_printf(&s, ", L1D private per thread");
+
+ prt_printf(&s, "\n");
+ } else if (thread_priv) {
+ prt_printf(&s, "Vulnerable: L1D private per thread\n");
+ } else if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
+ !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)) {
+ prt_printf(&s, "Not affected\n");
+ } else {
+ prt_printf(&s, "Vulnerable\n");
}
- if (thread_priv)
- return sprintf(buf, "Vulnerable: L1D private per thread\n");
-
- if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
- !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
- return sprintf(buf, "Not affected\n");
-
- return sprintf(buf, "Vulnerable\n");
+ return printbuf_written(&s);
}
ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
@@ -179,70 +176,66 @@ ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *b
ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct seq_buf s;
-
- seq_buf_init(&s, buf, PAGE_SIZE - 1);
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {
if (barrier_nospec_enabled)
- seq_buf_printf(&s, "Mitigation: __user pointer sanitization");
+ prt_printf(&s, "Mitigation: __user pointer sanitization");
else
- seq_buf_printf(&s, "Vulnerable");
+ prt_printf(&s, "Vulnerable");
if (security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31))
- seq_buf_printf(&s, ", ori31 speculation barrier enabled");
+ prt_printf(&s, ", ori31 speculation barrier enabled");
- seq_buf_printf(&s, "\n");
+ prt_printf(&s, "\n");
} else
- seq_buf_printf(&s, "Not affected\n");
+ prt_printf(&s, "Not affected\n");
- return s.len;
+ return printbuf_written(&s);
}
ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)
{
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
bool bcs, ccd;
- seq_buf_init(&s, buf, PAGE_SIZE - 1);
-
bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);
ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);
if (bcs || ccd) {
- seq_buf_printf(&s, "Mitigation: ");
+ prt_printf(&s, "Mitigation: ");
if (bcs)
- seq_buf_printf(&s, "Indirect branch serialisation (kernel only)");
+ prt_printf(&s, "Indirect branch serialisation (kernel only)");
if (bcs && ccd)
- seq_buf_printf(&s, ", ");
+ prt_printf(&s, ", ");
if (ccd)
- seq_buf_printf(&s, "Indirect branch cache disabled");
+ prt_printf(&s, "Indirect branch cache disabled");
} else if (count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
- seq_buf_printf(&s, "Mitigation: Software count cache flush");
+ prt_printf(&s, "Mitigation: Software count cache flush");
if (count_cache_flush_type == BRANCH_CACHE_FLUSH_HW)
- seq_buf_printf(&s, " (hardware accelerated)");
+ prt_printf(&s, " (hardware accelerated)");
} else if (btb_flush_enabled) {
- seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
+ prt_printf(&s, "Mitigation: Branch predictor state flush");
} else {
- seq_buf_printf(&s, "Vulnerable");
+ prt_printf(&s, "Vulnerable");
}
if (bcs || ccd || count_cache_flush_type != BRANCH_CACHE_FLUSH_NONE) {
if (link_stack_flush_type != BRANCH_CACHE_FLUSH_NONE)
- seq_buf_printf(&s, ", Software link stack flush");
+ prt_printf(&s, ", Software link stack flush");
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_HW)
- seq_buf_printf(&s, " (hardware accelerated)");
+ prt_printf(&s, " (hardware accelerated)");
}
- seq_buf_printf(&s, "\n");
+ prt_printf(&s, "\n");
- return s.len;
+ return printbuf_written(&s);
}
#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 20f6ed813bff..a1fd25243c48 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -12,7 +12,7 @@
#include <linux/libnvdimm.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/nd.h>
#include <asm/plpar_wrappers.h>
@@ -1142,7 +1142,7 @@ static ssize_t perf_stats_show(struct device *dev,
{
int index;
ssize_t rc;
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
struct nvdimm *dimm = to_nvdimm(dev);
@@ -1165,18 +1165,17 @@ static ssize_t perf_stats_show(struct device *dev,
* values. Since stat_id is essentially a char string of
* 8 bytes, simply use the string format specifier to print it.
*/
- seq_buf_init(&s, buf, PAGE_SIZE);
for (index = 0, stat = stats->scm_statistic;
index < be32_to_cpu(stats->num_statistics);
++index, ++stat) {
- seq_buf_printf(&s, "%.8s = 0x%016llX\n",
- stat->stat_id,
- be64_to_cpu(stat->stat_val));
+ prt_printf(&s, "%.8s = 0x%016llX\n",
+ stat->stat_id,
+ be64_to_cpu(stat->stat_val));
}
free_stats:
kfree(stats);
- return rc ? rc : (ssize_t)seq_buf_used(&s);
+ return rc ?: printbuf_written(&s);
}
static DEVICE_ATTR_ADMIN_RO(perf_stats);
@@ -1185,7 +1184,7 @@ static ssize_t flags_show(struct device *dev,
{
struct nvdimm *dimm = to_nvdimm(dev);
struct papr_scm_priv *p = nvdimm_provider_data(dimm);
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
u64 health;
int rc;
@@ -1196,29 +1195,28 @@ static ssize_t flags_show(struct device *dev,
/* Copy health_bitmap locally, check masks & update out buffer */
health = READ_ONCE(p->health_bitmap);
- seq_buf_init(&s, buf, PAGE_SIZE);
if (health & PAPR_PMEM_UNARMED_MASK)
- seq_buf_printf(&s, "not_armed ");
+ prt_printf(&s, "not_armed ");
if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
- seq_buf_printf(&s, "flush_fail ");
+ prt_printf(&s, "flush_fail ");
if (health & PAPR_PMEM_BAD_RESTORE_MASK)
- seq_buf_printf(&s, "restore_fail ");
+ prt_printf(&s, "restore_fail ");
if (health & PAPR_PMEM_ENCRYPTED)
- seq_buf_printf(&s, "encrypted ");
+ prt_printf(&s, "encrypted ");
if (health & PAPR_PMEM_SMART_EVENT_MASK)
- seq_buf_printf(&s, "smart_notify ");
+ prt_printf(&s, "smart_notify ");
if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
- seq_buf_printf(&s, "scrubbed locked ");
+ prt_printf(&s, "scrubbed locked ");
- if (seq_buf_used(&s))
- seq_buf_printf(&s, "\n");
+ if (printbuf_written(&s))
+ prt_printf(&s, "\n");
- return seq_buf_used(&s);
+ return printbuf_written(&s);
}
DEVICE_ATTR_RO(flags);
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts memory_stat_format() from seq_buf to printbuf. Printbuf is
simalar to seq_buf except that it heap allocates the string buffer:
here, we were already heap allocating the buffer with kmalloc() so the
conversion is trivial.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
---
mm/memcontrol.c | 54 ++++++++++++++++++++++++-------------------------
1 file changed, 27 insertions(+), 27 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b69979c9ced5..54897e4ac4ef 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -62,7 +62,7 @@
#include <linux/file.h>
#include <linux/resume_user_mode.h>
#include <linux/psi.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
@@ -1490,13 +1490,10 @@ static const unsigned int memcg_vm_event_stat[] = {
#endif
};
-static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
+static void memory_stat_format(struct printbuf *out, struct mem_cgroup *memcg)
{
- struct seq_buf s;
int i;
- seq_buf_init(&s, buf, bufsize);
-
/*
* Provide statistics on the state of the memory subsystem as
* well as cumulative event counters that show past behavior.
@@ -1513,30 +1510,30 @@ static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
u64 size;
size = memcg_page_state_output(memcg, memory_stats[i].idx);
- seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size);
+ prt_printf(out, "%s %llu\n", memory_stats[i].name, size);
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
size += memcg_page_state_output(memcg,
NR_SLAB_RECLAIMABLE_B);
- seq_buf_printf(&s, "slab %llu\n", size);
+ prt_printf(out, "slab %llu\n", size);
}
}
/* Accumulated memory events */
- seq_buf_printf(&s, "pgscan %lu\n",
- memcg_events(memcg, PGSCAN_KSWAPD) +
- memcg_events(memcg, PGSCAN_DIRECT));
- seq_buf_printf(&s, "pgsteal %lu\n",
- memcg_events(memcg, PGSTEAL_KSWAPD) +
- memcg_events(memcg, PGSTEAL_DIRECT));
+ prt_printf(out, "pgscan %lu\n",
+ memcg_events(memcg, PGSCAN_KSWAPD) +
+ memcg_events(memcg, PGSCAN_DIRECT));
+ prt_printf(out, "pgsteal %lu\n",
+ memcg_events(memcg, PGSTEAL_KSWAPD) +
+ memcg_events(memcg, PGSTEAL_DIRECT));
for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++)
- seq_buf_printf(&s, "%s %lu\n",
- vm_event_name(memcg_vm_event_stat[i]),
- memcg_events(memcg, memcg_vm_event_stat[i]));
+ prt_printf(out, "%s %lu\n",
+ vm_event_name(memcg_vm_event_stat[i]),
+ memcg_events(memcg, memcg_vm_event_stat[i]));
/* The above should easily fit into one page */
- WARN_ON_ONCE(seq_buf_has_overflowed(&s));
+ WARN_ON_ONCE(!printbuf_remaining(out));
}
#define K(x) ((x) << (PAGE_SHIFT-10))
@@ -1573,7 +1570,8 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *
void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
{
/* Use static buffer, for the caller is holding oom_lock. */
- static char buf[PAGE_SIZE];
+ static char _buf[PAGE_SIZE];
+ struct printbuf buf = PRINTBUF_EXTERN(_buf, sizeof(_buf));
lockdep_assert_held(&oom_lock);
@@ -1596,8 +1594,8 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
pr_info("Memory cgroup stats for ");
pr_cont_cgroup_path(memcg->css.cgroup);
pr_cont(":");
- memory_stat_format(memcg, buf, sizeof(buf));
- pr_info("%s", buf);
+ memory_stat_format(&buf, memcg);
+ pr_info("%s", buf.buf);
}
/*
@@ -6401,14 +6399,16 @@ static int memory_events_local_show(struct seq_file *m, void *v)
static int memory_stat_show(struct seq_file *m, void *v)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
- char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ struct printbuf buf = PRINTBUF;
+ int ret;
- if (!buf)
- return -ENOMEM;
- memory_stat_format(memcg, buf, PAGE_SIZE);
- seq_puts(m, buf);
- kfree(buf);
- return 0;
+ memory_stat_format(&buf, memcg);
+ ret = buf.allocation_failure ? -ENOMEM : 0;
+ if (!ret)
+ seq_puts(m, buf.buf);
+
+ printbuf_exit(&buf);
+ return ret;
}
#ifdef CONFIG_NUMA
--
2.35.1
From: Kent Overstreet <[email protected]>
All users have now been converted to printbufs.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Steven Rostedt <[email protected]>
---
include/linux/seq_buf.h | 162 ----------------
lib/Makefile | 2 +-
lib/seq_buf.c | 397 ----------------------------------------
3 files changed, 1 insertion(+), 560 deletions(-)
delete mode 100644 include/linux/seq_buf.h
delete mode 100644 lib/seq_buf.c
diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h
deleted file mode 100644
index 5b31c5147969..000000000000
--- a/include/linux/seq_buf.h
+++ /dev/null
@@ -1,162 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_SEQ_BUF_H
-#define _LINUX_SEQ_BUF_H
-
-#include <linux/fs.h>
-
-/*
- * Trace sequences are used to allow a function to call several other functions
- * to create a string of data to use.
- */
-
-/**
- * seq_buf - seq buffer structure
- * @buffer: pointer to the buffer
- * @size: size of the buffer
- * @len: the amount of data inside the buffer
- * @readpos: The next position to read in the buffer.
- */
-struct seq_buf {
- char *buffer;
- size_t size;
- size_t len;
- loff_t readpos;
-};
-
-static inline void seq_buf_clear(struct seq_buf *s)
-{
- s->len = 0;
- s->readpos = 0;
-}
-
-static inline void
-seq_buf_init(struct seq_buf *s, char *buf, unsigned int size)
-{
- s->buffer = buf;
- s->size = size;
- seq_buf_clear(s);
-}
-
-/*
- * seq_buf have a buffer that might overflow. When this happens
- * the len and size are set to be equal.
- */
-static inline bool
-seq_buf_has_overflowed(struct seq_buf *s)
-{
- return s->len > s->size;
-}
-
-static inline void
-seq_buf_set_overflow(struct seq_buf *s)
-{
- s->len = s->size + 1;
-}
-
-/*
- * How much buffer is left on the seq_buf?
- */
-static inline unsigned int
-seq_buf_buffer_left(struct seq_buf *s)
-{
- if (seq_buf_has_overflowed(s))
- return 0;
-
- return s->size - s->len;
-}
-
-/* How much buffer was written? */
-static inline unsigned int seq_buf_used(struct seq_buf *s)
-{
- return min(s->len, s->size);
-}
-
-/**
- * seq_buf_terminate - Make sure buffer is nul terminated
- * @s: the seq_buf descriptor to terminate.
- *
- * This makes sure that the buffer in @s is nul terminated and
- * safe to read as a string.
- *
- * Note, if this is called when the buffer has overflowed, then
- * the last byte of the buffer is zeroed, and the len will still
- * point passed it.
- *
- * After this function is called, s->buffer is safe to use
- * in string operations.
- */
-static inline void seq_buf_terminate(struct seq_buf *s)
-{
- if (WARN_ON(s->size == 0))
- return;
-
- if (seq_buf_buffer_left(s))
- s->buffer[s->len] = 0;
- else
- s->buffer[s->size - 1] = 0;
-}
-
-/**
- * seq_buf_get_buf - get buffer to write arbitrary data to
- * @s: the seq_buf handle
- * @bufp: the beginning of the buffer is stored here
- *
- * Return the number of bytes available in the buffer, or zero if
- * there's no space.
- */
-static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp)
-{
- WARN_ON(s->len > s->size + 1);
-
- if (s->len < s->size) {
- *bufp = s->buffer + s->len;
- return s->size - s->len;
- }
-
- *bufp = NULL;
- return 0;
-}
-
-/**
- * seq_buf_commit - commit data to the buffer
- * @s: the seq_buf handle
- * @num: the number of bytes to commit
- *
- * Commit @num bytes of data written to a buffer previously acquired
- * by seq_buf_get. To signal an error condition, or that the data
- * didn't fit in the available space, pass a negative @num value.
- */
-static inline void seq_buf_commit(struct seq_buf *s, int num)
-{
- if (num < 0) {
- seq_buf_set_overflow(s);
- } else {
- /* num must be negative on overflow */
- BUG_ON(s->len + num > s->size);
- s->len += num;
- }
-}
-
-extern __printf(2, 3)
-int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);
-extern __printf(2, 0)
-int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);
-extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s);
-extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf,
- int cnt);
-extern int seq_buf_puts(struct seq_buf *s, const char *str);
-extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
-extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);
-extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
- unsigned int len);
-extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc);
-extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str,
- int prefix_type, int rowsize, int groupsize,
- const void *buf, size_t len, bool ascii);
-
-#ifdef CONFIG_BINARY_PRINTF
-extern int
-seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
-#endif
-
-#endif /* _LINUX_SEQ_BUF_H */
diff --git a/lib/Makefile b/lib/Makefile
index d44f8d03d66b..9ed57a1f9fa0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -32,7 +32,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
idr.o extable.o irq_regs.o argv_split.o \
flex_proportions.o ratelimit.o show_mem.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
- earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
+ earlycpio.o siphash.o dec_and_lock.o \
nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o \
buildid.o cpumask.o printbuf.o
diff --git a/lib/seq_buf.c b/lib/seq_buf.c
deleted file mode 100644
index 0a68f7aa85d6..000000000000
--- a/lib/seq_buf.c
+++ /dev/null
@@ -1,397 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * seq_buf.c
- *
- * Copyright (C) 2014 Red Hat Inc, Steven Rostedt <[email protected]>
- *
- * The seq_buf is a handy tool that allows you to pass a descriptor around
- * to a buffer that other functions can write to. It is similar to the
- * seq_file functionality but has some differences.
- *
- * To use it, the seq_buf must be initialized with seq_buf_init().
- * This will set up the counters within the descriptor. You can call
- * seq_buf_init() more than once to reset the seq_buf to start
- * from scratch.
- */
-#include <linux/uaccess.h>
-#include <linux/seq_file.h>
-#include <linux/seq_buf.h>
-
-/**
- * seq_buf_can_fit - can the new data fit in the current buffer?
- * @s: the seq_buf descriptor
- * @len: The length to see if it can fit in the current buffer
- *
- * Returns true if there's enough unused space in the seq_buf buffer
- * to fit the amount of new data according to @len.
- */
-static bool seq_buf_can_fit(struct seq_buf *s, size_t len)
-{
- return s->len + len <= s->size;
-}
-
-/**
- * seq_buf_print_seq - move the contents of seq_buf into a seq_file
- * @m: the seq_file descriptor that is the destination
- * @s: the seq_buf descriptor that is the source.
- *
- * Returns zero on success, non zero otherwise
- */
-int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s)
-{
- unsigned int len = seq_buf_used(s);
-
- return seq_write(m, s->buffer, len);
-}
-
-/**
- * seq_buf_vprintf - sequence printing of information.
- * @s: seq_buf descriptor
- * @fmt: printf format string
- * @args: va_list of arguments from a printf() type function
- *
- * Writes a vnprintf() format into the sequencce buffer.
- *
- * Returns zero on success, -1 on overflow.
- */
-int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
-{
- int len;
-
- WARN_ON(s->size == 0);
-
- if (s->len < s->size) {
- len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args);
- if (s->len + len < s->size) {
- s->len += len;
- return 0;
- }
- }
- seq_buf_set_overflow(s);
- return -1;
-}
-
-/**
- * seq_buf_printf - sequence printing of information
- * @s: seq_buf descriptor
- * @fmt: printf format string
- *
- * Writes a printf() format into the sequence buffer.
- *
- * Returns zero on success, -1 on overflow.
- */
-int seq_buf_printf(struct seq_buf *s, const char *fmt, ...)
-{
- va_list ap;
- int ret;
-
- va_start(ap, fmt);
- ret = seq_buf_vprintf(s, fmt, ap);
- va_end(ap);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(seq_buf_printf);
-
-#ifdef CONFIG_BINARY_PRINTF
-/**
- * seq_buf_bprintf - Write the printf string from binary arguments
- * @s: seq_buf descriptor
- * @fmt: The format string for the @binary arguments
- * @binary: The binary arguments for @fmt.
- *
- * When recording in a fast path, a printf may be recorded with just
- * saving the format and the arguments as they were passed to the
- * function, instead of wasting cycles converting the arguments into
- * ASCII characters. Instead, the arguments are saved in a 32 bit
- * word array that is defined by the format string constraints.
- *
- * This function will take the format and the binary array and finish
- * the conversion into the ASCII string within the buffer.
- *
- * Returns zero on success, -1 on overflow.
- */
-int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
-{
- unsigned int len = seq_buf_buffer_left(s);
- int ret;
-
- WARN_ON(s->size == 0);
-
- if (s->len < s->size) {
- ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
- if (s->len + ret < s->size) {
- s->len += ret;
- return 0;
- }
- }
- seq_buf_set_overflow(s);
- return -1;
-}
-#endif /* CONFIG_BINARY_PRINTF */
-
-/**
- * seq_buf_puts - sequence printing of simple string
- * @s: seq_buf descriptor
- * @str: simple string to record
- *
- * Copy a simple string into the sequence buffer.
- *
- * Returns zero on success, -1 on overflow
- */
-int seq_buf_puts(struct seq_buf *s, const char *str)
-{
- size_t len = strlen(str);
-
- WARN_ON(s->size == 0);
-
- /* Add 1 to len for the trailing null byte which must be there */
- len += 1;
-
- if (seq_buf_can_fit(s, len)) {
- memcpy(s->buffer + s->len, str, len);
- /* Don't count the trailing null byte against the capacity */
- s->len += len - 1;
- return 0;
- }
- seq_buf_set_overflow(s);
- return -1;
-}
-
-/**
- * seq_buf_putc - sequence printing of simple character
- * @s: seq_buf descriptor
- * @c: simple character to record
- *
- * Copy a single character into the sequence buffer.
- *
- * Returns zero on success, -1 on overflow
- */
-int seq_buf_putc(struct seq_buf *s, unsigned char c)
-{
- WARN_ON(s->size == 0);
-
- if (seq_buf_can_fit(s, 1)) {
- s->buffer[s->len++] = c;
- return 0;
- }
- seq_buf_set_overflow(s);
- return -1;
-}
-
-/**
- * seq_buf_putmem - write raw data into the sequenc buffer
- * @s: seq_buf descriptor
- * @mem: The raw memory to copy into the buffer
- * @len: The length of the raw memory to copy (in bytes)
- *
- * There may be cases where raw memory needs to be written into the
- * buffer and a strcpy() would not work. Using this function allows
- * for such cases.
- *
- * Returns zero on success, -1 on overflow
- */
-int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len)
-{
- WARN_ON(s->size == 0);
-
- if (seq_buf_can_fit(s, len)) {
- memcpy(s->buffer + s->len, mem, len);
- s->len += len;
- return 0;
- }
- seq_buf_set_overflow(s);
- return -1;
-}
-
-#define MAX_MEMHEX_BYTES 8U
-#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
-
-/**
- * seq_buf_putmem_hex - write raw memory into the buffer in ASCII hex
- * @s: seq_buf descriptor
- * @mem: The raw memory to write its hex ASCII representation of
- * @len: The length of the raw memory to copy (in bytes)
- *
- * This is similar to seq_buf_putmem() except instead of just copying the
- * raw memory into the buffer it writes its ASCII representation of it
- * in hex characters.
- *
- * Returns zero on success, -1 on overflow
- */
-int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
- unsigned int len)
-{
- unsigned char hex[HEX_CHARS];
- const unsigned char *data = mem;
- unsigned int start_len;
- int i, j;
-
- WARN_ON(s->size == 0);
-
- BUILD_BUG_ON(MAX_MEMHEX_BYTES * 2 >= HEX_CHARS);
-
- while (len) {
- start_len = min(len, MAX_MEMHEX_BYTES);
-#ifdef __BIG_ENDIAN
- for (i = 0, j = 0; i < start_len; i++) {
-#else
- for (i = start_len-1, j = 0; i >= 0; i--) {
-#endif
- hex[j++] = hex_asc_hi(data[i]);
- hex[j++] = hex_asc_lo(data[i]);
- }
- if (WARN_ON_ONCE(j == 0 || j/2 > len))
- break;
-
- /* j increments twice per loop */
- hex[j++] = ' ';
-
- seq_buf_putmem(s, hex, j);
- if (seq_buf_has_overflowed(s))
- return -1;
-
- len -= start_len;
- data += start_len;
- }
- return 0;
-}
-
-/**
- * seq_buf_path - copy a path into the sequence buffer
- * @s: seq_buf descriptor
- * @path: path to write into the sequence buffer.
- * @esc: set of characters to escape in the output
- *
- * Write a path name into the sequence buffer.
- *
- * Returns the number of written bytes on success, -1 on overflow
- */
-int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc)
-{
- char *buf;
- size_t size = seq_buf_get_buf(s, &buf);
- int res = -1;
-
- WARN_ON(s->size == 0);
-
- if (size) {
- char *p = d_path(path, buf, size);
- if (!IS_ERR(p)) {
- char *end = mangle_path(buf, p, esc);
- if (end)
- res = end - buf;
- }
- }
- seq_buf_commit(s, res);
-
- return res;
-}
-
-/**
- * seq_buf_to_user - copy the sequence buffer to user space
- * @s: seq_buf descriptor
- * @ubuf: The userspace memory location to copy to
- * @cnt: The amount to copy
- *
- * Copies the sequence buffer into the userspace memory pointed to
- * by @ubuf. It starts from the last read position (@s->readpos)
- * and writes up to @cnt characters or till it reaches the end of
- * the content in the buffer (@s->len), which ever comes first.
- *
- * On success, it returns a positive number of the number of bytes
- * it copied.
- *
- * On failure it returns -EBUSY if all of the content in the
- * sequence has been already read, which includes nothing in the
- * sequence (@s->len == @s->readpos).
- *
- * Returns -EFAULT if the copy to userspace fails.
- */
-int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt)
-{
- int len;
- int ret;
-
- if (!cnt)
- return 0;
-
- len = seq_buf_used(s);
-
- if (len <= s->readpos)
- return -EBUSY;
-
- len -= s->readpos;
- if (cnt > len)
- cnt = len;
- ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
- if (ret == cnt)
- return -EFAULT;
-
- cnt -= ret;
-
- s->readpos += cnt;
- return cnt;
-}
-
-/**
- * seq_buf_hex_dump - print formatted hex dump into the sequence buffer
- * @s: seq_buf descriptor
- * @prefix_str: string to prefix each line with;
- * caller supplies trailing spaces for alignment if desired
- * @prefix_type: controls whether prefix of an offset, address, or none
- * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
- * @rowsize: number of bytes to print per line; must be 16 or 32
- * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
- * @buf: data blob to dump
- * @len: number of bytes in the @buf
- * @ascii: include ASCII after the hex output
- *
- * Function is an analogue of print_hex_dump() and thus has similar interface.
- *
- * linebuf size is maximal length for one line.
- * 32 * 3 - maximum bytes per line, each printed into 2 chars + 1 for
- * separating space
- * 2 - spaces separating hex dump and ascii representation
- * 32 - ascii representation
- * 1 - terminating '\0'
- *
- * Returns zero on success, -1 on overflow
- */
-int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, int prefix_type,
- int rowsize, int groupsize,
- const void *buf, size_t len, bool ascii)
-{
- const u8 *ptr = buf;
- int i, linelen, remaining = len;
- unsigned char linebuf[32 * 3 + 2 + 32 + 1];
- int ret;
-
- if (rowsize != 16 && rowsize != 32)
- rowsize = 16;
-
- for (i = 0; i < len; i += rowsize) {
- linelen = min(remaining, rowsize);
- remaining -= rowsize;
-
- hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
- linebuf, sizeof(linebuf), ascii);
-
- switch (prefix_type) {
- case DUMP_PREFIX_ADDRESS:
- ret = seq_buf_printf(s, "%s%p: %s\n",
- prefix_str, ptr + i, linebuf);
- break;
- case DUMP_PREFIX_OFFSET:
- ret = seq_buf_printf(s, "%s%.8x: %s\n",
- prefix_str, i, linebuf);
- break;
- default:
- ret = seq_buf_printf(s, "%s%s\n", prefix_str, linebuf);
- break;
- }
- if (ret)
- return ret;
- }
- return 0;
-}
--
2.35.1
From: Kent Overstreet <[email protected]>
This adds printbufs: a printbuf points to a char * buffer and knows the
size of the output buffer as well as the current output position.
Future patches will be adding more features to printbuf, but initially
printbufs are targeted at refactoring and improving our existing code in
lib/vsprintf.c - so this initial printbuf patch has the features
required for that.
Signed-off-by: Kent Overstreet <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
---
include/linux/printbuf.h | 122 +++++++++++++++++++++++++++++++++++++++
1 file changed, 122 insertions(+)
create mode 100644 include/linux/printbuf.h
diff --git a/include/linux/printbuf.h b/include/linux/printbuf.h
new file mode 100644
index 000000000000..1aa3331bf00b
--- /dev/null
+++ b/include/linux/printbuf.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/* Copyright (C) 2022 Kent Overstreet */
+
+#ifndef _LINUX_PRINTBUF_H
+#define _LINUX_PRINTBUF_H
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+/*
+ * Printbufs: String buffer for outputting (printing) to, for vsnprintf
+ */
+
+struct printbuf {
+ char *buf;
+ unsigned size;
+ unsigned pos;
+};
+
+/*
+ * Returns size remaining of output buffer:
+ */
+static inline unsigned printbuf_remaining_size(struct printbuf *out)
+{
+ return out->pos < out->size ? out->size - out->pos : 0;
+}
+
+/*
+ * Returns number of characters we can print to the output buffer - i.e.
+ * excluding the terminating nul:
+ */
+static inline unsigned printbuf_remaining(struct printbuf *out)
+{
+ return out->pos < out->size ? out->size - out->pos - 1 : 0;
+}
+
+static inline unsigned printbuf_written(struct printbuf *out)
+{
+ return out->size ? min(out->pos, out->size - 1) : 0;
+}
+
+/*
+ * Returns true if output was truncated:
+ */
+static inline bool printbuf_overflowed(struct printbuf *out)
+{
+ return out->pos >= out->size;
+}
+
+static inline void printbuf_nul_terminate(struct printbuf *out)
+{
+ if (out->pos < out->size)
+ out->buf[out->pos] = 0;
+ else if (out->size)
+ out->buf[out->size - 1] = 0;
+}
+
+static inline void __prt_char(struct printbuf *out, char c)
+{
+ if (printbuf_remaining(out))
+ out->buf[out->pos] = c;
+ out->pos++;
+}
+
+static inline void prt_char(struct printbuf *out, char c)
+{
+ __prt_char(out, c);
+ printbuf_nul_terminate(out);
+}
+
+static inline void __prt_chars(struct printbuf *out, char c, unsigned n)
+{
+ unsigned i, can_print = min(n, printbuf_remaining(out));
+
+ for (i = 0; i < can_print; i++)
+ out->buf[out->pos++] = c;
+ out->pos += n - can_print;
+}
+
+static inline void prt_chars(struct printbuf *out, char c, unsigned n)
+{
+ __prt_chars(out, c, n);
+ printbuf_nul_terminate(out);
+}
+
+static inline void prt_bytes(struct printbuf *out, const void *b, unsigned n)
+{
+ unsigned i, can_print = min(n, printbuf_remaining(out));
+
+ for (i = 0; i < can_print; i++)
+ out->buf[out->pos++] = ((char *) b)[i];
+ out->pos += n - can_print;
+
+ printbuf_nul_terminate(out);
+}
+
+static inline void prt_str(struct printbuf *out, const char *str)
+{
+ prt_bytes(out, str, strlen(str));
+}
+
+static inline void prt_hex_byte(struct printbuf *out, u8 byte)
+{
+ __prt_char(out, hex_asc_hi(byte));
+ __prt_char(out, hex_asc_lo(byte));
+ printbuf_nul_terminate(out);
+}
+
+static inline void prt_hex_byte_upper(struct printbuf *out, u8 byte)
+{
+ __prt_char(out, hex_asc_upper_hi(byte));
+ __prt_char(out, hex_asc_upper_lo(byte));
+ printbuf_nul_terminate(out);
+}
+
+#define PRINTBUF_EXTERN(_buf, _size) \
+((struct printbuf) { \
+ .buf = _buf, \
+ .size = _size, \
+})
+
+#endif /* _LINUX_PRINTBUF_H */
--
2.35.1
From: Kent Overstreet <[email protected]>
This patch cleans up printf_spec handling: these functions only use
spec.field_width and they do not interpret it in the normal way -
instead it's a number of bits/bytes passed in to print, so these
functions are changed to take that parameter directly.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 60 +++++++++++++++++++++++---------------------------
1 file changed, 28 insertions(+), 32 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 06cfa06aa4ee..0ff7d9fea6da 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -53,6 +53,7 @@
#include <asm/unaligned.h>
#include <linux/string_helpers.h>
+#include <linux/pretty-printers.h>
#include "kstrtox.h"
/* Disable pointer hashing if requested */
@@ -1126,18 +1127,23 @@ void resource_string(struct printbuf *out, struct resource *res,
}
static noinline_for_stack
-void hex_string(struct printbuf *out, u8 *addr,
- struct printf_spec spec, const char *fmt)
+void hex_string(struct printbuf *out, const u8 *addr,
+ int len, const char *fmt)
{
- int i, len = 1; /* if we pass '%ph[CDN]', field width remains
- negative value, fallback to the default */
char separator;
- if (spec.field_width == 0)
- /* nothing to print */
+ /* nothing to print */
+ if (len == 0)
return;
- if (check_pointer_spec(out, addr, spec))
+ /* if we pass '%ph[CDN]', field width remains
+ negative value, fallback to the default */
+ if (len < 0)
+ len = 1;
+
+ len = min(len, 64);
+
+ if (check_pointer(out, addr))
return;
switch (fmt[1]) {
@@ -1155,34 +1161,21 @@ void hex_string(struct printbuf *out, u8 *addr,
break;
}
- if (spec.field_width > 0)
- len = min_t(int, spec.field_width, 64);
-
- for (i = 0; i < len; ++i) {
- __prt_char(out, hex_asc_hi(addr[i]));
- __prt_char(out, hex_asc_lo(addr[i]));
-
- if (separator && i != len - 1)
- __prt_char(out, separator);
- }
-
- printbuf_nul_terminate(out);
+ prt_hex_bytes(out, addr, len, 1, separator);
}
static noinline_for_stack
-void bitmap_string(struct printbuf *out, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+void bitmap_string(struct printbuf *out, unsigned long *bitmap, int nr_bits)
{
+ struct printf_spec spec = { .flags = SMALL | ZEROPAD, .base = 16 };
const int CHUNKSZ = 32;
- int nr_bits = max_t(int, spec.field_width, 0);
int i, chunksz;
bool first = true;
- if (check_pointer_spec(out, bitmap, spec))
- return;
+ nr_bits = max(nr_bits, 0);
- /* reused to print numbers */
- spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
+ if (check_pointer(out, bitmap))
+ return;
chunksz = nr_bits & (CHUNKSZ - 1);
if (chunksz == 0)
@@ -1211,13 +1204,14 @@ void bitmap_string(struct printbuf *out, unsigned long *bitmap,
static noinline_for_stack
void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
- struct printf_spec spec, const char *fmt)
+ int nr_bits)
{
- int nr_bits = max_t(int, spec.field_width, 0);
bool first = true;
int rbot, rtop;
- if (check_pointer_spec(out, bitmap, spec))
+ nr_bits = max(nr_bits, 0);
+
+ if (check_pointer(out, bitmap))
return ;
for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
@@ -2232,13 +2226,15 @@ void pointer(struct printbuf *out, const char *fmt,
resource_string(out, ptr, fmt[0] == 'R');
return do_width_precision(out, prev_pos, spec);
case 'h':
- return hex_string(out, ptr, spec, fmt);
+ /* Uses field_width but _not_ as field size */
+ return hex_string(out, ptr, spec.field_width, fmt);
case 'b':
+ /* Uses field_width but _not_ as field size */
switch (fmt[1]) {
case 'l':
- return bitmap_list_string(out, ptr, spec, fmt);
+ return bitmap_list_string(out, ptr, spec.field_width);
default:
- return bitmap_string(out, ptr, spec, fmt);
+ return bitmap_string(out, ptr, spec.field_width);
}
case 'M': /* Colon separated: 00:01:02:03:04:05 */
case 'm': /* Contiguous: 000102030405 */
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf. We're using printbuf in external
buffer mode, so it's a direct conversion, aside from some trivial
refactoring in cpu_show_meltdown() to make the code more consistent.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: [email protected]
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index f276aff521e8..50c12711a249 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -19,7 +19,7 @@
#include <linux/fs_parser.h>
#include <linux/sysfs.h>
#include <linux/kernfs.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/seq_file.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
@@ -51,7 +51,7 @@ static struct kernfs_node *kn_mongrp;
/* Kernel fs node for "mon_data" directory under root */
static struct kernfs_node *kn_mondata;
-static struct seq_buf last_cmd_status;
+static struct printbuf last_cmd_status;
static char last_cmd_status_buf[512];
struct dentry *debugfs_resctrl;
@@ -59,13 +59,13 @@ struct dentry *debugfs_resctrl;
void rdt_last_cmd_clear(void)
{
lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_clear(&last_cmd_status);
+ printbuf_reset(&last_cmd_status);
}
void rdt_last_cmd_puts(const char *s)
{
lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_puts(&last_cmd_status, s);
+ prt_str(&last_cmd_status, s);
}
void rdt_last_cmd_printf(const char *fmt, ...)
@@ -74,7 +74,7 @@ void rdt_last_cmd_printf(const char *fmt, ...)
va_start(ap, fmt);
lockdep_assert_held(&rdtgroup_mutex);
- seq_buf_vprintf(&last_cmd_status, fmt, ap);
+ prt_vprintf(&last_cmd_status, fmt, ap);
va_end(ap);
}
@@ -833,7 +833,7 @@ static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
int len;
mutex_lock(&rdtgroup_mutex);
- len = seq_buf_used(&last_cmd_status);
+ len = printbuf_written(&last_cmd_status);
if (len)
seq_printf(seq, "%.*s", len, last_cmd_status_buf);
else
@@ -3248,8 +3248,8 @@ int __init rdtgroup_init(void)
{
int ret = 0;
- seq_buf_init(&last_cmd_status, last_cmd_status_buf,
- sizeof(last_cmd_status_buf));
+ last_cmd_status = PRINTBUF_EXTERN(last_cmd_status_buf,
+ sizeof(last_cmd_status_buf));
ret = rdtgroup_setup_root();
if (ret)
--
2.35.1
From: Kent Overstreet <[email protected]>
This adds two new-style printbuf helpers for printing simple u64s, and
converts num_to_str() to be a simple wrapper around prt_u64_minwidth().
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
include/linux/kernel.h | 4 +-
lib/vsprintf.c | 94 ++++++++++++++++++++----------------------
2 files changed, 48 insertions(+), 50 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 1906861ece7a..9ba5a53c6ad5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -202,12 +202,14 @@ static inline void might_fault(void) { }
void do_exit(long error_code) __noreturn;
+struct printbuf;
+extern void prt_u64_minwidth(struct printbuf *out, u64 num, unsigned width);
+extern void prt_u64(struct printbuf *out, u64 num);
extern int num_to_str(char *buf, int size,
unsigned long long num, unsigned int width);
/* lib/printf utilities */
-struct printbuf;
extern __printf(2, 3) void prt_printf(struct printbuf *out, const char *fmt, ...);
extern __printf(2, 0) void prt_vprintf(struct printbuf *out, const char *fmt, va_list);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 87adc528c6c7..6001710352c4 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -368,41 +368,51 @@ char *put_dec(char *buf, unsigned long long n)
#endif
-/*
- * Convert passed number to decimal string.
- * Returns the length of string. On buffer overflow, returns 0.
- *
- * If speed is not important, use snprintf(). It's easy to read the code.
+/**
+ * prt_u64_minwidth - print a u64, in decimal, with zero padding
+ * @out: printbuf to output to
+ * @num: u64 to print
+ * @width: minimum width
*/
-int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
+void prt_u64_minwidth(struct printbuf *out, u64 num, unsigned width)
{
/* put_dec requires 2-byte alignment of the buffer. */
char tmp[sizeof(num) * 3] __aligned(2);
- int idx, len;
+ unsigned len = put_dec(tmp, num) - tmp;
- /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
- if (num <= 9) {
- tmp[0] = '0' + num;
- len = 1;
- } else {
- len = put_dec(tmp, num) - tmp;
- }
+ printbuf_make_room(out, max(len, width));
- if (len > size || width > size)
- return 0;
+ if (width > len)
+ __prt_chars_reserved(out, '0', width - len);
- if (width > len) {
- width = width - len;
- for (idx = 0; idx < width; idx++)
- buf[idx] = ' ';
- } else {
- width = 0;
- }
+ while (len)
+ __prt_char_reserved(out, tmp[--len]);
+ printbuf_nul_terminate(out);
+}
- for (idx = 0; idx < len; ++idx)
- buf[idx + width] = tmp[len - idx - 1];
+/**
+ * prt_u64 - print a simple u64, in decimal
+ * @out: printbuf to output to
+ * @num: u64 to print
+ */
+void prt_u64(struct printbuf *out, u64 num)
+{
+ prt_u64_minwidth(out, num, 0);
+}
- return len + width;
+/*
+ * Convert passed number to decimal string.
+ * Returns the length of string. On buffer overflow, returns 0.
+ *
+ * Consider switching to printbufs and using prt_u64() or prt_u64_minwith()
+ * instead.
+ */
+int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
+{
+ struct printbuf out = PRINTBUF_EXTERN(buf, size);
+
+ prt_u64_minwidth(&out, num, width);
+ return out.pos;
}
#define SIGN 1 /* unsigned/signed, must be 1 */
@@ -993,20 +1003,6 @@ static const struct printf_spec default_dec_spec = {
.precision = -1,
};
-static const struct printf_spec default_dec02_spec = {
- .base = 10,
- .field_width = 2,
- .precision = -1,
- .flags = ZEROPAD,
-};
-
-static const struct printf_spec default_dec04_spec = {
- .base = 10,
- .field_width = 4,
- .precision = -1,
- .flags = ZEROPAD,
-};
-
static noinline_for_stack
void resource_string(struct printbuf *out, struct resource *res,
struct printf_spec spec, const char *fmt)
@@ -1206,12 +1202,12 @@ void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
prt_char(out, ',');
first = false;
- number(out, rbot, default_dec_spec);
+ prt_u64(out, rbot);
if (rtop == rbot + 1)
continue;
prt_char(out, '-');
- number(out, rtop - 1, default_dec_spec);
+ prt_u64(out, rtop - 1);
}
}
@@ -1753,21 +1749,21 @@ void date_str(struct printbuf *out,
int year = tm->tm_year + (r ? 0 : 1900);
int mon = tm->tm_mon + (r ? 0 : 1);
- number(out, year, default_dec04_spec);
+ prt_u64_minwidth(out, year, 4);
prt_char(out, '-');
- number(out, mon, default_dec02_spec);
+ prt_u64_minwidth(out, mon, 2);
prt_char(out, '-');
- number(out, tm->tm_mday, default_dec02_spec);
+ prt_u64_minwidth(out, tm->tm_mday, 2);
}
static noinline_for_stack
void time_str(struct printbuf *out, const struct rtc_time *tm, bool r)
{
- number(out, tm->tm_hour, default_dec02_spec);
+ prt_u64_minwidth(out, tm->tm_hour, 2);
prt_char(out, ':');
- number(out, tm->tm_min, default_dec02_spec);
+ prt_u64_minwidth(out, tm->tm_min, 2);
prt_char(out, ':');
- number(out, tm->tm_sec, default_dec02_spec);
+ prt_u64_minwidth(out, tm->tm_sec, 2);
}
static noinline_for_stack
@@ -2045,7 +2041,7 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
str_spec.precision = precision;
break;
case 'p': /* phandle */
- number(out, (unsigned int)dn->phandle, default_dec_spec);
+ prt_u64(out, (unsigned int)dn->phandle);
break;
case 'P': /* path-spec */
p = fwnode_get_name(of_fwnode_handle(dn));
--
2.35.1
From: Kent Overstreet <[email protected]>
We're attempting to consolidate printf_spec and format string handling
in the top level vpr_buf(), this changes time_and_date() to not
take printf_spec.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 2042c17f571e..784f7cb64926 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1736,14 +1736,14 @@ void time_str(struct printbuf *out, const struct rtc_time *tm, bool r)
static noinline_for_stack
void rtc_str(struct printbuf *out, const struct rtc_time *tm,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
bool have_t = true, have_d = true;
bool raw = false, iso8601_separator = true;
bool found = true;
int count = 2;
- if (check_pointer_spec(out, tm, spec))
+ if (check_pointer(out, tm))
return;
switch (fmt[count]) {
@@ -1781,7 +1781,7 @@ void rtc_str(struct printbuf *out, const struct rtc_time *tm,
static noinline_for_stack
void time64_str(struct printbuf *out, const time64_t time,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
struct rtc_time rtc_time;
struct tm tm;
@@ -1799,21 +1799,20 @@ void time64_str(struct printbuf *out, const time64_t time,
rtc_time.tm_isdst = 0;
- rtc_str(out, &rtc_time, spec, fmt);
+ rtc_str(out, &rtc_time, fmt);
}
static noinline_for_stack
-void time_and_date(struct printbuf *out,
- void *ptr, struct printf_spec spec,
+void time_and_date(struct printbuf *out, void *ptr,
const char *fmt)
{
switch (fmt[1]) {
case 'R':
- return rtc_str(out, (const struct rtc_time *)ptr, spec, fmt);
+ return rtc_str(out, (const struct rtc_time *)ptr, fmt);
case 'T':
- return time64_str(out, *(const time64_t *)ptr, spec, fmt);
+ return time64_str(out, *(const time64_t *)ptr, fmt);
default:
- return error_string_spec(out, "(%pt?)", spec);
+ return error_string(out, "(%pt?)");
}
}
@@ -2297,7 +2296,8 @@ void pointer(struct printbuf *out, const char *fmt,
dentry_name(out, ptr, fmt);
return do_width_precision(out, prev_pos, spec);
case 't':
- return time_and_date(out, ptr, spec, fmt);
+ time_and_date(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'C':
return clock(out, ptr, spec, fmt);
case 'D':
--
2.35.1
From: Kent Overstreet <[email protected]>
printbuf now needs to know the number of characters that would have been
written if the buffer was too small, like snprintf(); this changes
string_get_size() to return the the return value of snprintf().
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Andy Shevchenko <[email protected]>
---
include/linux/string_helpers.h | 4 ++--
lib/string_helpers.c | 7 +++----
2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 67de398944e8..52e0f1d283b9 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -19,8 +19,8 @@ enum string_size_units {
STRING_UNITS_2, /* use binary powers of 2^10 */
};
-void string_get_size(u64 size, u64 blk_size, enum string_size_units units,
- char *buf, int len);
+int string_get_size(u64 size, u64 blk_size, enum string_size_units units,
+ char *buf, int len);
#define UNESCAPE_SPACE BIT(0)
#define UNESCAPE_OCTAL BIT(1)
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 7be20bcc6137..d247bf945f16 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -33,8 +33,8 @@
* at least 9 bytes and will always be zero terminated.
*
*/
-void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
- char *buf, int len)
+int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
+ char *buf, int len)
{
static const char *const units_10[] = {
"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
@@ -127,8 +127,7 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
else
unit = units_str[units][i];
- snprintf(buf, len, "%u%s %s", (u32)size,
- tmp, unit);
+ return snprintf(buf, len, "%u%s %s", (u32)size, tmp, unit);
}
EXPORT_SYMBOL(string_get_size);
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf. Here we're using printbuf with
an external buffer, meaning it's a direct conversion.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]
---
tools/testing/nvdimm/test/ndtest.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
index 4d1a947367f9..a2097955dace 100644
--- a/tools/testing/nvdimm/test/ndtest.c
+++ b/tools/testing/nvdimm/test/ndtest.c
@@ -12,7 +12,7 @@
#include <linux/ndctl.h>
#include <nd-core.h>
#include <linux/printk.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include "../watermark.h"
#include "nfit_test.h"
@@ -740,32 +740,30 @@ static ssize_t flags_show(struct device *dev,
{
struct nvdimm *nvdimm = to_nvdimm(dev);
struct ndtest_dimm *dimm = nvdimm_provider_data(nvdimm);
- struct seq_buf s;
+ struct printbuf s = PRINTBUF_EXTERN(buf, PAGE_SIZE);
u64 flags;
flags = dimm->flags;
- seq_buf_init(&s, buf, PAGE_SIZE);
if (flags & PAPR_PMEM_UNARMED_MASK)
- seq_buf_printf(&s, "not_armed ");
+ prt_printf(&s, "not_armed ");
if (flags & PAPR_PMEM_BAD_SHUTDOWN_MASK)
- seq_buf_printf(&s, "flush_fail ");
+ prt_printf(&s, "flush_fail ");
if (flags & PAPR_PMEM_BAD_RESTORE_MASK)
- seq_buf_printf(&s, "restore_fail ");
+ prt_printf(&s, "restore_fail ");
if (flags & PAPR_PMEM_SAVE_MASK)
- seq_buf_printf(&s, "save_fail ");
+ prt_printf(&s, "save_fail ");
if (flags & PAPR_PMEM_SMART_EVENT_MASK)
- seq_buf_printf(&s, "smart_notify ");
+ prt_printf(&s, "smart_notify ");
+ if (printbuf_written(&s))
+ prt_printf(&s, "\n");
- if (seq_buf_used(&s))
- seq_buf_printf(&s, "\n");
-
- return seq_buf_used(&s);
+ return printbuf_written(&s);
}
static DEVICE_ATTR_RO(flags);
--
2.35.1
From: Kent Overstreet <[email protected]>
Two changes:
- We're attempting to consolidate printf_spec and format string
handling in the top level vpr_buf(), this changes resource_string to
not take printf_spec
- With the new printbuf helpers there's no need to use a separate stack
allocated buffer, so this patch deletes it.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 51 ++++++++++++++++++++++++--------------------------
1 file changed, 24 insertions(+), 27 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 5cc8337ada0c..2c5f10bc59e2 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1032,7 +1032,7 @@ static const struct printf_spec default_dec_spec = {
static noinline_for_stack
void resource_string(struct printbuf *out, struct resource *res,
- struct printf_spec spec, const char *fmt)
+ int decode)
{
#ifndef IO_RSRC_PRINTK_SIZE
#define IO_RSRC_PRINTK_SIZE 6
@@ -1071,62 +1071,58 @@ void resource_string(struct printbuf *out, struct resource *res,
#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
- char sym_buf[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
- 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
- struct printbuf sym = PRINTBUF_EXTERN(sym_buf, sizeof(sym_buf));
- int decode = (fmt[0] == 'R') ? 1 : 0;
const struct printf_spec *specp;
- if (check_pointer_spec(out, res, spec))
+ if (check_pointer(out, res))
return;
- prt_char(&sym, '[');
+ prt_char(out, '[');
if (res->flags & IORESOURCE_IO) {
- string_nocheck(&sym, "io ", str_spec);
+ string_nocheck(out, "io ", str_spec);
specp = &io_spec;
} else if (res->flags & IORESOURCE_MEM) {
- string_nocheck(&sym, "mem ", str_spec);
+ string_nocheck(out, "mem ", str_spec);
specp = &mem_spec;
} else if (res->flags & IORESOURCE_IRQ) {
- string_nocheck(&sym, "irq ", str_spec);
+ string_nocheck(out, "irq ", str_spec);
specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_DMA) {
- string_nocheck(&sym, "dma ", str_spec);
+ string_nocheck(out, "dma ", str_spec);
specp = &default_dec_spec;
} else if (res->flags & IORESOURCE_BUS) {
- string_nocheck(&sym, "bus ", str_spec);
+ string_nocheck(out, "bus ", str_spec);
specp = &bus_spec;
} else {
- string_nocheck(&sym, "??? ", str_spec);
+ string_nocheck(out, "??? ", str_spec);
specp = &mem_spec;
decode = 0;
}
if (decode && res->flags & IORESOURCE_UNSET) {
- string_nocheck(&sym, "size ", str_spec);
- number(&sym, resource_size(res), *specp);
+ string_nocheck(out, "size ", str_spec);
+ number(out, resource_size(res), *specp);
} else {
- number(&sym, res->start, *specp);
+ number(out, res->start, *specp);
if (res->start != res->end) {
- prt_char(&sym, '-');
- number(&sym, res->end, *specp);
+ prt_char(out, '-');
+ number(out, res->end, *specp);
}
}
if (decode) {
if (res->flags & IORESOURCE_MEM_64)
- string_nocheck(&sym, " 64bit", str_spec);
+ string_nocheck(out, " 64bit", str_spec);
if (res->flags & IORESOURCE_PREFETCH)
- string_nocheck(&sym, " pref", str_spec);
+ string_nocheck(out, " pref", str_spec);
if (res->flags & IORESOURCE_WINDOW)
- string_nocheck(&sym, " window", str_spec);
+ string_nocheck(out, " window", str_spec);
if (res->flags & IORESOURCE_DISABLED)
- string_nocheck(&sym, " disabled", str_spec);
+ string_nocheck(out, " disabled", str_spec);
} else {
- string_nocheck(&sym, " flags ", str_spec);
- number(&sym, res->flags, default_flag_spec);
+ string_nocheck(out, " flags ", str_spec);
+ number(out, res->flags, default_flag_spec);
}
- prt_char(&sym, ']');
+ prt_char(out, ']');
- string_nocheck(out, sym_buf, spec);
+ printbuf_nul_terminate(out);
}
static noinline_for_stack
@@ -2301,7 +2297,8 @@ void pointer(struct printbuf *out, const char *fmt,
return do_width_precision(out, prev_pos, spec);
case 'R':
case 'r':
- return resource_string(out, ptr, spec, fmt);
+ resource_string(out, ptr, fmt[0] == 'R');
+ return do_width_precision(out, prev_pos, spec);
case 'h':
return hex_string(out, ptr, spec, fmt);
case 'b':
--
2.35.1
From: Kent Overstreet <[email protected]>
We're attempting to consolidate printf_spec and format string handling
in the top level vpr_buf(), this changes time_and_date() to not
take printf_spec.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 784f7cb64926..38d16aa79e56 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1917,12 +1917,12 @@ void format_page_flags(struct printbuf *out, unsigned long flags)
static noinline_for_stack
void flags_string(struct printbuf *out, void *flags_ptr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
unsigned long flags;
const struct trace_print_flags *names;
- if (check_pointer_spec(out, flags_ptr, spec))
+ if (check_pointer(out, flags_ptr))
return;
switch (fmt[1]) {
@@ -1937,7 +1937,7 @@ void flags_string(struct printbuf *out, void *flags_ptr,
names = gfpflag_names;
break;
default:
- return error_string_spec(out, "(%pG?)", spec);
+ return error_string(out, "(%pG?)");
}
return format_flags(out, flags, names);
@@ -2310,7 +2310,8 @@ void pointer(struct printbuf *out, const char *fmt,
#endif
case 'G':
- return flags_string(out, ptr, spec, fmt);
+ flags_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'O':
return device_node_string(out, ptr, spec, fmt + 1);
case 'f':
--
2.35.1
From: Kent Overstreet <[email protected]>
This adds options to printbuf for specifying whether units should be
printed raw (default) or with human readable units, and for controlling
whether human-readable units should be base 2 (default), or base 10.
This also adds new helpers that obey these options:
- pr_human_readable_u64
- pr_human_readable_s64
These obey printbuf->si_units
- pr_units_u64
- pr_units_s64
These obey both printbuf-human_readable_units and printbuf->si_units
Signed-off-by: Kent Overstreet <[email protected]>
---
include/linux/printbuf.h | 15 +++++++++++
lib/printbuf.c | 57 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 72 insertions(+)
diff --git a/include/linux/printbuf.h b/include/linux/printbuf.h
index c1a482b6c0a8..ebbc4a55fc04 100644
--- a/include/linux/printbuf.h
+++ b/include/linux/printbuf.h
@@ -57,11 +57,20 @@
*
* Make sure you use prt_newline() instead of \n in the format string for indent
* level and tabstops to work corretly.
+ *
+ * Output units: printbuf->units exists to tell pretty-printers how to output
+ * numbers: a raw value (e.g. directly from a superblock field), as bytes, or as
+ * human readable bytes. prt_units() obeys it.
*/
#include <linux/kernel.h>
#include <linux/string.h>
+enum printbuf_si {
+ PRINTBUF_UNITS_2, /* use binary powers of 2^10 */
+ PRINTBUF_UNITS_10, /* use powers of 10^3 (standard SI) */
+};
+
struct printbuf {
char *buf;
unsigned size;
@@ -75,6 +84,8 @@ struct printbuf {
u8 atomic;
bool allocation_failure:1;
bool heap_allocated:1;
+ enum printbuf_si si_units:1;
+ bool human_readable_units:1;
u8 tabstop;
u8 tabstops[4];
};
@@ -88,6 +99,10 @@ void printbuf_indent_add(struct printbuf *, unsigned);
void printbuf_indent_sub(struct printbuf *, unsigned);
void prt_tab(struct printbuf *);
void prt_tab_rjust(struct printbuf *);
+void prt_human_readable_u64(struct printbuf *, u64);
+void prt_human_readable_s64(struct printbuf *, s64);
+void prt_units_u64(struct printbuf *, u64);
+void prt_units_s64(struct printbuf *, s64);
/* Initializer for a heap allocated printbuf: */
#define PRINTBUF ((struct printbuf) { .heap_allocated = true })
diff --git a/lib/printbuf.c b/lib/printbuf.c
index 395c681e3acb..047470025748 100644
--- a/lib/printbuf.c
+++ b/lib/printbuf.c
@@ -10,6 +10,7 @@
#include <linux/err.h>
#include <linux/slab.h>
+#include <linux/string_helpers.h>
#include <linux/printbuf.h>
static inline size_t printbuf_linelen(struct printbuf *buf)
@@ -199,3 +200,59 @@ void prt_tab_rjust(struct printbuf *buf)
buf->tabstop++;
}
EXPORT_SYMBOL(prt_tab_rjust);
+
+/**
+ * prt_human_readable_u64 - Print out a u64 in human readable units
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units
+ */
+void prt_human_readable_u64(struct printbuf *buf, u64 v)
+{
+ printbuf_make_room(buf, 10);
+ buf->pos += string_get_size(v, 1, !buf->si_units,
+ buf->buf + buf->pos,
+ printbuf_remaining_size(buf));
+}
+EXPORT_SYMBOL(prt_human_readable_u64);
+
+/**
+ * prt_human_readable_s64 - Print out a s64 in human readable units
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units
+ */
+void prt_human_readable_s64(struct printbuf *buf, s64 v)
+{
+ if (v < 0)
+ prt_char(buf, '-');
+ prt_human_readable_u64(buf, abs(v));
+}
+EXPORT_SYMBOL(prt_human_readable_s64);
+
+/**
+ * prt_units_u64 - Print out a u64 according to printbuf unit options
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void prt_units_u64(struct printbuf *out, u64 v)
+{
+ if (out->human_readable_units)
+ prt_human_readable_u64(out, v);
+ else
+ prt_printf(out, "%llu", v);
+}
+EXPORT_SYMBOL(prt_units_u64);
+
+/**
+ * prt_units_s64 - Print out a s64 according to printbuf unit options
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void prt_units_s64(struct printbuf *out, s64 v)
+{
+ if (v < 0)
+ prt_char(out, '-');
+ prt_units_u64(out, abs(v));
+}
+EXPORT_SYMBOL(prt_units_s64);
--
2.35.1
From: Kent Overstreet <[email protected]>
The upcoming patch to switch tracing from seq_buf to printbuf means
we're no longer pulling in headers that we used to; this adds a missing
include so things don't break.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: [email protected]
---
drivers/acpi/apei/erst-dbg.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c
index 8bc71cdc2270..370993c9c381 100644
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -11,6 +11,7 @@
* Author: Huang Ying <[email protected]>
*/
+#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/uaccess.h>
--
2.35.1
From: Kent Overstreet <[email protected]>
This implements a new printbuf version of d_path()/mangle_path(), which
will replace the seq_buf version.
Part of what we're trying to do with printbufs is standardizing a
calling convention so they don't have to live in lib/vsprintf.c, and can
instead with the code for the types they're printing - so this patch
adds prt_path() to d_path.c, another patch will switch vsprintf.c to use
it.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Alexander Viro <[email protected]>
---
fs/d_path.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/dcache.h | 1 +
2 files changed, 36 insertions(+)
diff --git a/fs/d_path.c b/fs/d_path.c
index e4e0ebad1f15..1bd9e85f2f65 100644
--- a/fs/d_path.c
+++ b/fs/d_path.c
@@ -5,6 +5,7 @@
#include <linux/fs_struct.h>
#include <linux/fs.h>
#include <linux/slab.h>
+#include <linux/printbuf.h>
#include <linux/prefetch.h>
#include "mount.h"
@@ -294,6 +295,40 @@ char *d_path(const struct path *path, char *buf, int buflen)
}
EXPORT_SYMBOL(d_path);
+/**
+ * prt_path - format a path for output
+ * @out: printbuf to output to
+ * @path: path to write into the sequence buffer.
+ * @esc: set of characters to escape in the output
+ *
+ * Write a path name into the sequence buffer.
+ *
+ * Returns 0 on success, or error code from d_path
+ */
+int prt_path(struct printbuf *out, const struct path *path, const char *esc)
+{
+ char *p, *buf;
+ size_t size;
+again:
+ buf = out->buf + out->pos;
+ size = printbuf_remaining_size(out);
+
+ p = d_path(path, buf, size);
+ if (IS_ERR(p)) {
+ printbuf_make_room(out, max_t(size_t, 64, size * 2));
+ if (printbuf_remaining_size(out) > size)
+ goto again;
+
+ return PTR_ERR(p);
+ }
+
+ p = mangle_path(buf, p, esc);
+ if (p)
+ out->pos += p - buf;
+ return 0;
+}
+EXPORT_SYMBOL(prt_path);
+
/*
* Helper function for dentry_operations.d_dname() members
*/
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index c73e5e327e76..bdd5940aa75a 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -293,6 +293,7 @@ extern char *d_absolute_path(const struct path *, char *, int);
extern char *d_path(const struct path *, char *, int);
extern char *dentry_path_raw(const struct dentry *, char *, int);
extern char *dentry_path(const struct dentry *, char *, int);
+extern int prt_path(struct printbuf *, const struct path *, const char *);
/* Allocation counts.. */
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf. We're using printbuf in external
buffer mode, so it's a direct conversion, aside from some trivial
refactoring in cpu_show_meltdown() to make the code more consistent.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: [email protected]
---
drivers/pci/p2pdma.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 4496a7c5c478..8e29e7cabad3 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -18,7 +18,7 @@
#include <linux/memremap.h>
#include <linux/percpu-refcount.h>
#include <linux/random.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/xarray.h>
struct pci_p2pdma {
@@ -275,12 +275,9 @@ static int pci_bridge_has_acs_redir(struct pci_dev *pdev)
return 0;
}
-static void seq_buf_print_bus_devfn(struct seq_buf *buf, struct pci_dev *pdev)
+static void prt_bus_devfn(struct printbuf *buf, struct pci_dev *pdev)
{
- if (!buf)
- return;
-
- seq_buf_printf(buf, "%s;", pci_name(pdev));
+ prt_printf(buf, "%s;", pci_name(pdev));
}
static bool cpu_supports_p2pdma(void)
@@ -454,13 +451,11 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
struct pci_dev *a = provider, *b = client, *bb;
bool acs_redirects = false;
struct pci_p2pdma *p2pdma;
- struct seq_buf acs_list;
int acs_cnt = 0;
int dist_a = 0;
int dist_b = 0;
char buf[128];
-
- seq_buf_init(&acs_list, buf, sizeof(buf));
+ struct printbuf acs_list = PRINTBUF_EXTERN(buf, sizeof(buf));
/*
* Note, we don't need to take references to devices returned by
@@ -471,7 +466,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
dist_b = 0;
if (pci_bridge_has_acs_redir(a)) {
- seq_buf_print_bus_devfn(&acs_list, a);
+ prt_bus_devfn(&acs_list, a);
acs_cnt++;
}
@@ -500,7 +495,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
break;
if (pci_bridge_has_acs_redir(bb)) {
- seq_buf_print_bus_devfn(&acs_list, bb);
+ prt_bus_devfn(&acs_list, bb);
acs_cnt++;
}
@@ -515,11 +510,11 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
}
if (verbose) {
- acs_list.buffer[acs_list.len-1] = 0; /* drop final semicolon */
+ acs_list.buf[acs_list.pos-1] = 0; /* drop final semicolon */
pci_warn(client, "ACS redirect is set between the client and provider (%s)\n",
pci_name(provider));
pci_warn(client, "to disable ACS redirect for this path, add the kernel parameter: pci=disable_acs_redir=%s\n",
- acs_list.buffer);
+ acs_list.buf);
}
acs_redirects = true;
--
2.35.1
From: Kent Overstreet <[email protected]>
Like the upcoming vsprintf.c conversion, this converts string_escape_mem
to prt_escaped_string(), which uses and outputs to a printbuf, and makes
string_escape_mem() a smaller wrapper to support existing users.
The new printbuf helpers greatly simplify the code.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Andy Shevchenko <[email protected]>
---
include/linux/string_helpers.h | 4 +
lib/string_helpers.c | 217 ++++++++++++++++++---------------
2 files changed, 126 insertions(+), 95 deletions(-)
diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 4d72258d42fd..67de398944e8 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -10,6 +10,7 @@
struct device;
struct file;
struct task_struct;
+struct printbuf;
/* Descriptions of the types of units to
* print in */
@@ -62,6 +63,8 @@ static inline int string_unescape_any_inplace(char *buf)
#define ESCAPE_ALL_MASK GENMASK(8, 0)
+void prt_escaped_string(struct printbuf *out, const char *src, size_t isz,
+ unsigned int flags, const char *only);
int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
unsigned int flags, const char *only);
@@ -71,6 +74,7 @@ static inline int string_escape_mem_any_np(const char *src, size_t isz,
return string_escape_mem(src, isz, dst, osz, ESCAPE_ANY_NP, only);
}
+
static inline int string_escape_str(const char *src, char *dst, size_t sz,
unsigned int flags, const char *only)
{
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 5ed3beb066e6..7be20bcc6137 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -15,6 +15,7 @@
#include <linux/fs.h>
#include <linux/limits.h>
#include <linux/mm.h>
+#include <linux/printbuf.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/string_helpers.h>
@@ -301,19 +302,14 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
}
EXPORT_SYMBOL(string_unescape);
-static bool escape_passthrough(unsigned char c, char **dst, char *end)
+static bool escape_passthrough(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
-
- if (out < end)
- *out = c;
- *dst = out + 1;
+ prt_char(out, c);
return true;
}
-static bool escape_space(unsigned char c, char **dst, char *end)
+static bool escape_space(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
unsigned char to;
switch (c) {
@@ -336,20 +332,13 @@ static bool escape_space(unsigned char c, char **dst, char *end)
return false;
}
- if (out < end)
- *out = '\\';
- ++out;
- if (out < end)
- *out = to;
- ++out;
-
- *dst = out;
+ prt_char(out, '\\');
+ prt_char(out, to);
return true;
}
-static bool escape_special(unsigned char c, char **dst, char *end)
+static bool escape_special(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
unsigned char to;
switch (c) {
@@ -369,83 +358,43 @@ static bool escape_special(unsigned char c, char **dst, char *end)
return false;
}
- if (out < end)
- *out = '\\';
- ++out;
- if (out < end)
- *out = to;
- ++out;
-
- *dst = out;
+ prt_char(out, '\\');
+ prt_char(out, to);
return true;
}
-static bool escape_null(unsigned char c, char **dst, char *end)
+static bool escape_null(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
-
if (c)
return false;
- if (out < end)
- *out = '\\';
- ++out;
- if (out < end)
- *out = '0';
- ++out;
-
- *dst = out;
+ prt_char(out, '\\');
+ prt_char(out, '0');
return true;
}
-static bool escape_octal(unsigned char c, char **dst, char *end)
+static bool escape_octal(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
-
- if (out < end)
- *out = '\\';
- ++out;
- if (out < end)
- *out = ((c >> 6) & 0x07) + '0';
- ++out;
- if (out < end)
- *out = ((c >> 3) & 0x07) + '0';
- ++out;
- if (out < end)
- *out = ((c >> 0) & 0x07) + '0';
- ++out;
-
- *dst = out;
+ prt_char(out, '\\');
+ prt_char(out, ((c >> 6) & 0x07) + '0');
+ prt_char(out, ((c >> 3) & 0x07) + '0');
+ prt_char(out, ((c >> 0) & 0x07) + '0');
return true;
}
-static bool escape_hex(unsigned char c, char **dst, char *end)
+static bool escape_hex(struct printbuf *out, unsigned char c)
{
- char *out = *dst;
-
- if (out < end)
- *out = '\\';
- ++out;
- if (out < end)
- *out = 'x';
- ++out;
- if (out < end)
- *out = hex_asc_hi(c);
- ++out;
- if (out < end)
- *out = hex_asc_lo(c);
- ++out;
-
- *dst = out;
+ prt_char(out, '\\');
+ prt_char(out, 'x');
+ prt_hex_byte(out, c);
return true;
}
/**
- * string_escape_mem - quote characters in the given memory buffer
+ * prt_escaped_string - quote characters in the given memory buffer
+ * @out: printbuf to output to (escaped)
* @src: source buffer (unescaped)
* @isz: source buffer size
- * @dst: destination buffer (escaped)
- * @osz: destination buffer size
* @flags: combination of the flags
* @only: NULL-terminated string containing characters used to limit
* the selected escape class. If characters are included in @only
@@ -510,18 +459,11 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
* or %ESCAPE_HEX, because they cover most of the other character classes.
* %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
* the above.
- *
- * Return:
- * The total size of the escaped output that would be generated for
- * the given input and flags. To check whether the output was
- * truncated, compare the return value to osz. There is room left in
- * dst for a '\0' terminator if and only if ret < osz.
*/
-int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
- unsigned int flags, const char *only)
+void prt_escaped_string(struct printbuf *out,
+ const char *src, size_t isz,
+ unsigned int flags, const char *only)
{
- char *p = dst;
- char *end = p + osz;
bool is_dict = only && *only;
bool is_append = flags & ESCAPE_APPEND;
@@ -549,41 +491,126 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
* %ESCAPE_NA cases.
*/
if (!(is_append || in_dict) && is_dict &&
- escape_passthrough(c, &p, end))
+ escape_passthrough(out, c))
continue;
if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
- flags & ESCAPE_NAP && escape_passthrough(c, &p, end))
+ flags & ESCAPE_NAP && escape_passthrough(out, c))
continue;
if (!(is_append && in_dict) && isprint(c) &&
- flags & ESCAPE_NP && escape_passthrough(c, &p, end))
+ flags & ESCAPE_NP && escape_passthrough(out, c))
continue;
if (!(is_append && in_dict) && isascii(c) &&
- flags & ESCAPE_NA && escape_passthrough(c, &p, end))
+ flags & ESCAPE_NA && escape_passthrough(out, c))
continue;
- if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+ if (flags & ESCAPE_SPACE && escape_space(out, c))
continue;
- if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+ if (flags & ESCAPE_SPECIAL && escape_special(out, c))
continue;
- if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+ if (flags & ESCAPE_NULL && escape_null(out, c))
continue;
/* ESCAPE_OCTAL and ESCAPE_HEX always go last */
- if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
+ if (flags & ESCAPE_OCTAL && escape_octal(out, c))
continue;
- if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
+ if (flags & ESCAPE_HEX && escape_hex(out, c))
continue;
- escape_passthrough(c, &p, end);
+ escape_passthrough(out, c);
}
+}
+EXPORT_SYMBOL(prt_escaped_string);
+
+/**
+ * string_escape_mem - quote characters in the given memory buffer
+ * @src: source buffer (unescaped)
+ * @isz: source buffer size
+ * @dst: destination buffer (escaped)
+ * @osz: destination buffer size
+ * @flags: combination of the flags
+ * @only: NULL-terminated string containing characters used to limit
+ * the selected escape class. If characters are included in @only
+ * that would not normally be escaped by the classes selected
+ * in @flags, they will be copied to @dst unescaped.
+ *
+ * Description:
+ * The process of escaping byte buffer includes several parts. They are applied
+ * in the following sequence.
+ *
+ * 1. The character is not matched to the one from @only string and thus
+ * must go as-is to the output.
+ * 2. The character is matched to the printable and ASCII classes, if asked,
+ * and in case of match it passes through to the output.
+ * 3. The character is matched to the printable or ASCII class, if asked,
+ * and in case of match it passes through to the output.
+ * 4. The character is checked if it falls into the class given by @flags.
+ * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
+ * character. Note that they actually can't go together, otherwise
+ * %ESCAPE_HEX will be ignored.
+ *
+ * Caller must provide valid source and destination pointers. Be aware that
+ * destination buffer will not be NULL-terminated, thus caller have to append
+ * it if needs. The supported flags are::
+ *
+ * %ESCAPE_SPACE: (special white space, not space itself)
+ * '\f' - form feed
+ * '\n' - new line
+ * '\r' - carriage return
+ * '\t' - horizontal tab
+ * '\v' - vertical tab
+ * %ESCAPE_SPECIAL:
+ * '\"' - double quote
+ * '\\' - backslash
+ * '\a' - alert (BEL)
+ * '\e' - escape
+ * %ESCAPE_NULL:
+ * '\0' - null
+ * %ESCAPE_OCTAL:
+ * '\NNN' - byte with octal value NNN (3 digits)
+ * %ESCAPE_ANY:
+ * all previous together
+ * %ESCAPE_NP:
+ * escape only non-printable characters, checked by isprint()
+ * %ESCAPE_ANY_NP:
+ * all previous together
+ * %ESCAPE_HEX:
+ * '\xHH' - byte with hexadecimal value HH (2 digits)
+ * %ESCAPE_NA:
+ * escape only non-ascii characters, checked by isascii()
+ * %ESCAPE_NAP:
+ * escape only non-printable or non-ascii characters
+ * %ESCAPE_APPEND:
+ * append characters from @only to be escaped by the given classes
+ *
+ * %ESCAPE_APPEND would help to pass additional characters to the escaped, when
+ * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
+ *
+ * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
+ * higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
+ * It doesn't make much sense to use either of them without %ESCAPE_OCTAL
+ * or %ESCAPE_HEX, because they cover most of the other character classes.
+ * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
+ * the above.
+ *
+ * Return:
+ * The total size of the escaped output that would be generated for
+ * the given input and flags. To check whether the output was
+ * truncated, compare the return value to osz. There is room left in
+ * dst for a '\0' terminator if and only if ret < osz.
+ */
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
+ unsigned int flags, const char *only)
+{
+ struct printbuf out = PRINTBUF_EXTERN(dst, osz);
- return p - dst;
+ prt_escaped_string(&out, src, isz, flags, only);
+ return out.pos;
}
EXPORT_SYMBOL(string_escape_mem);
--
2.35.1
From: Kent Overstreet <[email protected]>
This makes printbufs optionally heap allocated: a printbuf initialized
with the PRINTBUF initializer will automatically heap allocate and
resize as needed.
Allocations are done with GFP_KERNEL: code should use e.g.
memalloc_nofs_save()/restore() as needed. Since we do not currently have
memalloc_nowait_save()/restore(), in contexts where it is not safe to
block we provide the helpers
printbuf_atomic_inc()
printbuf_atomic_dec()
When the atomic count is nonzero, memory allocations will be done with
GFP_NOWAIT.
On memory allocation failure, output will be truncated. Code that wishes
to check for memory allocation failure (in contexts where we should
return -ENOMEM) should check if printbuf->allocation_failure is set.
Since printbufs are expected to be typically used for log messages and
on a best effort basis, we don't return errors directly.
Other helpers provided by this patch:
- printbuf_make_room(buf, extra)
Reallocates if necessary to make room for @extra bytes (not including
terminating null).
- printbuf_str(buf)
Returns a null terminated string equivalent to the contents of @buf.
If @buf was never allocated (or allocation failed), returns a
constant empty string.
- printbuf_exit(buf)
Releases memory allocated by a printbuf.
Signed-off-by: Kent Overstreet <[email protected]>
---
include/linux/printbuf.h | 124 +++++++++++++++++++++++++++++++++------
lib/Makefile | 2 +-
lib/printbuf.c | 76 ++++++++++++++++++++++++
3 files changed, 184 insertions(+), 18 deletions(-)
create mode 100644 lib/printbuf.c
diff --git a/include/linux/printbuf.h b/include/linux/printbuf.h
index 1aa3331bf00b..71f631c49f4e 100644
--- a/include/linux/printbuf.h
+++ b/include/linux/printbuf.h
@@ -4,19 +4,73 @@
#ifndef _LINUX_PRINTBUF_H
#define _LINUX_PRINTBUF_H
-#include <linux/kernel.h>
-#include <linux/string.h>
-
/*
- * Printbufs: String buffer for outputting (printing) to, for vsnprintf
+ * Printbufs: Simple strings for printing to, with optional heap allocation
+ *
+ * This code has provisions for use in userspace, to aid in making other code
+ * portable between kernelspace and userspace.
+ *
+ * Basic example:
+ * struct printbuf buf = PRINTBUF;
+ *
+ * prt_printf(&buf, "foo=");
+ * foo_to_text(&buf, foo);
+ * printk("%s", buf.buf);
+ * printbuf_exit(&buf);
+ *
+ * Or
+ * struct printbuf buf = PRINTBUF_EXTERN(char_buf, char_buf_size)
+ *
+ * We can now write pretty printers instead of writing code that dumps
+ * everything to the kernel log buffer, and then those pretty-printers can be
+ * used by other code that outputs to kernel log, sysfs, debugfs, etc.
+ *
+ * Memory allocation: Outputing to a printbuf may allocate memory. This
+ * allocation is done with GFP_KERNEL, by default: use the newer
+ * memalloc_*_(save|restore) functions as needed.
+ *
+ * Since no equivalent yet exists for GFP_ATOMIC/GFP_NOWAIT, memory allocations
+ * will be done with GFP_NOWAIT if printbuf->atomic is nonzero.
+ *
+ * It's allowed to grab the output buffer and free it later with kfree() instead
+ * of using printbuf_exit(), if the user just needs a heap allocated string at
+ * the end.
+ *
+ * Memory allocation failures: We don't return errors directly, because on
+ * memory allocation failure we usually don't want to bail out and unwind - we
+ * want to print what we've got, on a best-effort basis. But code that does want
+ * to return -ENOMEM may check printbuf.allocation_failure.
*/
+#include <linux/kernel.h>
+#include <linux/string.h>
+
struct printbuf {
char *buf;
unsigned size;
unsigned pos;
+ /*
+ * If nonzero, allocations will be done with GFP_ATOMIC:
+ */
+ u8 atomic;
+ bool allocation_failure:1;
+ bool heap_allocated:1;
};
+int printbuf_make_room(struct printbuf *, unsigned);
+const char *printbuf_str(const struct printbuf *);
+void printbuf_exit(struct printbuf *);
+
+/* Initializer for a heap allocated printbuf: */
+#define PRINTBUF ((struct printbuf) { .heap_allocated = true })
+
+/* Initializer a printbuf that points to an external buffer: */
+#define PRINTBUF_EXTERN(_buf, _size) \
+((struct printbuf) { \
+ .buf = _buf, \
+ .size = _size, \
+})
+
/*
* Returns size remaining of output buffer:
*/
@@ -49,26 +103,36 @@ static inline bool printbuf_overflowed(struct printbuf *out)
static inline void printbuf_nul_terminate(struct printbuf *out)
{
+ printbuf_make_room(out, 1);
+
if (out->pos < out->size)
out->buf[out->pos] = 0;
else if (out->size)
out->buf[out->size - 1] = 0;
}
-static inline void __prt_char(struct printbuf *out, char c)
+/* Doesn't call printbuf_make_room(), doesn't nul terminate: */
+static inline void __prt_char_reserved(struct printbuf *out, char c)
{
if (printbuf_remaining(out))
out->buf[out->pos] = c;
out->pos++;
}
+/* Doesn't nul terminate: */
+static inline void __prt_char(struct printbuf *out, char c)
+{
+ printbuf_make_room(out, 1);
+ __prt_char_reserved(out, c);
+}
+
static inline void prt_char(struct printbuf *out, char c)
{
__prt_char(out, c);
printbuf_nul_terminate(out);
}
-static inline void __prt_chars(struct printbuf *out, char c, unsigned n)
+static inline void __prt_chars_reserved(struct printbuf *out, char c, unsigned n)
{
unsigned i, can_print = min(n, printbuf_remaining(out));
@@ -79,13 +143,18 @@ static inline void __prt_chars(struct printbuf *out, char c, unsigned n)
static inline void prt_chars(struct printbuf *out, char c, unsigned n)
{
- __prt_chars(out, c, n);
+ printbuf_make_room(out, n);
+ __prt_chars_reserved(out, c, n);
printbuf_nul_terminate(out);
}
static inline void prt_bytes(struct printbuf *out, const void *b, unsigned n)
{
- unsigned i, can_print = min(n, printbuf_remaining(out));
+ unsigned i, can_print;
+
+ printbuf_make_room(out, n);
+
+ can_print = min(n, printbuf_remaining(out));
for (i = 0; i < can_print; i++)
out->buf[out->pos++] = ((char *) b)[i];
@@ -101,22 +170,43 @@ static inline void prt_str(struct printbuf *out, const char *str)
static inline void prt_hex_byte(struct printbuf *out, u8 byte)
{
- __prt_char(out, hex_asc_hi(byte));
- __prt_char(out, hex_asc_lo(byte));
+ printbuf_make_room(out, 2);
+ __prt_char_reserved(out, hex_asc_hi(byte));
+ __prt_char_reserved(out, hex_asc_lo(byte));
printbuf_nul_terminate(out);
}
static inline void prt_hex_byte_upper(struct printbuf *out, u8 byte)
{
- __prt_char(out, hex_asc_upper_hi(byte));
- __prt_char(out, hex_asc_upper_lo(byte));
+ printbuf_make_room(out, 2);
+ __prt_char_reserved(out, hex_asc_upper_hi(byte));
+ __prt_char_reserved(out, hex_asc_upper_lo(byte));
printbuf_nul_terminate(out);
}
-#define PRINTBUF_EXTERN(_buf, _size) \
-((struct printbuf) { \
- .buf = _buf, \
- .size = _size, \
-})
+/**
+ * printbuf_reset - re-use a printbuf without freeing and re-initializing it:
+ */
+static inline void printbuf_reset(struct printbuf *buf)
+{
+ buf->pos = 0;
+ buf->allocation_failure = 0;
+}
+
+/**
+ * printbuf_atomic_inc - mark as entering an atomic section
+ */
+static inline void printbuf_atomic_inc(struct printbuf *buf)
+{
+ buf->atomic++;
+}
+
+/**
+ * printbuf_atomic_inc - mark as leaving an atomic section
+ */
+static inline void printbuf_atomic_dec(struct printbuf *buf)
+{
+ buf->atomic--;
+}
#endif /* _LINUX_PRINTBUF_H */
diff --git a/lib/Makefile b/lib/Makefile
index 17e48da223e2..d44f8d03d66b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -34,7 +34,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
is_single_threaded.o plist.o decompress.o kobject_uevent.o \
earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
nmi_backtrace.o nodemask.o win_minmax.o memcat_p.o \
- buildid.o cpumask.o
+ buildid.o cpumask.o printbuf.o
lib-$(CONFIG_PRINTK) += dump_stack.o
diff --git a/lib/printbuf.c b/lib/printbuf.c
new file mode 100644
index 000000000000..e3e5a791b244
--- /dev/null
+++ b/lib/printbuf.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: LGPL-2.1+
+/* Copyright (C) 2022 Kent Overstreet */
+
+#ifdef __KERNEL__
+#include <linux/export.h>
+#include <linux/kernel.h>
+#else
+#define EXPORT_SYMBOL(x)
+#endif
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/printbuf.h>
+
+int printbuf_make_room(struct printbuf *out, unsigned extra)
+{
+ unsigned new_size;
+ char *buf;
+
+ if (!out->heap_allocated)
+ return 0;
+
+ /* Reserved space for terminating nul: */
+ extra += 1;
+
+ if (out->pos + extra < out->size)
+ return 0;
+
+ new_size = roundup_pow_of_two(out->size + extra);
+
+ /*
+ * Note: output buffer must be freeable with kfree(), it's not required
+ * that the user use printbuf_exit().
+ */
+ buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
+
+ if (!buf) {
+ out->allocation_failure = true;
+ return -ENOMEM;
+ }
+
+ out->buf = buf;
+ out->size = new_size;
+ return 0;
+}
+EXPORT_SYMBOL(printbuf_make_room);
+
+/**
+ * printbuf_str - returns printbuf's buf as a C string, guaranteed to be null
+ * terminated
+ */
+const char *printbuf_str(const struct printbuf *buf)
+{
+ /*
+ * If we've written to a printbuf then it's guaranteed to be a null
+ * terminated string - but if we haven't, then we might not have
+ * allocated a buffer at all:
+ */
+ return buf->pos
+ ? buf->buf
+ : "";
+}
+EXPORT_SYMBOL(printbuf_str);
+
+/**
+ * printbuf_exit - exit a printbuf, freeing memory it owns and poisoning it
+ * against accidental use.
+ */
+void printbuf_exit(struct printbuf *buf)
+{
+ if (buf->heap_allocated) {
+ kfree(buf->buf);
+ buf->buf = ERR_PTR(-EINTR); /* poison value */
+ }
+}
+EXPORT_SYMBOL(printbuf_exit);
--
2.35.1
From: Kent Overstreet <[email protected]>
This patch adds two new features to printbuf for structured formatting:
- Indent level: the indent level, as a number of spaces, may be
increased with pr_indent_add() and decreased with pr_indent_sub().
Subsequent lines, when started with pr_newline() (not "\n", although
that may change) will then be intended according to the current
indent level. This helps with pretty-printers that structure a large
amonut of data across multiple lines and multiple functions.
- Tabstops: Tabstops may be set by assigning to the printbuf->tabstops
array.
Then, pr_tab() may be used to advance to the next tabstop, printing
as many spaces as required - leaving previous output left justified
to the previous tabstop. pr_tab_rjust() advances to the next tabstop
but inserts the spaces just after the previous tabstop - right
justifying the previously-outputted text to the next tabstop.
Signed-off-by: Kent Overstreet <[email protected]>
---
include/linux/printbuf.h | 30 ++++++++++
lib/printbuf.c | 125 +++++++++++++++++++++++++++++++++++++++
2 files changed, 155 insertions(+)
diff --git a/include/linux/printbuf.h b/include/linux/printbuf.h
index 71f631c49f4e..c1a482b6c0a8 100644
--- a/include/linux/printbuf.h
+++ b/include/linux/printbuf.h
@@ -40,6 +40,23 @@
* memory allocation failure we usually don't want to bail out and unwind - we
* want to print what we've got, on a best-effort basis. But code that does want
* to return -ENOMEM may check printbuf.allocation_failure.
+ *
+ * Indenting, tabstops:
+ *
+ * To aid is writing multi-line pretty printers spread across multiple
+ * functions, printbufs track the current indent level.
+ *
+ * printbuf_indent_push() and printbuf_indent_pop() increase and decrease the current indent
+ * level, respectively.
+ *
+ * To use tabstops, set printbuf->tabstops[]; they are in units of spaces, from
+ * start of line. Once set, prt_tab() will output spaces up to the next tabstop.
+ * prt_tab_rjust() will also advance the current line of text up to the next
+ * tabstop, but it does so by shifting text since the previous tabstop up to the
+ * next tabstop - right justifying it.
+ *
+ * Make sure you use prt_newline() instead of \n in the format string for indent
+ * level and tabstops to work corretly.
*/
#include <linux/kernel.h>
@@ -49,18 +66,29 @@ struct printbuf {
char *buf;
unsigned size;
unsigned pos;
+ unsigned last_newline;
+ unsigned last_field;
+ unsigned indent;
/*
* If nonzero, allocations will be done with GFP_ATOMIC:
*/
u8 atomic;
bool allocation_failure:1;
bool heap_allocated:1;
+ u8 tabstop;
+ u8 tabstops[4];
};
int printbuf_make_room(struct printbuf *, unsigned);
const char *printbuf_str(const struct printbuf *);
void printbuf_exit(struct printbuf *);
+void prt_newline(struct printbuf *);
+void printbuf_indent_add(struct printbuf *, unsigned);
+void printbuf_indent_sub(struct printbuf *, unsigned);
+void prt_tab(struct printbuf *);
+void prt_tab_rjust(struct printbuf *);
+
/* Initializer for a heap allocated printbuf: */
#define PRINTBUF ((struct printbuf) { .heap_allocated = true })
@@ -191,6 +219,8 @@ static inline void printbuf_reset(struct printbuf *buf)
{
buf->pos = 0;
buf->allocation_failure = 0;
+ buf->indent = 0;
+ buf->tabstop = 0;
}
/**
diff --git a/lib/printbuf.c b/lib/printbuf.c
index e3e5a791b244..395c681e3acb 100644
--- a/lib/printbuf.c
+++ b/lib/printbuf.c
@@ -12,6 +12,11 @@
#include <linux/slab.h>
#include <linux/printbuf.h>
+static inline size_t printbuf_linelen(struct printbuf *buf)
+{
+ return buf->pos - buf->last_newline;
+}
+
int printbuf_make_room(struct printbuf *out, unsigned extra)
{
unsigned new_size;
@@ -74,3 +79,123 @@ void printbuf_exit(struct printbuf *buf)
}
}
EXPORT_SYMBOL(printbuf_exit);
+
+void prt_newline(struct printbuf *buf)
+{
+ unsigned i;
+
+ printbuf_make_room(buf, 1 + buf->indent);
+
+ __prt_char(buf, '\n');
+
+ buf->last_newline = buf->pos;
+
+ for (i = 0; i < buf->indent; i++)
+ __prt_char(buf, ' ');
+
+ printbuf_nul_terminate(buf);
+
+ buf->last_field = buf->pos;
+ buf->tabstop = 0;
+}
+EXPORT_SYMBOL(prt_newline);
+
+/**
+ * printbuf_indent_add - add to the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to add to the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces more spaces.
+ */
+void printbuf_indent_add(struct printbuf *buf, unsigned spaces)
+{
+ if (WARN_ON_ONCE(buf->indent + spaces < buf->indent))
+ spaces = 0;
+
+ buf->indent += spaces;
+ while (spaces--)
+ prt_char(buf, ' ');
+}
+EXPORT_SYMBOL(printbuf_indent_add);
+
+/**
+ * printbuf_indent_sub - subtract from the current indent level
+ *
+ * @buf: printbuf to control
+ * @spaces: number of spaces to subtract from the current indent level
+ *
+ * Subsequent lines, and the current line if the output position is at the start
+ * of the current line, will be indented by @spaces less spaces.
+ */
+void printbuf_indent_sub(struct printbuf *buf, unsigned spaces)
+{
+ if (WARN_ON_ONCE(spaces > buf->indent))
+ spaces = buf->indent;
+
+ if (buf->last_newline + buf->indent == buf->pos) {
+ buf->pos -= spaces;
+ printbuf_nul_terminate(buf);
+ }
+ buf->indent -= spaces;
+}
+EXPORT_SYMBOL(printbuf_indent_sub);
+
+/**
+ * prt_tab - Advance printbuf to the next tabstop
+ *
+ * @buf: printbuf to control
+ *
+ * Advance output to the next tabstop by printing spaces.
+ */
+void prt_tab(struct printbuf *out)
+{
+ int spaces = max_t(int, 0, out->tabstops[out->tabstop] - printbuf_linelen(out));
+
+ BUG_ON(out->tabstop > ARRAY_SIZE(out->tabstops));
+
+ prt_chars(out, ' ', spaces);
+
+ out->last_field = out->pos;
+ out->tabstop++;
+}
+EXPORT_SYMBOL(prt_tab);
+
+/**
+ * prt_tab_rjust - Advance printbuf to the next tabstop, right justifying
+ * previous output
+ *
+ * @buf: printbuf to control
+ *
+ * Advance output to the next tabstop by inserting spaces immediately after the
+ * previous tabstop, right justifying previously outputted text.
+ */
+void prt_tab_rjust(struct printbuf *buf)
+{
+ BUG_ON(buf->tabstop > ARRAY_SIZE(buf->tabstops));
+
+ if (printbuf_linelen(buf) < buf->tabstops[buf->tabstop]) {
+ unsigned move = buf->pos - buf->last_field;
+ unsigned shift = buf->tabstops[buf->tabstop] -
+ printbuf_linelen(buf);
+
+ printbuf_make_room(buf, shift);
+
+ if (buf->last_field + shift < buf->size)
+ memmove(buf->buf + buf->last_field + shift,
+ buf->buf + buf->last_field,
+ min(move, buf->size - 1 - buf->last_field - shift));
+
+ if (buf->last_field < buf->size)
+ memset(buf->buf + buf->last_field, ' ',
+ min(shift, buf->size - buf->last_field));
+
+ buf->pos += shift;
+ printbuf_nul_terminate(buf);
+ }
+
+ buf->last_field = buf->pos;
+ buf->tabstop++;
+}
+EXPORT_SYMBOL(prt_tab_rjust);
--
2.35.1
From: Kent Overstreet <[email protected]>
- eliminate on-stack buffer in device_node_string
- eliminate unnecessary uses of printf_spec, lift format string
precision/field width to pointer()
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 73 ++++++++++++++++++++------------------------------
1 file changed, 29 insertions(+), 44 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 38d16aa79e56..06cfa06aa4ee 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1963,25 +1963,20 @@ void fwnode_full_name_string(struct printbuf *out,
static noinline_for_stack
void device_node_string(struct printbuf *out, struct device_node *dn,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
- char tbuf[sizeof("xxxx") + 1];
const char *p;
int ret;
- unsigned start = out->pos;
struct property *prop;
bool has_mult, pass;
- struct printf_spec str_spec = spec;
- str_spec.field_width = -1;
-
if (fmt[0] != 'F')
- return error_string_spec(out, "(%pO?)", spec);
+ return error_string(out, "(%pO?)");
if (!IS_ENABLED(CONFIG_OF))
- return error_string_spec(out, "(%pOF?)", spec);
+ return error_string(out, "(%pOF?)");
- if (check_pointer_spec(out, dn, spec))
+ if (check_pointer(out, dn))
return;
/* simple case without anything any more format specifiers */
@@ -1990,7 +1985,6 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
fmt = "f";
for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
- int precision;
if (pass)
prt_char(out, ':');
@@ -1998,43 +1992,41 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
case 'f': /* full_name */
fwnode_full_name_string(out, of_fwnode_handle(dn));
break;
- case 'n': /* name */
- p = fwnode_get_name(of_fwnode_handle(dn));
- precision = str_spec.precision;
- str_spec.precision = strchrnul(p, '@') - p;
- string_spec(out, p, str_spec);
- str_spec.precision = precision;
+ case 'n': { /* name */
+ const char *name = fwnode_get_name(of_fwnode_handle(dn));
+ unsigned len = strchrnul(name, '@') - name;
+
+ prt_bytes(out, name, len);
break;
+ }
case 'p': /* phandle */
- prt_u64(out, (unsigned int)dn->phandle);
+ prt_u64(out, dn->phandle);
break;
case 'P': /* path-spec */
p = fwnode_get_name(of_fwnode_handle(dn));
if (!p[1])
p = "/";
- string_spec(out, p, str_spec);
+ string(out, p);
break;
case 'F': /* flags */
- tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
- tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
- tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
- tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
- tbuf[4] = 0;
- string_nocheck(out, tbuf, str_spec);
+ prt_char(out, of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-');
+ prt_char(out, of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-');
+ prt_char(out, of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-');
+ prt_char(out, of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-');
break;
case 'c': /* major compatible string_spec */
ret = of_property_read_string(dn, "compatible", &p);
if (!ret)
- string_spec(out, p, str_spec);
+ string(out, p);
break;
case 'C': /* full compatible string_spec */
has_mult = false;
of_property_for_each_string(dn, "compatible", prop, p) {
if (has_mult)
- string_nocheck(out, ",", str_spec);
- string_nocheck(out, "\"", str_spec);
- string_spec(out, p, str_spec);
- string_nocheck(out, "\"", str_spec);
+ prt_char(out, ',');
+ prt_char(out, '\"');
+ string(out, p);
+ prt_char(out, '\"');
has_mult = true;
}
@@ -2043,39 +2035,30 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
break;
}
}
-
- widen_string(out, out->pos - start, spec);
}
static noinline_for_stack
void fwnode_string(struct printbuf *out,
struct fwnode_handle *fwnode,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
- struct printf_spec str_spec = spec;
- unsigned start = out->pos;
-
- str_spec.field_width = -1;
-
if (*fmt != 'w')
- return error_string_spec(out, "(%pf?)", spec);
+ return error_string(out, "(%pf?)");
- if (check_pointer_spec(out, fwnode, spec))
+ if (check_pointer(out, fwnode))
return;
fmt++;
switch (*fmt) {
case 'P': /* name */
- string_spec(out, fwnode_get_name(fwnode), str_spec);
+ string(out, fwnode_get_name(fwnode));
break;
case 'f': /* full_name */
default:
fwnode_full_name_string(out, fwnode);
break;
}
-
- widen_string(out, out->pos - start, spec);
}
int __init no_hash_pointers_enable(char *str)
@@ -2313,9 +2296,11 @@ void pointer(struct printbuf *out, const char *fmt,
flags_string(out, ptr, fmt);
return do_width_precision(out, prev_pos, spec);
case 'O':
- return device_node_string(out, ptr, spec, fmt + 1);
+ device_node_string(out, ptr, fmt + 1);
+ return do_width_precision(out, prev_pos, spec);
case 'f':
- return fwnode_string(out, ptr, spec, fmt + 1);
+ fwnode_string(out, ptr, fmt + 1);
+ return do_width_precision(out, prev_pos, spec);
case 'x':
return pointer_string(out, ptr, spec);
case 'e':
--
2.35.1
From: Kent Overstreet <[email protected]>
printf_spec is right now something of a mess - it's a grab-bag of state
that's interpreted inconsistently by different code, and it's scattered
throughout vsprintf.c.
We'd like to get it out of the pretty-printers, and have it be solely
the responsibility of vsprintf()/vpr_buf(), the code that parses and
handles format strings.
Most of the code that uses printf_spec is only using it for a minimum &
maximum field width - that can be done at the toplevel by checking how
much we just printed, and padding or truncating it as necessary. This
patch takes those "simple" uses of printf_spec and moves them as far up
the call stack as possible.
This patch also renames some helpers and creates new ones that don't
take printf_spec:
- do_width_precision: new helper that handles with/precision of
printf_spec
- error_string -> error_string_spec
- check_pointer -> check_pointer_spec
- string -> string_spec
Next patches will be reducing/eliminating uses of the *_spec versions.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 248 ++++++++++++++++++++++++++++---------------------
1 file changed, 141 insertions(+), 107 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 6001710352c4..5cc8337ada0c 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -616,6 +616,19 @@ void widen_string(struct printbuf *out, int n,
prt_chars(out, ' ', spaces);
}
+static void do_width_precision(struct printbuf *out, unsigned prev_pos,
+ struct printf_spec spec)
+{
+ unsigned n = out->pos - prev_pos;
+
+ if (n > spec.precision) {
+ out->pos -= n - spec.precision;
+ n = spec.precision;
+ }
+
+ widen_string(out, n, spec);
+}
+
/* Handle string from a well known address. */
static void string_nocheck(struct printbuf *out,
const char *s,
@@ -648,7 +661,7 @@ static void err_ptr(struct printbuf *out, void *ptr,
}
/* Be careful: error messages must fit into the given buffer. */
-static void error_string(struct printbuf *out, const char *s,
+static void error_string_spec(struct printbuf *out, const char *s,
struct printf_spec spec)
{
/*
@@ -678,7 +691,7 @@ static const char *check_pointer_msg(const void *ptr)
return NULL;
}
-static int check_pointer(struct printbuf *out,
+static int check_pointer_spec(struct printbuf *out,
const void *ptr,
struct printf_spec spec)
{
@@ -686,7 +699,7 @@ static int check_pointer(struct printbuf *out,
err_msg = check_pointer_msg(ptr);
if (err_msg) {
- error_string(out, err_msg, spec);
+ error_string_spec(out, err_msg, spec);
return -EFAULT;
}
@@ -694,16 +707,47 @@ static int check_pointer(struct printbuf *out,
}
static noinline_for_stack
-void string(struct printbuf *out,
+void string_spec(struct printbuf *out,
const char *s,
struct printf_spec spec)
{
- if (check_pointer(out, s, spec))
+ if (check_pointer_spec(out, s, spec))
return;
string_nocheck(out, s, spec);
}
+static void error_string(struct printbuf *out, const char *s)
+{
+ /*
+ * Hard limit to avoid a completely insane messages. It actually
+ * works pretty well because most error messages are in
+ * the many pointer format modifiers.
+ */
+ prt_bytes(out, s, min(strlen(s), 2 * sizeof(void *)));
+}
+
+static int check_pointer(struct printbuf *out, const void *ptr)
+{
+ const char *err_msg;
+
+ err_msg = check_pointer_msg(ptr);
+ if (err_msg) {
+ error_string(out, err_msg);
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+static void string(struct printbuf *out, const char *s)
+{
+ if (check_pointer(out, s))
+ return;
+
+ prt_str(out, s);
+}
+
static void pointer_string(struct printbuf *out,
const void *ptr,
struct printf_spec spec)
@@ -805,7 +849,7 @@ static void ptr_to_id(struct printbuf *out,
if (ret) {
spec.field_width = 2 * sizeof(ptr);
/* string length must be less than default_width */
- return error_string(out, str, spec);
+ return error_string_spec(out, str, spec);
}
pointer_string(out, (const void *)hashval, spec);
@@ -846,7 +890,7 @@ void restricted_pointer(struct printbuf *out,
if (in_irq() || in_serving_softirq() || in_nmi()) {
if (spec.field_width == -1)
spec.field_width = 2 * sizeof(ptr);
- return error_string(out, "pK-error", spec);
+ return error_string_spec(out, "pK-error", spec);
}
/*
@@ -876,14 +920,12 @@ void restricted_pointer(struct printbuf *out,
}
static noinline_for_stack
-void dentry_name(struct printbuf *out,
- const struct dentry *d, struct printf_spec spec,
+void dentry_name(struct printbuf *out, const struct dentry *d,
const char *fmt)
{
- const char *array[4], *s;
+ const char *array[4];
const struct dentry *p;
- int depth;
- int i, n;
+ int i, depth;
switch (fmt[1]) {
case '2': case '3': case '4':
@@ -895,7 +937,7 @@ void dentry_name(struct printbuf *out,
rcu_read_lock();
for (i = 0; i < depth; i++, d = p) {
- if (check_pointer(out, d, spec)) {
+ if (check_pointer(out, d)) {
rcu_read_unlock();
return;
}
@@ -909,56 +951,46 @@ void dentry_name(struct printbuf *out,
break;
}
}
- s = array[--i];
- for (n = 0; n != spec.precision; n++) {
- char c = *s++;
- if (!c) {
- if (!i)
- break;
- c = '/';
- s = array[--i];
- }
- prt_char(out, c);
+ while (1) {
+ prt_str(out, array[--i]);
+ if (!i)
+ break;
+ prt_char(out, '/');
}
rcu_read_unlock();
-
- widen_string(out, n, spec);
}
static noinline_for_stack
-void file_dentry_name(struct printbuf *out,
- const struct file *f,
- struct printf_spec spec, const char *fmt)
+void file_dentry_name(struct printbuf *out, const struct file *f,
+ const char *fmt)
{
- if (check_pointer(out, f, spec))
+ if (check_pointer(out, f))
return;
- return dentry_name(out, f->f_path.dentry, spec, fmt);
+ return dentry_name(out, f->f_path.dentry, fmt);
}
#ifdef CONFIG_BLOCK
static noinline_for_stack
-void bdev_name(struct printbuf *out,
- struct block_device *bdev,
- struct printf_spec spec, const char *fmt)
+void bdev_name(struct printbuf *out, struct block_device *bdev)
{
struct gendisk *hd;
- if (check_pointer(out, bdev, spec))
+ if (check_pointer(out, bdev))
return;
hd = bdev->bd_disk;
- string(out, hd->disk_name, spec);
+ string(out, hd->disk_name);
if (bdev->bd_partno) {
if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
prt_char(out, 'p');
- number(out, bdev->bd_partno, spec);
+ prt_u64(out, bdev->bd_partno);
}
}
#endif
static noinline_for_stack
void symbol_string(struct printbuf *out, void *ptr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
unsigned long value;
#ifdef CONFIG_KALLSYMS
@@ -981,17 +1013,12 @@ void symbol_string(struct printbuf *out, void *ptr,
else
sprint_symbol_no_offset(sym, value);
- string_nocheck(out, sym, spec);
+ prt_str(out, sym);
#else
special_hex_number(out, value, sizeof(void *));
#endif
}
-static const struct printf_spec default_str_spec = {
- .field_width = -1,
- .precision = -1,
-};
-
static const struct printf_spec default_flag_spec = {
.base = 16,
.precision = -1,
@@ -1050,7 +1077,7 @@ void resource_string(struct printbuf *out, struct resource *res,
int decode = (fmt[0] == 'R') ? 1 : 0;
const struct printf_spec *specp;
- if (check_pointer(out, res, spec))
+ if (check_pointer_spec(out, res, spec))
return;
prt_char(&sym, '[');
@@ -1114,7 +1141,7 @@ void hex_string(struct printbuf *out, u8 *addr,
/* nothing to print */
return;
- if (check_pointer(out, addr, spec))
+ if (check_pointer_spec(out, addr, spec))
return;
switch (fmt[1]) {
@@ -1155,7 +1182,7 @@ void bitmap_string(struct printbuf *out, unsigned long *bitmap,
int i, chunksz;
bool first = true;
- if (check_pointer(out, bitmap, spec))
+ if (check_pointer_spec(out, bitmap, spec))
return;
/* reused to print numbers */
@@ -1194,7 +1221,7 @@ void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
bool first = true;
int rbot, rtop;
- if (check_pointer(out, bitmap, spec))
+ if (check_pointer_spec(out, bitmap, spec))
return ;
for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
@@ -1221,7 +1248,7 @@ void mac_address_string(struct printbuf *out, u8 *addr,
char separator;
bool reversed = false;
- if (check_pointer(out, addr, spec))
+ if (check_pointer_spec(out, addr, spec))
return;
switch (fmt[1]) {
@@ -1522,7 +1549,7 @@ void ip_addr_string(struct printbuf *out, const void *ptr,
{
char *err_fmt_msg;
- if (check_pointer(out, ptr, spec))
+ if (check_pointer_spec(out, ptr, spec))
return;
switch (fmt[1]) {
@@ -1543,12 +1570,12 @@ void ip_addr_string(struct printbuf *out, const void *ptr,
case AF_INET6:
return ip6_addr_string_sa(out, &sa->v6, spec, fmt);
default:
- return error_string(out, "(einval)", spec);
+ return error_string_spec(out, "(einval)", spec);
}}
}
err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
- return error_string(out, err_fmt_msg, spec);
+ return error_string_spec(out, err_fmt_msg, spec);
}
static noinline_for_stack
@@ -1563,7 +1590,7 @@ void escaped_string(struct printbuf *out, u8 *addr,
if (spec.field_width == 0)
return; /* nothing to print */
- if (check_pointer(out, addr, spec))
+ if (check_pointer_spec(out, addr, spec))
return;
do {
@@ -1608,7 +1635,7 @@ static void va_format(struct printbuf *out,
{
va_list va;
- if (check_pointer(out, va_fmt, spec))
+ if (check_pointer_spec(out, va_fmt, spec))
return;
va_copy(va, *va_fmt->va);
@@ -1617,16 +1644,13 @@ static void va_format(struct printbuf *out,
}
static noinline_for_stack
-void uuid_string(struct printbuf *out, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+void uuid_string(struct printbuf *out, const u8 *addr, const char *fmt)
{
- char uuid_buf[UUID_STRING_LEN + 1];
- struct printbuf uuid = PRINTBUF_EXTERN(uuid_buf, sizeof(uuid_buf));
int i;
const u8 *index = uuid_index;
bool uc = false;
- if (check_pointer(out, addr, spec))
+ if (check_pointer(out, addr))
return;
switch (*(++fmt)) {
@@ -1643,30 +1667,28 @@ void uuid_string(struct printbuf *out, const u8 *addr,
for (i = 0; i < 16; i++) {
if (uc)
- prt_hex_byte_upper(&uuid, addr[index[i]]);
+ prt_hex_byte_upper(out, addr[index[i]]);
else
- prt_hex_byte(&uuid, addr[index[i]]);
+ prt_hex_byte(out, addr[index[i]]);
switch (i) {
case 3:
case 5:
case 7:
case 9:
- prt_char(&uuid, '-');
+ prt_char(out, '-');
break;
}
}
-
- string_nocheck(out, uuid_buf, spec);
}
static noinline_for_stack
void netdev_bits(struct printbuf *out, const void *addr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
unsigned long long num;
int size;
- if (check_pointer(out, addr, spec))
+ if (check_pointer(out, addr))
return;
switch (fmt[1]) {
@@ -1676,7 +1698,7 @@ void netdev_bits(struct printbuf *out, const void *addr,
special_hex_number(out, num, size);
break;
default:
- error_string(out, "(%pN?)", spec);
+ error_string(out, "(%pN?)");
break;
}
}
@@ -1691,9 +1713,9 @@ void fourcc_string(struct printbuf *out, const u32 *fourcc,
u32 orig, val;
if (fmt[1] != 'c' || fmt[2] != 'c')
- return error_string(out, "(%p4?)", spec);
+ return error_string_spec(out, "(%p4?)", spec);
- if (check_pointer(out, fourcc, spec))
+ if (check_pointer_spec(out, fourcc, spec))
return;
orig = get_unaligned(fourcc);
@@ -1714,17 +1736,17 @@ void fourcc_string(struct printbuf *out, const u32 *fourcc,
special_hex_number(&output, orig, sizeof(u32));
prt_char(&output, ')');
- string(out, output_buf, spec);
+ string_spec(out, output_buf, spec);
}
static noinline_for_stack
void address_val(struct printbuf *out, const void *addr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
unsigned long long num;
int size;
- if (check_pointer(out, addr, spec))
+ if (check_pointer(out, addr))
return;
switch (fmt[1]) {
@@ -1775,7 +1797,7 @@ void rtc_str(struct printbuf *out, const struct rtc_time *tm,
bool found = true;
int count = 2;
- if (check_pointer(out, tm, spec))
+ if (check_pointer_spec(out, tm, spec))
return;
switch (fmt[count]) {
@@ -1845,7 +1867,7 @@ void time_and_date(struct printbuf *out,
case 'T':
return time64_str(out, *(const time64_t *)ptr, spec, fmt);
default:
- return error_string(out, "(%pt?)", spec);
+ return error_string_spec(out, "(%pt?)", spec);
}
}
@@ -1854,16 +1876,16 @@ void clock(struct printbuf *out, struct clk *clk,
struct printf_spec spec, const char *fmt)
{
if (!IS_ENABLED(CONFIG_HAVE_CLK))
- return error_string(out, "(%pC?)", spec);
+ return error_string_spec(out, "(%pC?)", spec);
- if (check_pointer(out, clk, spec))
+ if (check_pointer_spec(out, clk, spec))
return;
switch (fmt[1]) {
case 'n':
default:
#ifdef CONFIG_COMMON_CLK
- return string(out, __clk_get_name(clk), spec);
+ return string_spec(out, __clk_get_name(clk), spec);
#else
return ptr_to_id(out, clk, spec);
#endif
@@ -1881,7 +1903,7 @@ void format_flags(struct printbuf *out, unsigned long flags,
if ((flags & mask) != mask)
continue;
- string(out, names->name, default_str_spec);
+ string(out, names->name);
flags &= ~mask;
if (flags)
@@ -1939,7 +1961,7 @@ void format_page_flags(struct printbuf *out, unsigned long flags)
if (append)
prt_char(out, '|');
- string(out, pff[i].name, default_str_spec);
+ string(out, pff[i].name);
prt_char(out, '=');
number(out, (flags >> pff[i].shift) & pff[i].mask, *pff[i].spec);
@@ -1955,7 +1977,7 @@ void flags_string(struct printbuf *out, void *flags_ptr,
unsigned long flags;
const struct trace_print_flags *names;
- if (check_pointer(out, flags_ptr, spec))
+ if (check_pointer_spec(out, flags_ptr, spec))
return;
switch (fmt[1]) {
@@ -1970,7 +1992,7 @@ void flags_string(struct printbuf *out, void *flags_ptr,
names = gfpflag_names;
break;
default:
- return error_string(out, "(%pG?)", spec);
+ return error_string_spec(out, "(%pG?)", spec);
}
return format_flags(out, flags, names);
@@ -1987,10 +2009,8 @@ void fwnode_full_name_string(struct printbuf *out,
struct fwnode_handle *__fwnode =
fwnode_get_nth_parent(fwnode, depth);
- string(out, fwnode_get_name_prefix(__fwnode),
- default_str_spec);
- string(out, fwnode_get_name(__fwnode),
- default_str_spec);
+ string(out, fwnode_get_name_prefix(__fwnode));
+ string(out, fwnode_get_name(__fwnode));
fwnode_handle_put(__fwnode);
}
@@ -2011,12 +2031,12 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
str_spec.field_width = -1;
if (fmt[0] != 'F')
- return error_string(out, "(%pO?)", spec);
+ return error_string_spec(out, "(%pO?)", spec);
if (!IS_ENABLED(CONFIG_OF))
- return error_string(out, "(%pOF?)", spec);
+ return error_string_spec(out, "(%pOF?)", spec);
- if (check_pointer(out, dn, spec))
+ if (check_pointer_spec(out, dn, spec))
return;
/* simple case without anything any more format specifiers */
@@ -2037,7 +2057,7 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
p = fwnode_get_name(of_fwnode_handle(dn));
precision = str_spec.precision;
str_spec.precision = strchrnul(p, '@') - p;
- string(out, p, str_spec);
+ string_spec(out, p, str_spec);
str_spec.precision = precision;
break;
case 'p': /* phandle */
@@ -2047,7 +2067,7 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
p = fwnode_get_name(of_fwnode_handle(dn));
if (!p[1])
p = "/";
- string(out, p, str_spec);
+ string_spec(out, p, str_spec);
break;
case 'F': /* flags */
tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
@@ -2057,18 +2077,18 @@ void device_node_string(struct printbuf *out, struct device_node *dn,
tbuf[4] = 0;
string_nocheck(out, tbuf, str_spec);
break;
- case 'c': /* major compatible string */
+ case 'c': /* major compatible string_spec */
ret = of_property_read_string(dn, "compatible", &p);
if (!ret)
- string(out, p, str_spec);
+ string_spec(out, p, str_spec);
break;
- case 'C': /* full compatible string */
+ case 'C': /* full compatible string_spec */
has_mult = false;
of_property_for_each_string(dn, "compatible", prop, p) {
if (has_mult)
string_nocheck(out, ",", str_spec);
string_nocheck(out, "\"", str_spec);
- string(out, p, str_spec);
+ string_spec(out, p, str_spec);
string_nocheck(out, "\"", str_spec);
has_mult = true;
@@ -2093,16 +2113,16 @@ void fwnode_string(struct printbuf *out,
str_spec.field_width = -1;
if (*fmt != 'w')
- return error_string(out, "(%pf?)", spec);
+ return error_string_spec(out, "(%pf?)", spec);
- if (check_pointer(out, fwnode, spec))
+ if (check_pointer_spec(out, fwnode, spec))
return;
fmt++;
switch (*fmt) {
case 'P': /* name */
- string(out, fwnode_get_name(fwnode), str_spec);
+ string_spec(out, fwnode_get_name(fwnode), str_spec);
break;
case 'f': /* full_name */
default:
@@ -2269,13 +2289,16 @@ static noinline_for_stack
void pointer(struct printbuf *out, const char *fmt,
void *ptr, struct printf_spec spec)
{
+ unsigned prev_pos = out->pos;
+
switch (*fmt) {
case 'S':
case 's':
ptr = dereference_symbol_descriptor(ptr);
fallthrough;
case 'B':
- return symbol_string(out, ptr, spec, fmt);
+ symbol_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'R':
case 'r':
return resource_string(out, ptr, spec, fmt);
@@ -2306,28 +2329,34 @@ void pointer(struct printbuf *out, const char *fmt,
case 'E':
return escaped_string(out, ptr, spec, fmt);
case 'U':
- return uuid_string(out, ptr, spec, fmt);
+ uuid_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'V':
return va_format(out, ptr, spec, fmt);
case 'K':
return restricted_pointer(out, ptr, spec);
case 'N':
- return netdev_bits(out, ptr, spec, fmt);
+ netdev_bits(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case '4':
return fourcc_string(out, ptr, spec, fmt);
case 'a':
- return address_val(out, ptr, spec, fmt);
+ address_val(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'd':
- return dentry_name(out, ptr, spec, fmt);
+ dentry_name(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 't':
return time_and_date(out, ptr, spec, fmt);
case 'C':
return clock(out, ptr, spec, fmt);
case 'D':
- return file_dentry_name(out, ptr, spec, fmt);
+ file_dentry_name(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
#ifdef CONFIG_BLOCK
case 'g':
- return bdev_name(out, ptr, spec, fmt);
+ bdev_name(out, ptr);
+ return do_width_precision(out, prev_pos, spec);
#endif
case 'G':
@@ -2347,9 +2376,9 @@ void pointer(struct printbuf *out, const char *fmt,
case 'k':
switch (fmt[1]) {
case 's':
- return string(out, ptr, spec);
+ return string_spec(out, ptr, spec);
default:
- return error_string(out, "(einval)", spec);
+ return error_string_spec(out, "(einval)", spec);
}
default:
return default_pointer(out, ptr, spec);
@@ -2627,7 +2656,12 @@ void prt_vprintf(struct printbuf *out, const char *fmt, va_list args)
break;
case FORMAT_TYPE_STR:
- string(out, va_arg(args, char *), spec);
+ /*
+ * we can't use string() then do_width_precision
+ * afterwards: people use the field width for passing
+ * non nul terminated strings
+ */
+ string_spec(out, va_arg(args, char *), spec);
break;
case FORMAT_TYPE_PTR:
@@ -3096,7 +3130,7 @@ void prt_bstrprintf(struct printbuf *out, const char *fmt, const u32 *bin_buf)
case FORMAT_TYPE_STR: {
const char *str_arg = args;
args += strlen(str_arg) + 1;
- string(out, (char *)str_arg, spec);
+ string_spec(out, (char *)str_arg, spec);
break;
}
--
2.35.1
From: Kent Overstreet <[email protected]>
The current test code checks that sprintf never writes past the
terminating nul. This is a rather strange requirement, completely
separate from writing past the end of the buffer, which of course we
can't do: writing anywhere to the buffer passed to snprintf, within size
of course, should be perfectly fine.
Since this check has no documentation as to where it comes from or what
depends on it, and it's getting in the way of further refactoring
(printf_spec handling is right now scattered massively throughout the
code, and we'd like to consolidate it) - delete it.
Also, many current pretty-printers building up their output on the
stack, and then copy it to the actual output buffer - by eliminating
this requirement we can kill those extra buffers.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/test_printf.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 4bd15a593fbd..da91301eae50 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -84,12 +84,6 @@ do_test(int bufsize, const char *expect, int elen,
return 1;
}
- if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) {
- pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
- bufsize, fmt);
- return 1;
- }
-
if (memchr_inv(test_buffer + bufsize, FILL_CHAR, BUF_SIZE + PAD_SIZE - bufsize)) {
pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond buffer\n", bufsize, fmt);
return 1;
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts most of the hexdump code to printbufs, along with some
significant cleanups and a bit of reorganization. The old non-printbuf
functions are mostly left as wrappers around the new printbuf versions.
Big note: byte swabbing behaviour
Previously, hex_dump_to_buffer() would byteswab the groups of bytes
being printed on little endian machines. This behaviour is... not
standard or typical for a hex dumper, and this behaviour was silently
added/changed without documentation (in 2007).
Given that the hex dumpers are just used for debugging output, nothing
is likely to break, and hopefully by reverting to more standard
behaviour the end result will be _less_ confusion, modulo a few kernel
developers who will certainly be annoyed by their tools changing.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Mikulas Patocka <[email protected]>
---
include/linux/kernel.h | 6 +
lib/hexdump.c | 246 ++++++++++++++++++++++++-----------------
lib/test_hexdump.c | 30 +----
3 files changed, 159 insertions(+), 123 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5c4f4b6d36ab..1906861ece7a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -293,6 +293,12 @@ extern int hex_to_bin(unsigned char ch);
extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
extern char *bin2hex(char *dst, const void *src, size_t count);
+struct printbuf;
+void prt_hex_bytes(struct printbuf *, const void *, unsigned, unsigned, unsigned);
+void prt_hex_line(struct printbuf *, const void *, size_t, int, int, bool);
+void prt_hex_dump(struct printbuf *, const void *, size_t,
+ const char *, int, unsigned, unsigned, bool);
+
bool mac_pton(const char *s, u8 *mac);
/*
diff --git a/lib/hexdump.c b/lib/hexdump.c
index 06833d404398..9556f15ad295 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -9,6 +9,7 @@
#include <linux/kernel.h>
#include <linux/minmax.h>
#include <linux/export.h>
+#include <linux/printbuf.h>
#include <asm/unaligned.h>
const char hex_asc[] = "0123456789abcdef";
@@ -79,32 +80,40 @@ int hex2bin(u8 *dst, const char *src, size_t count)
EXPORT_SYMBOL(hex2bin);
/**
- * bin2hex - convert binary data to an ascii hexadecimal string
- * @dst: ascii hexadecimal result
- * @src: binary data
- * @count: binary data length
+ * prt_hex_bytes - Print a string of hex bytes, with optional separator
+ *
+ * @out: The printbuf to output to
+ * @addr: Buffer to print
+ * @nr: Number of bytes to print
+ * @separator: Optional separator character between each byte
*/
-char *bin2hex(char *dst, const void *src, size_t count)
+void prt_hex_bytes(struct printbuf *out, const void *buf, unsigned len,
+ unsigned groupsize, unsigned separator)
{
- const unsigned char *_src = src;
+ const u8 *ptr = buf;
+ unsigned i;
- while (count--)
- dst = hex_byte_pack(dst, *_src++);
- return dst;
+ if (!groupsize)
+ groupsize = 1;
+
+ for (i = 0; i < len ; ++i) {
+ if (i && separator && !(i % groupsize))
+ __prt_char(out, separator);
+ prt_hex_byte(out, ptr[i]);
+ }
}
-EXPORT_SYMBOL(bin2hex);
+EXPORT_SYMBOL(prt_hex_bytes);
/**
- * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
+ * prt_hex_line - convert a blob of data to "hex ASCII" in memory
+ * @out: printbuf to output to
* @buf: data blob to dump
* @len: number of bytes in the @buf
* @rowsize: number of bytes to print per line; must be 16 or 32
* @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
- * @linebuf: where to put the converted data
- * @linebuflen: total size of @linebuf, including space for terminating NUL
* @ascii: include ASCII after the hex output
*
- * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
+ * prt_hex_line() works on one "line" of output at a time, i.e.,
* 16 or 32 bytes of input data converted to hex + ASCII output.
*
* Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
@@ -117,22 +126,13 @@ EXPORT_SYMBOL(bin2hex);
*
* example output buffer:
* 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
- *
- * Return:
- * The amount of bytes placed in the buffer without terminating NUL. If the
- * output was truncated, then the return value is the number of bytes
- * (excluding the terminating NUL) which would have been written to the final
- * string if enough space had been available.
*/
-int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
- char *linebuf, size_t linebuflen, bool ascii)
+void prt_hex_line(struct printbuf *out, const void *buf, size_t len,
+ int rowsize, int groupsize, bool ascii)
{
+ unsigned saved_pos = out->pos;
const u8 *ptr = buf;
- int ngroups;
- u8 ch;
- int j, lx = 0;
- int ascii_column;
- int ret;
+ int i, ngroups;
if (rowsize != 16 && rowsize != 32)
rowsize = 16;
@@ -145,84 +145,127 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
groupsize = 1;
ngroups = len / groupsize;
- ascii_column = rowsize * 2 + rowsize / groupsize + 1;
-
- if (!linebuflen)
- goto overflow1;
if (!len)
- goto nil;
-
- if (groupsize == 8) {
- const u64 *ptr8 = buf;
-
- for (j = 0; j < ngroups; j++) {
- ret = snprintf(linebuf + lx, linebuflen - lx,
- "%s%16.16llx", j ? " " : "",
- get_unaligned(ptr8 + j));
- if (ret >= linebuflen - lx)
- goto overflow1;
- lx += ret;
- }
- } else if (groupsize == 4) {
- const u32 *ptr4 = buf;
-
- for (j = 0; j < ngroups; j++) {
- ret = snprintf(linebuf + lx, linebuflen - lx,
- "%s%8.8x", j ? " " : "",
- get_unaligned(ptr4 + j));
- if (ret >= linebuflen - lx)
- goto overflow1;
- lx += ret;
- }
- } else if (groupsize == 2) {
- const u16 *ptr2 = buf;
-
- for (j = 0; j < ngroups; j++) {
- ret = snprintf(linebuf + lx, linebuflen - lx,
- "%s%4.4x", j ? " " : "",
- get_unaligned(ptr2 + j));
- if (ret >= linebuflen - lx)
- goto overflow1;
- lx += ret;
- }
- } else {
- for (j = 0; j < len; j++) {
- if (linebuflen < lx + 2)
- goto overflow2;
- ch = ptr[j];
- linebuf[lx++] = hex_asc_hi(ch);
- if (linebuflen < lx + 2)
- goto overflow2;
- linebuf[lx++] = hex_asc_lo(ch);
- if (linebuflen < lx + 2)
- goto overflow2;
- linebuf[lx++] = ' ';
+ return;
+
+ prt_hex_bytes(out, ptr, len, groupsize, ' ');
+
+ if (ascii) {
+ unsigned ascii_column = rowsize * 2 + rowsize / groupsize + 1;
+
+ prt_chars(out, ' ', max_t(int, 0, ascii_column - (out->pos - saved_pos)));
+
+ for (i = 0; i < len; i++) {
+ u8 ch = ptr[i];
+ prt_char(out, isascii(ch) && isprint(ch) ? ch : '.');
}
- if (j)
- lx--;
}
- if (!ascii)
- goto nil;
+}
+EXPORT_SYMBOL(prt_hex_line);
- while (lx < ascii_column) {
- if (linebuflen < lx + 2)
- goto overflow2;
- linebuf[lx++] = ' ';
- }
- for (j = 0; j < len; j++) {
- if (linebuflen < lx + 2)
- goto overflow2;
- ch = ptr[j];
- linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
+/**
+ * prt_hex_dump - print multiline formatted hex dump
+ * @out: printbuf to output to
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ * @prefix_str: string to prefix each line with;
+ * caller supplies trailing spaces for alignment if desired
+ * @prefix_type: controls whether prefix of an offset, address, or none
+ * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
+ * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
+ * @ascii: include ASCII after the hex output
+ *
+ * Function is an analogue of print_hex_dump() and thus has similar interface.
+ *
+ * linebuf size is maximal length for one line.
+ * 32 * 3 - maximum bytes per line, each printed into 2 chars + 1 for
+ * separating space
+ * 2 - spaces separating hex dump and ascii representation
+ * 32 - ascii representation
+ * 1 - terminating '\0'
+ */
+void prt_hex_dump(struct printbuf *out, const void *buf, size_t len,
+ const char *prefix_str, int prefix_type,
+ unsigned rowsize, unsigned groupsize, bool ascii)
+{
+ const u8 *ptr = buf;
+ size_t i;
+
+ if (rowsize != 16 && rowsize != 32)
+ rowsize = 16;
+
+ for (i = 0; i < len; i += rowsize) {
+ prt_str(out, prefix_str);
+
+ switch (prefix_type) {
+ case DUMP_PREFIX_ADDRESS:
+ prt_printf(out, "%p: ", ptr + i);
+ break;
+ case DUMP_PREFIX_OFFSET:
+ prt_printf(out, "%.8zx: ", i);
+ break;
+ }
+
+ prt_hex_line(out, ptr + i, min_t(size_t, len - i, rowsize),
+ rowsize, groupsize, ascii);
+ prt_char(out, '\n');
}
-nil:
- linebuf[lx] = '\0';
- return lx;
-overflow2:
- linebuf[lx++] = '\0';
-overflow1:
- return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
+}
+
+/**
+ * bin2hex - convert binary data to an ascii hexadecimal string
+ * @dst: ascii hexadecimal result
+ * @src: binary data
+ * @count: binary data length
+ */
+char *bin2hex(char *dst, const void *src, size_t count)
+{
+ struct printbuf out = PRINTBUF_EXTERN(dst, count * 4);
+
+ prt_hex_bytes(&out, src, count, 0, 0);
+ return dst + out.pos;
+}
+EXPORT_SYMBOL(bin2hex);
+
+/**
+ * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
+ * @buf: data blob to dump
+ * @len: number of bytes in the @buf
+ * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
+ * @linebuf: where to put the converted data
+ * @linebuflen: total size of @linebuf, including space for terminating NUL
+ * @ascii: include ASCII after the hex output
+ *
+ * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
+ * 16 or 32 bytes of input data converted to hex + ASCII output.
+ *
+ * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
+ * to a hex + ASCII dump at the supplied memory location.
+ * The converted output is always NUL-terminated.
+ *
+ * E.g.:
+ * hex_dump_to_buffer(frame->data, frame->len, 16, 1,
+ * linebuf, sizeof(linebuf), true);
+ *
+ * example output buffer:
+ * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
+ *
+ * Return:
+ * The amount of bytes placed in the buffer without terminating NUL. If the
+ * output was truncated, then the return value is the number of bytes
+ * (excluding the terminating NUL) which would have been written to the final
+ * string if enough space had been available.
+ */
+int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
+ char *linebuf, size_t linebuflen, bool ascii)
+{
+ struct printbuf out = PRINTBUF_EXTERN(linebuf, linebuflen);
+
+ prt_hex_line(&out, buf, len, rowsize, groupsize, ascii);
+ return out.pos;
}
EXPORT_SYMBOL(hex_dump_to_buffer);
@@ -262,6 +305,11 @@ void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
int rowsize, int groupsize,
const void *buf, size_t len, bool ascii)
{
+ /*
+ * XXX: this code does the exact same thing as prt_hex_dump(): we should
+ * be able to call that and printk() the result, except printk is
+ * restricted to 1024 bytes of output per call
+ */
const u8 *ptr = buf;
int i, linelen, remaining = len;
unsigned char linebuf[32 * 3 + 2 + 32 + 1];
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index 5144899d3c6b..f9e97879dcdf 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -25,36 +25,19 @@ static const char * const test_data_1[] __initconst = {
"4c", "d1", "19", "99", "43", "b1", "af", "0c",
};
-static const char * const test_data_2_le[] __initconst = {
- "32be", "7bdb", "180a", "b293",
- "ba70", "24c4", "837d", "9b34",
- "9ca6", "ad31", "0f9c", "e9ac",
- "d14c", "9919", "b143", "0caf",
-};
-
-static const char * const test_data_2_be[] __initconst = {
+static const char * const test_data_2[] __initconst = {
"be32", "db7b", "0a18", "93b2",
"70ba", "c424", "7d83", "349b",
"a69c", "31ad", "9c0f", "ace9",
"4cd1", "1999", "43b1", "af0c",
};
-static const char * const test_data_4_le[] __initconst = {
- "7bdb32be", "b293180a", "24c4ba70", "9b34837d",
- "ad319ca6", "e9ac0f9c", "9919d14c", "0cafb143",
-};
-
-static const char * const test_data_4_be[] __initconst = {
+static const char * const test_data_4[] __initconst = {
"be32db7b", "0a1893b2", "70bac424", "7d83349b",
"a69c31ad", "9c0face9", "4cd11999", "43b1af0c",
};
-static const char * const test_data_8_le[] __initconst = {
- "b293180a7bdb32be", "9b34837d24c4ba70",
- "e9ac0f9cad319ca6", "0cafb1439919d14c",
-};
-
-static const char * const test_data_8_be[] __initconst = {
+static const char * const test_data_8[] __initconst = {
"be32db7b0a1893b2", "70bac4247d83349b",
"a69c31ad9c0face9", "4cd1199943b1af0c",
};
@@ -73,7 +56,6 @@ static void __init test_hexdump_prepare_test(size_t len, int rowsize,
size_t l = len;
int gs = groupsize, rs = rowsize;
unsigned int i;
- const bool is_be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
if (rs != 16 && rs != 32)
rs = 16;
@@ -85,11 +67,11 @@ static void __init test_hexdump_prepare_test(size_t len, int rowsize,
gs = 1;
if (gs == 8)
- result = is_be ? test_data_8_be : test_data_8_le;
+ result = test_data_8;
else if (gs == 4)
- result = is_be ? test_data_4_be : test_data_4_le;
+ result = test_data_4;
else if (gs == 2)
- result = is_be ? test_data_2_be : test_data_2_le;
+ result = test_data_2;
else
result = test_data_1;
--
2.35.1
From: Kent Overstreet <[email protected]>
- We're attempting to consolidate printf_spec and format string
handling in the top level vpr_buf(), this changes fourcc_string() to
not take printf_spec
- With the new printbuf helpers there's no need to use a separate stack
allocated buffer, so this patch deletes it.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 2c5f10bc59e2..f47f10659737 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1701,17 +1701,15 @@ void netdev_bits(struct printbuf *out, const void *addr,
static noinline_for_stack
void fourcc_string(struct printbuf *out, const u32 *fourcc,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
- char output_buf[sizeof("0123 little-endian (0x01234567)")];
- struct printbuf output = PRINTBUF_EXTERN(output_buf, sizeof(output_buf));
unsigned int i;
u32 orig, val;
if (fmt[1] != 'c' || fmt[2] != 'c')
- return error_string_spec(out, "(%p4?)", spec);
+ return error_string(out, "(%p4?)");
- if (check_pointer_spec(out, fourcc, spec))
+ if (check_pointer(out, fourcc))
return;
orig = get_unaligned(fourcc);
@@ -1721,18 +1719,16 @@ void fourcc_string(struct printbuf *out, const u32 *fourcc,
unsigned char c = val >> (i * 8);
/* Print non-control ASCII characters as-is, dot otherwise */
- prt_char(&output, isascii(c) && isprint(c) ? c : '.');
+ prt_char(out, isascii(c) && isprint(c) ? c : '.');
}
- prt_char(&output, ' ');
- prt_str(&output, orig & BIT(31) ? "big-endian" : "little-endian");
-
- prt_char(&output, ' ');
- prt_char(&output, '(');
- special_hex_number(&output, orig, sizeof(u32));
- prt_char(&output, ')');
+ prt_char(out, ' ');
+ prt_str(out, orig & BIT(31) ? "big-endian" : "little-endian");
- string_spec(out, output_buf, spec);
+ prt_char(out, ' ');
+ prt_char(out, '(');
+ special_hex_number(out, orig, sizeof(u32));
+ prt_char(out, ')');
}
static noinline_for_stack
@@ -2336,7 +2332,8 @@ void pointer(struct printbuf *out, const char *fmt,
netdev_bits(out, ptr, fmt);
return do_width_precision(out, prev_pos, spec);
case '4':
- return fourcc_string(out, ptr, spec, fmt);
+ fourcc_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'a':
address_val(out, ptr, fmt);
return do_width_precision(out, prev_pos, spec);
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts the seq_bufs in dynevent_cmd and trace_seq to printbufs.
- read_pos in seq_buf doesn't exist in printbuf, so is added to
trace_seq
- seq_buf_to_user doesn't have a printbuf equivalent, so is inlined
into trace_seq_to_user
- seq_buf_putmem_hex currently swabs bytes on little endian, hardcoded
to 8 byte units. This patch switches it to prt_hex_bytes(), which
does _not_ swab.
Otherwise this is largely a direct conversion, with a few slight
refactorings and cleanups.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
---
include/linux/trace_events.h | 2 +-
include/linux/trace_seq.h | 17 ++--
kernel/trace/trace.c | 45 ++++-------
kernel/trace/trace_dynevent.c | 34 ++++----
kernel/trace/trace_events_filter.c | 2 +-
kernel/trace/trace_events_synth.c | 2 +-
kernel/trace/trace_functions_graph.c | 6 +-
kernel/trace/trace_kprobe.c | 2 +-
kernel/trace/trace_seq.c | 111 ++++++++++++++-------------
9 files changed, 103 insertions(+), 118 deletions(-)
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index b18759a673c6..4cb7cacb57b1 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -496,7 +496,7 @@ struct dynevent_cmd;
typedef int (*dynevent_create_fn_t)(struct dynevent_cmd *cmd);
struct dynevent_cmd {
- struct seq_buf seq;
+ struct printbuf seq;
const char *event_name;
unsigned int n_fields;
enum dynevent_type type;
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index 5a2c650d9e1c..d2b51007b3b9 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -2,10 +2,12 @@
#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <asm/page.h>
+struct seq_file;
+
/*
* Trace sequences are used to allow a function to call several other functions
* to create a string of data to use (up to a max of PAGE_SIZE).
@@ -13,14 +15,16 @@
struct trace_seq {
char buffer[PAGE_SIZE];
- struct seq_buf seq;
+ struct printbuf seq;
+ unsigned readpos;
int full;
};
static inline void
trace_seq_init(struct trace_seq *s)
{
- seq_buf_init(&s->seq, s->buffer, PAGE_SIZE);
+ s->seq = PRINTBUF_EXTERN(s->buffer, PAGE_SIZE);
+ s->readpos = 0;
s->full = 0;
}
@@ -39,7 +43,7 @@ trace_seq_init(struct trace_seq *s)
*/
static inline int trace_seq_used(struct trace_seq *s)
{
- return seq_buf_used(&s->seq);
+ return printbuf_written(&s->seq);
}
/**
@@ -54,7 +58,7 @@ static inline int trace_seq_used(struct trace_seq *s)
static inline char *
trace_seq_buffer_ptr(struct trace_seq *s)
{
- return s->buffer + seq_buf_used(&s->seq);
+ return s->buffer + printbuf_written(&s->seq);
}
/**
@@ -66,7 +70,7 @@ trace_seq_buffer_ptr(struct trace_seq *s)
*/
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
{
- return s->full || seq_buf_has_overflowed(&s->seq);
+ return s->full || printbuf_overflowed(&s->seq);
}
/*
@@ -87,6 +91,7 @@ extern void trace_seq_putc(struct trace_seq *s, unsigned char c);
extern void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len);
extern void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
unsigned int len);
+struct path;
extern int trace_seq_path(struct trace_seq *s, const struct path *path);
extern void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d3005279165d..b27fe1e45138 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1673,15 +1673,15 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
{
int len;
- if (trace_seq_used(s) <= s->seq.readpos)
+ if (trace_seq_used(s) <= s->readpos)
return -EBUSY;
- len = trace_seq_used(s) - s->seq.readpos;
+ len = trace_seq_used(s) - s->readpos;
if (cnt > len)
cnt = len;
- memcpy(buf, s->buffer + s->seq.readpos, cnt);
+ memcpy(buf, s->buffer + s->readpos, cnt);
- s->seq.readpos += cnt;
+ s->readpos += cnt;
return cnt;
}
@@ -3728,11 +3728,7 @@ static bool trace_safe_str(struct trace_iterator *iter, const char *str,
static const char *show_buffer(struct trace_seq *s)
{
- struct seq_buf *seq = &s->seq;
-
- seq_buf_terminate(seq);
-
- return seq->buffer;
+ return printbuf_str(&s->seq);
}
static DEFINE_STATIC_KEY_FALSE(trace_no_verify);
@@ -6759,12 +6755,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
trace_access_lock(iter->cpu_file);
while (trace_find_next_entry_inc(iter) != NULL) {
enum print_line_t ret;
- int save_len = iter->seq.seq.len;
+ int save_pos = iter->seq.seq.pos;
ret = print_trace_line(iter);
if (ret == TRACE_TYPE_PARTIAL_LINE) {
/* don't print partial lines */
- iter->seq.seq.len = save_len;
+ iter->seq.seq.pos = save_pos;
break;
}
if (ret != TRACE_TYPE_NO_CONSUME)
@@ -6786,7 +6782,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* Now copy what we have to the user */
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
- if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq))
+ if (iter->seq.readpos >= trace_seq_used(&iter->seq))
trace_seq_init(&iter->seq);
/*
@@ -6812,16 +6808,15 @@ static size_t
tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
{
size_t count;
- int save_len;
int ret;
/* Seq buffer is page-sized, exactly what we need. */
for (;;) {
- save_len = iter->seq.seq.len;
+ unsigned save_pos = iter->seq.seq.pos;
ret = print_trace_line(iter);
if (trace_seq_has_overflowed(&iter->seq)) {
- iter->seq.seq.len = save_len;
+ iter->seq.seq.pos = save_pos;
break;
}
@@ -6831,14 +6826,14 @@ tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
* anyway to be safe.
*/
if (ret == TRACE_TYPE_PARTIAL_LINE) {
- iter->seq.seq.len = save_len;
+ iter->seq.seq.pos = save_pos;
break;
}
- count = trace_seq_used(&iter->seq) - save_len;
+ count = trace_seq_used(&iter->seq) - save_pos;
if (rem < count) {
rem = 0;
- iter->seq.seq.len = save_len;
+ iter->seq.seq.pos = save_pos;
break;
}
@@ -9826,20 +9821,8 @@ static struct notifier_block trace_die_notifier = {
void
trace_printk_seq(struct trace_seq *s)
{
- /* Probably should print a warning here. */
- if (s->seq.len >= TRACE_MAX_PRINT)
- s->seq.len = TRACE_MAX_PRINT;
-
- /*
- * More paranoid code. Although the buffer size is set to
- * PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just
- * an extra layer of protection.
- */
- if (WARN_ON_ONCE(s->seq.len >= s->seq.size))
- s->seq.len = s->seq.size - 1;
-
/* should be zero ended, but we are paranoid. */
- s->buffer[s->seq.len] = 0;
+ printbuf_nul_terminate(&s->seq);
printk(KERN_TRACE "%s", s->buffer);
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 154996684fb5..c14f99af79ed 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -290,21 +290,19 @@ int dynevent_arg_add(struct dynevent_cmd *cmd,
struct dynevent_arg *arg,
dynevent_check_arg_fn_t check_arg)
{
- int ret = 0;
-
if (check_arg) {
- ret = check_arg(arg);
+ int ret = check_arg(arg);
if (ret)
return ret;
}
- ret = seq_buf_printf(&cmd->seq, " %s%c", arg->str, arg->separator);
- if (ret) {
+ prt_printf(&cmd->seq, " %s%c", arg->str, arg->separator);
+ if (printbuf_overflowed(&cmd->seq)) {
pr_err("String is too long: %s%c\n", arg->str, arg->separator);
return -E2BIG;
}
- return ret;
+ return 0;
}
/**
@@ -335,25 +333,23 @@ int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
struct dynevent_arg_pair *arg_pair,
dynevent_check_arg_fn_t check_arg)
{
- int ret = 0;
-
if (check_arg) {
- ret = check_arg(arg_pair);
+ int ret = check_arg(arg_pair);
if (ret)
return ret;
}
- ret = seq_buf_printf(&cmd->seq, " %s%c%s%c", arg_pair->lhs,
- arg_pair->operator, arg_pair->rhs,
- arg_pair->separator);
- if (ret) {
+ prt_printf(&cmd->seq, " %s%c%s%c", arg_pair->lhs,
+ arg_pair->operator, arg_pair->rhs,
+ arg_pair->separator);
+ if (printbuf_overflowed(&cmd->seq)) {
pr_err("field string is too long: %s%c%s%c\n", arg_pair->lhs,
arg_pair->operator, arg_pair->rhs,
arg_pair->separator);
return -E2BIG;
}
- return ret;
+ return 0;
}
/**
@@ -368,15 +364,13 @@ int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
*/
int dynevent_str_add(struct dynevent_cmd *cmd, const char *str)
{
- int ret = 0;
-
- ret = seq_buf_puts(&cmd->seq, str);
- if (ret) {
+ prt_str(&cmd->seq, str);
+ if (printbuf_overflowed(&cmd->seq)) {
pr_err("String is too long: %s\n", str);
return -E2BIG;
}
- return ret;
+ return 0;
}
/**
@@ -405,7 +399,7 @@ void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
{
memset(cmd, '\0', sizeof(*cmd));
- seq_buf_init(&cmd->seq, buf, maxlen);
+ cmd->seq = PRINTBUF_EXTERN(buf, maxlen);
cmd->type = type;
cmd->run_command = run_command;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 4b1057ab9d96..9d5137df1a15 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1059,7 +1059,7 @@ static void append_filter_err(struct trace_array *tr,
FILT_ERR_ERRNO, 0);
}
trace_seq_putc(s, 0);
- buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
+ buf = kstrdup(printbuf_str(&s->seq), GFP_KERNEL);
if (buf) {
kfree(filter->filter_string);
filter->filter_string = buf;
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 720c75429c8f..914b4e5e32a5 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1495,7 +1495,7 @@ static int synth_event_run_command(struct dynevent_cmd *cmd)
struct synth_event *se;
int ret;
- ret = create_or_delete_synth_event(cmd->seq.buffer);
+ ret = create_or_delete_synth_event(cmd->seq.buf);
if (ret)
return ret;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 203204cadf92..9f270fdde99b 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -1022,9 +1022,9 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
goto out;
/* Strip ending newline */
- if (s->buffer[s->seq.len - 1] == '\n') {
- s->buffer[s->seq.len - 1] = '\0';
- s->seq.len--;
+ if (s->buffer[s->seq.pos - 1] == '\n') {
+ s->buffer[s->seq.pos - 1] = '\0';
+ s->seq.pos--;
}
trace_seq_puts(s, " */\n");
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 23f7f0ec4f4c..2917d74bc41e 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -919,7 +919,7 @@ static int create_or_delete_trace_kprobe(const char *raw_command)
static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
{
- return create_or_delete_trace_kprobe(cmd->seq.buffer);
+ return create_or_delete_trace_kprobe(printbuf_str(&cmd->seq));
}
/**
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 9c90b3a7dce2..48c08f29c342 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -25,11 +25,9 @@
*/
#include <linux/uaccess.h>
#include <linux/seq_file.h>
+#include <linux/string.h>
#include <linux/trace_seq.h>
-/* How much buffer is left on the trace_seq? */
-#define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq)
-
/*
* trace_seq should work with being initialized with 0s.
*/
@@ -54,7 +52,7 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
__trace_seq_init(s);
- ret = seq_buf_print_seq(m, &s->seq);
+ ret = seq_write(m, s->seq.buf, printbuf_written(&s->seq));
/*
* Only reset this buffer if we successfully wrote to the
@@ -80,7 +78,7 @@ int trace_print_seq(struct seq_file *m, struct trace_seq *s)
*/
void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
va_list ap;
if (s->full)
@@ -89,12 +87,12 @@ void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
__trace_seq_init(s);
va_start(ap, fmt);
- seq_buf_vprintf(&s->seq, fmt, ap);
+ prt_vprintf(&s->seq, fmt, ap);
va_end(ap);
/* If we can't write it all, don't bother writing anything */
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
}
}
@@ -111,17 +109,17 @@ EXPORT_SYMBOL_GPL(trace_seq_printf);
void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
int nmaskbits)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return;
__trace_seq_init(s);
- seq_buf_printf(&s->seq, "%*pb", nmaskbits, maskp);
+ prt_printf(&s->seq, "%*pb", nmaskbits, maskp);
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
}
}
@@ -140,18 +138,18 @@ EXPORT_SYMBOL_GPL(trace_seq_bitmask);
*/
void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return;
__trace_seq_init(s);
- seq_buf_vprintf(&s->seq, fmt, args);
+ prt_vprintf(&s->seq, fmt, args);
/* If we can't write it all, don't bother writing anything */
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
}
}
@@ -174,18 +172,18 @@ EXPORT_SYMBOL_GPL(trace_seq_vprintf);
*/
void trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return;
__trace_seq_init(s);
- seq_buf_bprintf(&s->seq, fmt, binary);
+ prt_bstrprintf(&s->seq, fmt, binary);
/* If we can't write it all, don't bother writing anything */
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(!printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
return;
}
@@ -211,12 +209,12 @@ void trace_seq_puts(struct trace_seq *s, const char *str)
__trace_seq_init(s);
- if (len > TRACE_SEQ_BUF_LEFT(s)) {
+ if (len > printbuf_remaining(&s->seq)) {
s->full = 1;
return;
}
- seq_buf_putmem(&s->seq, str, len);
+ prt_bytes(&s->seq, str, len);
}
EXPORT_SYMBOL_GPL(trace_seq_puts);
@@ -237,12 +235,12 @@ void trace_seq_putc(struct trace_seq *s, unsigned char c)
__trace_seq_init(s);
- if (TRACE_SEQ_BUF_LEFT(s) < 1) {
+ if (!printbuf_remaining(&s->seq)) {
s->full = 1;
return;
}
- seq_buf_putc(&s->seq, c);
+ prt_char(&s->seq, c);
}
EXPORT_SYMBOL_GPL(trace_seq_putc);
@@ -263,12 +261,12 @@ void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len)
__trace_seq_init(s);
- if (len > TRACE_SEQ_BUF_LEFT(s)) {
+ if (len > printbuf_remaining(&s->seq)) {
s->full = 1;
return;
}
- seq_buf_putmem(&s->seq, mem, len);
+ prt_bytes(&s->seq, mem, len);
}
EXPORT_SYMBOL_GPL(trace_seq_putmem);
@@ -285,24 +283,17 @@ EXPORT_SYMBOL_GPL(trace_seq_putmem);
void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
unsigned int len)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return;
__trace_seq_init(s);
- /* Each byte is represented by two chars */
- if (len * 2 > TRACE_SEQ_BUF_LEFT(s)) {
- s->full = 1;
- return;
- }
+ prt_hex_bytes(&s->seq, mem, len, 8, ' ');
- /* The added spaces can still cause an overflow */
- seq_buf_putmem_hex(&s->seq, mem, len);
-
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
return;
}
@@ -323,22 +314,22 @@ EXPORT_SYMBOL_GPL(trace_seq_putmem_hex);
*/
int trace_seq_path(struct trace_seq *s, const struct path *path)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return 0;
__trace_seq_init(s);
- if (TRACE_SEQ_BUF_LEFT(s) < 1) {
+ if (printbuf_remaining(&s->seq) < 1) {
s->full = 1;
return 0;
}
- seq_buf_path(&s->seq, path, "\n");
+ prt_path(&s->seq, path, "\n");
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
return 0;
}
@@ -369,8 +360,25 @@ EXPORT_SYMBOL_GPL(trace_seq_path);
*/
int trace_seq_to_user(struct trace_seq *s, char __user *ubuf, int cnt)
{
+ int ret, len;
+
__trace_seq_init(s);
- return seq_buf_to_user(&s->seq, ubuf, cnt);
+
+ len = printbuf_written(&s->seq);
+ if (len <= s->readpos)
+ return -EBUSY;
+
+ len -= s->readpos;
+ if (cnt > len)
+ cnt = len;
+ ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
+ if (ret == cnt)
+ return -EFAULT;
+
+ cnt -= ret;
+
+ s->readpos += cnt;
+ return cnt;
}
EXPORT_SYMBOL_GPL(trace_seq_to_user);
@@ -378,24 +386,19 @@ int trace_seq_hex_dump(struct trace_seq *s, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
const void *buf, size_t len, bool ascii)
{
- unsigned int save_len = s->seq.len;
+ unsigned int save_pos = s->seq.pos;
if (s->full)
return 0;
__trace_seq_init(s);
- if (TRACE_SEQ_BUF_LEFT(s) < 1) {
- s->full = 1;
- return 0;
- }
-
- seq_buf_hex_dump(&(s->seq), prefix_str,
- prefix_type, rowsize, groupsize,
- buf, len, ascii);
+ prt_hex_dump(&s->seq, buf, len,
+ prefix_str, prefix_type,
+ rowsize, groupsize, ascii);
- if (unlikely(seq_buf_has_overflowed(&s->seq))) {
- s->seq.len = save_len;
+ if (unlikely(printbuf_overflowed(&s->seq))) {
+ s->seq.pos = save_pos;
s->full = 1;
return 0;
}
--
2.35.1
From: Kent Overstreet <[email protected]>
seq_buf is being deprecated, this converts to printbuf.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
---
drivers/input/joystick/analog.c | 23 ++++++++++-------------
1 file changed, 10 insertions(+), 13 deletions(-)
diff --git a/drivers/input/joystick/analog.c b/drivers/input/joystick/analog.c
index 3088c5b829f0..a8c5f90e8208 100644
--- a/drivers/input/joystick/analog.c
+++ b/drivers/input/joystick/analog.c
@@ -19,7 +19,7 @@
#include <linux/input.h>
#include <linux/gameport.h>
#include <linux/jiffies.h>
-#include <linux/seq_buf.h>
+#include <linux/printbuf.h>
#include <linux/timex.h>
#include <linux/timekeeping.h>
@@ -339,24 +339,21 @@ static void analog_calibrate_timer(struct analog_port *port)
static void analog_name(struct analog *analog)
{
- struct seq_buf s;
+ struct printbuf buf = PRINTBUF_EXTERN(analog->name, sizeof(analog->name));
- seq_buf_init(&s, analog->name, sizeof(analog->name));
- seq_buf_printf(&s, "Analog %d-axis %d-button",
- hweight8(analog->mask & ANALOG_AXES_STD),
- hweight8(analog->mask & ANALOG_BTNS_STD) + !!(analog->mask & ANALOG_BTNS_CHF) * 2 +
- hweight16(analog->mask & ANALOG_BTNS_GAMEPAD) + !!(analog->mask & ANALOG_HBTN_CHF) * 4);
+ prt_printf(&buf, "Analog %d-axis %d-button",
+ hweight8(analog->mask & ANALOG_AXES_STD),
+ hweight8(analog->mask & ANALOG_BTNS_STD) + !!(analog->mask & ANALOG_BTNS_CHF) * 2 +
+ hweight16(analog->mask & ANALOG_BTNS_GAMEPAD) + !!(analog->mask & ANALOG_HBTN_CHF) * 4);
if (analog->mask & ANALOG_HATS_ALL)
- seq_buf_printf(&s, " %d-hat",
- hweight16(analog->mask & ANALOG_HATS_ALL));
-
+ prt_printf(&buf, " %d-hat", hweight16(analog->mask & ANALOG_HATS_ALL));
if (analog->mask & ANALOG_HAT_FCS)
- seq_buf_printf(&s, " FCS");
+ prt_printf(&buf, " FCS");
if (analog->mask & ANALOG_ANY_CHF)
- seq_buf_printf(&s, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF");
+ prt_printf(&buf, (analog->mask & ANALOG_SAITEK) ? " Saitek" : " CHF");
- seq_buf_printf(&s, (analog->mask & ANALOG_GAMEPAD) ? " gamepad" : " joystick");
+ prt_printf(&buf, (analog->mask & ANALOG_GAMEPAD) ? " gamepad" : " joystick");
}
/*
--
2.35.1
From: Kent Overstreet <[email protected]>
- We're attempting to consolidate printf_spec and format string
handling in the top level vpr_buf(), this changes ip_addr_string() to
not take printf_spec
- With the new printbuf helpers there's no need to use a separate stack
allocated buffer, so this patch deletes it.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 114 ++++++++++++++++---------------------------------
1 file changed, 37 insertions(+), 77 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index f47f10659737..076e2d23be47 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1276,13 +1276,13 @@ void mac_address_string(struct printbuf *out, u8 *addr,
}
static noinline_for_stack
-void ip4_string(struct printbuf *out,
- const u8 *addr, const char *fmt)
+void ip4_string(struct printbuf *out, const u8 *addr, const char *fmt)
{
- int i;
- bool leading_zeros = (fmt[0] == 'i');
- int index;
- int step;
+ struct printf_spec spec = default_dec_spec;
+ int i, index, step;
+
+ if (fmt[0] == 'i')
+ spec.precision = 3;
switch (fmt[2]) {
case 'h':
@@ -1306,19 +1306,9 @@ void ip4_string(struct printbuf *out,
break;
}
for (i = 0; i < 4; i++) {
- char temp[4] __aligned(2); /* hold each IP quad in reverse order */
- int digits = put_dec_trunc8(temp, addr[index]) - temp;
- if (leading_zeros) {
- if (digits < 3)
- prt_char(out, '0');
- if (digits < 2)
- prt_char(out, '0');
- }
- /* reverse the digits in the quad */
- while (digits--)
- prt_char(out, temp[digits]);
- if (i < 3)
+ if (i)
prt_char(out, '.');
+ number(out, addr[index], spec);
index += step;
}
}
@@ -1401,8 +1391,6 @@ void ip6_compressed_string(struct printbuf *out, const char *addr)
__prt_char(out, ':');
ip4_string(out, &in6.s6_addr[12], "I4");
}
-
- printbuf_nul_terminate(out);
}
static noinline_for_stack
@@ -1420,41 +1408,20 @@ void ip6_string(struct printbuf *out, const char *addr, const char *fmt)
static noinline_for_stack
void ip6_addr_string(struct printbuf *out, const u8 *addr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
- char ip6_addr_buf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
- struct printbuf ip6_addr = PRINTBUF_EXTERN(ip6_addr_buf, sizeof(ip6_addr_buf));
-
if (fmt[0] == 'I' && fmt[2] == 'c')
- ip6_compressed_string(&ip6_addr, addr);
+ ip6_compressed_string(out, addr);
else
- ip6_string(&ip6_addr, addr, fmt);
-
- string_nocheck(out, ip6_addr_buf, spec);
-}
-
-static noinline_for_stack
-void ip4_addr_string(struct printbuf *out, const u8 *addr,
- struct printf_spec spec, const char *fmt)
-{
- char ip4_addr_buf[sizeof("255.255.255.255")];
- struct printbuf ip4_addr = PRINTBUF_EXTERN(ip4_addr_buf, sizeof(ip4_addr_buf));
-
- ip4_string(&ip4_addr, addr, fmt);
-
- string_nocheck(out, ip4_addr_buf, spec);
+ ip6_string(out, addr, fmt);
}
static noinline_for_stack
void ip6_addr_string_sa(struct printbuf *out,
const struct sockaddr_in6 *sa,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
bool have_p = false, have_s = false, have_f = false, have_c = false;
- char ip6_addr_buf[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
- sizeof(":12345") + sizeof("/123456789") +
- sizeof("%1234567890")];
- struct printbuf ip6_addr = PRINTBUF_EXTERN(ip6_addr_buf, sizeof(ip6_addr_buf));
const u8 *addr = (const u8 *) &sa->sin6_addr;
char fmt6[2] = { fmt[0], '6' };
@@ -1477,41 +1444,35 @@ void ip6_addr_string_sa(struct printbuf *out,
}
if (have_p || have_s || have_f)
- prt_char(&ip6_addr, '[');
+ prt_char(out, '[');
if (fmt6[0] == 'I' && have_c)
- ip6_compressed_string(&ip6_addr, addr);
+ ip6_compressed_string(out, addr);
else
- ip6_string(&ip6_addr, addr, fmt6);
+ ip6_string(out, addr, fmt6);
if (have_p || have_s || have_f)
- prt_char(&ip6_addr, ']');
+ prt_char(out, ']');
if (have_p) {
- prt_char(&ip6_addr, ':');
- number(&ip6_addr, ntohs(sa->sin6_port), spec);
+ prt_char(out, ':');
+ prt_u64(out, ntohs(sa->sin6_port));
}
if (have_f) {
- prt_char(&ip6_addr, '/');
- number(&ip6_addr, ntohl(sa->sin6_flowinfo &
- IPV6_FLOWINFO_MASK), spec);
+ prt_char(out, '/');
+ prt_u64(out, ntohl(sa->sin6_flowinfo & IPV6_FLOWINFO_MASK));
}
if (have_s) {
- prt_char(&ip6_addr, '%');
- number(&ip6_addr, sa->sin6_scope_id, spec);
+ prt_char(out, '%');
+ prt_u64(out, sa->sin6_scope_id);
}
-
- string_nocheck(out, ip6_addr_buf, spec);
}
static noinline_for_stack
-void ip4_addr_string_sa(struct printbuf *out,
- const struct sockaddr_in *sa,
- struct printf_spec spec, const char *fmt)
+void ip4_addr_string_sa(struct printbuf *out, const struct sockaddr_in *sa,
+ const char *fmt)
{
bool have_p = false;
- char ip4_addr_buf[sizeof("255.255.255.255") + sizeof(":12345")];
- struct printbuf ip4_addr = PRINTBUF_EXTERN(ip4_addr_buf, sizeof(ip4_addr_buf));
const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
char fmt4[3] = { fmt[0], '4', 0 };
@@ -1530,29 +1491,27 @@ void ip4_addr_string_sa(struct printbuf *out,
}
}
- ip4_string(&ip4_addr, addr, fmt4);
+ ip4_string(out, addr, fmt4);
if (have_p) {
- prt_char(&ip4_addr, ':');
- number(&ip4_addr, ntohs(sa->sin_port), spec);
+ prt_char(out, ':');
+ prt_u64(out, ntohs(sa->sin_port));
}
-
- string_nocheck(out, ip4_addr_buf, spec);
}
static noinline_for_stack
void ip_addr_string(struct printbuf *out, const void *ptr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
char *err_fmt_msg;
- if (check_pointer_spec(out, ptr, spec))
+ if (check_pointer(out, ptr))
return;
switch (fmt[1]) {
case '6':
- return ip6_addr_string(out, ptr, spec, fmt);
+ return ip6_addr_string(out, ptr, fmt);
case '4':
- return ip4_addr_string(out, ptr, spec, fmt);
+ return ip4_string(out, ptr, fmt);
case 'S': {
const union {
struct sockaddr raw;
@@ -1562,16 +1521,16 @@ void ip_addr_string(struct printbuf *out, const void *ptr,
switch (sa->raw.sa_family) {
case AF_INET:
- return ip4_addr_string_sa(out, &sa->v4, spec, fmt);
+ return ip4_addr_string_sa(out, &sa->v4, fmt);
case AF_INET6:
- return ip6_addr_string_sa(out, &sa->v6, spec, fmt);
+ return ip6_addr_string_sa(out, &sa->v6, fmt);
default:
- return error_string_spec(out, "(einval)", spec);
+ return error_string(out, "(einval)");
}}
}
err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
- return error_string_spec(out, err_fmt_msg, spec);
+ error_string(out, err_fmt_msg);
}
static noinline_for_stack
@@ -2318,7 +2277,8 @@ void pointer(struct printbuf *out, const char *fmt,
* 4: 001.002.003.004
* 6: 000102...0f
*/
- return ip_addr_string(out, ptr, spec, fmt);
+ ip_addr_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'E':
return escaped_string(out, ptr, spec, fmt);
case 'U':
--
2.35.1
From: Kent Overstreet <[email protected]>
This converts from seq_buf to printbuf.
This code was using seq_buf for building up dynamically allocated
strings; the conversion uses printbuf's heap allocation functionality to
simplify things (no longer need to calculate size of the output string).
Also, alphabetize the #includes.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
---
kernel/trace/trace_events_synth.c | 51 ++++++++++---------------------
1 file changed, 16 insertions(+), 35 deletions(-)
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 5e8c07aef071..720c75429c8f 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -5,13 +5,14 @@
* Copyright (C) 2015, 2020 Tom Zanussi <[email protected]>
*/
-#include <linux/module.h>
#include <linux/kallsyms.h>
-#include <linux/security.h>
+#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/printbuf.h>
+#include <linux/rculist.h>
+#include <linux/security.h>
#include <linux/slab.h>
#include <linux/stacktrace.h>
-#include <linux/rculist.h>
#include <linux/tracefs.h>
/* for gfp flag names */
@@ -611,7 +612,7 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
struct synth_field *field;
int len, ret = -ENOMEM;
- struct seq_buf s;
+ struct printbuf buf;
ssize_t size;
if (!strcmp(field_type, "unsigned")) {
@@ -654,28 +655,16 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
goto free;
}
- len = strlen(field_type) + 1;
-
- if (array)
- len += strlen(array);
-
- if (prefix)
- len += strlen(prefix);
-
- field->type = kzalloc(len, GFP_KERNEL);
- if (!field->type)
- goto free;
-
- seq_buf_init(&s, field->type, len);
+ buf = PRINTBUF;
if (prefix)
- seq_buf_puts(&s, prefix);
- seq_buf_puts(&s, field_type);
+ prt_str(&buf, prefix);
+ prt_str(&buf, field_type);
if (array)
- seq_buf_puts(&s, array);
- if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
+ prt_str(&buf, array);
+ if (buf.allocation_failure)
goto free;
- s.buffer[s.len] = '\0';
+ field->type = buf.buf;
size = synth_field_size(field->type);
if (size < 0) {
@@ -687,23 +676,15 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
goto free;
} else if (size == 0) {
if (synth_field_is_string(field->type)) {
- char *type;
-
- len = sizeof("__data_loc ") + strlen(field->type) + 1;
- type = kzalloc(len, GFP_KERNEL);
- if (!type)
- goto free;
-
- seq_buf_init(&s, type, len);
- seq_buf_puts(&s, "__data_loc ");
- seq_buf_puts(&s, field->type);
+ buf = PRINTBUF;
+ prt_str(&buf, "__data_loc ");
+ prt_str(&buf, field->type);
- if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
+ if (buf.allocation_failure)
goto free;
- s.buffer[s.len] = '\0';
kfree(field->type);
- field->type = type;
+ field->type = buf.buf;
field->is_dynamic = true;
size = sizeof(u64);
--
2.35.1
From: Kent Overstreet <[email protected]>
- We're attempting to consolidate printf_spec and format string
handling in the top level ptr_vprintf(), this changes
mac_address_string() to not take printf_spec
- With the new printbuf helpers there's no need to use a separate stack
allocated buffer, so this patch deletes it.
Signed-off-by: Kent Overstreet <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
---
lib/vsprintf.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 076e2d23be47..2042c17f571e 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1236,15 +1236,13 @@ void bitmap_list_string(struct printbuf *out, unsigned long *bitmap,
static noinline_for_stack
void mac_address_string(struct printbuf *out, u8 *addr,
- struct printf_spec spec, const char *fmt)
+ const char *fmt)
{
- char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
- char *p = mac_addr;
int i;
char separator;
bool reversed = false;
- if (check_pointer_spec(out, addr, spec))
+ if (check_pointer(out, addr))
return;
switch (fmt[1]) {
@@ -1263,16 +1261,13 @@ void mac_address_string(struct printbuf *out, u8 *addr,
for (i = 0; i < 6; i++) {
if (reversed)
- p = hex_byte_pack(p, addr[5 - i]);
+ prt_hex_byte(out, addr[5 - i]);
else
- p = hex_byte_pack(p, addr[i]);
+ prt_hex_byte(out, addr[i]);
if (fmt[0] == 'M' && i != 5)
- *p++ = separator;
+ prt_char(out, separator);
}
- *p = '\0';
-
- string_nocheck(out, mac_addr, spec);
}
static noinline_for_stack
@@ -2267,7 +2262,8 @@ void pointer(struct printbuf *out, const char *fmt,
case 'm': /* Contiguous: 000102030405 */
/* [mM]F (FDDI) */
/* [mM]R (Reverse order; Bluetooth) */
- return mac_address_string(out, ptr, spec, fmt);
+ mac_address_string(out, ptr, fmt);
+ return do_width_precision(out, prev_pos, spec);
case 'I': /* Formatted IP supported
* 4: 1.2.3.4
* 6: 0001:0203:...:0708
--
2.35.1
On Mon, Aug 08, 2022 at 03:41:25AM +0100, Matthew Wilcox (Oracle) wrote:
> From: Kent Overstreet <[email protected]>
>
> This implements a new printbuf version of d_path()/mangle_path(), which
> will replace the seq_buf version.
>
> Part of what we're trying to do with printbufs is standardizing a
> calling convention so they don't have to live in lib/vsprintf.c, and can
> instead with the code for the types they're printing - so this patch
> adds prt_path() to d_path.c, another patch will switch vsprintf.c to use
> it.
To use it for *what*? If you mean replacing %pd with it - forget about that.
Not going to happen.
There's a hard requirement for printk - it should be safe to call in any
locking environment. d_path() isn't, and that's impossible to avoid.
On 8/8/22 00:17, Al Viro wrote:
> On Mon, Aug 08, 2022 at 03:41:25AM +0100, Matthew Wilcox (Oracle) wrote:
>> From: Kent Overstreet <[email protected]>
>>
>> This implements a new printbuf version of d_path()/mangle_path(), which
>> will replace the seq_buf version.
>>
>> Part of what we're trying to do with printbufs is standardizing a
>> calling convention so they don't have to live in lib/vsprintf.c, and can
>> instead with the code for the types they're printing - so this patch
>> adds prt_path() to d_path.c, another patch will switch vsprintf.c to use
>> it.
>
> To use it for *what*? If you mean replacing %pd with it - forget about that.
> Not going to happen.
>
> There's a hard requirement for printk - it should be safe to call in any
> locking environment. d_path() isn't, and that's impossible to avoid.
Oof, good catch. It was to replace seq_buf_path() in this patch series,
and is only used in trace_seq.c. I'll have to investigate what's going
on in the tracing code, because now that you mention it that did look
suspect.
On Mon 08-08-22 03:41:18, Matthew Wilcox wrote:
> From: Kent Overstreet <[email protected]>
>
> This converts memory_stat_format() from seq_buf to printbuf. Printbuf is
> simalar to seq_buf except that it heap allocates the string buffer:
> here, we were already heap allocating the buffer with kmalloc() so the
> conversion is trivial.
The changelog probably needs an update because the oom path doesn't
allocated and for somebody just reading this patch in isolation the
PRINTBUF_EXTERN doesn't really seem very obvious.
> Signed-off-by: Kent Overstreet <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> -static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
> +static void memory_stat_format(struct printbuf *out, struct mem_cgroup *memcg)
> {
> - struct seq_buf s;
> int i;
>
> - seq_buf_init(&s, buf, bufsize);
> -
When is the buffer cleared?
> /*
> * Provide statistics on the state of the memory subsystem as
> * well as cumulative event counters that show past behavior.
[...]
> #define K(x) ((x) << (PAGE_SHIFT-10))
> @@ -1573,7 +1570,8 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *
> void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
> {
> /* Use static buffer, for the caller is holding oom_lock. */
> - static char buf[PAGE_SIZE];
> + static char _buf[PAGE_SIZE];
> + struct printbuf buf = PRINTBUF_EXTERN(_buf, sizeof(_buf));
>
> lockdep_assert_held(&oom_lock);
the buffer is static here!
>
--
Michal Hocko
SUSE Labs
On Mon, Aug 8, 2022 at 4:41 AM Matthew Wilcox (Oracle)
<[email protected]> wrote:
>
> From: Kent Overstreet <[email protected]>
>
> Like the upcoming vsprintf.c conversion, this converts string_escape_mem
> to prt_escaped_string(), which uses and outputs to a printbuf, and makes
> string_escape_mem() a smaller wrapper to support existing users.
>
> The new printbuf helpers greatly simplify the code.
...
> struct device;
> struct file;
> struct task_struct;
> +struct printbuf;
Keep it ordered?
...
> @@ -71,6 +74,7 @@ static inline int string_escape_mem_any_np(const char *src, size_t isz,
> return string_escape_mem(src, isz, dst, osz, ESCAPE_ANY_NP, only);
> }
>
> +
> static inline int string_escape_str(const char *src, char *dst, size_t sz,
> unsigned int flags, const char *only)
> {
Stray change.
...
> if (!(is_append || in_dict) && is_dict &&
> - escape_passthrough(c, &p, end))
> + escape_passthrough(out, c))
That (a bit strange) indentation is on purpose. Can we keep it?
> continue;
...
Not sure if the below was in the original text, but maybe it makes
sense to amend.
> + * Description:
> + * The process of escaping byte buffer includes several parts. They are applied
a byte in the buffer (?)
> + * in the following sequence.
> + *
> + * 1. The character is not matched to the one from @only string and thus
> + * must go as-is to the output.
> + * 2. The character is matched to the printable and ASCII classes, if asked,
> + * and in case of match it passes through to the output.
> + * 3. The character is matched to the printable or ASCII class, if asked,
> + * and in case of match it passes through to the output.
> + * 4. The character is checked if it falls into the class given by @flags.
> + * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
> + * character. Note that they actually can't go together, otherwise
> + * %ESCAPE_HEX will be ignored.
> + *
> + * Caller must provide valid source and destination pointers. Be aware that
> + * destination buffer will not be NULL-terminated, thus caller have to append
the caller has
> + * it if needs. The supported flags are::
if needed.
--
With Best Regards,
Andy Shevchenko
On Mon 08-08-22 11:48:53, Michal Hocko wrote:
> On Mon 08-08-22 03:41:18, Matthew Wilcox wrote:
> > From: Kent Overstreet <[email protected]>
> >
> > This converts memory_stat_format() from seq_buf to printbuf. Printbuf is
> > simalar to seq_buf except that it heap allocates the string buffer:
> > here, we were already heap allocating the buffer with kmalloc() so the
> > conversion is trivial.
>
> The changelog probably needs an update because the oom path doesn't
> allocated and for somebody just reading this patch in isolation the
> PRINTBUF_EXTERN doesn't really seem very obvious.
>
> > Signed-off-by: Kent Overstreet <[email protected]>
> > Cc: Johannes Weiner <[email protected]>
> > Cc: Michal Hocko <[email protected]>
> > Cc: Roman Gushchin <[email protected]>
>
> > -static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
> > +static void memory_stat_format(struct printbuf *out, struct mem_cgroup *memcg)
> > {
> > - struct seq_buf s;
> > int i;
> >
> > - seq_buf_init(&s, buf, bufsize);
> > -
>
> When is the buffer cleared?
>
> > /*
> > * Provide statistics on the state of the memory subsystem as
> > * well as cumulative event counters that show past behavior.
> [...]
> > #define K(x) ((x) << (PAGE_SHIFT-10))
> > @@ -1573,7 +1570,8 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *
> > void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
> > {
> > /* Use static buffer, for the caller is holding oom_lock. */
> > - static char buf[PAGE_SIZE];
> > + static char _buf[PAGE_SIZE];
> > + struct printbuf buf = PRINTBUF_EXTERN(_buf, sizeof(_buf));
> >
> > lockdep_assert_held(&oom_lock);
>
> the buffer is static here!
And answering to myself. THere is an internal pos field which gets
initialized by PRINTBUF_EXTERN even when not mentioned explicitly
because it gets a default 0 initialization
Acked-by: Michal Hocko <[email protected]>
--
Michal Hocko
SUSE Labs
On Mon, Aug 8, 2022 at 4:41 AM Matthew Wilcox (Oracle)
<[email protected]> wrote:
>
> From: Kent Overstreet <[email protected]>
>
> printbuf now needs to know the number of characters that would have been
> written if the buffer was too small, like snprintf(); this changes
> string_get_size() to return the the return value of snprintf().
the the --> the
Acked-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Kent Overstreet <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> ---
> include/linux/string_helpers.h | 4 ++--
> lib/string_helpers.c | 7 +++----
> 2 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
> index 67de398944e8..52e0f1d283b9 100644
> --- a/include/linux/string_helpers.h
> +++ b/include/linux/string_helpers.h
> @@ -19,8 +19,8 @@ enum string_size_units {
> STRING_UNITS_2, /* use binary powers of 2^10 */
> };
>
> -void string_get_size(u64 size, u64 blk_size, enum string_size_units units,
> - char *buf, int len);
> +int string_get_size(u64 size, u64 blk_size, enum string_size_units units,
> + char *buf, int len);
>
> #define UNESCAPE_SPACE BIT(0)
> #define UNESCAPE_OCTAL BIT(1)
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index 7be20bcc6137..d247bf945f16 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -33,8 +33,8 @@
> * at least 9 bytes and will always be zero terminated.
> *
> */
> -void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
> - char *buf, int len)
> +int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
> + char *buf, int len)
> {
> static const char *const units_10[] = {
> "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
> @@ -127,8 +127,7 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
> else
> unit = units_str[units][i];
>
> - snprintf(buf, len, "%u%s %s", (u32)size,
> - tmp, unit);
> + return snprintf(buf, len, "%u%s %s", (u32)size, tmp, unit);
> }
> EXPORT_SYMBOL(string_get_size);
>
> --
> 2.35.1
>
--
With Best Regards,
Andy Shevchenko
On Mon, Aug 8, 2022 at 4:41 AM Matthew Wilcox (Oracle)
<[email protected]> wrote:
>
> From: Kent Overstreet <[email protected]>
>
> The upcoming patch to switch tracing from seq_buf to printbuf means
> we're no longer pulling in headers that we used to; this adds a missing
> include so things don't break.
>
> Signed-off-by: Kent Overstreet <[email protected]>
> Cc: [email protected]
Acked-by: Rafael J. Wysocki <[email protected]>
> ---
> drivers/acpi/apei/erst-dbg.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c
> index 8bc71cdc2270..370993c9c381 100644
> --- a/drivers/acpi/apei/erst-dbg.c
> +++ b/drivers/acpi/apei/erst-dbg.c
> @@ -11,6 +11,7 @@
> * Author: Huang Ying <[email protected]>
> */
>
> +#include <linux/fs.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/uaccess.h>
> --
> 2.35.1
>
On 8/8/22 08:03, Andy Shevchenko wrote:
> On Mon, Aug 8, 2022 at 4:41 AM Matthew Wilcox (Oracle)
> <[email protected]> wrote:
>>
>> From: Kent Overstreet <[email protected]>
>>
>> Like the upcoming vsprintf.c conversion, this converts string_escape_mem
>> to prt_escaped_string(), which uses and outputs to a printbuf, and makes
>> string_escape_mem() a smaller wrapper to support existing users.
>>
>> The new printbuf helpers greatly simplify the code.
>
> ...
>
>> struct device;
>> struct file;
>> struct task_struct;
>> +struct printbuf;
>
> Keep it ordered?
I generally try to keep my #includes alphabetized, missed this :)
>
> ...
>
>> @@ -71,6 +74,7 @@ static inline int string_escape_mem_any_np(const char *src, size_t isz,
>> return string_escape_mem(src, isz, dst, osz, ESCAPE_ANY_NP, only);
>> }
>>
>> +
>> static inline int string_escape_str(const char *src, char *dst, size_t sz,
>> unsigned int flags, const char *only)
>> {
>
> Stray change.
Fixed
> ...
>
>> if (!(is_append || in_dict) && is_dict &&
>> - escape_passthrough(c, &p, end))
>> + escape_passthrough(out, c))
>
> That (a bit strange) indentation is on purpose. Can we keep it?
Yep, done
>> continue;
>
> ...
>
> Not sure if the below was in the original text, but maybe it makes
> sense to amend.
>
>> + * Description:
>> + * The process of escaping byte buffer includes several parts. They are applied
>
> a byte in the buffer (?)
See below
>
>> + * in the following sequence.
>> + *
>> + * 1. The character is not matched to the one from @only string and thus
>> + * must go as-is to the output.
>> + * 2. The character is matched to the printable and ASCII classes, if asked,
>> + * and in case of match it passes through to the output.
>> + * 3. The character is matched to the printable or ASCII class, if asked,
>> + * and in case of match it passes through to the output.
>> + * 4. The character is checked if it falls into the class given by @flags.
>> + * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
>> + * character. Note that they actually can't go together, otherwise
>> + * %ESCAPE_HEX will be ignored.
>> + *
>> + * Caller must provide valid source and destination pointers. Be aware that
>> + * destination buffer will not be NULL-terminated, thus caller have to append
>
> the caller has
Yeah I'm actually not changing the function comment for
string_escape_mem(), that's just git getting confused since I reused
most of it for prt_escaped_mem(). I'll leave any fixups for that for you
if that's ok - the docs look clear enough to me.
Cheers
On Mon, Aug 08, 2022 at 03:41:23AM +0100, Matthew Wilcox (Oracle) wrote:
> From: Kent Overstreet <[email protected]>
>
> This converts from seq_buf to printbuf. We're using printbuf in external
> buffer mode, so it's a direct conversion, aside from some trivial
> refactoring in cpu_show_meltdown() to make the code more consistent.
I don't object to the patch, but it would be nice if the commit log
hinted at what the advantage is. I assume it's faster/safer/better in
some way, but I have no idea what.
Also, cpu_show_meltdown() doesn't appear in this patch, so maybe
that's relevant to some other patch but not this one?
> Signed-off-by: Kent Overstreet <[email protected]>
> Cc: [email protected]
> ---
> drivers/pci/p2pdma.c | 21 ++++++++-------------
> 1 file changed, 8 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index 4496a7c5c478..8e29e7cabad3 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -18,7 +18,7 @@
> #include <linux/memremap.h>
> #include <linux/percpu-refcount.h>
> #include <linux/random.h>
> -#include <linux/seq_buf.h>
> +#include <linux/printbuf.h>
> #include <linux/xarray.h>
>
> struct pci_p2pdma {
> @@ -275,12 +275,9 @@ static int pci_bridge_has_acs_redir(struct pci_dev *pdev)
> return 0;
> }
>
> -static void seq_buf_print_bus_devfn(struct seq_buf *buf, struct pci_dev *pdev)
> +static void prt_bus_devfn(struct printbuf *buf, struct pci_dev *pdev)
> {
> - if (!buf)
> - return;
> -
> - seq_buf_printf(buf, "%s;", pci_name(pdev));
> + prt_printf(buf, "%s;", pci_name(pdev));
> }
>
> static bool cpu_supports_p2pdma(void)
> @@ -454,13 +451,11 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
> struct pci_dev *a = provider, *b = client, *bb;
> bool acs_redirects = false;
> struct pci_p2pdma *p2pdma;
> - struct seq_buf acs_list;
> int acs_cnt = 0;
> int dist_a = 0;
> int dist_b = 0;
> char buf[128];
> -
> - seq_buf_init(&acs_list, buf, sizeof(buf));
> + struct printbuf acs_list = PRINTBUF_EXTERN(buf, sizeof(buf));
>
> /*
> * Note, we don't need to take references to devices returned by
> @@ -471,7 +466,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
> dist_b = 0;
>
> if (pci_bridge_has_acs_redir(a)) {
> - seq_buf_print_bus_devfn(&acs_list, a);
> + prt_bus_devfn(&acs_list, a);
> acs_cnt++;
> }
>
> @@ -500,7 +495,7 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
> break;
>
> if (pci_bridge_has_acs_redir(bb)) {
> - seq_buf_print_bus_devfn(&acs_list, bb);
> + prt_bus_devfn(&acs_list, bb);
> acs_cnt++;
> }
>
> @@ -515,11 +510,11 @@ calc_map_type_and_dist(struct pci_dev *provider, struct pci_dev *client,
> }
>
> if (verbose) {
> - acs_list.buffer[acs_list.len-1] = 0; /* drop final semicolon */
> + acs_list.buf[acs_list.pos-1] = 0; /* drop final semicolon */
> pci_warn(client, "ACS redirect is set between the client and provider (%s)\n",
> pci_name(provider));
> pci_warn(client, "to disable ACS redirect for this path, add the kernel parameter: pci=disable_acs_redir=%s\n",
> - acs_list.buffer);
> + acs_list.buf);
> }
> acs_redirects = true;
>
> --
> 2.35.1
>
On 8/8/22 14:30, Dan Williams wrote:
> Matthew Wilcox (Oracle) wrote:
>> From: Kent Overstreet <[email protected]>
>>
>> This converts from seq_buf to printbuf. Here we're using printbuf with
>> an external buffer, meaning it's a direct conversion.
>>
>> Signed-off-by: Kent Overstreet <[email protected]>
>> Cc: Dan Williams <[email protected]>
>> Cc: Dave Hansen <[email protected]>
>> Cc: [email protected]
>
> My Acked-by still applies:
>
> https://lore.kernel.org/all/[email protected]/
>
> ...and Shivaprasad's Tested-by should still apply:
>
> https://lore.kernel.org/all/[email protected]/
Whoops - got them now, thanks!
Matthew Wilcox (Oracle) wrote:
> From: Kent Overstreet <[email protected]>
>
> This converts from seq_buf to printbuf. Here we're using printbuf with
> an external buffer, meaning it's a direct conversion.
>
> Signed-off-by: Kent Overstreet <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: [email protected]
My Acked-by still applies:
https://lore.kernel.org/all/[email protected]/
...and Shivaprasad's Tested-by should still apply:
https://lore.kernel.org/all/[email protected]/
On 8/8/22 13:51, Bjorn Helgaas wrote:
> I don't object to the patch, but it would be nice if the commit log
> hinted at what the advantage is. I assume it's faster/safer/better in
> some way, but I have no idea what.
Printbufs have some additional features over seq_buf but they're not
used here. The main one you might be interested in is heap allocation:
that means no need to statically allocate buffers on the stack and no
need to calculate the buffer size, printbufs will reallocate as necessary.
I generally haven't been converting code to use that unless it's obvious
that we're in a context where it's safe to allocate memory and can deal
with allocation failures.
I notice that in calc_map_type_and_dist() you're using xa_store() which
can fail, but you're not checking for that or returning errors properly
:) perhaps a fix for that could also switch to using printbuf in
heap-allocation mode.
> Also, cpu_show_meltdown() doesn't appear in this patch, so maybe
> that's relevant to some other patch but not this one?
Whoops, was copying the commit message from another patch, yeah.n
On Mon, Aug 08, 2022 at 02:42:03PM -0400, Kent Overstreet wrote:
> On 8/8/22 13:51, Bjorn Helgaas wrote:
> > I don't object to the patch, but it would be nice if the commit log
> > hinted at what the advantage is. I assume it's faster/safer/better in
> > some way, but I have no idea what.
>
> Printbufs have some additional features over seq_buf but they're not used
> here. The main one you might be interested in is heap allocation: that means
> no need to statically allocate buffers on the stack and no need to calculate
> the buffer size, printbufs will reallocate as necessary.
This doesn't tell me what the advantage of this patch is, since I
don't think *this* patch uses heap allocation.
As far as I can tell, this particular patch doesn't improve safety or
readability, so "convert X to Y even though we don't use any fancy Y
features" is a pointless message.
But if printbufs are better than seq_buf overall, and converting this
gets us closer to the goal of removing seq_buf completely, that's a
perfectly acceptable reason. Just say that.
> I generally haven't been converting code to use that unless it's obvious
> that we're in a context where it's safe to allocate memory and can deal with
> allocation failures.
>
> I notice that in calc_map_type_and_dist() you're using xa_store() which can
> fail, but you're not checking for that or returning errors properly :)
> perhaps a fix for that could also switch to using printbuf in
> heap-allocation mode.
>
> > Also, cpu_show_meltdown() doesn't appear in this patch, so maybe
> > that's relevant to some other patch but not this one?
>
> Whoops, was copying the commit message from another patch, yeah.n
On Mon, Aug 08, 2022 at 09:07:34PM -0500, Bjorn Helgaas wrote:
> This doesn't tell me what the advantage of this patch is, since I
> don't think *this* patch uses heap allocation.
>
> As far as I can tell, this particular patch doesn't improve safety or
> readability, so "convert X to Y even though we don't use any fancy Y
> features" is a pointless message.
>
> But if printbufs are better than seq_buf overall, and converting this
> gets us closer to the goal of removing seq_buf completely, that's a
> perfectly acceptable reason. Just say that.
Which still brings me back to a point made long time ago: Why are
we doing the renaming to start with? Add the new functionality and
or changes to seq_buf gradually instead of doing a tree wide sweep.
I don't think the new naming has a huge advantage (in fact I think
the old one actually is a little better, but the biggest argument here
really is to not change something if we don't have to).
That will massively reduce the churn at the cost of Kent having to
rework the code a bit, but that seems like a worthwhile tradeoff and
one that we've usuall made in the past.
On Mon, Aug 08, 2022 at 03:41:17AM +0100, Matthew Wilcox (Oracle) wrote:
> From: Kent Overstreet <[email protected]>
>
> seq_buf is being deprecated, this converts to printbuf.
>
> Signed-off-by: Kent Overstreet <[email protected]>
Acked-by: Dmitry Torokhov <[email protected]>
Thanks.
--
Dmitry
On Mon 2022-08-08 03:40:56, Matthew Wilcox (Oracle) wrote:
> [all this code is from Kent, I'm helping him out because he's having
> trouble with git send-email and OAUTH]
>
> This should (hopefully) be the final iteration of this patch series.
>
> Previous discussion:
> https://lore.kernel.org/linux-mm/[email protected]/
>
> Changes since v4:
>
> - %pf(%p) format extension has been dropped for now, since it turned out to be
> a bit controversial. I think we're going to want it, but I'm leaving it for a
> future patch series.
> - There was a small off by one error in the patch converting
> trace_events_synth. The original code using seq_buf had to calculate the size
> of the string to allocate; since printbufs have native support for heap
> allocating strings, the version of the patch in this series just uses that
> for a nice cleanup.
>
> What are printbufs, and why?
> ============================
>
> Printbufs are like the existing seq_buf, with some differences and new features:
>
> - Heap allocation (optional)
>
> Currently, we have no standard mechanism for printing to a heap-allocated
> string: code that needs to do this must calculate the size of the buffer to
> allocate, which is tedious and error prone. IOW, this is a major ergonomic
> improvement.
>
> - Indent level
>
> Any time we're printing structured multi-line data, proper indenting makes
> the output considerably more readable. Printbufs have state for the current
> indent level, controlled by printbuf_indent_add() and printbuf_indent_sub()
> and obeyed by prt_newline().
>
> In the future this may work with just \n, pending work to do this without
> performance regressions.
>
> - Tab stops
>
> Printing reports with nicely aligned columns is something we do a _lot_, and
> printbufs make this a lot easier. After setting tabstops (byte offsets from
> start of line), prt_tab() will output spaces up to the next tabstop, and
> pr_tab_rjust() will right justify output since the previous output against
> the next tabstap.
>
> In the future this may work with just \t, pending work to do this without
> performance regressions.
The more I think about this patchset the more doubts I have.
My first reaction was rather positive because
1. __prt_char(out, c)
looks more safe and sane than repeating the following code
pattern in vsprintf code
if (buf < end)
*buf = '0';
++buf;
2. printk("%pf", meaningful_function_name(ptr))
is more user friendly, extendable. With a type check,
it might be even more safe than
printk("%pxyz", ptr);
3. pretty print API would allow to avoid some tricky use of
temporary buffers in vsprintf code, for example, see
https://lore.kernel.org/r/[email protected]
What are the concerns?
It seems that the motivation for the pretty print is to allow
printing more pretty/fancy multi-line debug messages. The API
should be usable inside vsprintf.c and also outside.
1. vsprintf() is very important core API. It is used (not only for)
when kernel wants to provide a human readable feedback, for
example, via printk(), trace_printk(), procfs, sysfs, debugfs.
If a bug in vsprintf() blocks printk()/trace_printk() then
crash_dump might be the only way to debug the kernel.
2. My experience with printk() is that external APIs are big source of
problems. Some of them are even solved by hacks, for example:
+ Console drivers have to check oops_in_progress before taking
port->lock to prevent a deadlock.
+ printk_deferred() or printk_once() have to be used by code that
might be called by printk().
This patchset adds another external API.
The %pf feature allows writing crazy callbacks called inside
vsprintf()/printk() without any proper review and self-tests.
People would want to extend the pretty print API for a
profs/sysfs/debugfs use-case. They would take it easily.
There is a lower risk in this case because only a particular
file is affected, the API is called in a well defined context.
But it looks like a call for problems if we allow to call
the same complicated code also from vsprintf() or printk()
in any context.
3. Features usually complicate the code immediately or later.
For example, the record based ring buffer complicated the printk()
code a lot. It introduced many regressions. Development of the
lockless variant was a real challenge. And it did not solve
everything. Peple still complain that pr_cont() is not reliable.
Multi-line output might be mixed, ...
The pretty print API is actually designed for multi-line output.
But it will not help when used with printk() that uses 1k buffers
internally. And adding support for "unlimited" printk() messages
would be another challenge. It would bring new problems,
for example, one printk() caller might block others for too long, ...
Any opinion is really appreciated.
Best Regards,
Petr
PS: I am sorry that I did not react on this patchset for months. I was
overloaded, sick twice, and had vacation.
A more detailed review of the patchset would help me to have
stronger opinion about it. I am not clever and experienced enough
to see all the consequences on the first look.
On 9/23/22 03:10, Petr Mladek wrote:
> It seems that the motivation for the pretty print is to allow
> printing more pretty/fancy multi-line debug messages. The API
> should be usable inside vsprintf.c and also outside.
>
> 1. vsprintf() is very important core API. It is used (not only for)
> when kernel wants to provide a human readable feedback, for
> example, via printk(), trace_printk(), procfs, sysfs, debugfs.
>
> If a bug in vsprintf() blocks printk()/trace_printk() then
> crash_dump might be the only way to debug the kernel.
All the more reason for that code to be written with safe APIs, wouldn't
you say?
> 2. My experience with printk() is that external APIs are big source of
> problems. Some of them are even solved by hacks, for example:
>
> + Console drivers have to check oops_in_progress before taking
> port->lock to prevent a deadlock.
>
> + printk_deferred() or printk_once() have to be used by code that
> might be called by printk().
>
> This patchset adds another external API.
We should differentiate between sprintf and printk.
sprintf is _just_ for formatting strings, it doesn't have the same
concerns as printk re: locking the output buffer - or any locking
concerns whatsover, it's a pure function that doesn't mutate outside
system state.
This patch series is about introducing a safe common API for sprintf and
other code that outputs to strings, and I'd also note that even Linus
agreed on the need for such an API, because it gets rid of the separate
stack-allocated buffers that have been a problem in the past.
There's no impact on printk. The extra feature that printbufs add - heap
allocation - isn't used by printk.
> The %pf feature allows writing crazy callbacks called inside
> vsprintf()/printk() without any proper review and self-tests.
I came to similar conclusions about %pf after the discussion with Linus;
that part has been dropped from the patch set for now.
I do think we can do it safely in the future, and in the meantime it
_may_ be worthwhile for use in a much more limited - probably not, I'd
rather hold off and do it right. But since it hasn't been in the patch
set the last few times I posted it, let's leave this out of the discussion.
(I think the way to make it safe will be to output to a heap allocated
buffer instead of the printk buffer directly; however, that's not an
option currently because we'd need to plumb through a gfp flags
parameter and obviously we're not going to do that to printk. However,
we're looking at switching from gfp flags to the memalloc_*() API, which
would make this work).
> People would want to extend the pretty print API for a
> profs/sysfs/debugfs use-case. They would take it easily.
> There is a lower risk in this case because only a particular
> file is affected, the API is called in a well defined context.
> But it looks like a call for problems if we allow to call
> the same complicated code also from vsprintf() or printk()
> in any context.
Since %pf isn't getting added, this isn't a concern.
_But_, introducing a common API so that we can use the same code for
outputting to the system console, or procfs, or debugfs, is precisely
what this is all about! We've got a fair amount of code duplication
(some of which this patch series addresses; see the hexdump patches)
because of this lack of a common API - often messily, with subtle
differences for absolutely no reason.
We _want_ common, reusable, generic code.
Without %pf, to use printbuf code for outputting to the console the
standard approach is going to be something like
struct printbuf buf = PRINTBUF;
prt_foo(&buf, foo);
printk("%s\n", buf.buf);
printbuf_exit(&buf);
Obviously, this isn't the greatest ergonomic-wise, %pf would be better
in that respect. But this is still quite a bit better than completely
duplicated code - one for outputting to a seq_buf, another set for
seq_file, another for printk()...
I also have a patch series in the works for a printbuf based replacement
for seq_file - eliminating that API fragmentation as well. I've just
been waiting for movement on this patch series...
> 3. Features usually complicate the code immediately or later.
>
> For example, the record based ring buffer complicated the printk()
> code a lot. It introduced many regressions. Development of the
> lockless variant was a real challenge. And it did not solve
> everything. Peple still complain that pr_cont() is not reliable.
> Multi-line output might be mixed, ...
I'm not seeing the complications this patch series introduces in its
current form. There's heap allocation, which replaces open-coded output
buffer allocation that's currently done all over the place. And there's
tabstops and indenting; given the amount of columnar data presented in
procfs and debugfs, I think those are reasonable additions.
In return, you get a whole ton of code that was previously using raw
pointer arithmetic converted to safe APIs, and we have a start on
standardizing a lot of different code on a common API.
And, the sprintf code ends up a whole lot more readable and easier to
work on.
> The pretty print API is actually designed for multi-line output.
> But it will not help when used with printk() that uses 1k buffers
> internally. And adding support for "unlimited" printk() messages
> would be another challenge. It would bring new problems,
> for example, one printk() caller might block others for too long, ...
I'm not seeing that this is a real difficulty, since we're not doing %pf
at this time.
- add a printk_string_as_lines(), which takes a string buffer (not a
format string) and calls printk() on it one line at a time. This would
be an easy way around the current 1k buffer.
- or, if the printk code wants to keep the output lines together and
not have them interspersed with other output, that should be easier when
we're presenting you the output already formatted and all you need to do
is memcpy().
Basically, we've got broad agreement that calling arbitrary
pretty-printers from printk() context is a bad idea, so since we won't
be doing that this looks like a non-issue to me as well.
> A more detailed review of the patchset would help me to have
> stronger opinion about it. I am not clever and experienced enough
> to see all the consequences on the first look.
There's really not a lot in the way of functional changes, since %pf has
been dropped - it's just refactoring and converting to common APIs, and
it was pretty mechanical as far as refactorings go.
Besides what we've talked about, the other thing I was doing that might
be worth discussing was working on separating the pretty-printers in
vsprintf.c from the format string parsing code. What I was seeing was a
lot of code mixing parsing of the format string, and I think that code
would be _much_ easier to read and work on with the format string
parsing confined to pointer(), and having it call pretty-printers with a
normal function call interface with well-typed arguments.
I have additional patches finishing this work for around half of the
pretty-printers in vsprintf.c, but you were complaining about the patch
series growing, so I haven't posted them yet...
Anyways, I hope this addresses some concerns.
Cheers,
Kent