2013-03-30 02:27:32

by Tejun Heo

Subject: [PATCHSET] arch: unify task dump debug info

Hello,

There are multiple ways a task can be dumped - explicit call to
dump_stack(), triggering WARN() or BUG(), through sysrq-t and so on.
Most of what gets printed is upto each architecture and the current
state is not particularly pretty. Different pieces of information are
presented differently depending on which path the dump takes and which
architecture it's running on. This is messy for no good reason and
makes it exceedingly difficult to add or modify debug information to
task dumps.

In all archs except for s390, there's nothing arch-specific about the
printed debug information. This patchset updates all those archs to
use the same helpers to consistently print out the same debug
information.

An example WARN dump after this patchset.

WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
Modules linked in:
Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #18 empty empty/S3992
0000000000000009 ffff88007c861e08 ffffffff81c61525 ffff88007c861e48
ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a041
0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
Call Trace:
[<ffffffff81c61525>] dump_stack+0x19/0x1b
[<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
[<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8234a076>] init_workqueues+0x35/0x505
...

And BUG dump.

kernel BUG at /work/os/work/kernel/workqueue.c:4841!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
...
Stack:
ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
Call Trace:
[<ffffffff81000312>] do_one_initcall+0x122/0x170
[<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
...

This patchset contains the following five patches.

0001-x86-don-t-show-trace-beyond-show_stack-NULL-NULL.patch
0002-sparc32-make-show_stack-acquire-fp-if-_ksp-is-not-sp.patch
0003-dump_stack-consolidate-dump_stack-implementations-an.patch
0004-dump_stack-implement-arch-specific-hardware-descript.patch
0005-dump_stack-unify-debug-information-printed-by-show_r.patch

0001-0002 update stack dumping functions in x86 and sparc32 in
preparation.

0003 makes all arches except s390 and blackfin use generic
dump_stack(). blackfin still uses the generic helper to print the
same info. s390 is left alone as its current debug info includes
arch-specific stuff.

0004 properly abstracts DMI identifier printing in WARN() and
show_regs() so that all dumps print out the information. This enables
show_regs() to use the same debug info message.

0005 updates show_regs() of all arches except for s390 to use a common
generic helper to print debug info.

While this patchset changes how debug info is printed on some archs,
the printed information is always superset of what used to be there.

This patchset makes task dump debug messages consistent and enables
adding more information. Workqueue is scheduled to add worker
information including the workqueue in use and work item specific
description.

This patchset is based on top of v3.9-rc4 and available in the
following git branch.

git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git review-unify-dump

While this patch touches a lot of archs, it isn't too likely to cause
non-trivial conflicts with arch-specfic changes and would probably be
best to route together either through -tip or -mm.

x86 is tested but other archs are either only compile tested or not
tested at all. Changes to most archs are generally trivial.

diffstat follows. Thanks.

arch/alpha/kernel/process.c | 1
arch/alpha/kernel/traps.c | 7 ---
arch/arc/kernel/stacktrace.c | 7 ---
arch/arc/kernel/troubleshoot.c | 1
arch/arm/kernel/process.c | 8 +---
arch/arm/kernel/traps.c | 7 ---
arch/arm64/kernel/process.c | 7 ---
arch/arm64/kernel/traps.c | 7 ---
arch/avr32/kernel/process.c | 13 +------
arch/blackfin/kernel/dumpstack.c | 1
arch/blackfin/kernel/trace.c | 2 +
arch/c6x/kernel/traps.c | 10 -----
arch/cris/arch-v10/kernel/process.c | 3 +
arch/cris/arch-v32/kernel/process.c | 3 +
arch/cris/kernel/traps.c | 7 ---
arch/frv/kernel/traps.c | 14 -------
arch/h8300/kernel/process.c | 2 +
arch/h8300/kernel/traps.c | 7 ---
arch/hexagon/kernel/traps.c | 8 ----
arch/hexagon/kernel/vm_events.c | 2 +
arch/ia64/kernel/process.c | 12 +-----
arch/ia64/kernel/setup.c | 1
arch/m32r/kernel/process.c | 2 +
arch/m32r/kernel/traps.c | 9 ----
arch/m68k/kernel/traps.c | 12 ------
arch/metag/kernel/process.c | 2 +
arch/metag/kernel/traps.c | 6 ---
arch/microblaze/kernel/process.c | 2 +
arch/microblaze/kernel/traps.c | 6 ---
arch/mips/kernel/traps.c | 15 --------
arch/mn10300/kernel/process.c | 1
arch/mn10300/kernel/traps.c | 11 ------
arch/openrisc/kernel/process.c | 1
arch/openrisc/kernel/traps.c | 11 ------
arch/parisc/kernel/traps.c | 10 +----
arch/powerpc/kernel/process.c | 14 +------
arch/score/kernel/traps.c | 12 +-----
arch/sh/kernel/dumpstack.c | 6 ---
arch/sh/kernel/process_32.c | 6 ---
arch/sh/kernel/process_64.c | 1
arch/sparc/kernel/process_32.c | 23 ++++--------
arch/sparc/kernel/process_64.c | 2 +
arch/sparc/kernel/traps_64.c | 7 ---
arch/tile/kernel/process.c | 3 -
arch/um/kernel/sysrq.c | 12 ------
arch/um/sys-ppc/sysrq.c | 2 +
arch/unicore32/kernel/process.c | 6 ---
arch/unicore32/kernel/traps.c | 6 ---
arch/x86/include/asm/bug.h | 3 -
arch/x86/kernel/dumpstack.c | 28 ++++++---------
arch/x86/kernel/dumpstack_32.c | 4 --
arch/x86/kernel/dumpstack_64.c | 6 ---
arch/x86/kernel/process.c | 24 -------------
arch/x86/kernel/process_32.c | 2 -
arch/x86/kernel/process_64.c | 1
arch/x86/kernel/setup.c | 1
arch/xtensa/kernel/traps.c | 10 +----
drivers/firmware/dmi_scan.c | 26 ++++++++++++++
include/linux/dmi.h | 2 +
include/linux/printk.h | 4 ++
kernel/panic.c | 6 ---
lib/dump_stack.c | 66 ++++++++++++++++++++++++++++++++++--
62 files changed, 167 insertions(+), 334 deletions(-)

--
tejun

2013-03-30 02:27:50

by Tejun Heo

Subject: [PATCH 1/5] x86: don't show trace beyond show_stack(NULL, NULL)

show_stack(current or NULL, NULL) is used to print the backtrace of
the current task. As trace beyond the function itself isn't of much
interest to anyone, don't show it by determining sp and bp in
show_stack()'s frame and passing them to show_stack_log_lvl().

This brings show_stack(NULL, NULL)'s behavior in line with
dump_stack().

Signed-off-by: Tejun Heo <[email protected]>
---
arch/x86/kernel/dumpstack.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index c8797d5..dd1a7c3 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -176,7 +176,19 @@ void show_trace(struct task_struct *task, struct pt_regs *regs,

void show_stack(struct task_struct *task, unsigned long *sp)
{
- show_stack_log_lvl(task, NULL, sp, 0, "");
+ unsigned long bp = 0;
+ unsigned long stack;
+
+ /*
+ * Stack frames below this one aren't interesting. Don't show them
+ * if we're printing for %current.
+ */
+ if (!sp && (!task || task == current)) {
+ sp = &stack;
+ bp = stack_frame(current, NULL);
+ }
+
+ show_stack_log_lvl(task, NULL, sp, bp, "");
}

/*
--
1.8.1.4

2013-03-30 02:27:53

by Tejun Heo

Subject: [PATCH 2/5] sparc32: make show_stack() acquire %fp if @_ksp is not specified

show_stack(current or NULL, NULL) is used by arch-independent code to
dump backtrace of the current task; however, sparc32 show_stack()
doesn't implement it and wouldn't print any backtrace when NULL @_ksp
is specfied.

Make show_stack() acquire and use %fp if @tsk is NULL or current and
@_ksp is NULL. This makes %fp fetching in dump_stack() unnecessary.
Make it use NULL for @_ksp instead.

Only compile tested.

Signed-off-by: Tejun Heo <[email protected]>
---
arch/sparc/kernel/process_32.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 62eede1..0d57b24 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -153,11 +153,13 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
struct reg_window32 *rw;
int count = 0;

- if (tsk != NULL)
- task_base = (unsigned long) task_stack_page(tsk);
- else
- task_base = (unsigned long) current_thread_info();
+ if (!tsk)
+ tsk = current;

+ if (tsk == current && !_ksp)
+ __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
+
+ task_base = (unsigned long) task_stack_page(tsk);
fp = (unsigned long) _ksp;
do {
/* Bogus frame pointer? */
@@ -175,11 +177,7 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)

void dump_stack(void)
{
- unsigned long *ksp;
-
- __asm__ __volatile__("mov %%fp, %0"
- : "=r" (ksp));
- show_stack(current, ksp);
+ show_stack(current, NULL);
}

EXPORT_SYMBOL(dump_stack);
--
1.8.1.4

2013-03-30 02:28:02

by Tejun Heo

Subject: [PATCH 4/5] dump_stack: implement arch-specific hardware description in task dumps

x86 and ia64 can acquire extra hardware identification information
from DMI and print it along with task dumps; however, the usage isn't
consistent.

* x86 show_regs() collects vendor, product and board strings and print
them out with PID, comm and utsname. Some of the information is
printed again later in the same dump.

* warn_slowpath_common() explicitly accesses the DMI board and prints
it out with "Hardware name:" label. This applies to both x86 and
ia64 but is irrelevant on all other archs.

* ia64 doesn't show DMI information on other non-WARN dumps.

This patch introduces arch-specific hardware description used by
dump_stack(). It can be set by calling dump_stack_set_arch_desc()
during boot and printed out along with utsname.

dmi_set_dump_stack_arch_desc() is added which sets arch-specific
description from DMI data. It uses the same information and
formatting as x86 show_regs() is using. The function is called from
x86 and ia64 boot code right after dmi_scan_machine().

This makes the explicit DMI handling in warn_slowpath_common()
unnecessary. Removed.

show_regs() isn't yet converted to use generic debug information
printing and this patch doesn't remove the duplicate DMI handling in
x86 show_regs(). The next patch will unify show_regs() handling and
remove the duplication.

An example WARN dump follows.

WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
Modules linked in:
Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #18 empty empty/S3992
0000000000000009 ffff88007c861e08 ffffffff81c61525 ffff88007c861e48
ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a041
0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
Call Trace:
[<ffffffff81c61525>] dump_stack+0x19/0x1b
[<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
[<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8234a076>] init_workqueues+0x35/0x505
...

Signed-off-by: Tejun Heo <[email protected]>
---
arch/ia64/kernel/setup.c | 1 +
arch/x86/kernel/setup.c | 1 +
drivers/firmware/dmi_scan.c | 26 ++++++++++++++++++++++++++
include/linux/dmi.h | 2 ++
include/linux/printk.h | 1 +
kernel/panic.c | 6 ------
lib/dump_stack.c | 26 ++++++++++++++++++++++++--
7 files changed, 55 insertions(+), 8 deletions(-)

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 2029cc0..13bfdd2 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -1063,6 +1063,7 @@ check_bugs (void)
static int __init run_dmi_scan(void)
{
dmi_scan_machine();
+ dmi_set_dump_stack_arch_desc();
return 0;
}
core_initcall(run_dmi_scan);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 90d8cc9..91b9e7c 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -970,6 +970,7 @@ void __init setup_arch(char **cmdline_p)
efi_init();

dmi_scan_machine();
+ dmi_set_dump_stack_arch_desc();

/*
* VMware detection requires dmi to be available, so this
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 4cd392d..9e7766b 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -521,6 +521,32 @@ void __init dmi_scan_machine(void)
}

/**
+ * dmi_set_dump_stack_arch_desc - set arch description for dump_stack()
+ *
+ * Invoke dump_stack_set_arch_desc() with DMI system information so that
+ * DMI identifiers are printed out on task dumps. Arch boot code should
+ * call this function after dmi_scan_machine() if it wants to print out DMI
+ * identifiers on task dumps.
+ */
+void __init dmi_set_dump_stack_arch_desc(void)
+{
+ const char *vendor, *product, *board;
+
+ vendor = dmi_get_system_info(DMI_SYS_VENDOR);
+ if (!vendor)
+ vendor = "";
+ product = dmi_get_system_info(DMI_PRODUCT_NAME);
+ if (!product)
+ product = "";
+
+ /* Board Name is optional */
+ board = dmi_get_system_info(DMI_BOARD_NAME);
+
+ dump_stack_set_arch_desc("%s %s%s%s", vendor, product,
+ board ? "/" : "", board ? board : "");
+}
+
+/**
* dmi_matches - check if dmi_system_id structure matches system DMI data
* @dmi: pointer to the dmi_system_id structure to check
*/
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index f156cca..b6eb7a0 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -99,6 +99,7 @@ extern const char * dmi_get_system_info(int field);
extern const struct dmi_device * dmi_find_device(int type, const char *name,
const struct dmi_device *from);
extern void dmi_scan_machine(void);
+extern void dmi_set_dump_stack_arch_desc(void);
extern bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp);
extern int dmi_name_in_vendors(const char *str);
extern int dmi_name_in_serial(const char *str);
@@ -114,6 +115,7 @@ static inline const char * dmi_get_system_info(int field) { return NULL; }
static inline const struct dmi_device * dmi_find_device(int type, const char *name,
const struct dmi_device *from) { return NULL; }
static inline void dmi_scan_machine(void) { return; }
+static inline void dmi_set_dump_stack_arch_desc(void) { }
static inline bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
{
if (yearp)
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 952c1b2..73788ff 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -177,6 +177,7 @@ static inline void setup_log_buf(int early)
}
#endif

+extern void dump_stack_set_arch_desc(const char *fmt, ...);
extern void dump_stack_print_info(const char *log_lvl);
extern void dump_stack(void) __cold;

diff --git a/kernel/panic.c b/kernel/panic.c
index 7c57cc9..167ec09 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -22,7 +22,6 @@
#include <linux/sysrq.h>
#include <linux/init.h>
#include <linux/nmi.h>
-#include <linux/dmi.h>

#define PANIC_TIMER_STEP 100
#define PANIC_BLINK_SPD 18
@@ -400,13 +399,8 @@ struct slowpath_args {
static void warn_slowpath_common(const char *file, int line, void *caller,
unsigned taint, struct slowpath_args *args)
{
- const char *board;
-
printk(KERN_WARNING "------------[ cut here ]------------\n");
printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
- board = dmi_get_system_info(DMI_PRODUCT_NAME);
- if (board)
- printk(KERN_WARNING "Hardware name: %s\n", board);

if (args)
vprintk(args->fmt, args->args);
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 5a67cfc..93573ec 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -8,6 +8,28 @@
#include <linux/utsname.h>
#include <linux/export.h>

+static char dump_stack_arch_desc_str[128];
+
+/**
+ * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
+ * @fmt: printf-style format string
+ * @...: arguments for the format string
+ *
+ * The configured string will be printed right after utsname during task
+ * dumps. Usually used to add arch-specific system identifiers. If an
+ * arch wants to make use of such an ID string, it should initialize this
+ * as soon as possible during boot.
+ */
+void __init dump_stack_set_arch_desc(const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
+ fmt, args);
+ va_end(args);
+}
+
/**
* dump_stack_print_info - print generic debug info for dump_stack()
* @log_lvl: log level
@@ -17,11 +39,11 @@
*/
void dump_stack_print_info(const char *log_lvl)
{
- printk("%sPid: %d, comm: %.20s %s %s %.*s\n",
+ printk("%sPid: %d, comm: %.20s %s %s %.*s %s\n",
log_lvl, current->pid, current->comm, print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ init_utsname()->version, dump_stack_arch_desc_str);
}

/**
--
1.8.1.4

2013-03-30 02:27:58

by Tejun Heo

Subject: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

Both dump_stack() and show_stack() are currently implemented by each
architecture. show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack(). On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task
which triggered dump_stack().

There's no reason to require archs to implement two separate but
mostly identical functions. It leads to unnecessary subtle
differences among archs and makes it very tedius to add generic debug
information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin and s390.
Blackfin's dump_stack() does something wonky that I don't understand
and s390 prints its own debug information which includes fields which
aren't accessible from arch-indepdent code.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information. This is
used in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
printed. This is because the top frame was determined in
dump_stack() on those archs while generic dump_stack() can't do that
reliably. It can be compensated by inlining dump_stack() but not
sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack(). They do
now.

An example WARN dump follows.

WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
Hardware name: empty
Modules linked in:
Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #17
0000000000000009 ffff88007c861e08 ffffffff81c61545 ffff88007c861e48
ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
Call Trace:
[<ffffffff81c61545>] dump_stack+0x19/0x1b
[<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8234a071>] init_workqueues+0x35/0x505
...

Signed-off-by: Tejun Heo <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: [email protected]
Cc: Mike Frysinger <[email protected]>
Cc: [email protected]
---
arch/alpha/kernel/traps.c | 7 -------
arch/arc/kernel/stacktrace.c | 7 -------
arch/arm/kernel/traps.c | 7 -------
arch/arm64/kernel/traps.c | 7 -------
arch/avr32/kernel/process.c | 8 --------
arch/blackfin/kernel/dumpstack.c | 1 +
arch/c6x/kernel/traps.c | 9 ---------
arch/cris/kernel/traps.c | 7 -------
arch/frv/kernel/traps.c | 11 -----------
arch/h8300/kernel/traps.c | 7 -------
arch/hexagon/kernel/traps.c | 8 --------
arch/ia64/kernel/process.c | 8 --------
arch/m32r/kernel/traps.c | 9 ---------
arch/m68k/kernel/traps.c | 12 ------------
arch/metag/kernel/traps.c | 6 ------
arch/microblaze/kernel/traps.c | 6 ------
arch/mips/kernel/traps.c | 13 -------------
arch/mn10300/kernel/traps.c | 11 -----------
arch/openrisc/kernel/traps.c | 11 -----------
arch/parisc/kernel/traps.c | 8 --------
arch/powerpc/kernel/process.c | 6 ------
arch/score/kernel/traps.c | 10 ----------
arch/sh/kernel/dumpstack.c | 6 ------
arch/sparc/kernel/process_32.c | 7 -------
arch/sparc/kernel/traps_64.c | 7 -------
arch/um/kernel/sysrq.c | 12 ------------
arch/unicore32/kernel/traps.c | 6 ------
arch/x86/kernel/dumpstack.c | 18 ------------------
arch/xtensa/kernel/traps.c | 8 --------
include/linux/printk.h | 1 +
lib/dump_stack.c | 28 +++++++++++++++++++++++++---
31 files changed, 27 insertions(+), 245 deletions(-)

diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 4037461..affccb9 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c
@@ -169,13 +169,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
dik_show_trace(sp);
}

-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void
die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15)
{
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c
index a63ff84..ca0207b 100644
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -220,13 +220,6 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
show_stacktrace(tsk, NULL);
}

-/* Expected by Rest of kernel code */
-void dump_stack(void)
-{
- show_stacktrace(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
/* Another API expected by schedular, shows up in "ps" as Wait Channel
* Ofcourse just returning schedule( ) would be pointless so unwind until
* the function is not in schedular code
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 1c08911..18b32e8 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -204,13 +204,6 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
}
#endif

-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index b3c5f62..61d7dd2 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -167,13 +167,6 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
}
}

-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index fd78f58..c1cafdb 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -213,14 +213,6 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
}

-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace_log_lvl(current, &stack, NULL, "");
-}
-EXPORT_SYMBOL(dump_stack);
-
static const char *cpu_modes[] = {
"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
diff --git a/arch/blackfin/kernel/dumpstack.c b/arch/blackfin/kernel/dumpstack.c
index 5cfbaa2..95ba6d9 100644
--- a/arch/blackfin/kernel/dumpstack.c
+++ b/arch/blackfin/kernel/dumpstack.c
@@ -168,6 +168,7 @@ void dump_stack(void)
#endif
trace_buffer_save(tflags);
dump_bfin_trace_buffer();
+ dump_stack_print_info(KERN_DEFAULT);
show_stack(current, &stack);
trace_buffer_restore(tflags);
}
diff --git a/arch/c6x/kernel/traps.c b/arch/c6x/kernel/traps.c
index 1be74e5..d0b96ef 100644
--- a/arch/c6x/kernel/traps.c
+++ b/arch/c6x/kernel/traps.c
@@ -67,15 +67,6 @@ void show_regs(struct pt_regs *regs)
pr_err("A31: %08lx B31: %08lx\n", regs->a31, regs->b31);
}

-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
-
void die(char *str, struct pt_regs *fp, int nr)
{
console_verbose();
diff --git a/arch/cris/kernel/traps.c b/arch/cris/kernel/traps.c
index a11ad32..0ffda73 100644
--- a/arch/cris/kernel/traps.c
+++ b/arch/cris/kernel/traps.c
@@ -147,13 +147,6 @@ show_stack(void)
#endif

void
-dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
-void
set_nmi_handler(void (*handler)(struct pt_regs *))
{
nmi_handler = handler;
diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c
index 5cfd142..cfcd802 100644
--- a/arch/frv/kernel/traps.c
+++ b/arch/frv/kernel/traps.c
@@ -466,17 +466,6 @@ asmlinkage void compound_exception(unsigned long esfr1,
BUG();
} /* end compound_exception() */

-/*****************************************************************************/
-/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *task, unsigned long *sp)
{
}
diff --git a/arch/h8300/kernel/traps.c b/arch/h8300/kernel/traps.c
index 7833aa3..cfe494d 100644
--- a/arch/h8300/kernel/traps.c
+++ b/arch/h8300/kernel/traps.c
@@ -164,10 +164,3 @@ void show_trace_task(struct task_struct *tsk)
{
show_stack(tsk,(unsigned long *)tsk->thread.esp0);
}
-
-void dump_stack(void)
-{
- show_stack(NULL,NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
diff --git a/arch/hexagon/kernel/traps.c b/arch/hexagon/kernel/traps.c
index be5e2dd..cc2171b 100644
--- a/arch/hexagon/kernel/traps.c
+++ b/arch/hexagon/kernel/traps.c
@@ -191,14 +191,6 @@ void show_stack(struct task_struct *task, unsigned long *fp)
do_show_stack(task, fp, 0);
}

-void dump_stack(void)
-{
- unsigned long *fp;
- asm("%0 = r30" : "=r" (fp));
- show_stack(current, fp);
-}
-EXPORT_SYMBOL(dump_stack);
-
int die(const char *str, struct pt_regs *regs, long err)
{
static struct {
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index e34f565..29fb256 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -96,14 +96,6 @@ show_stack (struct task_struct *task, unsigned long *sp)
}

void
-dump_stack (void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-void
show_regs (struct pt_regs *regs)
{
unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
diff --git a/arch/m32r/kernel/traps.c b/arch/m32r/kernel/traps.c
index 3bcb207..5623ea3 100644
--- a/arch/m32r/kernel/traps.c
+++ b/arch/m32r/kernel/traps.c
@@ -169,15 +169,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
show_trace(task, sp);
}

-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(current, &stack);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void show_registers(struct pt_regs *regs)
{
int i = 0;
diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c
index f32ab22..88fcd8c 100644
--- a/arch/m68k/kernel/traps.c
+++ b/arch/m68k/kernel/traps.c
@@ -992,18 +992,6 @@ void show_stack(struct task_struct *task, unsigned long *stack)
}

/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(&stack);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-/*
* The vector number returned in the frame pointer may also contain
* the "fs" (Fault Status) bits on ColdFire. These are in the bottom
* 2 bits, and upper 2 bits. So we need to mask out the real vector
diff --git a/arch/metag/kernel/traps.c b/arch/metag/kernel/traps.c
index 8961f24..2ceeaae 100644
--- a/arch/metag/kernel/traps.c
+++ b/arch/metag/kernel/traps.c
@@ -987,9 +987,3 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)

show_trace(tsk, sp, NULL);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
diff --git a/arch/microblaze/kernel/traps.c b/arch/microblaze/kernel/traps.c
index 30e6b50..cb61953 100644
--- a/arch/microblaze/kernel/traps.c
+++ b/arch/microblaze/kernel/traps.c
@@ -75,9 +75,3 @@ void show_stack(struct task_struct *task, unsigned long *sp)

debug_show_held_locks(task);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index a200b5b..93f9b26 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -206,19 +206,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
show_stacktrace(task, &regs);
}

-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- struct pt_regs regs;
-
- prepare_frametrace(&regs);
- show_backtrace(current, &regs);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void show_code(unsigned int __user *pc)
{
long i;
diff --git a/arch/mn10300/kernel/traps.c b/arch/mn10300/kernel/traps.c
index b900e5a..a7a987c 100644
--- a/arch/mn10300/kernel/traps.c
+++ b/arch/mn10300/kernel/traps.c
@@ -294,17 +294,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
}

/*
- * the architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
-/*
* dump the register file in the specified exception frame
*/
void show_registers_only(struct pt_regs *regs)
diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c
index 5cce396..3d3f606 100644
--- a/arch/openrisc/kernel/traps.c
+++ b/arch/openrisc/kernel/traps.c
@@ -105,17 +105,6 @@ void show_trace_task(struct task_struct *tsk)
*/
}

-/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
void show_registers(struct pt_regs *regs)
{
int i;
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index aeb8f8f..e64cf5f 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -158,14 +158,6 @@ void show_regs(struct pt_regs *regs)
}
}

-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void do_show_stack(struct unwind_frame_info *info)
{
int i = 1;
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 59dd545..2e6f83a 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1360,12 +1360,6 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
} while (count++ < kstack_depth_to_print);
}

-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
#ifdef CONFIG_PPC64
/* Called with hard IRQs off */
void __ppc64_runlatch_on(void)
diff --git a/arch/score/kernel/traps.c b/arch/score/kernel/traps.c
index 0e46fb1..a38f435 100644
--- a/arch/score/kernel/traps.c
+++ b/arch/score/kernel/traps.c
@@ -149,16 +149,6 @@ static void show_registers(struct pt_regs *regs)
printk(KERN_NOTICE "\n");
}

-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- show_stack(current_thread_info()->task,
- (long *) get_irq_regs()->regs[0]);
-}
-EXPORT_SYMBOL(dump_stack);
-
void __die(const char *str, struct pt_regs *regs, const char *file,
const char *func, unsigned long line)
{
diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
index 7617dc4..b959f55 100644
--- a/arch/sh/kernel/dumpstack.c
+++ b/arch/sh/kernel/dumpstack.c
@@ -158,9 +158,3 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
(unsigned long)task_stack_page(tsk));
show_trace(tsk, sp, NULL);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 0d57b24..fe99fbd 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -175,13 +175,6 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
printk("\n");
}

-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
/*
* Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
*/
diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index 8d38ca9..b3f833a 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -2350,13 +2350,6 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
} while (++count < 16);
}

-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static inline struct reg_window *kernel_stack_up(struct reg_window *rw)
{
unsigned long fp = rw->ins[6];
diff --git a/arch/um/kernel/sysrq.c b/arch/um/kernel/sysrq.c
index e562ff8..7d101a2 100644
--- a/arch/um/kernel/sysrq.c
+++ b/arch/um/kernel/sysrq.c
@@ -35,18 +35,6 @@ void show_trace(struct task_struct *task, unsigned long * stack)
}
#endif

-/*
- * stack dumps generator - this is used by arch-independent code.
- * And this is identical to i386 currently.
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
/*Stolen from arch/i386/kernel/traps.c */
static const int kstack_depth_to_print = 24;

diff --git a/arch/unicore32/kernel/traps.c b/arch/unicore32/kernel/traps.c
index 0870b68..c54e324 100644
--- a/arch/unicore32/kernel/traps.c
+++ b/arch/unicore32/kernel/traps.c
@@ -170,12 +170,6 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
c_backtrace(fp, mode);
}

-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index dd1a7c3..deb6421 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -191,24 +191,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
show_stack_log_lvl(task, NULL, sp, bp, "");
}

-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- unsigned long bp;
- unsigned long stack;
-
- bp = stack_frame(current, NULL);
- printk("Pid: %d, comm: %.20s %s %s %.*s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
- show_trace(NULL, NULL, &stack, bp);
-}
-EXPORT_SYMBOL(dump_stack);
-
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 923db5c..384b7c7 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -481,14 +481,6 @@ void show_stack(struct task_struct *task, unsigned long *sp)
show_trace(task, stack);
}

-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-
void show_code(unsigned int *pc)
{
long i;
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 822171f..952c1b2 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -177,6 +177,7 @@ static inline void setup_log_buf(int early)
}
#endif

+extern void dump_stack_print_info(const char *log_lvl);
extern void dump_stack(void) __cold;

#ifndef pr_fmt
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 42f4f55..5a67cfc 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -4,12 +4,34 @@
*/

#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/utsname.h>
#include <linux/export.h>

-void dump_stack(void)
+/**
+ * dump_stack_print_info - print generic debug info for dump_stack()
+ * @log_lvl: log level
+ *
+ * Arch-specific dump_stack() implementations can use this function to
+ * print out the same debug information as the generic dump_stack().
+ */
+void dump_stack_print_info(const char *log_lvl)
{
- printk(KERN_NOTICE
- "This architecture does not implement dump_stack()\n");
+ printk("%sPid: %d, comm: %.20s %s %s %.*s\n",
+ log_lvl, current->pid, current->comm, print_tainted(),
+ init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
}

+/**
+ * dump_stack - dump the current task information and its stack trace
+ *
+ * Architectures can override this implementation by implementing its own.
+ */
+void dump_stack(void)
+{
+ dump_stack_print_info(KERN_DEFAULT);
+ show_stack(NULL, NULL);
+}
EXPORT_SYMBOL(dump_stack);
--
1.8.1.4

2013-03-30 02:28:16

by Tejun Heo

Subject: [PATCH 5/5] dump_stack: unify debug information printed by show_regs()

show_regs() is inherently arch-dependent but it does make sense to
print generic debug information and some archs already do albeit in
slightly different forms. This patch introduces a generic function to
print debug information from show_regs() so that different archs print
out the same information and it's much easier to modify what's
printed.

show_regs_print_current() prints out the same debug info as
dump_stack() does plus CPU, task and thread_info pointers.

* Archs which didn't print debug info now do.

alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
um, xtensa

* Already prints debug info. Replaced with show_regs_print_current().
The printed information is superset of what used to be there.

arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* The printed debug information includes arch-specific bits. Left
alone.

s390

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

kernel BUG at /work/os/work/kernel/workqueue.c:4841!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
Call Trace:
[<ffffffff81000312>] do_one_initcall+0x122/0x170
[<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
...

Signed-off-by: Tejun Heo <[email protected]>
---
arch/alpha/kernel/process.c | 1 +
arch/arc/kernel/troubleshoot.c | 1 +
arch/arm/kernel/process.c | 8 ++------
arch/arm64/kernel/process.c | 7 +------
arch/avr32/kernel/process.c | 5 ++---
arch/blackfin/kernel/trace.c | 2 ++
arch/c6x/kernel/traps.c | 1 +
arch/cris/arch-v10/kernel/process.c | 3 +++
arch/cris/arch-v32/kernel/process.c | 3 +++
arch/frv/kernel/traps.c | 3 +--
arch/h8300/kernel/process.c | 2 ++
arch/hexagon/kernel/vm_events.c | 2 ++
arch/ia64/kernel/process.c | 4 ++--
arch/m32r/kernel/process.c | 2 ++
arch/metag/kernel/process.c | 2 ++
arch/microblaze/kernel/process.c | 2 ++
arch/mips/kernel/traps.c | 2 +-
arch/mn10300/kernel/process.c | 1 +
arch/openrisc/kernel/process.c | 1 +
arch/parisc/kernel/traps.c | 2 ++
arch/powerpc/kernel/process.c | 8 ++------
arch/score/kernel/traps.c | 2 ++
arch/sh/kernel/process_32.c | 6 +-----
arch/sh/kernel/process_64.c | 1 +
arch/sparc/kernel/process_32.c | 2 ++
arch/sparc/kernel/process_64.c | 2 ++
arch/tile/kernel/process.c | 3 +--
arch/um/sys-ppc/sysrq.c | 2 ++
arch/unicore32/kernel/process.c | 6 +-----
arch/x86/include/asm/bug.h | 3 ---
arch/x86/kernel/dumpstack_32.c | 4 +---
arch/x86/kernel/dumpstack_64.c | 6 +-----
arch/x86/kernel/process.c | 24 ------------------------
arch/x86/kernel/process_32.c | 2 --
arch/x86/kernel/process_64.c | 1 -
arch/xtensa/kernel/traps.c | 2 ++
include/linux/printk.h | 2 ++
lib/dump_stack.c | 16 ++++++++++++++++
38 files changed, 70 insertions(+), 76 deletions(-)

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 63d27fb..7085cb8 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -194,6 +194,7 @@ machine_power_off(void)
void
show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
dik_show_regs(regs, NULL);
}

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 7c10873..96be1e6 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -163,6 +163,7 @@ void show_regs(struct pt_regs *regs)
return;

print_task_path_n_nm(tsk, buf);
+ show_regs_print_info(KERN_INFO);

if (current->thread.cause_code)
show_ecr_verbose(regs);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 047d3e4..3e63a0a 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -273,11 +273,8 @@ void __show_regs(struct pt_regs *regs)
unsigned long flags;
char buf[64];

- printk("CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
+
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->ARM_lr);
printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
@@ -332,7 +329,6 @@ void __show_regs(struct pt_regs *regs)
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
__show_regs(regs);
dump_stack();
}
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 0337cdb..4f812bb 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -178,11 +178,7 @@ void __show_regs(struct pt_regs *regs)
{
int i;

- printk("CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->regs[30]);
printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
@@ -199,7 +195,6 @@ void __show_regs(struct pt_regs *regs)
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
__show_regs(regs);
}

diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index c1cafdb..63c9e8c 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -224,6 +224,8 @@ void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
unsigned long lr = regs->lr;
unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;

+ show_regs_print_info(log_lvl);
+
if (!user_mode(regs)) {
sp = (unsigned long)regs + FRAME_SIZE_FULL;

@@ -261,9 +263,6 @@ void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
regs->sr & SR_I0M ? '0' : '.',
regs->sr & SR_GM ? 'G' : 'g');
printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
- printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
- log_lvl, current->comm, current->pid, current,
- task_thread_info(current));
}

void show_regs(struct pt_regs *regs)
diff --git a/arch/blackfin/kernel/trace.c b/arch/blackfin/kernel/trace.c
index f7f7a18..c36efa0 100644
--- a/arch/blackfin/kernel/trace.c
+++ b/arch/blackfin/kernel/trace.c
@@ -853,6 +853,8 @@ void show_regs(struct pt_regs *fp)
unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();

pr_notice("\n");
+ show_regs_print_info(KERN_NOTICE);
+
if (CPUID != bfin_cpuid())
pr_notice("Compiled for cpu family 0x%04x (Rev %d), "
"but running on:0x%04x (Rev %d)\n",
diff --git a/arch/c6x/kernel/traps.c b/arch/c6x/kernel/traps.c
index d0b96ef..dcc2c2f 100644
--- a/arch/c6x/kernel/traps.c
+++ b/arch/c6x/kernel/traps.c
@@ -31,6 +31,7 @@ void __init trap_init(void)
void show_regs(struct pt_regs *regs)
{
pr_err("\n");
+ show_regs_print_info(KERN_ERR);
pr_err("PC: %08lx SP: %08lx\n", regs->pc, regs->sp);
pr_err("Status: %08lx ORIG_A4: %08lx\n", regs->csr, regs->orig_a4);
pr_err("A0: %08lx B0: %08lx\n", regs->a0, regs->b0);
diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c
index b101875..9087bbf 100644
--- a/arch/cris/arch-v10/kernel/process.c
+++ b/arch/cris/arch-v10/kernel/process.c
@@ -175,6 +175,9 @@ unsigned long get_wchan(struct task_struct *p)
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
+
+ show_regs_print_info(KERN_DEFAULT);
+
printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
regs->irp, regs->srp, regs->dccr, usp, regs->mof );
printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c
index 2b23ef0..09fd16c 100644
--- a/arch/cris/arch-v32/kernel/process.c
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -170,6 +170,9 @@ get_wchan(struct task_struct *p)
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
+
+ show_regs_print_info(KERN_DEFAULT);
+
printk("ERP: %08lx SRP: %08lx CCS: %08lx USP: %08lx MOF: %08lx\n",
regs->erp, regs->srp, regs->ccs, usp, regs->mof);

diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c
index cfcd802..4bff48c 100644
--- a/arch/frv/kernel/traps.c
+++ b/arch/frv/kernel/traps.c
@@ -497,6 +497,7 @@ void show_regs(struct pt_regs *regs)
int loop;

printk("\n");
+ show_regs_print_info(KERN_DEFAULT);

printk("Frame: @%08lx [%s]\n",
(unsigned long) regs,
@@ -511,8 +512,6 @@ void show_regs(struct pt_regs *regs)
else
printk(" | ");
}
-
- printk("Process %s (pid: %d)\n", current->comm, current->pid);
}

void die_if_kernel(const char *str, ...)
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index b609f63..8f235a3 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -110,6 +110,8 @@ void machine_power_off(void)

void show_regs(struct pt_regs * regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("\nPC: %08lx Status: %02x",
regs->pc, regs->ccr);
printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
diff --git a/arch/hexagon/kernel/vm_events.c b/arch/hexagon/kernel/vm_events.c
index 9b5a4a2..f337281 100644
--- a/arch/hexagon/kernel/vm_events.c
+++ b/arch/hexagon/kernel/vm_events.c
@@ -33,6 +33,8 @@
*/
void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_EMERG);
+
printk(KERN_EMERG "restart_r0: \t0x%08lx syscall_nr: %ld\n",
regs->restart_r0, regs->syscall_nr);
printk(KERN_EMERG "preds: \t\t0x%08lx\n", regs->preds);
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 29fb256..492dc45 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -101,8 +101,8 @@ show_regs (struct pt_regs *regs)
unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;

print_modules();
- printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
- smp_processor_id(), current->comm);
+ printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n",
regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
init_utsname()->release);
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index bde899e..892a1d9 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -91,6 +91,8 @@ void machine_power_off(void)
void show_regs(struct pt_regs * regs)
{
printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
+
printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
regs->bpc, regs->psw, regs->lr, regs->fp);
printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
diff --git a/arch/metag/kernel/process.c b/arch/metag/kernel/process.c
index c6efe62..cfe4e7f 100644
--- a/arch/metag/kernel/process.c
+++ b/arch/metag/kernel/process.c
@@ -152,6 +152,8 @@ void show_regs(struct pt_regs *regs)
"D1.7 "
};

+ show_regs_print_info(KERN_INFO);
+
pr_info(" pt_regs @ %p\n", regs);
pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index fa0ea60..d55700c 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -20,6 +20,8 @@

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_INFO);
+
pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
regs->r1, regs->r2, regs->r3, regs->r4);
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 93f9b26..1b383a9 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -231,7 +231,7 @@ static void __show_regs(const struct pt_regs *regs)
unsigned int cause = regs->cp0_cause;
int i;

- printk("Cpu %d\n", smp_processor_id());
+ show_regs_print_info(KERN_DEFAULT);

/*
* Saved main processor registers
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 84f4e97..1223770 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -155,6 +155,7 @@ void machine_power_off(void)

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
}

/*
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index 00c233b..386af25 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -90,6 +90,7 @@ void show_regs(struct pt_regs *regs)
{
extern void show_registers(struct pt_regs *regs);

+ show_regs_print_info(KERN_DEFAULT);
/* __PHX__ cleanup this mess */
show_registers(regs);
}
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index e64cf5f..f702bff 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -126,6 +126,8 @@ void show_regs(struct pt_regs *regs)
user = user_mode(regs);
level = user ? KERN_DEBUG : KERN_CRIT;

+ show_regs_print_info(level);
+
print_gr(level, regs);

for (i = 0; i < 8; i += 4)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2e6f83a..fd1b300 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -829,6 +829,8 @@ void show_regs(struct pt_regs * regs)
{
int i, trap;

+ show_regs_print_info(KERN_DEFAULT);
+
printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
regs->nip, regs->link, regs->ctr);
printk("REGS: %p TRAP: %04lx %s (%s)\n",
@@ -848,12 +850,6 @@ void show_regs(struct pt_regs * regs)
#else
printk("DAR: "REG", DSISR: %08lx\n", regs->dar, regs->dsisr);
#endif
- printk("TASK = %p[%d] '%s' THREAD: %p",
- current, task_pid_nr(current), current->comm, task_thread_info(current));
-
-#ifdef CONFIG_SMP
- printk(" CPU: %d", raw_smp_processor_id());
-#endif /* CONFIG_SMP */

for (i = 0; i < 32; i++) {
if ((i % REGS_PER_LINE) == 0)
diff --git a/arch/score/kernel/traps.c b/arch/score/kernel/traps.c
index a38f435..1517a7d 100644
--- a/arch/score/kernel/traps.c
+++ b/arch/score/kernel/traps.c
@@ -117,6 +117,8 @@ static void show_code(unsigned int *pc)
*/
void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("r0 : %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3],
regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 73eb66f..ebd3933 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -32,11 +32,7 @@
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
- printk("CPU : %d \t\t%s (%s %.*s)\n\n",
- smp_processor_id(), print_tainted(), init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);

print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("PR is at %s\n", regs->pr);
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index e611c85..174d124 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -40,6 +40,7 @@ void show_regs(struct pt_regs *regs)
unsigned long long ah, al, bh, bl, ch, cl;

printk("\n");
+ show_regs_print_info(KERN_DEFAULT);

ah = (regs->pc) >> 32;
al = (regs->pc) & 0xffffffff;
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index fe99fbd..9e78f9a 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -123,6 +123,8 @@ void show_regs(struct pt_regs *r)
{
struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];

+ show_regs_print_info(KERN_DEFAULT);
+
printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
r->psr, r->pc, r->npc, r->y, print_tainted());
printk("PC: <%pS>\n", (void *) r->pc);
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index cdb80b2..2415a95 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -186,6 +186,8 @@ static void show_regwindow(struct pt_regs *regs)

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate,
regs->tpc, regs->tnpc, regs->y, print_tainted());
printk("TPC: <%pS>\n", (void *) regs->tpc);
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index caf93ae..302691d 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -620,8 +620,7 @@ void show_regs(struct pt_regs *regs)
int i;

pr_err("\n");
- pr_err(" Pid: %d, comm: %20s, CPU: %d\n",
- tsk->pid, tsk->comm, smp_processor_id());
+ show_regs_print_info(KERN_ERR);
#ifdef __tilegx__
for (i = 0; i < 51; i += 3)
pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
diff --git a/arch/um/sys-ppc/sysrq.c b/arch/um/sys-ppc/sysrq.c
index f889449..1ff1ad7 100644
--- a/arch/um/sys-ppc/sysrq.c
+++ b/arch/um/sys-ppc/sysrq.c
@@ -11,6 +11,8 @@
void show_regs(struct pt_regs_subarch *regs)
{
printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
+
printk("show_regs(): insert regs here.\n");
#if 0
printk("\n");
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index 872d7e2..c412484 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -159,11 +159,7 @@ void __show_regs(struct pt_regs *regs)
unsigned long flags;
char buf[64];

- printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->UCreg_lr);
printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 11e1152..2f03ff0 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -37,7 +37,4 @@ do { \

#include <asm-generic/bug.h>

-
-extern void show_regs_common(void);
-
#endif /* _ASM_X86_BUG_H */
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 1038a41..9026cef 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -86,11 +86,9 @@ void show_regs(struct pt_regs *regs)
{
int i;

+ show_regs_print_info(KERN_EMERGE);
__show_regs(regs, !user_mode_vm(regs));

- pr_emerg("Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
- TASK_COMM_LEN, current->comm, task_pid_nr(current),
- current_thread_info(), current, task_thread_info(current));
/*
* When in-kernel, we also print out the stack and code at the
* time of the fault..
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index b653675..addb207 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -249,14 +249,10 @@ void show_regs(struct pt_regs *regs)
{
int i;
unsigned long sp;
- const int cpu = smp_processor_id();
- struct task_struct *cur = current;

sp = regs->sp;
- printk("CPU %d ", cpu);
+ show_regs_print_info(KERN_DEFAULT);
__show_regs(regs, 1);
- printk(KERN_DEFAULT "Process %s (pid: %d, threadinfo %p, task %p)\n",
- cur->comm, cur->pid, task_thread_info(cur), cur);

/*
* When in-kernel, we also print out the stack and code at the
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae100..7646378 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -121,30 +121,6 @@ void exit_thread(void)
drop_fpu(me);
}

-void show_regs_common(void)
-{
- const char *vendor, *product, *board;
-
- vendor = dmi_get_system_info(DMI_SYS_VENDOR);
- if (!vendor)
- vendor = "";
- product = dmi_get_system_info(DMI_PRODUCT_NAME);
- if (!product)
- product = "";
-
- /* Board Name is optional */
- board = dmi_get_system_info(DMI_BOARD_NAME);
-
- printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s %s%s%s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version,
- vendor, product,
- board ? "/" : "",
- board ? board : "");
-}
-
void flush_thread(void)
{
struct task_struct *tsk = current;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b5a8905..7305f7d 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -84,8 +84,6 @@ void __show_regs(struct pt_regs *regs, int all)
savesegment(gs, gs);
}

- show_regs_common();
-
printk(KERN_DEFAULT "EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
(u16)regs->cs, regs->ip, regs->flags,
smp_processor_id());
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0f49677..355ae06 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -62,7 +62,6 @@ void __show_regs(struct pt_regs *regs, int all)
unsigned int fsindex, gsindex;
unsigned int ds, cs, es;

- show_regs_common();
printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
printk_address(regs->ip, 1);
printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 384b7c7..458186d 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -383,6 +383,8 @@ void show_regs(struct pt_regs * regs)
{
int i, wmask;

+ show_regs_print_info(KERN_DEFAULT);
+
wmask = regs->wmask & ~1;

for (i = 0; i < 16; i++) {
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 73788ff..d42b26a 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -181,6 +181,8 @@ extern void dump_stack_set_arch_desc(const char *fmt, ...);
extern void dump_stack_print_info(const char *log_lvl);
extern void dump_stack(void) __cold;

+extern void show_regs_print_info(const char *log_lvl);
+
#ifndef pr_fmt
#define pr_fmt(fmt) fmt
#endif
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 93573ec..520a878 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -57,3 +57,19 @@ void dump_stack(void)
show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);
+
+/**
+ * show_regs_print_info - print generic debug info for show_regs()
+ * @log_lvl: log level
+ *
+ * show_regs() implementations can use this function to print out generic
+ * debug information.
+ */
+void show_regs_print_info(const char *log_lvl)
+{
+ dump_stack_print_info(log_lvl);
+
+ printk("%sCPU:%d task: %p ti: %p task.ti: %p\n",
+ log_lvl, raw_smp_processor_id(), current, current_thread_info(),
+ task_thread_info(current));
+}
--
1.8.1.4

2013-03-30 03:24:59

by Tejun Heo

Subject: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

show_regs() is inherently arch-dependent but it does make sense to
print generic debug information and some archs already do albeit in
slightly different forms. This patch introduces a generic function to
print debug information from show_regs() so that different archs print
out the same information and it's much easier to modify what's
printed.

show_regs_print_current() prints out the same debug info as
dump_stack() does plus CPU, task and thread_info pointers.

* Archs which didn't print debug info now do.

alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
um, xtensa

* Already prints debug info. Replaced with show_regs_print_current().
The printed information is superset of what used to be there.

arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* The printed debug information includes arch-specific bits. Left
alone.

s390

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

kernel BUG at /work/os/work/kernel/workqueue.c:4841!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
Call Trace:
[<ffffffff81000312>] do_one_initcall+0x122/0x170
[<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
...

v2: Typo fix in x86-32.

Signed-off-by: Tejun Heo <[email protected]>
---
Silly last minute mistake in x86-32. git branch updated accordingly.

Thanks.

arch/alpha/kernel/process.c | 1 +
arch/arc/kernel/troubleshoot.c | 1 +
arch/arm/kernel/process.c | 8 ++------
arch/arm64/kernel/process.c | 7 +------
arch/avr32/kernel/process.c | 5 ++---
arch/blackfin/kernel/trace.c | 2 ++
arch/c6x/kernel/traps.c | 1 +
arch/cris/arch-v10/kernel/process.c | 3 +++
arch/cris/arch-v32/kernel/process.c | 3 +++
arch/frv/kernel/traps.c | 3 +--
arch/h8300/kernel/process.c | 2 ++
arch/hexagon/kernel/vm_events.c | 2 ++
arch/ia64/kernel/process.c | 4 ++--
arch/m32r/kernel/process.c | 2 ++
arch/metag/kernel/process.c | 2 ++
arch/microblaze/kernel/process.c | 2 ++
arch/mips/kernel/traps.c | 2 +-
arch/mn10300/kernel/process.c | 1 +
arch/openrisc/kernel/process.c | 1 +
arch/parisc/kernel/traps.c | 2 ++
arch/powerpc/kernel/process.c | 8 ++------
arch/score/kernel/traps.c | 2 ++
arch/sh/kernel/process_32.c | 6 +-----
arch/sh/kernel/process_64.c | 1 +
arch/sparc/kernel/process_32.c | 2 ++
arch/sparc/kernel/process_64.c | 2 ++
arch/tile/kernel/process.c | 3 +--
arch/um/sys-ppc/sysrq.c | 2 ++
arch/unicore32/kernel/process.c | 6 +-----
arch/x86/include/asm/bug.h | 3 ---
arch/x86/kernel/dumpstack_32.c | 4 +---
arch/x86/kernel/dumpstack_64.c | 6 +-----
arch/x86/kernel/process.c | 24 ------------------------
arch/x86/kernel/process_32.c | 2 --
arch/x86/kernel/process_64.c | 1 -
arch/xtensa/kernel/traps.c | 2 ++
include/linux/printk.h | 2 ++
lib/dump_stack.c | 16 ++++++++++++++++
38 files changed, 70 insertions(+), 76 deletions(-)

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 63d27fb..7085cb8 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -194,6 +194,7 @@ machine_power_off(void)
void
show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
dik_show_regs(regs, NULL);
}

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 7c10873..96be1e6 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -163,6 +163,7 @@ void show_regs(struct pt_regs *regs)
return;

print_task_path_n_nm(tsk, buf);
+ show_regs_print_info(KERN_INFO);

if (current->thread.cause_code)
show_ecr_verbose(regs);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 047d3e4..3e63a0a 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -273,11 +273,8 @@ void __show_regs(struct pt_regs *regs)
unsigned long flags;
char buf[64];

- printk("CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
+
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->ARM_lr);
printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
@@ -332,7 +329,6 @@ void __show_regs(struct pt_regs *regs)
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
__show_regs(regs);
dump_stack();
}
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 0337cdb..4f812bb 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -178,11 +178,7 @@ void __show_regs(struct pt_regs *regs)
{
int i;

- printk("CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->regs[30]);
printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
@@ -199,7 +195,6 @@ void __show_regs(struct pt_regs *regs)
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
__show_regs(regs);
}

diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index c1cafdb..63c9e8c 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -224,6 +224,8 @@ void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
unsigned long lr = regs->lr;
unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;

+ show_regs_print_info(log_lvl);
+
if (!user_mode(regs)) {
sp = (unsigned long)regs + FRAME_SIZE_FULL;

@@ -261,9 +263,6 @@ void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
regs->sr & SR_I0M ? '0' : '.',
regs->sr & SR_GM ? 'G' : 'g');
printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
- printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
- log_lvl, current->comm, current->pid, current,
- task_thread_info(current));
}

void show_regs(struct pt_regs *regs)
diff --git a/arch/blackfin/kernel/trace.c b/arch/blackfin/kernel/trace.c
index f7f7a18..c36efa0 100644
--- a/arch/blackfin/kernel/trace.c
+++ b/arch/blackfin/kernel/trace.c
@@ -853,6 +853,8 @@ void show_regs(struct pt_regs *fp)
unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();

pr_notice("\n");
+ show_regs_print_info(KERN_NOTICE);
+
if (CPUID != bfin_cpuid())
pr_notice("Compiled for cpu family 0x%04x (Rev %d), "
"but running on:0x%04x (Rev %d)\n",
diff --git a/arch/c6x/kernel/traps.c b/arch/c6x/kernel/traps.c
index d0b96ef..dcc2c2f 100644
--- a/arch/c6x/kernel/traps.c
+++ b/arch/c6x/kernel/traps.c
@@ -31,6 +31,7 @@ void __init trap_init(void)
void show_regs(struct pt_regs *regs)
{
pr_err("\n");
+ show_regs_print_info(KERN_ERR);
pr_err("PC: %08lx SP: %08lx\n", regs->pc, regs->sp);
pr_err("Status: %08lx ORIG_A4: %08lx\n", regs->csr, regs->orig_a4);
pr_err("A0: %08lx B0: %08lx\n", regs->a0, regs->b0);
diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c
index b101875..9087bbf 100644
--- a/arch/cris/arch-v10/kernel/process.c
+++ b/arch/cris/arch-v10/kernel/process.c
@@ -175,6 +175,9 @@ unsigned long get_wchan(struct task_struct *p)
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
+
+ show_regs_print_info(KERN_DEFAULT);
+
printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
regs->irp, regs->srp, regs->dccr, usp, regs->mof );
printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c
index 2b23ef0..09fd16c 100644
--- a/arch/cris/arch-v32/kernel/process.c
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -170,6 +170,9 @@ get_wchan(struct task_struct *p)
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
+
+ show_regs_print_info(KERN_DEFAULT);
+
printk("ERP: %08lx SRP: %08lx CCS: %08lx USP: %08lx MOF: %08lx\n",
regs->erp, regs->srp, regs->ccs, usp, regs->mof);

diff --git a/arch/frv/kernel/traps.c b/arch/frv/kernel/traps.c
index cfcd802..4bff48c 100644
--- a/arch/frv/kernel/traps.c
+++ b/arch/frv/kernel/traps.c
@@ -497,6 +497,7 @@ void show_regs(struct pt_regs *regs)
int loop;

printk("\n");
+ show_regs_print_info(KERN_DEFAULT);

printk("Frame: @%08lx [%s]\n",
(unsigned long) regs,
@@ -511,8 +512,6 @@ void show_regs(struct pt_regs *regs)
else
printk(" | ");
}
-
- printk("Process %s (pid: %d)\n", current->comm, current->pid);
}

void die_if_kernel(const char *str, ...)
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index b609f63..8f235a3 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -110,6 +110,8 @@ void machine_power_off(void)

void show_regs(struct pt_regs * regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("\nPC: %08lx Status: %02x",
regs->pc, regs->ccr);
printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx",
diff --git a/arch/hexagon/kernel/vm_events.c b/arch/hexagon/kernel/vm_events.c
index 9b5a4a2..f337281 100644
--- a/arch/hexagon/kernel/vm_events.c
+++ b/arch/hexagon/kernel/vm_events.c
@@ -33,6 +33,8 @@
*/
void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_EMERG);
+
printk(KERN_EMERG "restart_r0: \t0x%08lx syscall_nr: %ld\n",
regs->restart_r0, regs->syscall_nr);
printk(KERN_EMERG "preds: \t\t0x%08lx\n", regs->preds);
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 29fb256..492dc45 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -101,8 +101,8 @@ show_regs (struct pt_regs *regs)
unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;

print_modules();
- printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
- smp_processor_id(), current->comm);
+ printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n",
regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
init_utsname()->release);
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index bde899e..892a1d9 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -91,6 +91,8 @@ void machine_power_off(void)
void show_regs(struct pt_regs * regs)
{
printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
+
printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
regs->bpc, regs->psw, regs->lr, regs->fp);
printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
diff --git a/arch/metag/kernel/process.c b/arch/metag/kernel/process.c
index c6efe62..cfe4e7f 100644
--- a/arch/metag/kernel/process.c
+++ b/arch/metag/kernel/process.c
@@ -152,6 +152,8 @@ void show_regs(struct pt_regs *regs)
"D1.7 "
};

+ show_regs_print_info(KERN_INFO);
+
pr_info(" pt_regs @ %p\n", regs);
pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index fa0ea60..d55700c 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -20,6 +20,8 @@

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_INFO);
+
pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
regs->r1, regs->r2, regs->r3, regs->r4);
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 93f9b26..1b383a9 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -231,7 +231,7 @@ static void __show_regs(const struct pt_regs *regs)
unsigned int cause = regs->cp0_cause;
int i;

- printk("Cpu %d\n", smp_processor_id());
+ show_regs_print_info(KERN_DEFAULT);

/*
* Saved main processor registers
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 84f4e97..1223770 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -155,6 +155,7 @@ void machine_power_off(void)

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
}

/*
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index 00c233b..386af25 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -90,6 +90,7 @@ void show_regs(struct pt_regs *regs)
{
extern void show_registers(struct pt_regs *regs);

+ show_regs_print_info(KERN_DEFAULT);
/* __PHX__ cleanup this mess */
show_registers(regs);
}
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index e64cf5f..f702bff 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -126,6 +126,8 @@ void show_regs(struct pt_regs *regs)
user = user_mode(regs);
level = user ? KERN_DEBUG : KERN_CRIT;

+ show_regs_print_info(level);
+
print_gr(level, regs);

for (i = 0; i < 8; i += 4)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2e6f83a..fd1b300 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -829,6 +829,8 @@ void show_regs(struct pt_regs * regs)
{
int i, trap;

+ show_regs_print_info(KERN_DEFAULT);
+
printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
regs->nip, regs->link, regs->ctr);
printk("REGS: %p TRAP: %04lx %s (%s)\n",
@@ -848,12 +850,6 @@ void show_regs(struct pt_regs * regs)
#else
printk("DAR: "REG", DSISR: %08lx\n", regs->dar, regs->dsisr);
#endif
- printk("TASK = %p[%d] '%s' THREAD: %p",
- current, task_pid_nr(current), current->comm, task_thread_info(current));
-
-#ifdef CONFIG_SMP
- printk(" CPU: %d", raw_smp_processor_id());
-#endif /* CONFIG_SMP */

for (i = 0; i < 32; i++) {
if ((i % REGS_PER_LINE) == 0)
diff --git a/arch/score/kernel/traps.c b/arch/score/kernel/traps.c
index a38f435..1517a7d 100644
--- a/arch/score/kernel/traps.c
+++ b/arch/score/kernel/traps.c
@@ -117,6 +117,8 @@ static void show_code(unsigned int *pc)
*/
void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("r0 : %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3],
regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 73eb66f..ebd3933 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -32,11 +32,7 @@
void show_regs(struct pt_regs * regs)
{
printk("\n");
- printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
- printk("CPU : %d \t\t%s (%s %.*s)\n\n",
- smp_processor_id(), print_tainted(), init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);

print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("PR is at %s\n", regs->pr);
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index e611c85..174d124 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -40,6 +40,7 @@ void show_regs(struct pt_regs *regs)
unsigned long long ah, al, bh, bl, ch, cl;

printk("\n");
+ show_regs_print_info(KERN_DEFAULT);

ah = (regs->pc) >> 32;
al = (regs->pc) & 0xffffffff;
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index fe99fbd..9e78f9a 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -123,6 +123,8 @@ void show_regs(struct pt_regs *r)
{
struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];

+ show_regs_print_info(KERN_DEFAULT);
+
printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
r->psr, r->pc, r->npc, r->y, print_tainted());
printk("PC: <%pS>\n", (void *) r->pc);
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index cdb80b2..2415a95 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -186,6 +186,8 @@ static void show_regwindow(struct pt_regs *regs)

void show_regs(struct pt_regs *regs)
{
+ show_regs_print_info(KERN_DEFAULT);
+
printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate,
regs->tpc, regs->tnpc, regs->y, print_tainted());
printk("TPC: <%pS>\n", (void *) regs->tpc);
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index caf93ae..302691d 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -620,8 +620,7 @@ void show_regs(struct pt_regs *regs)
int i;

pr_err("\n");
- pr_err(" Pid: %d, comm: %20s, CPU: %d\n",
- tsk->pid, tsk->comm, smp_processor_id());
+ show_regs_print_info(KERN_ERR);
#ifdef __tilegx__
for (i = 0; i < 51; i += 3)
pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
diff --git a/arch/um/sys-ppc/sysrq.c b/arch/um/sys-ppc/sysrq.c
index f889449..1ff1ad7 100644
--- a/arch/um/sys-ppc/sysrq.c
+++ b/arch/um/sys-ppc/sysrq.c
@@ -11,6 +11,8 @@
void show_regs(struct pt_regs_subarch *regs)
{
printk("\n");
+ show_regs_print_info(KERN_DEFAULT);
+
printk("show_regs(): insert regs here.\n");
#if 0
printk("\n");
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index 872d7e2..c412484 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -159,11 +159,7 @@ void __show_regs(struct pt_regs *regs)
unsigned long flags;
char buf[64];

- printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
- raw_smp_processor_id(), print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
+ show_regs_print_info(KERN_DEFAULT);
print_symbol("PC is at %s\n", instruction_pointer(regs));
print_symbol("LR is at %s\n", regs->UCreg_lr);
printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 11e1152..2f03ff0 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -37,7 +37,4 @@ do { \

#include <asm-generic/bug.h>

-
-extern void show_regs_common(void);
-
#endif /* _ASM_X86_BUG_H */
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 1038a41..f2a1770 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -86,11 +86,9 @@ void show_regs(struct pt_regs *regs)
{
int i;

+ show_regs_print_info(KERN_EMERG);
__show_regs(regs, !user_mode_vm(regs));

- pr_emerg("Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
- TASK_COMM_LEN, current->comm, task_pid_nr(current),
- current_thread_info(), current, task_thread_info(current));
/*
* When in-kernel, we also print out the stack and code at the
* time of the fault..
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index b653675..addb207 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -249,14 +249,10 @@ void show_regs(struct pt_regs *regs)
{
int i;
unsigned long sp;
- const int cpu = smp_processor_id();
- struct task_struct *cur = current;

sp = regs->sp;
- printk("CPU %d ", cpu);
+ show_regs_print_info(KERN_DEFAULT);
__show_regs(regs, 1);
- printk(KERN_DEFAULT "Process %s (pid: %d, threadinfo %p, task %p)\n",
- cur->comm, cur->pid, task_thread_info(cur), cur);

/*
* When in-kernel, we also print out the stack and code at the
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae100..7646378 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -121,30 +121,6 @@ void exit_thread(void)
drop_fpu(me);
}

-void show_regs_common(void)
-{
- const char *vendor, *product, *board;
-
- vendor = dmi_get_system_info(DMI_SYS_VENDOR);
- if (!vendor)
- vendor = "";
- product = dmi_get_system_info(DMI_PRODUCT_NAME);
- if (!product)
- product = "";
-
- /* Board Name is optional */
- board = dmi_get_system_info(DMI_BOARD_NAME);
-
- printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s %s%s%s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version,
- vendor, product,
- board ? "/" : "",
- board ? board : "");
-}
-
void flush_thread(void)
{
struct task_struct *tsk = current;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b5a8905..7305f7d 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -84,8 +84,6 @@ void __show_regs(struct pt_regs *regs, int all)
savesegment(gs, gs);
}

- show_regs_common();
-
printk(KERN_DEFAULT "EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
(u16)regs->cs, regs->ip, regs->flags,
smp_processor_id());
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0f49677..355ae06 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -62,7 +62,6 @@ void __show_regs(struct pt_regs *regs, int all)
unsigned int fsindex, gsindex;
unsigned int ds, cs, es;

- show_regs_common();
printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
printk_address(regs->ip, 1);
printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 384b7c7..458186d 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -383,6 +383,8 @@ void show_regs(struct pt_regs * regs)
{
int i, wmask;

+ show_regs_print_info(KERN_DEFAULT);
+
wmask = regs->wmask & ~1;

for (i = 0; i < 16; i++) {
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 73788ff..d42b26a 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -181,6 +181,8 @@ extern void dump_stack_set_arch_desc(const char *fmt, ...);
extern void dump_stack_print_info(const char *log_lvl);
extern void dump_stack(void) __cold;

+extern void show_regs_print_info(const char *log_lvl);
+
#ifndef pr_fmt
#define pr_fmt(fmt) fmt
#endif
diff --git a/lib/dump_stack.c b/lib/dump_stack.c
index 93573ec..520a878 100644
--- a/lib/dump_stack.c
+++ b/lib/dump_stack.c
@@ -57,3 +57,19 @@ void dump_stack(void)
show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);
+
+/**
+ * show_regs_print_info - print generic debug info for show_regs()
+ * @log_lvl: log level
+ *
+ * show_regs() implementations can use this function to print out generic
+ * debug information.
+ */
+void show_regs_print_info(const char *log_lvl)
+{
+ dump_stack_print_info(log_lvl);
+
+ printk("%sCPU:%d task: %p ti: %p task.ti: %p\n",
+ log_lvl, raw_smp_processor_id(), current, current_thread_info(),
+ task_thread_info(current));
+}
--
1.8.1.4

2013-03-30 03:29:37

by David Miller

Subject: Re: [PATCH 2/5] sparc32: make show_stack() acquire %fp if @_ksp is not specified

From: Tejun Heo <[email protected]>
Date: Fri, 29 Mar 2013 19:27:05 -0700

> show_stack(current or NULL, NULL) is used by arch-independent code to
> dump backtrace of the current task; however, sparc32 show_stack()
> doesn't implement it and wouldn't print any backtrace when NULL @_ksp
> is specfied.
>
> Make show_stack() acquire and use %fp if @tsk is NULL or current and
> @_ksp is NULL. This makes %fp fetching in dump_stack() unnecessary.
> Make it use NULL for @_ksp instead.
>
> Only compile tested.
>
> Signed-off-by: Tejun Heo <[email protected]>

Acked-by: David S. Miller <[email protected]>

2013-03-30 03:30:09

by David Miller

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

From: Tejun Heo <[email protected]>
Date: Fri, 29 Mar 2013 19:27:06 -0700

> Both dump_stack() and show_stack() are currently implemented by each
> architecture. show_stack(NULL, NULL) dumps the backtrace for the
> current task as does dump_stack(). On some archs, dump_stack() prints
> extra information - pid, utsname and so on - in addition to the
> backtrace while the two are identical on other archs.
>
> The usages in arch-independent code of the two functions indicate
> show_stack(NULL, NULL) should print out bare backtrace while
> dump_stack() is used for debugging purposes when something went wrong,
> so it does make sense to print additional information on the task
> which triggered dump_stack().
>
> There's no reason to require archs to implement two separate but
> mostly identical functions. It leads to unnecessary subtle
> differences among archs and makes it very tedius to add generic debug
> information.
>
> This patch expands the dummy fallback dump_stack() implementation in
> lib/dump_stack.c such that it prints out debug information (taken from
> x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> dump_stack() implementations in all archs except blackfin and s390.
> Blackfin's dump_stack() does something wonky that I don't understand
> and s390 prints its own debug information which includes fields which
> aren't accessible from arch-indepdent code.
>
> Debug information can be printed separately by calling
> dump_stack_print_info() so that arch-specific dump_stack()
> implementation can still emit the same debug information. This is
> used in blackfin.
>
> This patch brings the following behavior changes.
>
> * On some archs, an extra level in backtrace for show_stack() could be
> printed. This is because the top frame was determined in
> dump_stack() on those archs while generic dump_stack() can't do that
> reliably. It can be compensated by inlining dump_stack() but not
> sure whether that'd be necessary.
>
> * Most archs didn't use to print debug info on dump_stack(). They do
> now.
>
> An example WARN dump follows.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Hardware name: empty
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #17
> 0000000000000009 ffff88007c861e08 ffffffff81c61545 ffff88007c861e48
> ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61545>] dump_stack+0x19/0x1b
> [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
> [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a071>] init_workqueues+0x35/0x505
> ...
>
> Signed-off-by: Tejun Heo <[email protected]>

For sparc bits:

Acked-by: David S. Miller <[email protected]>

2013-03-30 03:30:58

by David Miller

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

From: Tejun Heo <[email protected]>
Date: Fri, 29 Mar 2013 20:24:45 -0700

> show_regs() is inherently arch-dependent but it does make sense to
> print generic debug information and some archs already do albeit in
> slightly different forms. This patch introduces a generic function to
> print debug information from show_regs() so that different archs print
> out the same information and it's much easier to modify what's
> printed.
>
> show_regs_print_current() prints out the same debug info as
> dump_stack() does plus CPU, task and thread_info pointers.
>
> * Archs which didn't print debug info now do.
>
> alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
> metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
> um, xtensa
>
> * Already prints debug info. Replaced with show_regs_print_current().
> The printed information is superset of what used to be there.
>
> arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
>
> * The printed debug information includes arch-specific bits. Left
> alone.
>
> s390
>
> Note that now all archs print the debug info before actual register
> dumps.
>
> An example BUG() dump follows.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
> RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> v2: Typo fix in x86-32.
>
> Signed-off-by: Tejun Heo <[email protected]>

For sparc bits:

Acked-by: David S. Miller <[email protected]>

2013-03-30 05:28:30

by Vineet Gupta

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

On 03/30/2013 07:57 AM, Tejun Heo wrote:
> Both dump_stack() and show_stack() are currently implemented by each
> architecture. show_stack(NULL, NULL) dumps the backtrace for the
> current task as does dump_stack(). On some archs, dump_stack() prints
> extra information - pid, utsname and so on - in addition to the
> backtrace while the two are identical on other archs.
>
> The usages in arch-independent code of the two functions indicate
> show_stack(NULL, NULL) should print out bare backtrace while
> dump_stack() is used for debugging purposes when something went wrong,
> so it does make sense to print additional information on the task
> which triggered dump_stack().
>
> There's no reason to require archs to implement two separate but
> mostly identical functions. It leads to unnecessary subtle
> differences among archs and makes it very tedius to add generic debug
> information.
>
> This patch expands the dummy fallback dump_stack() implementation in
> lib/dump_stack.c such that it prints out debug information (taken from
> x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> dump_stack() implementations in all archs except blackfin and s390.
> Blackfin's dump_stack() does something wonky that I don't understand
> and s390 prints its own debug information which includes fields which
> aren't accessible from arch-indepdent code.
>
> Debug information can be printed separately by calling
> dump_stack_print_info() so that arch-specific dump_stack()
> implementation can still emit the same debug information. This is
> used in blackfin.
>
> This patch brings the following behavior changes.
>
> * On some archs, an extra level in backtrace for show_stack() could be
> printed. This is because the top frame was determined in
> dump_stack() on those archs while generic dump_stack() can't do that
> reliably. It can be compensated by inlining dump_stack() but not
> sure whether that'd be necessary.
>
> * Most archs didn't use to print debug info on dump_stack(). They do
> now.
>
> An example WARN dump follows.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Hardware name: empty
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #17
> 0000000000000009 ffff88007c861e08 ffffffff81c61545 ffff88007c861e48
> ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61545>] dump_stack+0x19/0x1b
> [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
> [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a071>] init_workqueues+0x35/0x505
> ...
>
> Signed-off-by: Tejun Heo <[email protected]>

For arch/arc bits

Acked-by: Vineet Gupta <[email protected]>

Thx,
-Vineet

2013-03-30 06:13:42

by Vineet Gupta

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

Hi Tejun,

On 03/30/2013 08:54 AM, Tejun Heo wrote:
> show_regs() is inherently arch-dependent but it does make sense to
> print generic debug information and some archs already do albeit in
> slightly different forms. This patch introduces a generic function to
> print debug information from show_regs() so that different archs print
> out the same information and it's much easier to modify what's
> printed.
>
> show_regs_print_current() prints out the same debug info as
> dump_stack() does plus CPU, task and thread_info pointers.
>
> * Archs which didn't print debug info now do.
>
> alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
> metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
> um, xtensa
>
> * Already prints debug info. Replaced with show_regs_print_current().
> The printed information is superset of what used to be there.
>
> arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
>
> * The printed debug information includes arch-specific bits. Left
> alone.
>
> s390
>
> Note that now all archs print the debug info before actual register
> dumps.
>
> An example BUG() dump follows.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
> RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> v2: Typo fix in x86-32.
>
> Signed-off-by: Tejun Heo <[email protected]>
> ---
> Silly last minute mistake in x86-32. git branch updated accordingly.
>
> Thanks.
>
> arch/alpha/kernel/process.c | 1 +
> arch/arc/kernel/troubleshoot.c | 1 +
> arch/arm/kernel/process.c | 8 ++------
> arch/arm64/kernel/process.c | 7 +------
> arch/avr32/kernel/process.c | 5 ++---
> arch/blackfin/kernel/trace.c | 2 ++
> arch/c6x/kernel/traps.c | 1 +
> arch/cris/arch-v10/kernel/process.c | 3 +++
> arch/cris/arch-v32/kernel/process.c | 3 +++
> arch/frv/kernel/traps.c | 3 +--
> arch/h8300/kernel/process.c | 2 ++
> arch/hexagon/kernel/vm_events.c | 2 ++
> arch/ia64/kernel/process.c | 4 ++--
> arch/m32r/kernel/process.c | 2 ++
> arch/metag/kernel/process.c | 2 ++
> arch/microblaze/kernel/process.c | 2 ++
> arch/mips/kernel/traps.c | 2 +-
> arch/mn10300/kernel/process.c | 1 +
> arch/openrisc/kernel/process.c | 1 +
> arch/parisc/kernel/traps.c | 2 ++
> arch/powerpc/kernel/process.c | 8 ++------
> arch/score/kernel/traps.c | 2 ++
> arch/sh/kernel/process_32.c | 6 +-----
> arch/sh/kernel/process_64.c | 1 +
> arch/sparc/kernel/process_32.c | 2 ++
> arch/sparc/kernel/process_64.c | 2 ++
> arch/tile/kernel/process.c | 3 +--
> arch/um/sys-ppc/sysrq.c | 2 ++
> arch/unicore32/kernel/process.c | 6 +-----
> arch/x86/include/asm/bug.h | 3 ---
> arch/x86/kernel/dumpstack_32.c | 4 +---
> arch/x86/kernel/dumpstack_64.c | 6 +-----
> arch/x86/kernel/process.c | 24 ------------------------
> arch/x86/kernel/process_32.c | 2 --
> arch/x86/kernel/process_64.c | 1 -
> arch/xtensa/kernel/traps.c | 2 ++
> include/linux/printk.h | 2 ++
> lib/dump_stack.c | 16 ++++++++++++++++
> 38 files changed, 70 insertions(+), 76 deletions(-)
>
[..]
>
> diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
> index 7c10873..96be1e6 100644
> --- a/arch/arc/kernel/troubleshoot.c
> +++ b/arch/arc/kernel/troubleshoot.c
> @@ -163,6 +163,7 @@ void show_regs(struct pt_regs *regs)
> return;
>
> print_task_path_n_nm(tsk, buf);
> + show_regs_print_info(KERN_INFO);
>
> if (current->thread.cause_code)
> show_ecr_verbose(regs);

With print-fatal-signals enabled, this will also be called for dumping user mode
register state. With your patch, we now get something like this

----------->8-------------------------
[ARCLinux]$ ./crash
crash/50: potentially unexpected fatal signal 11. <-- [1]
/sbin/crash, TGID 50 <-- [2]
Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 <-- [3]
CPU:0 task: 8e11c2c0 ti: 8e136000 task.ti: 8e136000

[ECR]: 0x00230400 => Misaligned r/w from 0x0001036a
[EFA]: 0x0001036a
[ERET]: 0x0001036a (PC of Faulting Instr)
...
...
----------->8-------------------------

Clearly there's duplication (rather triplication) of task name and tgid output.

Although in line [2], ARC trouble-shooting code prints the task path (rather than
comm). This was done to help identify faulting LTP open posix tests with same name
in different directories: e.g. fork/6-1, sigqueue/6-1 ....
Is this something you want to add to generic code as well - although it's slightly
involved due to tsk/mm locking etc.

Also I personally prefer the more compact <task-nm>/<tgid> format of [1] vs. [3].

Anyhow, can you please fold the following into your patchset to reduce above
duplication.

------------------->
>From 15e8d65f35385148f81d87aadadd7791ba79663c Mon Sep 17 00:00:00 2001
From: Vineet Gupta <[email protected]>
Date: Sat, 30 Mar 2013 11:35:23 +0530
Subject: [PATCH] print-fatal-signals: reduce duplicated information

----------->8------------
[ARCLinux]$ ./crash
crash/50: potentially unexpected fatal signal 11. <-- [1]
/sbin/crash, TGID 50 <-- [2]
Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 <-- [3]
...
----------->8------------

Signed-off-by: Vineet Gupta <[email protected]>
---
arch/arc/kernel/troubleshoot.c | 2 +-
kernel/signal.c | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 96be1e6..0aec0198 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c
@@ -71,7 +71,7 @@ void print_task_path_n_nm(struct task_struct *tsk, char *buf)
}

done:
- pr_info("%s, TGID %u\n", path_nm, tsk->tgid);
+ pr_info("Path: %s\n", path_nm);
}
EXPORT_SYMBOL(print_task_path_n_nm);

diff --git a/kernel/signal.c b/kernel/signal.c
index dd72567..9c4ef65 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1160,8 +1160,7 @@ static int send_signal(int sig, struct siginfo *info, struct
task_struct *t,
static void print_fatal_signal(int signr)
{
struct pt_regs *regs = signal_pt_regs();
- printk(KERN_INFO "%s/%d: potentially unexpected fatal signal %d.\n",
- current->comm, task_pid_nr(current), signr);
+ printk(KERN_INFO "potentially unexpected fatal signal %d.\n", signr);

#if defined(__i386__) && !defined(__arch_um__)
printk(KERN_INFO "code at %08lx: ", regs->ip);
--
1.7.10.4

2013-03-30 11:45:47

by Heiko Carstens

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

On Fri, Mar 29, 2013 at 07:27:06PM -0700, Tejun Heo wrote:
> Both dump_stack() and show_stack() are currently implemented by each
> architecture. show_stack(NULL, NULL) dumps the backtrace for the
> current task as does dump_stack(). On some archs, dump_stack() prints
> extra information - pid, utsname and so on - in addition to the
> backtrace while the two are identical on other archs.

[...]

> This patch expands the dummy fallback dump_stack() implementation in
> lib/dump_stack.c such that it prints out debug information (taken from
> x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> dump_stack() implementations in all archs except blackfin and s390.
> Blackfin's dump_stack() does something wonky that I don't understand
> and s390 prints its own debug information which includes fields which
> aren't accessible from arch-indepdent code.

The couple of extra fields aren't worth an s390 version of dump_stack()
that differs from all other architectures.
Please drop the s390 version as well. Thanks!

2013-04-01 18:11:42

by Bjorn Helgaas

Subject: Re: [PATCH 4/5] dump_stack: implement arch-specific hardware description in task dumps

On Fri, Mar 29, 2013 at 8:27 PM, Tejun Heo <[email protected]> wrote:
> x86 and ia64 can acquire extra hardware identification information
> from DMI and print it along with task dumps; however, the usage isn't
> consistent.
>
> * x86 show_regs() collects vendor, product and board strings and print
> them out with PID, comm and utsname. Some of the information is
> printed again later in the same dump.
>
> * warn_slowpath_common() explicitly accesses the DMI board and prints
> it out with "Hardware name:" label. This applies to both x86 and
> ia64 but is irrelevant on all other archs.
>
> * ia64 doesn't show DMI information on other non-WARN dumps.
>
> This patch introduces arch-specific hardware description used by
> dump_stack(). It can be set by calling dump_stack_set_arch_desc()
> during boot and printed out along with utsname.
>
> dmi_set_dump_stack_arch_desc() is added which sets arch-specific
> description from DMI data. It uses the same information and
> formatting as x86 show_regs() is using. The function is called from
> x86 and ia64 boot code right after dmi_scan_machine().
>
> This makes the explicit DMI handling in warn_slowpath_common()
> unnecessary. Removed.
>
> show_regs() isn't yet converted to use generic debug information
> printing and this patch doesn't remove the duplicate DMI handling in
> x86 show_regs(). The next patch will unify show_regs() handling and
> remove the duplication.
>
> An example WARN dump follows.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #18 empty empty/S3992
> 0000000000000009 ffff88007c861e08 ffffffff81c61525 ffff88007c861e48
> ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a041
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61525>] dump_stack+0x19/0x1b
> [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
> [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a076>] init_workqueues+0x35/0x505
> ...
>
> Signed-off-by: Tejun Heo <[email protected]>
> ---
> arch/ia64/kernel/setup.c | 1 +
> arch/x86/kernel/setup.c | 1 +
> drivers/firmware/dmi_scan.c | 26 ++++++++++++++++++++++++++
> include/linux/dmi.h | 2 ++
> include/linux/printk.h | 1 +
> kernel/panic.c | 6 ------
> lib/dump_stack.c | 26 ++++++++++++++++++++++++--
> 7 files changed, 55 insertions(+), 8 deletions(-)
>
> diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
> index 2029cc0..13bfdd2 100644
> --- a/arch/ia64/kernel/setup.c
> +++ b/arch/ia64/kernel/setup.c
> @@ -1063,6 +1063,7 @@ check_bugs (void)
> static int __init run_dmi_scan(void)
> {
> dmi_scan_machine();
> + dmi_set_dump_stack_arch_desc();
> return 0;
> }
> core_initcall(run_dmi_scan);
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 90d8cc9..91b9e7c 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -970,6 +970,7 @@ void __init setup_arch(char **cmdline_p)
> efi_init();
>
> dmi_scan_machine();
> + dmi_set_dump_stack_arch_desc();
>
> /*
> * VMware detection requires dmi to be available, so this
> diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
> index 4cd392d..9e7766b 100644
> --- a/drivers/firmware/dmi_scan.c
> +++ b/drivers/firmware/dmi_scan.c
> @@ -521,6 +521,32 @@ void __init dmi_scan_machine(void)
> }
>
> /**
> + * dmi_set_dump_stack_arch_desc - set arch description for dump_stack()
> + *
> + * Invoke dump_stack_set_arch_desc() with DMI system information so that
> + * DMI identifiers are printed out on task dumps. Arch boot code should
> + * call this function after dmi_scan_machine() if it wants to print out DMI
> + * identifiers on task dumps.
> + */
> +void __init dmi_set_dump_stack_arch_desc(void)
> +{
> + const char *vendor, *product, *board;
> +
> + vendor = dmi_get_system_info(DMI_SYS_VENDOR);
> + if (!vendor)
> + vendor = "";
> + product = dmi_get_system_info(DMI_PRODUCT_NAME);
> + if (!product)
> + product = "";
> +
> + /* Board Name is optional */
> + board = dmi_get_system_info(DMI_BOARD_NAME);
> +
> + dump_stack_set_arch_desc("%s %s%s%s", vendor, product,
> + board ? "/" : "", board ? board : "");
> +}

Should this be combined or made consistent with dmi_dump_ids()? They
look almost the same but not quite (no BIOS version here).

> +
> +/**
> * dmi_matches - check if dmi_system_id structure matches system DMI data
> * @dmi: pointer to the dmi_system_id structure to check
> */
> diff --git a/include/linux/dmi.h b/include/linux/dmi.h
> index f156cca..b6eb7a0 100644
> --- a/include/linux/dmi.h
> +++ b/include/linux/dmi.h
> @@ -99,6 +99,7 @@ extern const char * dmi_get_system_info(int field);
> extern const struct dmi_device * dmi_find_device(int type, const char *name,
> const struct dmi_device *from);
> extern void dmi_scan_machine(void);
> +extern void dmi_set_dump_stack_arch_desc(void);
> extern bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp);
> extern int dmi_name_in_vendors(const char *str);
> extern int dmi_name_in_serial(const char *str);
> @@ -114,6 +115,7 @@ static inline const char * dmi_get_system_info(int field) { return NULL; }
> static inline const struct dmi_device * dmi_find_device(int type, const char *name,
> const struct dmi_device *from) { return NULL; }
> static inline void dmi_scan_machine(void) { return; }
> +static inline void dmi_set_dump_stack_arch_desc(void) { }
> static inline bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
> {
> if (yearp)
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index 952c1b2..73788ff 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -177,6 +177,7 @@ static inline void setup_log_buf(int early)
> }
> #endif
>
> +extern void dump_stack_set_arch_desc(const char *fmt, ...);
> extern void dump_stack_print_info(const char *log_lvl);
> extern void dump_stack(void) __cold;
>
> diff --git a/kernel/panic.c b/kernel/panic.c
> index 7c57cc9..167ec09 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -22,7 +22,6 @@
> #include <linux/sysrq.h>
> #include <linux/init.h>
> #include <linux/nmi.h>
> -#include <linux/dmi.h>
>
> #define PANIC_TIMER_STEP 100
> #define PANIC_BLINK_SPD 18
> @@ -400,13 +399,8 @@ struct slowpath_args {
> static void warn_slowpath_common(const char *file, int line, void *caller,
> unsigned taint, struct slowpath_args *args)
> {
> - const char *board;
> -
> printk(KERN_WARNING "------------[ cut here ]------------\n");
> printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
> - board = dmi_get_system_info(DMI_PRODUCT_NAME);
> - if (board)
> - printk(KERN_WARNING "Hardware name: %s\n", board);
>
> if (args)
> vprintk(args->fmt, args->args);
> diff --git a/lib/dump_stack.c b/lib/dump_stack.c
> index 5a67cfc..93573ec 100644
> --- a/lib/dump_stack.c
> +++ b/lib/dump_stack.c
> @@ -8,6 +8,28 @@
> #include <linux/utsname.h>
> #include <linux/export.h>
>
> +static char dump_stack_arch_desc_str[128];
> +
> +/**
> + * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
> + * @fmt: printf-style format string
> + * @...: arguments for the format string
> + *
> + * The configured string will be printed right after utsname during task
> + * dumps. Usually used to add arch-specific system identifiers. If an
> + * arch wants to make use of such an ID string, it should initialize this
> + * as soon as possible during boot.
> + */
> +void __init dump_stack_set_arch_desc(const char *fmt, ...)
> +{
> + va_list args;
> +
> + va_start(args, fmt);
> + vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
> + fmt, args);
> + va_end(args);
> +}
> +
> /**
> * dump_stack_print_info - print generic debug info for dump_stack()
> * @log_lvl: log level
> @@ -17,11 +39,11 @@
> */
> void dump_stack_print_info(const char *log_lvl)
> {
> - printk("%sPid: %d, comm: %.20s %s %s %.*s\n",
> + printk("%sPid: %d, comm: %.20s %s %s %.*s %s\n",
> log_lvl, current->pid, current->comm, print_tainted(),
> init_utsname()->release,
> (int)strcspn(init_utsname()->version, " "),
> - init_utsname()->version);
> + init_utsname()->version, dump_stack_arch_desc_str);
> }
>
> /**
> --
> 1.8.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

2013-04-02 06:48:24

by Martin Schwidefsky

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

On Sat, 30 Mar 2013 12:45:35 +0100
Heiko Carstens <[email protected]> wrote:

> On Fri, Mar 29, 2013 at 07:27:06PM -0700, Tejun Heo wrote:
> > Both dump_stack() and show_stack() are currently implemented by each
> > architecture. show_stack(NULL, NULL) dumps the backtrace for the
> > current task as does dump_stack(). On some archs, dump_stack() prints
> > extra information - pid, utsname and so on - in addition to the
> > backtrace while the two are identical on other archs.
>
> [...]
>
> > This patch expands the dummy fallback dump_stack() implementation in
> > lib/dump_stack.c such that it prints out debug information (taken from
> > x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> > dump_stack() implementations in all archs except blackfin and s390.
> > Blackfin's dump_stack() does something wonky that I don't understand
> > and s390 prints its own debug information which includes fields which
> > aren't accessible from arch-indepdent code.
>
> The couple of extra fields aren't worth an s390 version of dump_stack()
> that differs from all other architectures.
> Please drop the s390 version as well. Thanks!

Hmm, we would lose task_thread_info(current)->cpu and current->thread.ksp,
I don't care much about the kernel stack pointer which has been stored at
the last call to __switch_to but the cpu number might be interesting.
Could we add the cpu number to the generic dump_stack version?

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

2013-04-02 09:21:58

by Jesper Nilsson

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

On Fri, Mar 29, 2013 at 08:24:45PM -0700, Tejun Heo wrote:
> show_regs() is inherently arch-dependent but it does make sense to
> print generic debug information and some archs already do albeit in
> slightly different forms. This patch introduces a generic function to
> print debug information from show_regs() so that different archs print
> out the same information and it's much easier to modify what's
> printed.
>
> show_regs_print_current() prints out the same debug info as
> dump_stack() does plus CPU, task and thread_info pointers.
>
> * Archs which didn't print debug info now do.
>
> alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
> metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
> um, xtensa
>
> * Already prints debug info. Replaced with show_regs_print_current().
> The printed information is superset of what used to be there.
>
> arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
>
> * The printed debug information includes arch-specific bits. Left
> alone.
>
> s390
>
> Note that now all archs print the debug info before actual register
> dumps.
>
> An example BUG() dump follows.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
> RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> v2: Typo fix in x86-32.
>
> Signed-off-by: Tejun Heo <[email protected]>

For the CRIS bits:

Acked-by: Jesper Nilsson <[email protected]>

/^JN - Jesper Nilsson
--
Jesper Nilsson -- [email protected]

2013-04-02 09:22:27

by Jesper Nilsson

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

On Fri, Mar 29, 2013 at 07:27:06PM -0700, Tejun Heo wrote:
> Both dump_stack() and show_stack() are currently implemented by each
> architecture. show_stack(NULL, NULL) dumps the backtrace for the
> current task as does dump_stack(). On some archs, dump_stack() prints
> extra information - pid, utsname and so on - in addition to the
> backtrace while the two are identical on other archs.
>
> The usages in arch-independent code of the two functions indicate
> show_stack(NULL, NULL) should print out bare backtrace while
> dump_stack() is used for debugging purposes when something went wrong,
> so it does make sense to print additional information on the task
> which triggered dump_stack().
>
> There's no reason to require archs to implement two separate but
> mostly identical functions. It leads to unnecessary subtle
> differences among archs and makes it very tedius to add generic debug
> information.
>
> This patch expands the dummy fallback dump_stack() implementation in
> lib/dump_stack.c such that it prints out debug information (taken from
> x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> dump_stack() implementations in all archs except blackfin and s390.
> Blackfin's dump_stack() does something wonky that I don't understand
> and s390 prints its own debug information which includes fields which
> aren't accessible from arch-indepdent code.
>
> Debug information can be printed separately by calling
> dump_stack_print_info() so that arch-specific dump_stack()
> implementation can still emit the same debug information. This is
> used in blackfin.
>
> This patch brings the following behavior changes.
>
> * On some archs, an extra level in backtrace for show_stack() could be
> printed. This is because the top frame was determined in
> dump_stack() on those archs while generic dump_stack() can't do that
> reliably. It can be compensated by inlining dump_stack() but not
> sure whether that'd be necessary.
>
> * Most archs didn't use to print debug info on dump_stack(). They do
> now.
>
> An example WARN dump follows.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Hardware name: empty
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #17
> 0000000000000009 ffff88007c861e08 ffffffff81c61545 ffff88007c861e48
> ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61545>] dump_stack+0x19/0x1b
> [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
> [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a071>] init_workqueues+0x35/0x505
> ...
>
> Signed-off-by: Tejun Heo <[email protected]>
> Cc: Martin Schwidefsky <[email protected]>
> Cc: Heiko Carstens <[email protected]>
> Cc: [email protected]
> Cc: Mike Frysinger <[email protected]>
> Cc: [email protected]

For the CRIS bits:

Acked-by: Jesper Nilsson <[email protected]>

/^JN - Jesper Nilsson
--
Jesper Nilsson -- [email protected]

2013-04-02 09:26:38

by David Howells

Subject: Re: [PATCHSET] arch: unify task dump debug info

Tejun Heo <[email protected]> wrote:

> There are multiple ways a task can be dumped - explicit call to
> dump_stack(), triggering WARN() or BUG(), through sysrq-t and so on.
> Most of what gets printed is upto each architecture and the current
> state is not particularly pretty. Different pieces of information are
> presented differently depending on which path the dump takes and which
> architecture it's running on. This is messy for no good reason and
> makes it exceedingly difficult to add or modify debug information to
> task dumps.
>
> In all archs except for s390, there's nothing arch-specific about the
> printed debug information. This patchset updates all those archs to
> use the same helpers to consistently print out the same debug
> information.
>
> An example WARN dump after this patchset.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #18 empty empty/S3992
> 0000000000000009 ffff88007c861e08 ffffffff81c61525 ffff88007c861e48
> ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a041
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61525>] dump_stack+0x19/0x1b
> [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
> [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a076>] init_workqueues+0x35/0x505
> ...
>
> And BUG dump.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> ...
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> This patchset contains the following five patches.
>
> 0001-x86-don-t-show-trace-beyond-show_stack-NULL-NULL.patch
> 0002-sparc32-make-show_stack-acquire-fp-if-_ksp-is-not-sp.patch
> 0003-dump_stack-consolidate-dump_stack-implementations-an.patch
> 0004-dump_stack-implement-arch-specific-hardware-descript.patch
> 0005-dump_stack-unify-debug-information-printed-by-show_r.patch
>
> 0001-0002 update stack dumping functions in x86 and sparc32 in
> preparation.
>
> 0003 makes all arches except s390 and blackfin use generic
> dump_stack(). blackfin still uses the generic helper to print the
> same info. s390 is left alone as its current debug info includes
> arch-specific stuff.
>
> 0004 properly abstracts DMI identifier printing in WARN() and
> show_regs() so that all dumps print out the information. This enables
> show_regs() to use the same debug info message.
>
> 0005 updates show_regs() of all arches except for s390 to use a common
> generic helper to print debug info.
>
> While this patchset changes how debug info is printed on some archs,
> the printed information is always superset of what used to be there.
>
> This patchset makes task dump debug messages consistent and enables
> adding more information. Workqueue is scheduled to add worker
> information including the workqueue in use and work item specific
> description.
>
> This patchset is based on top of v3.9-rc4 and available in the
> following git branch.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git review-unify-dump
>
> While this patch touches a lot of archs, it isn't too likely to cause
> non-trivial conflicts with arch-specfic changes and would probably be
> best to route together either through -tip or -mm.
>
> x86 is tested but other archs are either only compile tested or not
> tested at all. Changes to most archs are generally trivial.

For FRV and MN10300 bits:

Acked-by: David Howells <[email protected]>

2013-04-02 18:07:58

by Tejun Heo

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

Hello, Vineet.

On Sat, Mar 30, 2013 at 11:43:11AM +0530, Vineet Gupta wrote:
> Although in line [2], ARC trouble-shooting code prints the task path (rather than
> comm). This was done to help identify faulting LTP open posix tests with same name
> in different directories: e.g. fork/6-1, sigqueue/6-1 ....
> Is this something you want to add to generic code as well - although it's slightly
> involved due to tsk/mm locking etc.

I don't think that'd be a particularly good idea. Paths can be pretty
long and in general we want to limit the scope of unsafe accesses from
dump functions. dump could easily be called from deep inside mmap
paths and you definitely don't wanna do get_mm_exec_file() which
involves read-locking mm->mmap_sem.

While it could be useful for arc where, supposedly, not a lot of
generic development and debugging would happen and flushing out bugs
in arch code is much more important, I don't really think it's a good
idea in general.

> Also I personally prefer the more compact <task-nm>/<tgid> format of [1] vs. [3].

It's taken from x86 messages which should be familiar to most number
of devs. Given that it's a last-resort debug thing, we can change
things but there's no reason to disturb more than necessary.

> Anyhow, can you please fold the following into your patchset to reduce above
> duplication.

Sure thing.

Thanks!

--
tejun

2013-04-02 18:24:59

by Tejun Heo

Subject: Re: [PATCH 4/5] dump_stack: implement arch-specific hardware description in task dumps

Hello,

On Mon, Apr 01, 2013 at 12:11:17PM -0600, Bjorn Helgaas wrote:
> > + dump_stack_set_arch_desc("%s %s%s%s", vendor, product,
> > + board ? "/" : "", board ? board : "");
> > +}
>
> Should this be combined or made consistent with dmi_dump_ids()? They
> look almost the same but not quite (no BIOS version here).

Yeah, that actually would be more useful. It'd likely be too long
tho. We can separate it out into its own line which one of the x86
debug paths is doing anyway. I'll look into it.

Thanks.

--
tejun

2013-04-02 18:26:12

by Tejun Heo

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

Hello, Martin.

On Tue, Apr 02, 2013 at 08:48:08AM +0200, Martin Schwidefsky wrote:
> > The couple of extra fields aren't worth an s390 version of dump_stack()
> > that differs from all other architectures.
> > Please drop the s390 version as well. Thanks!
>
> Hmm, we would lose task_thread_info(current)->cpu and current->thread.ksp,
> I don't care much about the kernel stack pointer which has been stored at
> the last call to __switch_to but the cpu number might be interesting.
> Could we add the cpu number to the generic dump_stack version?

Yeah, I can move CPU from show_regs() to dump_stack(). It actually
makes sense. I'll do that and convert s390 together with other archs.

Thanks!

--
tejun

2013-04-03 05:00:19

by Vineet Gupta

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

On 03/30/2013 08:54 AM, Tejun Heo wrote:
> show_regs() is inherently arch-dependent but it does make sense to
> print generic debug information and some archs already do albeit in
> slightly different forms. This patch introduces a generic function to
> print debug information from show_regs() so that different archs print
> out the same information and it's much easier to modify what's
> printed.
>
> show_regs_print_current() prints out the same debug info as
> dump_stack() does plus CPU, task and thread_info pointers.
>
> * Archs which didn't print debug info now do.
>
> alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
> metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
> um, xtensa
>
> * Already prints debug info. Replaced with show_regs_print_current().
> The printed information is superset of what used to be there.
>
> arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
>
> * The printed debug information includes arch-specific bits. Left
> alone.
>
> s390
>
> Note that now all archs print the debug info before actual register
> dumps.
>
> An example BUG() dump follows.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
> RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> v2: Typo fix in x86-32.
>
> Signed-off-by: Tejun Heo <[email protected]>

For arch/arc

Acked-by: Vineet Gupta <[email protected]>

Thx,
-vineet

2013-04-16 14:59:48

by James Hogan

Subject: Re: [PATCH 3/5] dump_stack: consolidate dump_stack() implementations and unify their behaviors

On 30/03/13 02:27, Tejun Heo wrote:
> Both dump_stack() and show_stack() are currently implemented by each
> architecture. show_stack(NULL, NULL) dumps the backtrace for the
> current task as does dump_stack(). On some archs, dump_stack() prints
> extra information - pid, utsname and so on - in addition to the
> backtrace while the two are identical on other archs.
>
> The usages in arch-independent code of the two functions indicate
> show_stack(NULL, NULL) should print out bare backtrace while
> dump_stack() is used for debugging purposes when something went wrong,
> so it does make sense to print additional information on the task
> which triggered dump_stack().
>
> There's no reason to require archs to implement two separate but
> mostly identical functions. It leads to unnecessary subtle
> differences among archs and makes it very tedius to add generic debug
> information.
>
> This patch expands the dummy fallback dump_stack() implementation in
> lib/dump_stack.c such that it prints out debug information (taken from
> x86) and invokes show_stack(NULL, NULL) and drops arch-specific
> dump_stack() implementations in all archs except blackfin and s390.
> Blackfin's dump_stack() does something wonky that I don't understand
> and s390 prints its own debug information which includes fields which
> aren't accessible from arch-indepdent code.
>
> Debug information can be printed separately by calling
> dump_stack_print_info() so that arch-specific dump_stack()
> implementation can still emit the same debug information. This is
> used in blackfin.
>
> This patch brings the following behavior changes.
>
> * On some archs, an extra level in backtrace for show_stack() could be
> printed. This is because the top frame was determined in
> dump_stack() on those archs while generic dump_stack() can't do that
> reliably. It can be compensated by inlining dump_stack() but not
> sure whether that'd be necessary.
>
> * Most archs didn't use to print debug info on dump_stack(). They do
> now.
>
> An example WARN dump follows.
>
> WARNING: at /work/os/work/kernel/workqueue.c:4840 init_workqueues+0x35/0x505()
> Hardware name: empty
> Modules linked in:
> Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc1-work+ #17
> 0000000000000009 ffff88007c861e08 ffffffff81c61545 ffff88007c861e48
> ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
> 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
> Call Trace:
> [<ffffffff81c61545>] dump_stack+0x19/0x1b
> [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
> [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8234a071>] init_workqueues+0x35/0x505
> ...
>
> Signed-off-by: Tejun Heo <[email protected]>
> Cc: Martin Schwidefsky <[email protected]>
> Cc: Heiko Carstens <[email protected]>
> Cc: [email protected]
> Cc: Mike Frysinger <[email protected]>
> Cc: [email protected]

For metag:
Acked-by: James Hogan <[email protected]>

2013-04-16 15:05:09

by James Hogan

Subject: Re: [PATCH v2 5/5] dump_stack: unify debug information printed by show_regs()

On 30/03/13 03:24, Tejun Heo wrote:
> show_regs() is inherently arch-dependent but it does make sense to
> print generic debug information and some archs already do albeit in
> slightly different forms. This patch introduces a generic function to
> print debug information from show_regs() so that different archs print
> out the same information and it's much easier to modify what's
> printed.
>
> show_regs_print_current() prints out the same debug info as
> dump_stack() does plus CPU, task and thread_info pointers.
>
> * Archs which didn't print debug info now do.
>
> alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
> metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
> um, xtensa
>
> * Already prints debug info. Replaced with show_regs_print_current().
> The printed information is superset of what used to be there.
>
> arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
>
> * The printed debug information includes arch-specific bits. Left
> alone.
>
> s390
>
> Note that now all archs print the debug info before actual register
> dumps.
>
> An example BUG() dump follows.
>
> kernel BUG at /work/os/work/kernel/workqueue.c:4841!
> invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
> Modules linked in:
> Pid: 1, comm: swapper/0 Tainted: G W 3.9.0-rc1-work+ #20 empty empty/S3992
> CPU:0 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
> RIP: 0010:[<ffffffff8234a042>] [<ffffffff8234a042>] init_workqueues+0x15/0x17
> RSP: 0000:ffff88007c861ec8 EFLAGS: 00010296
> RAX: 0000000000000024 RBX: ffffffff82446608 RCX: 0000000000000001
> RDX: 0000000000000046 RSI: 0000000000000000 RDI: 0000000000000009
> RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a02d
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Stack:
> ffff88007c861ef8 ffffffff81000312 ffffffff82446608 ffff88007c85e650
> 0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
> ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47730
> Call Trace:
> [<ffffffff81000312>] do_one_initcall+0x122/0x170
> [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
> ...
>
> v2: Typo fix in x86-32.
>
> Signed-off-by: Tejun Heo <[email protected]>

For metag:
Acked-by: James Hogan <[email protected]>

Cheers
James