hi,
patches available also as tarball in here:
http://people.redhat.com/~jolsa/perf_post_unwind_v9.tar.bz2
v9 changes:
- rebased to current tip tree
v8 changes:
- patch 2 - added dump registers ABI specification as suggested
by Stephane
- v7 patches 9,10,16,17 already in
v7 changes:
- omitted v6 patches 9 and 15
They need more work and will be sent separately. I dont want to hold off whole
patchset because of them. We could miss some related backtraces (syscall, vdso)
in this version.
- v6 patch 11, 14, 20 already in
v6 changes:
patch 01/23 - unrelated - ftrace stuff
patch 03/23 - added PERF_SAMPLE_REGS_USER bit
- added regs_user initialization
patch 07/23 - added PERF_SAMPLE_STACK_USER bit
- sample_stack_user changed to u32 and
added size check
new patches 1,9,10,20
v5 changes:
patch 1/19 - having just one enum set of the perf registers
patch 2/19 - using for_each_set_bit for scanning the mask
- single regs enum for both 32 and 64 bits versions
- using regs mask != 0 trigger to trigger the regs dump
patch 5/19 - adding perf_output_skip so we can skip undumped part of the stack in RB
patch 6/19 - using stack size != 0 trigger to trigger the stack dump
- do not zero the memory for non retrieved part of the stack dump
patch 7/19 - adding exclude_callchain_kernel attribute
patch 8/19 - this could be taken without the rest of the series
v4 changes:
- no real change from v3, just rebase
- v3 patch 06/17 got already merged
v3 changes:
patch 01/17
- added HAVE_PERF_REGS config option
patch 02/17, 04/17
- regs and stack perf interface is more general now
patch 06/17
- unrelated online fix for i386 compilation
patch 16/17
- few namespace fixies
---
Adding the post unwinding user stack backtrace using dwarf unwind
via libunwind. The original work was done by Frederic. I mostly took
his patches and make them compile in current kernel code plus I added
some stuff here and there.
The main idea is to store user registers and portion of user
stack when the sample data during the record phase. Then during
the report, when the data is presented, perform the actual dwarf
dwarf unwind.
attached patches:
01/13 perf: Unified API to record selective sets of arch registers
02/13 perf: Add ability to attach user level registers dump to sample
03/13 perf, x86: Add copy_from_user_nmi_nochk for best effort copy
04/13 perf: Factor __output_copy to be usable with specific copy function
05/13 perf: Add perf_output_skip function to skip bytes in sample
06/13 perf: Add ability to attach user stack dump to sample
07/13 perf: Add attribute to filter out callchains
08/13 perf, tool: Adding PERF_ATTR_SIZE_VER2 to the header swap check
09/13 perf, tool: Add interface to arch registers sets
10/13 perf, tool: Add libunwind dependency for dwarf cfi unwinding
11/13 perf, tool: Support user regs and stack in sample parsing
12/13 perf, tool: Support for dwarf cfi unwinding on post processing
13/13 perf, tool: Support for dwarf mode callchain on perf record
I tested on Fedora. There was not much gain on i386, because the
binaries are compiled with frame pointers. Thought the dwarf
backtrace is more accurate and unwraps calls in more details
(functions that do not set the frame pointers).
I could see some improvement on x86_64, where I got full backtrace
where current code could got just the first address out of the
instruction pointer.
Example on x86_64:
[dwarf]
perf record -g dwarf -e syscalls:sys_enter_write date
100.00% date libc-2.14.90.so [.] __GI___libc_write
|
--- __GI___libc_write
_IO_file_write@@GLIBC_2.2.5
new_do_write
_IO_do_write@@GLIBC_2.2.5
_IO_file_overflow@@GLIBC_2.2.5
0x4022cd
0x401ee6
__libc_start_main
0x4020b9
[frame pointer]
perf record -g fp -e syscalls:sys_enter_write date
100.00% date libc-2.14.90.so [.] __GI___libc_write
|
--- __GI___libc_write
Also I tested on coreutils binaries mainly, but I could see
getting wider backtraces with dwarf unwind for more complex
application like firefox.
Attached patches should work on both x86 and x86_64.
The unwind backtrace can be interrupted by following reasons:
- bug in unwind information of processed shared library
- bug in unwind processing code (most likely ;) )
- insufficient dump stack size
- until full syscall register storage and vdso support
we could miss some related backtraces
jirka
---
arch/Kconfig | 6 +
arch/x86/Kconfig | 1 +
arch/x86/include/asm/perf_event.h | 2 +
arch/x86/include/asm/perf_regs.h | 33 ++
arch/x86/include/asm/uaccess.h | 2 +
arch/x86/kernel/Makefile | 2 +
arch/x86/kernel/perf_regs.c | 105 ++++
arch/x86/lib/usercopy.c | 15 +-
include/linux/perf_event.h | 60 ++-
include/linux/perf_regs.h | 25 +
kernel/events/callchain.c | 36 +-
kernel/events/core.c | 191 +++++++-
kernel/events/internal.h | 69 ++-
kernel/events/ring_buffer.c | 10 +-
tools/perf/Makefile | 45 ++-
tools/perf/arch/x86/Makefile | 3 +
tools/perf/arch/x86/include/perf_regs.h | 80 +++
tools/perf/arch/x86/util/unwind.c | 111 ++++
tools/perf/builtin-record.c | 108 ++++-
tools/perf/builtin-report.c | 24 +-
tools/perf/builtin-script.c | 16 +-
tools/perf/builtin-test.c | 4 +-
tools/perf/builtin-top.c | 5 +-
tools/perf/config/feature-tests.mak | 25 +
tools/perf/perf.h | 9 +-
tools/perf/util/event.h | 16 +-
tools/perf/util/evlist.c | 8 +
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 43 ++-
tools/perf/util/header.c | 3 +
tools/perf/util/include/linux/compiler.h | 1 +
tools/perf/util/map.h | 7 +-
tools/perf/util/perf_regs.h | 14 +
tools/perf/util/python.c | 3 +-
.../perf/util/scripting-engines/trace-event-perl.c | 3 +-
.../util/scripting-engines/trace-event-python.c | 3 +-
tools/perf/util/session.c | 97 +++-
tools/perf/util/session.h | 11 +-
tools/perf/util/trace-event-scripting.c | 3 +-
tools/perf/util/trace-event.h | 5 +-
tools/perf/util/unwind.c | 567 ++++++++++++++++++++
tools/perf/util/unwind.h | 34 ++
42 files changed, 1707 insertions(+), 99 deletions(-)
This brings a new API to help the selective dump of registers on
event sampling, and its implementation for x86 arch.
Added HAVE_PERF_REGS config option to determine if the architecture
provides perf registers ABI.
The information about desired registers will be passed in u64 mask.
It's up to the architecture to map the registers into the mask bits.
For the x86 arch implementation, both 32 and 64 bit registers
bits are defined within single enum to ensure 64 bit system can
provide register dump for compat task if needed in the future.
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
arch/Kconfig | 6 +++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/perf_regs.h | 33 ++++++++++++++
arch/x86/kernel/Makefile | 2 +
arch/x86/kernel/perf_regs.c | 90 ++++++++++++++++++++++++++++++++++++++
include/linux/perf_regs.h | 19 ++++++++
6 files changed, 151 insertions(+), 0 deletions(-)
create mode 100644 arch/x86/include/asm/perf_regs.h
create mode 100644 arch/x86/kernel/perf_regs.c
create mode 100644 include/linux/perf_regs.h
diff --git a/arch/Kconfig b/arch/Kconfig
index 8c3d957..32f4873 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -222,6 +222,12 @@ config HAVE_PERF_EVENTS_NMI
subsystem. Also has support for calculating CPU cycle events
to determine how many clock cycles in a given period.
+config HAVE_PERF_REGS
+ bool
+ help
+ Support selective register dumps for perf events. This includes
+ bit-mapping of each registers and a unique architecture id.
+
config HAVE_ARCH_JUMP_LABEL
bool
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 94de2c5..acebbd6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -60,6 +60,7 @@ config X86
select HAVE_MIXED_BREAKPOINTS_REGS
select PERF_EVENTS
select HAVE_PERF_EVENTS_NMI
+ select HAVE_PERF_REGS
select ANON_INODES
select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
select HAVE_CMPXCHG_LOCAL if !M386
diff --git a/arch/x86/include/asm/perf_regs.h b/arch/x86/include/asm/perf_regs.h
new file mode 100644
index 0000000..3f2207b
--- /dev/null
+++ b/arch/x86/include/asm/perf_regs.h
@@ -0,0 +1,33 @@
+#ifndef _ASM_X86_PERF_REGS_H
+#define _ASM_X86_PERF_REGS_H
+
+enum perf_event_x86_regs {
+ PERF_REG_X86_AX,
+ PERF_REG_X86_BX,
+ PERF_REG_X86_CX,
+ PERF_REG_X86_DX,
+ PERF_REG_X86_SI,
+ PERF_REG_X86_DI,
+ PERF_REG_X86_BP,
+ PERF_REG_X86_SP,
+ PERF_REG_X86_IP,
+ PERF_REG_X86_FLAGS,
+ PERF_REG_X86_CS,
+ PERF_REG_X86_SS,
+ PERF_REG_X86_DS,
+ PERF_REG_X86_ES,
+ PERF_REG_X86_FS,
+ PERF_REG_X86_GS,
+ PERF_REG_X86_R8,
+ PERF_REG_X86_R9,
+ PERF_REG_X86_R10,
+ PERF_REG_X86_R11,
+ PERF_REG_X86_R12,
+ PERF_REG_X86_R13,
+ PERF_REG_X86_R14,
+ PERF_REG_X86_R15,
+
+ PERF_REG_X86_32_MAX = PERF_REG_X86_GS + 1,
+ PERF_REG_X86_64_MAX = PERF_REG_X86_R15 + 1,
+};
+#endif /* _ASM_X86_PERF_REGS_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8215e56..8d7a619 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -100,6 +100,8 @@ obj-$(CONFIG_SWIOTLB) += pci-swiotlb.o
obj-$(CONFIG_OF) += devicetree.o
obj-$(CONFIG_UPROBES) += uprobes.o
+obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
+
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
new file mode 100644
index 0000000..c00c92a
--- /dev/null
+++ b/arch/x86/kernel/perf_regs.c
@@ -0,0 +1,90 @@
+
+#include <linux/kernel.h>
+#include <linux/bug.h>
+#include <linux/stddef.h>
+#include <asm/perf_regs.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_X86_32
+#define PERF_REG_X86_MAX PERF_REG_X86_32_MAX
+#else
+#define PERF_REG_X86_MAX PERF_REG_X86_64_MAX
+#endif
+
+#define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
+
+static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
+ PT_REGS_OFFSET(PERF_REG_X86_AX, ax),
+ PT_REGS_OFFSET(PERF_REG_X86_BX, bx),
+ PT_REGS_OFFSET(PERF_REG_X86_CX, cx),
+ PT_REGS_OFFSET(PERF_REG_X86_DX, dx),
+ PT_REGS_OFFSET(PERF_REG_X86_SI, si),
+ PT_REGS_OFFSET(PERF_REG_X86_DI, di),
+ PT_REGS_OFFSET(PERF_REG_X86_BP, bp),
+ PT_REGS_OFFSET(PERF_REG_X86_SP, sp),
+ PT_REGS_OFFSET(PERF_REG_X86_IP, ip),
+ PT_REGS_OFFSET(PERF_REG_X86_FLAGS, flags),
+ PT_REGS_OFFSET(PERF_REG_X86_CS, cs),
+ PT_REGS_OFFSET(PERF_REG_X86_SS, ss),
+#ifdef CONFIG_X86_32
+ PT_REGS_OFFSET(PERF_REG_X86_DS, ds),
+ PT_REGS_OFFSET(PERF_REG_X86_ES, es),
+ PT_REGS_OFFSET(PERF_REG_X86_FS, fs),
+ PT_REGS_OFFSET(PERF_REG_X86_GS, gs),
+#else
+ /*
+ * The pt_regs struct does not store
+ * ds, es, fs, gs in 64 bit mode.
+ */
+ (unsigned int) -1,
+ (unsigned int) -1,
+ (unsigned int) -1,
+ (unsigned int) -1,
+#endif
+#ifdef CONFIG_X86_64
+ PT_REGS_OFFSET(PERF_REG_X86_R8, r8),
+ PT_REGS_OFFSET(PERF_REG_X86_R9, r9),
+ PT_REGS_OFFSET(PERF_REG_X86_R10, r10),
+ PT_REGS_OFFSET(PERF_REG_X86_R11, r11),
+ PT_REGS_OFFSET(PERF_REG_X86_R12, r12),
+ PT_REGS_OFFSET(PERF_REG_X86_R13, r13),
+ PT_REGS_OFFSET(PERF_REG_X86_R14, r14),
+ PT_REGS_OFFSET(PERF_REG_X86_R15, r15),
+#endif
+};
+
+u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+ if (WARN_ON_ONCE(idx > ARRAY_SIZE(pt_regs_offset)))
+ return 0;
+
+ return regs_get_register(regs, pt_regs_offset[idx]);
+}
+
+#define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
+
+#ifdef CONFIG_X86_32
+int perf_reg_validate(u64 mask)
+{
+ if (!mask || mask & REG_RESERVED)
+ return -EINVAL;
+
+ return 0;
+}
+#else /* CONFIG_X86_64 */
+#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
+ (1ULL << PERF_REG_X86_ES) | \
+ (1ULL << PERF_REG_X86_FS) | \
+ (1ULL << PERF_REG_X86_GS))
+
+int perf_reg_validate(u64 mask)
+{
+ if (!mask || mask & REG_RESERVED)
+ return -EINVAL;
+
+ if (mask & REG_NOSUPPORT)
+ return -EINVAL;
+
+ return 0;
+}
+#endif /* CONFIG_X86_32 */
diff --git a/include/linux/perf_regs.h b/include/linux/perf_regs.h
new file mode 100644
index 0000000..a2f1a98
--- /dev/null
+++ b/include/linux/perf_regs.h
@@ -0,0 +1,19 @@
+#ifndef _LINUX_PERF_REGS_H
+#define _LINUX_PERF_REGS_H
+
+#ifdef CONFIG_HAVE_PERF_REGS
+#include <asm/perf_regs.h>
+u64 perf_reg_value(struct pt_regs *regs, int idx);
+int perf_reg_validate(u64 mask);
+#else
+static inline u64 perf_reg_value(struct pt_regs *regs, int idx)
+{
+ return 0;
+}
+
+static inline int perf_reg_validate(u64 mask)
+{
+ return mask ? -ENOSYS : 0;
+}
+#endif /* CONFIG_HAVE_PERF_REGS */
+#endif /* _LINUX_PERF_REGS_H */
--
1.7.7.6
Adding copy_from_user_nmi_nochk that provides the best effort
copy regardless the requesting size crossing the task boundary.
This is going to be useful for stack dump we need in post
DWARF CFI based unwind, where we have predefined size of
the user stack to dump, and we need to store the most of
the requested dump size, regardless this size is crossing
the task boundary.
Signed-off-by: Jiri Olsa <[email protected]>
---
arch/x86/include/asm/uaccess.h | 2 ++
arch/x86/lib/usercopy.c | 15 +++++++++++----
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index e1f3a17..d8d6bcd 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -562,6 +562,8 @@ struct __large_struct { unsigned long buf[100]; };
#endif /* CONFIG_X86_WP_WORKS_OK */
extern unsigned long
+copy_from_user_nmi_nochk(void *to, const void __user *from, unsigned long n);
+extern unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
extern __must_check long
strncpy_from_user(char *dst, const char __user *src, long count);
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 4f74d94..29ca1c7 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -14,7 +14,7 @@
* best effort, GUP based copy_from_user() that is NMI-safe
*/
unsigned long
-copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
+copy_from_user_nmi_nochk(void *to, const void __user *from, unsigned long n)
{
unsigned long offset, addr = (unsigned long)from;
unsigned long size, len = 0;
@@ -22,9 +22,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
void *map;
int ret;
- if (__range_not_ok(from, n, TASK_SIZE))
- return len;
-
do {
ret = __get_user_pages_fast(addr, 1, 0, &page);
if (!ret)
@@ -46,4 +43,14 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
return len;
}
+EXPORT_SYMBOL_GPL(copy_from_user_nmi_nochk);
+
+unsigned long
+copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
+{
+ if (__range_not_ok(from, n, TASK_SIZE) == 0)
+ return 0;
+
+ return copy_from_user_nmi_nochk(to, from, n);
+}
EXPORT_SYMBOL_GPL(copy_from_user_nmi);
--
1.7.7.6
From: Frederic Weisbecker <[email protected]>
Adding a generic way to use __output_copy function with
specific copy function via DEFINE_PERF_OUTPUT_COPY macro.
Using this to add new __output_copy_user function, that provides
output copy from user pointers. For x86 the copy_from_user_nmi_nochk
function is used and __copy_from_user_inatomic for the rest
of the architectures.
This new function will be used in user stack dump on sample,
coming in next patches.
Signed-off-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
---
arch/x86/include/asm/perf_event.h | 2 +
include/linux/perf_event.h | 2 +-
kernel/events/internal.h | 62 ++++++++++++++++++++++++------------
kernel/events/ring_buffer.c | 4 +-
4 files changed, 46 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index cb4e43b..054d64f 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -262,4 +262,6 @@ static inline void perf_check_microcode(void) { }
static inline void amd_pmu_disable_virt(void) { }
#endif
+#define arch_perf_out_copy_user copy_from_user_nmi_nochk
+
#endif /* _ASM_X86_PERF_EVENT_H */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 3d4d847..d41394a 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1319,7 +1319,7 @@ static inline bool has_branch_stack(struct perf_event *event)
extern int perf_output_begin(struct perf_output_handle *handle,
struct perf_event *event, unsigned int size);
extern void perf_output_end(struct perf_output_handle *handle);
-extern void perf_output_copy(struct perf_output_handle *handle,
+extern unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index a096c19..7fd5408 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -2,6 +2,7 @@
#define _KERNEL_EVENTS_INTERNAL_H
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
/* Buffer handling */
@@ -76,30 +77,49 @@ static inline unsigned long perf_data_size(struct ring_buffer *rb)
return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
}
-static inline void
-__output_copy(struct perf_output_handle *handle,
- const void *buf, unsigned int len)
+#define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
+static inline unsigned int \
+func_name(struct perf_output_handle *handle, \
+ const void *buf, unsigned int len) \
+{ \
+ unsigned long size, written; \
+ \
+ do { \
+ size = min_t(unsigned long, handle->size, len); \
+ \
+ written = memcpy_func(handle->addr, buf, size); \
+ \
+ len -= written; \
+ handle->addr += written; \
+ buf += written; \
+ handle->size -= written; \
+ if (!handle->size) { \
+ struct ring_buffer *rb = handle->rb; \
+ \
+ handle->page++; \
+ handle->page &= rb->nr_pages - 1; \
+ handle->addr = rb->data_pages[handle->page]; \
+ handle->size = PAGE_SIZE << page_order(rb); \
+ } \
+ } while (len && written == size); \
+ \
+ return len; \
+}
+
+static inline int memcpy_common(void *dst, const void *src, size_t n)
{
- do {
- unsigned long size = min_t(unsigned long, handle->size, len);
-
- memcpy(handle->addr, buf, size);
-
- len -= size;
- handle->addr += size;
- buf += size;
- handle->size -= size;
- if (!handle->size) {
- struct ring_buffer *rb = handle->rb;
-
- handle->page++;
- handle->page &= rb->nr_pages - 1;
- handle->addr = rb->data_pages[handle->page];
- handle->size = PAGE_SIZE << page_order(rb);
- }
- } while (len);
+ memcpy(dst, src, n);
+ return n;
}
+DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
+
+#ifndef arch_perf_out_copy_user
+#define arch_perf_out_copy_user __copy_from_user_inatomic
+#endif
+
+DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
+
/* Callchain handling */
extern struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs);
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 6ddaba4..b4c2ad3 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -182,10 +182,10 @@ out:
return -ENOSPC;
}
-void perf_output_copy(struct perf_output_handle *handle,
+unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len)
{
- __output_copy(handle, buf, len);
+ return __output_copy(handle, buf, len);
}
void perf_output_end(struct perf_output_handle *handle)
--
1.7.7.6
From: Frederic Weisbecker <[email protected]>
Introducing following bits to the the perf_event_attr struct:
- exclude_callchain_kernel to filter out kernel callchain
from the sample dump
- exclude_callchain_user to filter out user callchain
from the sample dump
We need to be able to disable standard user callchain dump
when we use the dwarf cfi callchain mode, because frame
pointer based user callchains are useless in this mode.
Implementing also exclude_callchain_kernel to have complete
set of options.
Signed-off-by: Frederic Weisbecker <[email protected]>
[ Added kernel callchains filtering ]
Signed-off-by: Jiri Olsa <[email protected]>
CC: Andrew Vagin <[email protected]>
---
include/linux/perf_event.h | 5 ++++-
kernel/events/callchain.c | 36 +++++++++++++++++++++---------------
kernel/events/core.c | 6 +++++-
kernel/events/internal.h | 3 ++-
4 files changed, 32 insertions(+), 18 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d1d25f6..297ca3d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -268,7 +268,10 @@ struct perf_event_attr {
exclude_host : 1, /* don't count in host */
exclude_guest : 1, /* don't count in guest */
- __reserved_1 : 43;
+ exclude_callchain_kernel : 1, /* exclude kernel callchains */
+ exclude_callchain_user : 1, /* exclude user callchains */
+
+ __reserved_1 : 41;
union {
__u32 wakeup_events; /* wakeup every n events */
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 98d4597..cbed627 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -154,7 +154,8 @@ put_callchain_entry(int rctx)
}
struct perf_callchain_entry *
-perf_callchain(struct perf_event *event, struct pt_regs *regs)
+perf_callchain(struct perf_event *event, struct pt_regs *regs,
+ int kernel, int user)
{
int rctx;
struct perf_callchain_entry *entry;
@@ -169,24 +170,29 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs)
entry->nr = 0;
- if (!user_mode(regs)) {
+ if (kernel && !user_mode(regs)) {
perf_callchain_store(entry, PERF_CONTEXT_KERNEL);
perf_callchain_kernel(entry, regs);
- if (current->mm)
- regs = task_pt_regs(current);
- else
- regs = NULL;
}
- if (regs) {
- /*
- * Disallow cross-task user callchains.
- */
- if (event->ctx->task && event->ctx->task != current)
- goto exit_put;
-
- perf_callchain_store(entry, PERF_CONTEXT_USER);
- perf_callchain_user(entry, regs);
+ if (user) {
+ if (!user_mode(regs)) {
+ if (current->mm)
+ regs = task_pt_regs(current);
+ else
+ regs = NULL;
+ }
+
+ if (regs) {
+ /*
+ * Disallow cross-task user callchains.
+ */
+ if (event->ctx->task && event->ctx->task != current)
+ goto exit_put;
+
+ perf_callchain_store(entry, PERF_CONTEXT_USER);
+ perf_callchain_user(entry, regs);
+ }
}
exit_put:
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c4582bb..0902d4a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4130,8 +4130,12 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
int size = 1;
+ int kernel = !event->attr.exclude_callchain_kernel;
+ int user = !event->attr.exclude_callchain_user;
- data->callchain = perf_callchain(event, regs);
+ if (kernel || user)
+ data->callchain = perf_callchain(event, regs,
+ kernel, user);
if (data->callchain)
size += data->callchain->nr;
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index ce7bdfc..95d0215 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -126,7 +126,8 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
/* Callchain handling */
extern struct perf_callchain_entry *
-perf_callchain(struct perf_event *event, struct pt_regs *regs);
+perf_callchain(struct perf_event *event, struct pt_regs *regs,
+ int kernel, int user);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);
--
1.7.7.6
Adding libunwind to be linked with perf if available. It's required
for the to get dwarf cfi unwinding support.
Also building perf with the dwarf call frame informations by default,
so that we can unwind callchains in perf itself.
Adding LIBUNWIND_DIR Makefile variable allowing user to specify
the directory with libunwind to be linked. This is used for
debug purposes.
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
tools/perf/Makefile | 30 +++++++++++++++++++++++++++++-
tools/perf/config/feature-tests.mak | 25 +++++++++++++++++++++++++
2 files changed, 54 insertions(+), 1 deletions(-)
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 0548d93..a1ee011 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -38,6 +38,9 @@ include config/utilities.mak
# Define NO_NEWT if you do not want TUI support.
#
# Define NO_DEMANGLE if you do not want C++ symbol demangling.
+#
+# Define NO_LIBUNWIND if you do not want libunwind dependency for dwarf
+# backtrace post unwind.
$(OUTPUT)PERF-VERSION-FILE: .FORCE-PERF-VERSION-FILE
@$(SHELL_PATH) util/PERF-VERSION-GEN $(OUTPUT)
@@ -59,6 +62,7 @@ AR = $(CROSS_COMPILE)ar
ifeq ($(ARCH),i386)
ARCH := x86
NO_PERF_REGS := 0
+ LIBUNWIND_LIBS = -lunwind -lunwind-x86
endif
ifeq ($(ARCH),x86_64)
ARCH := x86
@@ -72,6 +76,7 @@ ifeq ($(ARCH),x86_64)
ARCH_INCLUDE = ../../arch/x86/lib/memcpy_64.S ../../arch/x86/lib/memset_64.S
endif
NO_PERF_REGS := 0
+ LIBUNWIND_LIBS = -lunwind -lunwind-x86_64
endif
# Treat warnings as errors unless directed not to
@@ -92,7 +97,7 @@ ifdef PARSER_DEBUG
PARSER_DEBUG_CFLAGS := -DPARSER_DEBUG
endif
-CFLAGS = -fno-omit-frame-pointer -ggdb3 -Wall -Wextra -std=gnu99 $(CFLAGS_WERROR) $(CFLAGS_OPTIMIZE) $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) $(PARSER_DEBUG_CFLAGS)
+CFLAGS = -fno-omit-frame-pointer -ggdb3 -funwind-tables -Wall -Wextra -std=gnu99 $(CFLAGS_WERROR) $(CFLAGS_OPTIMIZE) $(EXTRA_WARNINGS) $(EXTRA_CFLAGS) $(PARSER_DEBUG_CFLAGS)
EXTLIBS = -lpthread -lrt -lelf -lm
ALL_CFLAGS = $(CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
ALL_LDFLAGS = $(LDFLAGS)
@@ -457,6 +462,21 @@ ifneq ($(call try-cc,$(SOURCE_DWARF),$(FLAGS_DWARF)),y)
endif # Dwarf support
endif # NO_DWARF
+ifndef NO_LIBUNWIND
+# for linking with debug library, run like:
+# make DEBUG=1 LIBUNWIND_DIR=/opt/libunwind/
+ifdef LIBUNWIND_DIR
+ LIBUNWIND_CFLAGS := -I$(LIBUNWIND_DIR)/include
+ LIBUNWIND_LDFLAGS := -L$(LIBUNWIND_DIR)/lib
+endif
+
+FLAGS_UNWIND=$(LIBUNWIND_CFLAGS) $(ALL_CFLAGS) $(LIBUNWIND_LDFLAGS) $(ALL_LDFLAGS) $(EXTLIBS) $(LIBUNWIND_LIBS)
+ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND)),y)
+ msg := $(warning No libunwind found. Please install libunwind >= 0.99);
+ NO_LIBUNWIND := 1
+endif # Libunwind support
+endif # NO_LIBUNWIND
+
-include arch/$(ARCH)/Makefile
ifneq ($(OUTPUT),)
@@ -488,6 +508,14 @@ else
endif # PERF_HAVE_DWARF_REGS
endif # NO_DWARF
+ifdef NO_LIBUNWIND
+ BASIC_CFLAGS += -DNO_LIBUNWIND_SUPPORT
+else
+ EXTLIBS += $(LIBUNWIND_LIBS)
+ BASIC_CFLAGS := $(LIBUNWIND_CFLAGS) $(BASIC_CFLAGS)
+ BASIC_LDFLAGS := $(LIBUNWIND_LDFLAGS) $(BASIC_LDFLAGS)
+endif
+
ifdef NO_NEWT
BASIC_CFLAGS += -DNO_NEWT_SUPPORT
else
diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak
index 6c18785..2f1156a 100644
--- a/tools/perf/config/feature-tests.mak
+++ b/tools/perf/config/feature-tests.mak
@@ -154,3 +154,28 @@ int main(void)
return 0;
}
endef
+
+ifndef NO_LIBUNWIND
+define SOURCE_LIBUNWIND
+#include <libunwind.h>
+#include <stdlib.h>
+
+extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
+ unw_word_t ip,
+ unw_dyn_info_t *di,
+ unw_proc_info_t *pi,
+ int need_unwind_info, void *arg);
+
+
+#define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
+
+int main(void)
+{
+ unw_addr_space_t addr_space;
+ addr_space = unw_create_addr_space(NULL, 0);
+ unw_init_remote(NULL, addr_space, NULL);
+ dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL);
+ return 0;
+}
+endef
+endif
--
1.7.7.6
Introducing perf_output_skip function to be able to skip data
within the perf ring buffer.
When writing data into perf ring buffer we first reserve needed
place in ring buffer and then copy the actual data.
There's a possibility we won't be able to fill all the reserved
size with data, so we need a way to skip the remaining bytes.
This is going to be useful when storing the user stack dump,
where we might end up with less data than we originally requested.
Signed-off-by: Jiri Olsa <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
---
include/linux/perf_event.h | 2 ++
kernel/events/internal.h | 4 ++++
kernel/events/ring_buffer.c | 6 ++++++
3 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d41394a..8a73f75 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1321,6 +1321,8 @@ extern int perf_output_begin(struct perf_output_handle *handle,
extern void perf_output_end(struct perf_output_handle *handle);
extern unsigned int perf_output_copy(struct perf_output_handle *handle,
const void *buf, unsigned int len);
+extern unsigned int perf_output_skip(struct perf_output_handle *handle,
+ unsigned int len);
extern int perf_swevent_get_recursion_context(void);
extern void perf_swevent_put_recursion_context(int rctx);
extern void perf_event_enable(struct perf_event *event);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 7fd5408..ce7bdfc 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -114,6 +114,10 @@ static inline int memcpy_common(void *dst, const void *src, size_t n)
DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
+#define MEMCPY_SKIP(dst, src, n) (n)
+
+DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP)
+
#ifndef arch_perf_out_copy_user
#define arch_perf_out_copy_user __copy_from_user_inatomic
#endif
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index b4c2ad3..23cb34f 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -188,6 +188,12 @@ unsigned int perf_output_copy(struct perf_output_handle *handle,
return __output_copy(handle, buf, len);
}
+unsigned int perf_output_skip(struct perf_output_handle *handle,
+ unsigned int len)
+{
+ return __output_skip(handle, NULL, len);
+}
+
void perf_output_end(struct perf_output_handle *handle)
{
perf_output_put_handle(handle);
--
1.7.7.6
This brings the support for dwarf cfi unwinding on perf post
processing. Call frame informations are retrieved and then passed
to libunwind that requests memory and register content from the
applications.
Adding unwind object to handle the user stack backtrace based
on the user register values and user stack dump.
The unwind object access the libunwind via remote interface
and provides to it all the necessary data to unwind the stack.
The unwind interface provides following function:
unwind__get_entries
And callback (specified in above function) to retrieve
the backtrace entries:
typedef int (*unwind_entry_cb_t)(struct unwind_entry *entry,
void *arg);
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
tools/perf/Makefile | 2 +
tools/perf/arch/x86/Makefile | 3 +
tools/perf/arch/x86/util/unwind.c | 111 ++++
tools/perf/builtin-report.c | 24 +-
tools/perf/builtin-script.c | 16 +-
tools/perf/builtin-top.c | 5 +-
tools/perf/util/include/linux/compiler.h | 1 +
tools/perf/util/map.h | 7 +-
.../perf/util/scripting-engines/trace-event-perl.c | 3 +-
.../util/scripting-engines/trace-event-python.c | 3 +-
tools/perf/util/session.c | 61 ++-
tools/perf/util/session.h | 3 +-
tools/perf/util/trace-event-scripting.c | 3 +-
tools/perf/util/trace-event.h | 5 +-
tools/perf/util/unwind.c | 567 ++++++++++++++++++++
tools/perf/util/unwind.h | 34 ++
16 files changed, 811 insertions(+), 37 deletions(-)
create mode 100644 tools/perf/arch/x86/util/unwind.c
create mode 100644 tools/perf/util/unwind.c
create mode 100644 tools/perf/util/unwind.h
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index a1ee011..52e9e6c 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -328,6 +328,7 @@ LIB_H += util/cgroup.h
LIB_H += $(TRACE_EVENT_DIR)event-parse.h
LIB_H += util/target.h
LIB_H += util/perf_regs.h
+LIB_H += util/unwind.h
LIB_OBJS += $(OUTPUT)util/abspath.o
LIB_OBJS += $(OUTPUT)util/alias.o
@@ -514,6 +515,7 @@ else
EXTLIBS += $(LIBUNWIND_LIBS)
BASIC_CFLAGS := $(LIBUNWIND_CFLAGS) $(BASIC_CFLAGS)
BASIC_LDFLAGS := $(LIBUNWIND_LDFLAGS) $(BASIC_LDFLAGS)
+ LIB_OBJS += $(OUTPUT)util/unwind.o
endif
ifdef NO_NEWT
diff --git a/tools/perf/arch/x86/Makefile b/tools/perf/arch/x86/Makefile
index 744e629..815841c 100644
--- a/tools/perf/arch/x86/Makefile
+++ b/tools/perf/arch/x86/Makefile
@@ -2,4 +2,7 @@ ifndef NO_DWARF
PERF_HAVE_DWARF_REGS := 1
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
endif
+ifndef NO_LIBUNWIND
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o
+endif
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o
diff --git a/tools/perf/arch/x86/util/unwind.c b/tools/perf/arch/x86/util/unwind.c
new file mode 100644
index 0000000..78d956e
--- /dev/null
+++ b/tools/perf/arch/x86/util/unwind.c
@@ -0,0 +1,111 @@
+
+#include <errno.h>
+#include <libunwind.h>
+#include "perf_regs.h"
+#include "../../util/unwind.h"
+
+#ifdef ARCH_X86_64
+int unwind__arch_reg_id(int regnum)
+{
+ int id;
+
+ switch (regnum) {
+ case UNW_X86_64_RAX:
+ id = PERF_REG_X86_AX;
+ break;
+ case UNW_X86_64_RDX:
+ id = PERF_REG_X86_DX;
+ break;
+ case UNW_X86_64_RCX:
+ id = PERF_REG_X86_CX;
+ break;
+ case UNW_X86_64_RBX:
+ id = PERF_REG_X86_BX;
+ break;
+ case UNW_X86_64_RSI:
+ id = PERF_REG_X86_SI;
+ break;
+ case UNW_X86_64_RDI:
+ id = PERF_REG_X86_DI;
+ break;
+ case UNW_X86_64_RBP:
+ id = PERF_REG_X86_BP;
+ break;
+ case UNW_X86_64_RSP:
+ id = PERF_REG_X86_SP;
+ break;
+ case UNW_X86_64_R8:
+ id = PERF_REG_X86_R8;
+ break;
+ case UNW_X86_64_R9:
+ id = PERF_REG_X86_R9;
+ break;
+ case UNW_X86_64_R10:
+ id = PERF_REG_X86_R10;
+ break;
+ case UNW_X86_64_R11:
+ id = PERF_REG_X86_R11;
+ break;
+ case UNW_X86_64_R12:
+ id = PERF_REG_X86_R12;
+ break;
+ case UNW_X86_64_R13:
+ id = PERF_REG_X86_R13;
+ break;
+ case UNW_X86_64_R14:
+ id = PERF_REG_X86_R14;
+ break;
+ case UNW_X86_64_R15:
+ id = PERF_REG_X86_R15;
+ break;
+ case UNW_X86_64_RIP:
+ id = PERF_REG_X86_IP;
+ break;
+ default:
+ pr_err("unwind: invalid reg id %d\n", regnum);
+ return -EINVAL;
+ }
+
+ return id;
+}
+#else
+int unwind__arch_reg_id(int regnum)
+{
+ int id;
+
+ switch (regnum) {
+ case UNW_X86_EAX:
+ id = PERF_REG_X86_AX;
+ break;
+ case UNW_X86_EDX:
+ id = PERF_REG_X86_DX;
+ break;
+ case UNW_X86_ECX:
+ id = PERF_REG_X86_CX;
+ break;
+ case UNW_X86_EBX:
+ id = PERF_REG_X86_BX;
+ break;
+ case UNW_X86_ESI:
+ id = PERF_REG_X86_SI;
+ break;
+ case UNW_X86_EDI:
+ id = PERF_REG_X86_DI;
+ break;
+ case UNW_X86_EBP:
+ id = PERF_REG_X86_BP;
+ break;
+ case UNW_X86_ESP:
+ id = PERF_REG_X86_SP;
+ break;
+ case UNW_X86_EIP:
+ id = PERF_REG_X86_IP;
+ break;
+ default:
+ pr_err("unwind: invalid reg id %d\n", regnum);
+ return -EINVAL;
+ }
+
+ return id;
+}
+#endif /* ARCH_X86_64 */
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 69b1c11..37cc80e 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -69,8 +69,8 @@ static int perf_report__add_branch_hist_entry(struct perf_tool *tool,
if ((sort__has_parent || symbol_conf.use_callchain)
&& sample->callchain) {
- err = machine__resolve_callchain(machine, al->thread,
- sample->callchain, &parent);
+ err = machine__resolve_callchain(rep->session, machine,
+ al->thread, sample, &parent);
if (err)
return err;
}
@@ -130,7 +130,8 @@ out:
return err;
}
-static int perf_evsel__add_hist_entry(struct perf_evsel *evsel,
+static int perf_evsel__add_hist_entry(struct perf_session *session,
+ struct perf_evsel *evsel,
struct addr_location *al,
struct perf_sample *sample,
struct machine *machine)
@@ -140,8 +141,8 @@ static int perf_evsel__add_hist_entry(struct perf_evsel *evsel,
struct hist_entry *he;
if ((sort__has_parent || symbol_conf.use_callchain) && sample->callchain) {
- err = machine__resolve_callchain(machine, al->thread,
- sample->callchain, &parent);
+ err = machine__resolve_callchain(session, machine,
+ al->thread, sample, &parent);
if (err)
return err;
}
@@ -213,7 +214,8 @@ static int process_sample_event(struct perf_tool *tool,
if (al.map != NULL)
al.map->dso->hit = 1;
- if (perf_evsel__add_hist_entry(evsel, &al, sample, machine)) {
+ if (perf_evsel__add_hist_entry(rep->session, evsel, &al,
+ sample, machine)) {
pr_debug("problem incrementing symbol period, skipping event\n");
return -1;
}
@@ -396,17 +398,17 @@ static int __cmd_report(struct perf_report *rep)
desc);
}
- if (dump_trace) {
- perf_session__fprintf_nr_events(session, stdout);
- goto out_delete;
- }
-
if (verbose > 3)
perf_session__fprintf(session, stdout);
if (verbose > 2)
perf_session__fprintf_dsos(session, stdout);
+ if (dump_trace) {
+ perf_session__fprintf_nr_events(session, stdout);
+ goto out_delete;
+ }
+
nr_samples = 0;
list_for_each_entry(pos, &session->evlist->entries, node) {
struct hists *hists = &pos->hists;
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 1e60ab7..79b9cb0 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -387,7 +387,8 @@ static void print_sample_addr(union perf_event *event,
}
}
-static void print_sample_bts(union perf_event *event,
+static void print_sample_bts(struct perf_session *session,
+ union perf_event *event,
struct perf_sample *sample,
struct perf_evsel *evsel,
struct machine *machine,
@@ -401,7 +402,7 @@ static void print_sample_bts(union perf_event *event,
printf(" ");
else
printf("\n");
- perf_event__print_ip(event, sample, machine,
+ perf_event__print_ip(session, event, sample, machine,
PRINT_FIELD(SYM), PRINT_FIELD(DSO),
PRINT_FIELD(SYMOFFSET));
}
@@ -415,7 +416,8 @@ static void print_sample_bts(union perf_event *event,
printf("\n");
}
-static void process_event(union perf_event *event __unused,
+static void process_event(struct perf_session *session,
+ union perf_event *event __unused,
struct pevent *pevent,
struct perf_sample *sample,
struct perf_evsel *evsel,
@@ -430,7 +432,8 @@ static void process_event(union perf_event *event __unused,
print_sample_start(pevent, sample, thread, evsel);
if (is_bts_event(attr)) {
- print_sample_bts(event, sample, evsel, machine, thread);
+ print_sample_bts(session, event, sample, evsel,
+ machine, thread);
return;
}
@@ -446,7 +449,7 @@ static void process_event(union perf_event *event __unused,
printf(" ");
else
printf("\n");
- perf_event__print_ip(event, sample, machine,
+ perf_event__print_ip(session, event, sample, machine,
PRINT_FIELD(SYM), PRINT_FIELD(DSO),
PRINT_FIELD(SYMOFFSET));
}
@@ -537,7 +540,8 @@ static int process_sample_event(struct perf_tool *tool __used,
if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
return 0;
- scripting_ops->process_event(event, scr->session->pevent,
+ scripting_ops->process_event(scr->session, event,
+ scr->session->pevent,
sample, evsel, machine, thread);
evsel->hists.stats.total_period += sample->period;
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 35e86c6..ba91641 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -774,8 +774,9 @@ static void perf_event__process_sample(struct perf_tool *tool,
if ((sort__has_parent || symbol_conf.use_callchain) &&
sample->callchain) {
- err = machine__resolve_callchain(machine, al.thread,
- sample->callchain, &parent);
+ err = machine__resolve_callchain(top->session,
+ machine, al.thread,
+ sample, &parent);
if (err)
return;
}
diff --git a/tools/perf/util/include/linux/compiler.h b/tools/perf/util/include/linux/compiler.h
index 547628e..2dc8671 100644
--- a/tools/perf/util/include/linux/compiler.h
+++ b/tools/perf/util/include/linux/compiler.h
@@ -10,5 +10,6 @@
#endif
#define __used __attribute__((__unused__))
+#define __packed __attribute__((__packed__))
#endif
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 03a1e9b..42211f7 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -157,9 +157,12 @@ int machine__init(struct machine *self, const char *root_dir, pid_t pid);
void machine__exit(struct machine *self);
void machine__delete(struct machine *self);
-int machine__resolve_callchain(struct machine *machine,
+struct perf_session;
+struct perf_sample;
+int machine__resolve_callchain(struct perf_session *session,
+ struct machine *machine,
struct thread *thread,
- struct ip_callchain *chain,
+ struct perf_sample *sample,
struct symbol **parent);
int maps__set_kallsyms_ref_reloc_sym(struct map **maps, const char *symbol_name,
u64 addr);
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 02dfa19..5840dd1 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -375,7 +375,8 @@ static void perl_process_event_generic(union perf_event *pevent __unused,
LEAVE;
}
-static void perl_process_event(union perf_event *event,
+static void perl_process_event(struct perf_session *session __used,
+ union perf_event *event,
struct pevent *pevent,
struct perf_sample *sample,
struct perf_evsel *evsel,
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index ce4d1b0..e4b3510 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -214,7 +214,8 @@ struct event_format *find_cache_event(struct pevent *pevent, int type)
return event;
}
-static void python_process_event(union perf_event *perf_event __unused,
+static void python_process_event(struct perf_session *session,
+ union perf_event *perf_event __unused,
struct pevent *pevent,
struct perf_sample *sample,
struct perf_evsel *evsel __unused,
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index ed6d8b5..c987ff9 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -16,6 +16,7 @@
#include "cpumap.h"
#include "event-parse.h"
#include "perf_regs.h"
+#include "unwind.h"
static int perf_session__open(struct perf_session *self, bool force)
{
@@ -292,10 +293,11 @@ struct branch_info *machine__resolve_bstack(struct machine *self,
return bi;
}
-int machine__resolve_callchain(struct machine *self,
- struct thread *thread,
- struct ip_callchain *chain,
- struct symbol **parent)
+static int
+resolve_callchain_sample(struct machine *machine,
+ struct thread *thread,
+ struct ip_callchain *chain,
+ struct symbol **parent)
{
u8 cpumode = PERF_RECORD_MISC_USER;
unsigned int i;
@@ -320,11 +322,14 @@ int machine__resolve_callchain(struct machine *self,
if (ip >= PERF_CONTEXT_MAX) {
switch (ip) {
case PERF_CONTEXT_HV:
- cpumode = PERF_RECORD_MISC_HYPERVISOR; break;
+ cpumode = PERF_RECORD_MISC_HYPERVISOR;
+ break;
case PERF_CONTEXT_KERNEL:
- cpumode = PERF_RECORD_MISC_KERNEL; break;
+ cpumode = PERF_RECORD_MISC_KERNEL;
+ break;
case PERF_CONTEXT_USER:
- cpumode = PERF_RECORD_MISC_USER; break;
+ cpumode = PERF_RECORD_MISC_USER;
+ break;
default:
pr_debug("invalid callchain context: "
"%"PRId64"\n", (s64) ip);
@@ -339,7 +344,7 @@ int machine__resolve_callchain(struct machine *self,
}
al.filtered = false;
- thread__find_addr_location(thread, self, cpumode,
+ thread__find_addr_location(thread, machine, cpumode,
MAP__FUNCTION, ip, &al, NULL);
if (al.sym != NULL) {
if (sort__has_parent && !*parent &&
@@ -358,6 +363,39 @@ int machine__resolve_callchain(struct machine *self,
return 0;
}
+static int unwind_entry(struct unwind_entry *entry, void *arg)
+{
+ struct callchain_cursor *cursor = arg;
+ return callchain_cursor_append(cursor, entry->ip,
+ entry->map, entry->sym);
+}
+
+int machine__resolve_callchain(struct perf_session *session,
+ struct machine *self,
+ struct thread *thread,
+ struct perf_sample *sample,
+ struct symbol **parent)
+{
+ int ret;
+
+ callchain_cursor_reset(&callchain_cursor);
+
+ ret = resolve_callchain_sample(self, thread, sample->callchain,
+ parent);
+ if (ret)
+ return ret;
+
+ /* Can we do dwarf post unwind? */
+ if (!((session->sample_type & PERF_SAMPLE_REGS_USER) &&
+ (session->sample_type & PERF_SAMPLE_STACK_USER)))
+ return 0;
+
+ return unwind__get_entries(unwind_entry,
+ &callchain_cursor,
+ self, thread,
+ session->sample_regs_user, sample);
+}
+
static int process_event_synth_tracing_data_stub(union perf_event *event __used,
struct perf_session *session __used)
{
@@ -1528,7 +1566,8 @@ struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
return NULL;
}
-void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
+void perf_event__print_ip(struct perf_session *session,
+ union perf_event *event, struct perf_sample *sample,
struct machine *machine, int print_sym,
int print_dso, int print_symoffset)
{
@@ -1544,8 +1583,8 @@ void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
if (symbol_conf.use_callchain && sample->callchain) {
- if (machine__resolve_callchain(machine, al.thread,
- sample->callchain, NULL) != 0) {
+ if (machine__resolve_callchain(session, machine,
+ al.thread, sample, NULL) != 0) {
if (verbose)
error("Failed to resolve callchain. Skipping\n");
return;
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 3436064..2ef39df 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -155,7 +155,8 @@ static inline int perf_session__synthesize_sample(struct perf_session *session,
struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
unsigned int type);
-void perf_event__print_ip(union perf_event *event, struct perf_sample *sample,
+void perf_event__print_ip(struct perf_session *session,
+ union perf_event *event, struct perf_sample *sample,
struct machine *machine, int print_sym,
int print_dso, int print_symoffset);
diff --git a/tools/perf/util/trace-event-scripting.c b/tools/perf/util/trace-event-scripting.c
index 474aa7a..17b66dd 100644
--- a/tools/perf/util/trace-event-scripting.c
+++ b/tools/perf/util/trace-event-scripting.c
@@ -35,7 +35,8 @@ static int stop_script_unsupported(void)
return 0;
}
-static void process_event_unsupported(union perf_event *event __unused,
+static void process_event_unsupported(struct perf_session *session __used,
+ union perf_event *event __unused,
struct pevent *pevent __unused,
struct perf_sample *sample __unused,
struct perf_evsel *evsel __unused,
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 8fef1d6..a3390a1 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -74,11 +74,14 @@ struct tracing_data *tracing_data_get(struct list_head *pattrs,
void tracing_data_put(struct tracing_data *tdata);
+struct perf_session;
+
struct scripting_ops {
const char *name;
int (*start_script) (const char *script, int argc, const char **argv);
int (*stop_script) (void);
- void (*process_event) (union perf_event *event,
+ void (*process_event) (struct perf_session *session,
+ union perf_event *event,
struct pevent *pevent,
struct perf_sample *sample,
struct perf_evsel *evsel,
diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c
new file mode 100644
index 0000000..00a42aa
--- /dev/null
+++ b/tools/perf/util/unwind.c
@@ -0,0 +1,567 @@
+/*
+ * Post mortem Dwarf CFI based unwinding on top of regs and stack dumps.
+ *
+ * Lots of this code have been borrowed or heavily inspired from parts of
+ * the libunwind 0.99 code which are (amongst other contributors I may have
+ * forgotten):
+ *
+ * Copyright (C) 2002-2007 Hewlett-Packard Co
+ * Contributed by David Mosberger-Tang <[email protected]>
+ *
+ * And the bugs have been added by:
+ *
+ * Copyright (C) 2010, Frederic Weisbecker <[email protected]>
+ * Copyright (C) 2012, Jiri Olsa <[email protected]>
+ *
+ */
+
+#include <elf.h>
+#include <gelf.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <linux/list.h>
+#include <libunwind.h>
+#include <libunwind-ptrace.h>
+#include "thread.h"
+#include "session.h"
+#include "perf_regs.h"
+#include "unwind.h"
+#include "util.h"
+
+extern int
+UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as,
+ unw_word_t ip,
+ unw_dyn_info_t *di,
+ unw_proc_info_t *pi,
+ int need_unwind_info, void *arg);
+
+#define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table)
+
+#define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */
+#define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */
+
+/* Pointer-encoding formats: */
+#define DW_EH_PE_omit 0xff
+#define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */
+#define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */
+#define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */
+#define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */
+#define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */
+
+/* Pointer-encoding application: */
+#define DW_EH_PE_absptr 0x00 /* absolute value */
+#define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */
+
+/*
+ * The following are not documented by LSB v1.3, yet they are used by
+ * GCC, presumably they aren't documented by LSB since they aren't
+ * used on Linux:
+ */
+#define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */
+#define DW_EH_PE_aligned 0x50 /* aligned pointer */
+
+/* Flags intentionaly not handled, since they're not needed:
+ * #define DW_EH_PE_indirect 0x80
+ * #define DW_EH_PE_uleb128 0x01
+ * #define DW_EH_PE_udata2 0x02
+ * #define DW_EH_PE_sleb128 0x09
+ * #define DW_EH_PE_sdata2 0x0a
+ * #define DW_EH_PE_textrel 0x20
+ * #define DW_EH_PE_datarel 0x30
+ */
+
+struct unwind_info {
+ struct perf_sample *sample;
+ struct machine *machine;
+ struct thread *thread;
+ u64 sample_uregs;
+};
+
+#define dw_read(ptr, type, end) ({ \
+ type *__p = (type *) ptr; \
+ type __v; \
+ if ((__p + 1) > (type *) end) \
+ return -EINVAL; \
+ __v = *__p++; \
+ ptr = (typeof(ptr)) __p; \
+ __v; \
+ })
+
+static int __dw_read_encoded_value(u8 **p, u8 *end, u64 *val,
+ u8 encoding)
+{
+ u8 *cur = *p;
+ *val = 0;
+
+ switch (encoding) {
+ case DW_EH_PE_omit:
+ *val = 0;
+ goto out;
+ case DW_EH_PE_ptr:
+ *val = dw_read(cur, unsigned long, end);
+ goto out;
+ default:
+ break;
+ }
+
+ switch (encoding & DW_EH_PE_APPL_MASK) {
+ case DW_EH_PE_absptr:
+ break;
+ case DW_EH_PE_pcrel:
+ *val = (unsigned long) cur;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if ((encoding & 0x07) == 0x00)
+ encoding |= DW_EH_PE_udata4;
+
+ switch (encoding & DW_EH_PE_FORMAT_MASK) {
+ case DW_EH_PE_sdata4:
+ *val += dw_read(cur, s32, end);
+ break;
+ case DW_EH_PE_udata4:
+ *val += dw_read(cur, u32, end);
+ break;
+ case DW_EH_PE_sdata8:
+ *val += dw_read(cur, s64, end);
+ break;
+ case DW_EH_PE_udata8:
+ *val += dw_read(cur, u64, end);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ out:
+ *p = cur;
+ return 0;
+}
+
+#define dw_read_encoded_value(ptr, end, enc) ({ \
+ u64 __v; \
+ if (__dw_read_encoded_value(&ptr, end, &__v, enc)) { \
+ return -EINVAL; \
+ } \
+ __v; \
+ })
+
+static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+ GElf_Shdr *shp, const char *name)
+{
+ Elf_Scn *sec = NULL;
+
+ while ((sec = elf_nextscn(elf, sec)) != NULL) {
+ char *str;
+
+ gelf_getshdr(sec, shp);
+ str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
+ if (!strcmp(name, str))
+ break;
+ }
+
+ return sec;
+}
+
+static u64 elf_section_offset(int fd, const char *name)
+{
+ Elf *elf;
+ GElf_Ehdr ehdr;
+ GElf_Shdr shdr;
+ u64 offset = 0;
+
+ elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+ if (elf == NULL)
+ return 0;
+
+ do {
+ if (gelf_getehdr(elf, &ehdr) == NULL)
+ break;
+
+ if (!elf_section_by_name(elf, &ehdr, &shdr, name))
+ break;
+
+ offset = shdr.sh_offset;
+ } while (0);
+
+ elf_end(elf);
+ return offset;
+}
+
+struct table_entry {
+ u32 start_ip_offset;
+ u32 fde_offset;
+};
+
+struct eh_frame_hdr {
+ unsigned char version;
+ unsigned char eh_frame_ptr_enc;
+ unsigned char fde_count_enc;
+ unsigned char table_enc;
+
+ /*
+ * The rest of the header is variable-length and consists of the
+ * following members:
+ *
+ * encoded_t eh_frame_ptr;
+ * encoded_t fde_count;
+ */
+
+ /* A single encoded pointer should not be more than 8 bytes. */
+ u64 enc[2];
+
+ /*
+ * struct {
+ * encoded_t start_ip;
+ * encoded_t fde_addr;
+ * } binary_search_table[fde_count];
+ */
+ char data[0];
+} __packed;
+
+static int unwind_spec_ehframe(struct dso *dso, struct machine *machine,
+ u64 offset, u64 *table_data, u64 *segbase,
+ u64 *fde_count)
+{
+ struct eh_frame_hdr hdr;
+ u8 *enc = (u8 *) &hdr.enc;
+ u8 *end = (u8 *) &hdr.data;
+ ssize_t r;
+
+ r = dso__data_read_offset(dso, machine, offset,
+ (u8 *) &hdr, sizeof(hdr));
+ if (r != sizeof(hdr))
+ return -EINVAL;
+
+ /* We dont need eh_frame_ptr, just skip it. */
+ dw_read_encoded_value(enc, end, hdr.eh_frame_ptr_enc);
+
+ *fde_count = dw_read_encoded_value(enc, end, hdr.fde_count_enc);
+ *segbase = offset;
+ *table_data = (enc - (u8 *) &hdr) + offset;
+ return 0;
+}
+
+static int read_unwind_spec(struct dso *dso, struct machine *machine,
+ u64 *table_data, u64 *segbase, u64 *fde_count)
+{
+ int ret = -EINVAL, fd;
+ u64 offset;
+
+ fd = dso__data_fd(dso, machine);
+ if (fd < 0)
+ return -EINVAL;
+
+ offset = elf_section_offset(fd, ".eh_frame_hdr");
+ close(fd);
+
+ if (offset)
+ ret = unwind_spec_ehframe(dso, machine, offset,
+ table_data, segbase,
+ fde_count);
+
+ /* TODO .debug_frame check if eh_frame_hdr fails */
+ return ret;
+}
+
+static struct map *find_map(unw_word_t ip, struct unwind_info *ui)
+{
+ struct addr_location al;
+
+ thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER,
+ MAP__FUNCTION, ip, &al);
+ return al.map;
+}
+
+static int
+find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
+ int need_unwind_info, void *arg)
+{
+ struct unwind_info *ui = arg;
+ struct map *map;
+ unw_dyn_info_t di;
+ u64 table_data, segbase, fde_count;
+
+ map = find_map(ip, ui);
+ if (!map || !map->dso)
+ return -EINVAL;
+
+ pr_debug("unwind: find_proc_info dso %s\n", map->dso->name);
+
+ if (read_unwind_spec(map->dso, ui->machine,
+ &table_data, &segbase, &fde_count))
+ return -EINVAL;
+
+ memset(&di, 0, sizeof(di));
+ di.format = UNW_INFO_FORMAT_REMOTE_TABLE;
+ di.start_ip = map->start;
+ di.end_ip = map->end;
+ di.u.rti.segbase = map->start + segbase;
+ di.u.rti.table_data = map->start + table_data;
+ di.u.rti.table_len = fde_count * sizeof(struct table_entry)
+ / sizeof(unw_word_t);
+ return dwarf_search_unwind_table(as, ip, &di, pi,
+ need_unwind_info, arg);
+}
+
+static int access_fpreg(unw_addr_space_t __used as, unw_regnum_t __used num,
+ unw_fpreg_t __used *val, int __used __write,
+ void __used *arg)
+{
+ pr_err("unwind: access_fpreg unsupported\n");
+ return -UNW_EINVAL;
+}
+
+static int get_dyn_info_list_addr(unw_addr_space_t __used as,
+ unw_word_t __used *dil_addr,
+ void __used *arg)
+{
+ return -UNW_ENOINFO;
+}
+
+static int resume(unw_addr_space_t __used as, unw_cursor_t __used *cu,
+ void __used *arg)
+{
+ pr_err("unwind: resume unsupported\n");
+ return -UNW_EINVAL;
+}
+
+static int
+get_proc_name(unw_addr_space_t __used as, unw_word_t __used addr,
+ char __used *bufp, size_t __used buf_len,
+ unw_word_t __used *offp, void __used *arg)
+{
+ pr_err("unwind: get_proc_name unsupported\n");
+ return -UNW_EINVAL;
+}
+
+static int access_dso_mem(struct unwind_info *ui, unw_word_t addr,
+ unw_word_t *data)
+{
+ struct addr_location al;
+ ssize_t size;
+
+ thread__find_addr_map(ui->thread, ui->machine, PERF_RECORD_MISC_USER,
+ MAP__FUNCTION, addr, &al);
+ if (!al.map) {
+ pr_debug("unwind: no map for %lx\n", (unsigned long)addr);
+ return -1;
+ }
+
+ if (!al.map->dso)
+ return -1;
+
+ size = dso__data_read_addr(al.map->dso, al.map, ui->machine,
+ addr, (u8 *) data, sizeof(*data));
+
+ return !(size == sizeof(*data));
+}
+
+static int reg_value(unw_word_t *valp, struct regs_dump *regs, int id,
+ u64 sample_regs)
+{
+ int i, idx = 0;
+
+ if (!(sample_regs & (1 << id)))
+ return -EINVAL;
+
+ for (i = 0; i < id; i++) {
+ if (sample_regs & (1 << i))
+ idx++;
+ }
+
+ *valp = regs->regs[idx];
+ return 0;
+}
+
+static int access_mem(unw_addr_space_t __used as,
+ unw_word_t addr, unw_word_t *valp,
+ int __write, void *arg)
+{
+ struct unwind_info *ui = arg;
+ struct stack_dump *stack = &ui->sample->user_stack;
+ unw_word_t start, end;
+ int offset;
+ int ret;
+
+ /* Don't support write, probably not needed. */
+ if (__write || !stack || !ui->sample->user_regs.regs) {
+ *valp = 0;
+ return 0;
+ }
+
+ ret = reg_value(&start, &ui->sample->user_regs, PERF_REG_SP,
+ ui->sample_uregs);
+ if (ret)
+ return ret;
+
+ end = start + stack->size;
+
+ /* Check overflow. */
+ if (addr + sizeof(unw_word_t) < addr)
+ return -EINVAL;
+
+ if (addr < start || addr + sizeof(unw_word_t) >= end) {
+ ret = access_dso_mem(ui, addr, valp);
+ if (ret) {
+ pr_debug("unwind: access_mem %p not inside range %p-%p\n",
+ (void *)addr, (void *)start, (void *)end);
+ *valp = 0;
+ return ret;
+ }
+ return 0;
+ }
+
+ offset = addr - start;
+ *valp = *(unw_word_t *)&stack->data[offset];
+ pr_debug("unwind: access_mem addr %p, val %lx, offset %d\n",
+ (void *)addr, (unsigned long)*valp, offset);
+ return 0;
+}
+
+static int access_reg(unw_addr_space_t __used as,
+ unw_regnum_t regnum, unw_word_t *valp,
+ int __write, void *arg)
+{
+ struct unwind_info *ui = arg;
+ int id, ret;
+
+ /* Don't support write, I suspect we don't need it. */
+ if (__write) {
+ pr_err("unwind: access_reg w %d\n", regnum);
+ return 0;
+ }
+
+ if (!ui->sample->user_regs.regs) {
+ *valp = 0;
+ return 0;
+ }
+
+ id = unwind__arch_reg_id(regnum);
+ if (id < 0)
+ return -EINVAL;
+
+ ret = reg_value(valp, &ui->sample->user_regs, id, ui->sample_uregs);
+ if (ret) {
+ pr_err("unwind: can't read reg %d\n", regnum);
+ return ret;
+ }
+
+ pr_debug("unwind: reg %d, val %lx\n", regnum, (unsigned long)*valp);
+ return 0;
+}
+
+static void put_unwind_info(unw_addr_space_t __used as,
+ unw_proc_info_t *pi __used,
+ void *arg __used)
+{
+ pr_debug("unwind: put_unwind_info called\n");
+}
+
+static int entry(u64 ip, struct thread *thread, struct machine *machine,
+ unwind_entry_cb_t cb, void *arg)
+{
+ struct unwind_entry e;
+ struct addr_location al;
+
+ thread__find_addr_location(thread, machine,
+ PERF_RECORD_MISC_USER,
+ MAP__FUNCTION, ip, &al, NULL);
+
+ e.ip = ip;
+ e.map = al.map;
+ e.sym = al.sym;
+
+ pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n",
+ al.sym ? al.sym->name : "''",
+ ip,
+ al.map ? al.map->map_ip(al.map, ip) : (u64) 0);
+
+ return cb(&e, arg);
+}
+
+static void display_error(int err)
+{
+ switch (err) {
+ case UNW_EINVAL:
+ pr_err("unwind: Only supports local.\n");
+ break;
+ case UNW_EUNSPEC:
+ pr_err("unwind: Unspecified error.\n");
+ break;
+ case UNW_EBADREG:
+ pr_err("unwind: Register unavailable.\n");
+ break;
+ default:
+ break;
+ }
+}
+
+static unw_accessors_t accessors = {
+ .find_proc_info = find_proc_info,
+ .put_unwind_info = put_unwind_info,
+ .get_dyn_info_list_addr = get_dyn_info_list_addr,
+ .access_mem = access_mem,
+ .access_reg = access_reg,
+ .access_fpreg = access_fpreg,
+ .resume = resume,
+ .get_proc_name = get_proc_name,
+};
+
+static int get_entries(struct unwind_info *ui, unwind_entry_cb_t cb,
+ void *arg)
+{
+ unw_addr_space_t addr_space;
+ unw_cursor_t c;
+ int ret;
+
+ addr_space = unw_create_addr_space(&accessors, 0);
+ if (!addr_space) {
+ pr_err("unwind: Can't create unwind address space.\n");
+ return -ENOMEM;
+ }
+
+ ret = unw_init_remote(&c, addr_space, ui);
+ if (ret)
+ display_error(ret);
+
+ while (!ret && (unw_step(&c) > 0)) {
+ unw_word_t ip;
+
+ unw_get_reg(&c, UNW_REG_IP, &ip);
+ ret = entry(ip, ui->thread, ui->machine, cb, arg);
+ }
+
+ unw_destroy_addr_space(addr_space);
+ return ret;
+}
+
+int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
+ struct machine *machine, struct thread *thread,
+ u64 sample_uregs, struct perf_sample *data)
+{
+ unw_word_t ip;
+ struct unwind_info ui = {
+ .sample = data,
+ .sample_uregs = sample_uregs,
+ .thread = thread,
+ .machine = machine,
+ };
+ int ret;
+
+ if (!data->user_regs.regs)
+ return -EINVAL;
+
+ ret = reg_value(&ip, &data->user_regs, PERF_REG_IP, sample_uregs);
+ if (ret)
+ return ret;
+
+ ret = entry(ip, thread, machine, cb, arg);
+ if (ret)
+ return -ENOMEM;
+
+ return get_entries(&ui, cb, arg);
+}
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
new file mode 100644
index 0000000..919bd6a
--- /dev/null
+++ b/tools/perf/util/unwind.h
@@ -0,0 +1,34 @@
+#ifndef __UNWIND_H
+#define __UNWIND_H
+
+#include "types.h"
+#include "event.h"
+#include "symbol.h"
+
+struct unwind_entry {
+ struct map *map;
+ struct symbol *sym;
+ u64 ip;
+};
+
+typedef int (*unwind_entry_cb_t)(struct unwind_entry *entry, void *arg);
+
+#ifndef NO_LIBUNWIND_SUPPORT
+int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
+ struct machine *machine,
+ struct thread *thread,
+ u64 sample_uregs,
+ struct perf_sample *data);
+int unwind__arch_reg_id(int regnum);
+#else
+static inline int
+unwind__get_entries(unwind_entry_cb_t cb __used, void *arg __used,
+ struct machine *machine __used,
+ struct thread *thread __used,
+ u64 sample_uregs __used,
+ struct perf_sample *data __used)
+{
+ return 0;
+}
+#endif /* NO_LIBUNWIND_SUPPORT */
+#endif /* __UNWIND_H */
--
1.7.7.6
This patch enables perf to use the dwarf unwind code.
It extends the perf record '-g' option with following arguments:
'fp' - provides framepointer based user
stack backtrace
'dwarf[,size]' - provides dwarf (libunwind) based user stack
backtrace. The size specifies the size of the
user stack dump. If omitted it is 8192 by default.
If libunwind is found during the perf build, then the 'dwarf'
argument becomes available for record command. The 'fp' stays as
default option in any case.
Examples: (perf compiled with libunwind)
perf record -g dwarf ls
- provides dwarf unwind with 8192 as stack dump size
perf record -g dwarf,4096 ls
- provides dwarf unwind with 4096 as stack dump size
perf record -g -- ls
perf record -g fp ls
- provides frame pointer unwind
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
tools/perf/builtin-record.c | 108 ++++++++++++++++++++++++++++++++++++++++++-
tools/perf/perf.h | 9 +++-
tools/perf/util/evsel.c | 13 +++++-
3 files changed, 126 insertions(+), 4 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f5a6452..fff130b 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -31,6 +31,15 @@
#include <sched.h>
#include <sys/mman.h>
+#define CALLCHAIN_HELP "do call-graph (stack chain/backtrace) recording: "
+
+#ifdef NO_LIBUNWIND_SUPPORT
+static char callchain_help[] = CALLCHAIN_HELP "[fp]";
+#else
+static unsigned long default_stack_dump_size = 8192;
+static char callchain_help[] = CALLCHAIN_HELP "[fp] dwarf";
+#endif
+
enum write_mode_t {
WRITE_FORCE,
WRITE_APPEND
@@ -732,6 +741,100 @@ error:
return ret;
}
+#ifndef NO_LIBUNWIND_SUPPORT
+static int get_stack_size(char *str, unsigned long *_size)
+{
+ char *endptr;
+ unsigned long size;
+ unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));
+
+ size = strtoul(str, &endptr, 0);
+
+ do {
+ if (*endptr)
+ break;
+
+ size = round_up(size, sizeof(u64));
+ if (!size || size > max_size)
+ break;
+
+ *_size = size;
+ return 0;
+
+ } while (0);
+
+ pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
+ max_size, str);
+ return -1;
+}
+#endif /* !NO_LIBUNWIND_SUPPORT */
+
+static int
+parse_callchain_opt(const struct option *opt __used, const char *arg,
+ int unset)
+{
+ struct perf_record *rec = (struct perf_record *)opt->value;
+ char *tok, *name, *saveptr = NULL;
+ char buf[20];
+ int ret = -1;
+
+ /* --no-call-graph */
+ if (unset)
+ return 0;
+
+ /* We specified default option if none is provided. */
+ BUG_ON(!arg);
+
+ /* We need buffer that we know we can write to. */
+ snprintf(buf, 20, "%s", arg);
+
+ tok = strtok_r((char *)buf, ",", &saveptr);
+ name = tok ? : (char *)buf;
+
+ do {
+ /* Framepointer style */
+ if (!strncmp(name, "fp", sizeof("fp"))) {
+ if (!strtok_r(NULL, ",", &saveptr)) {
+ rec->opts.call_graph = CALLCHAIN_FP;
+ ret = 0;
+ } else
+ pr_err("callchain: No more arguments "
+ "needed for -g fp\n");
+ break;
+
+#ifndef NO_LIBUNWIND_SUPPORT
+ /* Dwarf style */
+ } else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
+ ret = 0;
+ rec->opts.call_graph = CALLCHAIN_DWARF;
+ rec->opts.stack_dump_size = default_stack_dump_size;
+
+ tok = strtok_r(NULL, ",", &saveptr);
+ if (tok) {
+ unsigned long size = 0;
+
+ ret = get_stack_size(tok, &size);
+ rec->opts.stack_dump_size = size;
+ }
+
+ if (!ret)
+ pr_debug("callchain: stack dump size %d\n",
+ rec->opts.stack_dump_size);
+#endif /* !NO_LIBUNWIND_SUPPORT */
+ } else {
+ pr_err("callchain: Unknown -g option "
+ "value: %s\n", name);
+ break;
+ }
+
+ } while (0);
+
+ if (!ret)
+ pr_debug("callchain: type %d\n", rec->opts.call_graph);
+
+ return ret;
+}
+
static const char * const record_usage[] = {
"perf record [<options>] [<command>]",
"perf record [<options>] -- <command> [<options>]",
@@ -803,8 +906,9 @@ const struct option record_options[] = {
"number of mmap data pages"),
OPT_BOOLEAN(0, "group", &record.opts.group,
"put the counters into a counter group"),
- OPT_BOOLEAN('g', "call-graph", &record.opts.call_graph,
- "do call-graph (stack chain/backtrace) recording"),
+ OPT_CALLBACK_DEFAULT('g', "call-graph", &record, "mode[,dump_size]",
+ callchain_help, &parse_callchain_opt,
+ "fp"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show counter open errors, etc)"),
OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index f960ccb..87f4ec6 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -209,9 +209,15 @@ void pthread__unblock_sigwinch(void);
#include "util/target.h"
+enum perf_call_graph_mode {
+ CALLCHAIN_NONE,
+ CALLCHAIN_FP,
+ CALLCHAIN_DWARF
+};
+
struct perf_record_opts {
struct perf_target target;
- bool call_graph;
+ int call_graph;
bool group;
bool inherit_stat;
bool no_delay;
@@ -230,6 +236,7 @@ struct perf_record_opts {
u64 branch_stack;
u64 default_interval;
u64 user_interval;
+ u16 stack_dump_size;
};
#endif
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3a284b1..4ae977e 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -17,6 +17,8 @@
#include "thread_map.h"
#include "target.h"
#include "../../../include/linux/hw_breakpoint.h"
+#include "../../include/linux/perf_event.h"
+#include "perf_regs.h"
#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
#define GROUP_FD(group_fd, cpu) (*(int *)xyarray__entry(group_fd, cpu, 0))
@@ -367,9 +369,18 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts,
attr->mmap_data = track;
}
- if (opts->call_graph)
+ if (opts->call_graph) {
attr->sample_type |= PERF_SAMPLE_CALLCHAIN;
+ if (opts->call_graph == CALLCHAIN_DWARF) {
+ attr->sample_type |= PERF_SAMPLE_REGS_USER |
+ PERF_SAMPLE_STACK_USER;
+ attr->sample_regs_user = PERF_REGS_MASK;
+ attr->sample_stack_user = opts->stack_dump_size;
+ attr->exclude_callchain_user = 1;
+ }
+ }
+
if (perf_target__has_cpu(&opts->target))
attr->sample_type |= PERF_SAMPLE_CPU;
--
1.7.7.6
Adding following info to be parsed out of the event sample:
- user register set
- user stack dump
Both are global and specific to all events within the session.
This info will be used in the unwind patches coming in shortly.
Adding simple output printout (report -D) for both register and
stack dumps.
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
tools/perf/builtin-test.c | 4 ++--
tools/perf/util/event.h | 16 +++++++++++++++-
tools/perf/util/evlist.c | 8 ++++++++
tools/perf/util/evlist.h | 1 +
tools/perf/util/evsel.c | 30 +++++++++++++++++++++++++++++-
tools/perf/util/header.c | 2 ++
tools/perf/util/python.c | 3 ++-
tools/perf/util/session.c | 36 ++++++++++++++++++++++++++++++++++++
tools/perf/util/session.h | 8 ++++++--
9 files changed, 101 insertions(+), 7 deletions(-)
diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index d909eb7..000efb0 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -564,7 +564,7 @@ static int test__basic_mmap(void)
}
err = perf_event__parse_sample(event, attr.sample_type, sample_size,
- false, &sample, false);
+ false, 0, &sample, false);
if (err) {
pr_err("Can't parse sample, err = %d\n", err);
goto out_munmap;
@@ -790,7 +790,7 @@ static int test__PERF_RECORD(void)
err = perf_event__parse_sample(event, sample_type,
sample_size, true,
- &sample, false);
+ 0, &sample, false);
if (err < 0) {
if (verbose)
perf_event__fprintf(event, stderr);
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 1b19728..ed978eb 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -69,6 +69,16 @@ struct sample_event {
u64 array[];
};
+struct regs_dump {
+ u64 *regs;
+};
+
+struct stack_dump {
+ u16 offset;
+ u64 size;
+ char *data;
+};
+
struct perf_sample {
u64 ip;
u32 pid, tid;
@@ -82,6 +92,8 @@ struct perf_sample {
void *raw_data;
struct ip_callchain *callchain;
struct branch_stack *branch_stack;
+ struct regs_dump user_regs;
+ struct stack_dump user_stack;
};
#define BUILD_ID_SIZE 20
@@ -199,7 +211,9 @@ const char *perf_event__name(unsigned int id);
int perf_event__parse_sample(const union perf_event *event, u64 type,
int sample_size, bool sample_id_all,
- struct perf_sample *sample, bool swapped);
+ u64 sample_regs_user, struct perf_sample *data,
+ bool swapped);
+
int perf_event__synthesize_sample(union perf_event *event, u64 type,
const struct perf_sample *sample,
bool swapped);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 3edfd34..057a27d 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -689,6 +689,14 @@ bool perf_evlist__valid_sample_type(const struct perf_evlist *evlist)
return true;
}
+u64 perf_evlist__sample_regs_user(const struct perf_evlist *evlist)
+{
+ struct perf_evsel *first;
+
+ first = list_entry(evlist->entries.next, struct perf_evsel, node);
+ return first->attr.sample_regs_user;
+}
+
u64 perf_evlist__sample_type(const struct perf_evlist *evlist)
{
struct perf_evsel *first;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 40d4d3c..8dbf46c 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -124,6 +124,7 @@ u16 perf_evlist__id_hdr_size(const struct perf_evlist *evlist);
bool perf_evlist__valid_sample_type(const struct perf_evlist *evlist);
bool perf_evlist__valid_sample_id_all(const struct perf_evlist *evlist);
+u64 perf_evlist__sample_regs_user(const struct perf_evlist *evlist);
void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
struct list_head *list,
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index e817713..3a284b1 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -8,6 +8,7 @@
*/
#include <byteswap.h>
+#include <linux/bitops.h>
#include "asm/bug.h"
#include "evsel.h"
#include "evlist.h"
@@ -730,7 +731,8 @@ static bool sample_overlap(const union perf_event *event,
int perf_event__parse_sample(const union perf_event *event, u64 type,
int sample_size, bool sample_id_all,
- struct perf_sample *data, bool swapped)
+ u64 sample_regs_user, struct perf_sample *data,
+ bool swapped)
{
const u64 *array;
@@ -868,6 +870,32 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
sz /= sizeof(u64);
array += sz;
}
+
+ if (type & PERF_SAMPLE_REGS_USER) {
+ /* First u64 tells us if we have any regs in sample. */
+ u64 avail = *array++;
+
+ if (avail) {
+ data->user_regs.regs = (u64 *)array;
+ array += hweight_long(sample_regs_user);
+ }
+ }
+
+ if (type & PERF_SAMPLE_STACK_USER) {
+ u64 size = *array++;
+
+ data->user_stack.offset = ((char *)(array - 1)
+ - (char *) event);
+
+ if (!size) {
+ data->user_stack.size = 0;
+ } else {
+ data->user_stack.data = (char *)array;
+ array += size / sizeof(*array);
+ data->user_stack.size = *array;
+ }
+ }
+
return 0;
}
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 5d470a3..6ebf32c 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1821,6 +1821,8 @@ static const int attr_file_abi_sizes[] = {
[0] = PERF_ATTR_SIZE_VER0,
[1] = PERF_ATTR_SIZE_VER1,
[2] = PERF_ATTR_SIZE_VER2,
+ [3] = PERF_ATTR_SIZE_VER3,
+ [4] = PERF_ATTR_SIZE_VER4,
0,
};
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index e03b58a..a35d9c9 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -807,7 +807,8 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
first = list_entry(evlist->entries.next, struct perf_evsel, node);
err = perf_event__parse_sample(event, first->attr.sample_type,
perf_evsel__sample_size(first),
- sample_id_all, &pevent->sample, false);
+ sample_id_all, 0,
+ &pevent->sample, false);
if (err)
return PyErr_Format(PyExc_OSError,
"perf: can't parse sample, err=%d", err);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 8e4f075..ed6d8b5 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -15,6 +15,7 @@
#include "util.h"
#include "cpumap.h"
#include "event-parse.h"
+#include "perf_regs.h"
static int perf_session__open(struct perf_session *self, bool force)
{
@@ -88,6 +89,7 @@ void perf_session__update_sample_type(struct perf_session *self)
self->id_hdr_size = perf_evlist__id_hdr_size(self->evlist);
self->host_machine.id_hdr_size = self->id_hdr_size;
machines__set_id_hdr_size(&self->machines, self->id_hdr_size);
+ self->sample_regs_user = perf_evlist__sample_regs_user(self->evlist);
}
int perf_session__create_kernel_maps(struct perf_session *self)
@@ -861,6 +863,34 @@ static void branch_stack__printf(struct perf_sample *sample)
sample->branch_stack->entries[i].to);
}
+static void regs_dump__printf(u64 mask, u64 *regs)
+{
+ unsigned rid, i = 0;
+
+ for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) {
+ u64 val = regs[i++];
+
+ printf(".... %-5s 0x%" PRIx64 "\n",
+ perf_reg_name(rid), val);
+ }
+}
+
+static void regs_user__printf(struct perf_sample *sample, u64 mask)
+{
+ struct regs_dump *user_regs = &sample->user_regs;
+
+ if (user_regs->regs) {
+ printf("... user regs: mask 0x%" PRIx64 "\n", mask);
+ regs_dump__printf(mask, user_regs->regs);
+ }
+}
+
+static void stack_user__printf(struct stack_dump *dump)
+{
+ printf("... ustack: size %" PRIu64 ", offset 0x%x\n",
+ dump->size, dump->offset);
+}
+
static void perf_session__print_tstamp(struct perf_session *session,
union perf_event *event,
struct perf_sample *sample)
@@ -911,6 +941,12 @@ static void dump_sample(struct perf_session *session, union perf_event *event,
if (session->sample_type & PERF_SAMPLE_BRANCH_STACK)
branch_stack__printf(sample);
+
+ if (session->sample_type & PERF_SAMPLE_REGS_USER)
+ regs_user__printf(sample, session->sample_regs_user);
+
+ if (session->sample_type & PERF_SAMPLE_STACK_USER)
+ stack_user__printf(&sample->user_stack);
}
static struct machine *
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 7c435bd..3436064 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -43,6 +43,7 @@ struct perf_session {
struct hists hists;
u64 sample_type;
int sample_size;
+ u64 sample_regs_user;
int fd;
bool fd_pipe;
bool repipe;
@@ -134,9 +135,12 @@ static inline int perf_session__parse_sample(struct perf_session *session,
const union perf_event *event,
struct perf_sample *sample)
{
- return perf_event__parse_sample(event, session->sample_type,
+ return perf_event__parse_sample(event,
+ session->sample_type,
session->sample_size,
- session->sample_id_all, sample,
+ session->sample_id_all,
+ session->sample_regs_user,
+ sample,
session->header.needs_swap);
}
--
1.7.7.6
Adding header files to access unified API for arch registers.
util/perf_regs.h - global perf_reg declarations
arch/x86/include/perf_regs.h - x86 arch specific
Adding perf_reg_name function to obtain register name based
on the reg ID value, and PERF_REGS_MASK macro with mask
definition of all current arch registers (will be used in
unwind patches).
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/perf/Makefile | 13 +++++-
tools/perf/arch/x86/include/perf_regs.h | 80 +++++++++++++++++++++++++++++++
tools/perf/util/perf_regs.h | 14 +++++
3 files changed, 106 insertions(+), 1 deletions(-)
create mode 100644 tools/perf/arch/x86/include/perf_regs.h
create mode 100644 tools/perf/util/perf_regs.h
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 77f124f..0548d93 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -50,13 +50,15 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
-e s/s390x/s390/ -e s/parisc64/parisc/ \
-e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
-e s/sh[234].*/sh/ )
+NO_PERF_REGS := 1
CC = $(CROSS_COMPILE)gcc
AR = $(CROSS_COMPILE)ar
# Additional ARCH settings for x86
ifeq ($(ARCH),i386)
- ARCH := x86
+ ARCH := x86
+ NO_PERF_REGS := 0
endif
ifeq ($(ARCH),x86_64)
ARCH := x86
@@ -69,6 +71,7 @@ ifeq ($(ARCH),x86_64)
ARCH_CFLAGS := -DARCH_X86_64
ARCH_INCLUDE = ../../arch/x86/lib/memcpy_64.S ../../arch/x86/lib/memset_64.S
endif
+ NO_PERF_REGS := 0
endif
# Treat warnings as errors unless directed not to
@@ -319,6 +322,7 @@ LIB_H += $(ARCH_INCLUDE)
LIB_H += util/cgroup.h
LIB_H += $(TRACE_EVENT_DIR)event-parse.h
LIB_H += util/target.h
+LIB_H += util/perf_regs.h
LIB_OBJS += $(OUTPUT)util/abspath.o
LIB_OBJS += $(OUTPUT)util/alias.o
@@ -670,6 +674,13 @@ else
endif
endif
+ifeq ($(NO_PERF_REGS),0)
+ ifeq ($(ARCH),x86)
+ LIB_H += arch/x86/include/perf_regs.h
+ endif
+else
+ BASIC_CFLAGS += -DNO_PERF_REGS
+endif
ifdef NO_STRLCPY
BASIC_CFLAGS += -DNO_STRLCPY
diff --git a/tools/perf/arch/x86/include/perf_regs.h b/tools/perf/arch/x86/include/perf_regs.h
new file mode 100644
index 0000000..46fc9f1
--- /dev/null
+++ b/tools/perf/arch/x86/include/perf_regs.h
@@ -0,0 +1,80 @@
+#ifndef ARCH_PERF_REGS_H
+#define ARCH_PERF_REGS_H
+
+#include <stdlib.h>
+#include "../../util/types.h"
+#include "../../../../../arch/x86/include/asm/perf_regs.h"
+
+#ifndef ARCH_X86_64
+#define PERF_REGS_MASK ((1ULL << PERF_REG_X86_32_MAX) - 1)
+#else
+#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
+ (1ULL << PERF_REG_X86_ES) | \
+ (1ULL << PERF_REG_X86_FS) | \
+ (1ULL << PERF_REG_X86_GS))
+#define PERF_REGS_MASK (((1ULL << PERF_REG_X86_64_MAX) - 1) & ~REG_NOSUPPORT)
+#endif
+#define PERF_REG_IP PERF_REG_X86_IP
+#define PERF_REG_SP PERF_REG_X86_SP
+
+static inline const char *perf_reg_name(int id)
+{
+ switch (id) {
+ case PERF_REG_X86_AX:
+ return "AX";
+ case PERF_REG_X86_BX:
+ return "BX";
+ case PERF_REG_X86_CX:
+ return "CX";
+ case PERF_REG_X86_DX:
+ return "DX";
+ case PERF_REG_X86_SI:
+ return "SI";
+ case PERF_REG_X86_DI:
+ return "DI";
+ case PERF_REG_X86_BP:
+ return "BP";
+ case PERF_REG_X86_SP:
+ return "SP";
+ case PERF_REG_X86_IP:
+ return "IP";
+ case PERF_REG_X86_FLAGS:
+ return "FLAGS";
+ case PERF_REG_X86_CS:
+ return "CS";
+ case PERF_REG_X86_SS:
+ return "SS";
+ case PERF_REG_X86_DS:
+ return "DS";
+ case PERF_REG_X86_ES:
+ return "ES";
+ case PERF_REG_X86_FS:
+ return "FS";
+ case PERF_REG_X86_GS:
+ return "GS";
+#ifdef ARCH_X86_64
+ case PERF_REG_X86_R8:
+ return "R8";
+ case PERF_REG_X86_R9:
+ return "R9";
+ case PERF_REG_X86_R10:
+ return "R10";
+ case PERF_REG_X86_R11:
+ return "R11";
+ case PERF_REG_X86_R12:
+ return "R12";
+ case PERF_REG_X86_R13:
+ return "R13";
+ case PERF_REG_X86_R14:
+ return "R14";
+ case PERF_REG_X86_R15:
+ return "R15";
+#endif /* ARCH_X86_64 */
+ default:
+ return NULL;
+ }
+
+ return NULL;
+}
+
+#endif /* ARCH_PERF_REGS_H */
diff --git a/tools/perf/util/perf_regs.h b/tools/perf/util/perf_regs.h
new file mode 100644
index 0000000..3efb79a
--- /dev/null
+++ b/tools/perf/util/perf_regs.h
@@ -0,0 +1,14 @@
+#ifndef __PERF_REGS_H
+#define __PERF_REGS_H
+
+#ifndef NO_PERF_REGS_DEFS
+#include <perf_regs.h>
+#else
+#define PERF_REGS_MASK 0
+
+static inline const char *perf_reg_name(int id __used)
+{
+ return NULL;
+}
+#endif /* NO_PERF_REGS_DEFS */
+#endif /* __PERF_REGS_H */
--
1.7.7.6
Updating attr_file_abi_sizes array with PERF_ATTR_SIZE_VER2 version,
so we have the swap check complete.
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/perf/util/header.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 3a6d204..5d470a3 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1820,6 +1820,7 @@ out_free:
static const int attr_file_abi_sizes[] = {
[0] = PERF_ATTR_SIZE_VER0,
[1] = PERF_ATTR_SIZE_VER1,
+ [2] = PERF_ATTR_SIZE_VER2,
0,
};
--
1.7.7.6
Introducing PERF_SAMPLE_STACK_USER sample type bit to trigger
the dump of the user level stack on sample. The size of the
dump is specified by sample_stack_user value.
Being able to dump parts of the user stack, starting from the
stack pointer, will be useful to make a post mortem dwarf CFI
based stack unwinding.
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
---
include/linux/perf_event.h | 18 ++++++-
kernel/events/core.c | 121 +++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 137 insertions(+), 2 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 8a73f75..d1d25f6 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -131,8 +131,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_RAW = 1U << 10,
PERF_SAMPLE_BRANCH_STACK = 1U << 11,
PERF_SAMPLE_REGS_USER = 1U << 12,
+ PERF_SAMPLE_STACK_USER = 1U << 13,
- PERF_SAMPLE_MAX = 1U << 13, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 14, /* non-ABI */
};
/*
@@ -205,6 +206,7 @@ enum perf_event_read_format {
#define PERF_ATTR_SIZE_VER1 72 /* add: config2 */
#define PERF_ATTR_SIZE_VER2 80 /* add: branch_sample_type */
#define PERF_ATTR_SIZE_VER3 88 /* add: sample_regs_user */
+#define PERF_ATTR_SIZE_VER4 96 /* add: sample_stack_user */
/*
* Hardware event_id to monitor via a performance monitoring event:
@@ -289,6 +291,14 @@ struct perf_event_attr {
* See asm/perf_regs.h for details.
*/
__u64 sample_regs_user;
+
+ /*
+ * Defines size of the user stack to dump on samples.
+ */
+ __u32 sample_stack_user;
+
+ /* Align to u64. */
+ __u32 __reserved_2;
};
/*
@@ -568,6 +578,10 @@ enum perf_event_type {
*
* { u64 abi; # enum perf_sample_regs_abi
* u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER
+ *
+ * { u64 size;
+ * char data[size];
+ * u64 dyn_size; } && PERF_SAMPLE_STACK_USER
* };
*/
PERF_RECORD_SAMPLE = 9,
@@ -1160,6 +1174,7 @@ struct perf_sample_data {
struct perf_raw_record *raw;
struct perf_branch_stack *br_stack;
struct perf_regs_user regs_user;
+ u64 stack_user_size;
};
static inline void perf_sample_data_init(struct perf_sample_data *data,
@@ -1172,6 +1187,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
data->period = period;
data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE;
data->regs_user.regs = NULL;
+ data->stack_user_size = 0;
}
extern void perf_output_sample(struct perf_output_handle *handle,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d3ce975..c4582bb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3787,6 +3787,45 @@ static void perf_sample_regs_user(struct perf_regs_user *regs_user,
}
}
+static void
+perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
+ struct pt_regs *regs)
+{
+ /* Case of a kernel thread, nothing to dump */
+ if (!regs) {
+ u64 size = 0;
+ perf_output_put(handle, size);
+ } else {
+ unsigned long sp;
+ unsigned int rem;
+ u64 dyn_size;
+
+ /*
+ * We dump:
+ * static size
+ * - the size requested by user or the best one we can fit
+ * in to the sample max size
+ * data
+ * - user stack dump data
+ * dynamic size
+ * - the actual dumped size
+ */
+
+ /* Static size. */
+ perf_output_put(handle, dump_size);
+
+ /* Data. */
+ sp = user_stack_pointer(regs);
+ rem = __output_copy_user(handle, (void *) sp, dump_size);
+ dyn_size = dump_size - rem;
+
+ perf_output_skip(handle, rem);
+
+ /* Dynamic size. */
+ perf_output_put(handle, dyn_size);
+ }
+}
+
static void __perf_event_header__init_id(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event)
@@ -4064,6 +4103,11 @@ void perf_output_sample(struct perf_output_handle *handle,
mask);
}
}
+
+ if (sample_type & PERF_SAMPLE_STACK_USER)
+ perf_output_sample_ustack(handle,
+ data->stack_user_size,
+ data->regs_user.regs);
}
void perf_prepare_sample(struct perf_event_header *header,
@@ -4129,6 +4173,66 @@ void perf_prepare_sample(struct perf_event_header *header,
header->size += size;
}
+
+ if (sample_type & PERF_SAMPLE_STACK_USER) {
+ /*
+ * A first field that tells the _static_ size of the
+ * dump. 0 if there is nothing to dump (ie: we are in
+ * a kernel thread) otherwise the requested size.
+ */
+ u16 size = sizeof(u64);
+ u16 stack_size = 0;
+
+ if (!data->regs_user.regs)
+ perf_sample_regs_user(&data->regs_user, regs);
+
+ /*
+ * If there is something to dump, add space for the
+ * dump itself and for the field that tells the
+ * dynamic size, which is how many have been actually
+ * dumped.
+ */
+ if (data->regs_user.regs) {
+ /*
+ * XXX We need to check if we fit in with the
+ * requested stack size into the sample. If we
+ * don't, we customize the stack size to fit in.
+ *
+ * Either we need PERF_SAMPLE_STACK_USER bit to
+ * be allways processed as the last one or have
+ * additional check added in case new sample type
+ * is added, because we could eat up the rest of
+ * the sample size.
+ */
+
+ u16 header_size = header->size;
+
+ stack_size = (u16) event->attr.sample_stack_user;
+
+ /*
+ * Current header size plus static size and
+ * dynamic size.
+ */
+ header_size += 2 * sizeof(u64);
+
+ /* Do we fit in with the current stack dump size? */
+ if ((u16) (header_size + stack_size) < header_size) {
+ /*
+ * If we overflow the maximum size for the
+ * sample, we customize the stack dump size
+ * to fit in.
+ */
+ stack_size = USHRT_MAX - header_size
+ - sizeof(u64);
+ stack_size = round_up(stack_size, sizeof(u64));
+ }
+
+ size += sizeof(u64) + stack_size;
+ }
+
+ data->stack_user_size = stack_size;
+ header->size += size;
+ }
}
static void perf_event_output(struct perf_event *event,
@@ -6205,8 +6309,23 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
}
}
- if (attr->sample_type & PERF_SAMPLE_REGS_USER)
+ if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
ret = perf_reg_validate(attr->sample_regs_user);
+ if (ret)
+ return ret;
+ }
+
+ if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
+ /*
+ * We have __u32 type for the size, but so far
+ * we can only use __u16 as maximum due to the
+ * __u16 sample size limit.
+ */
+ if (attr->sample_stack_user >= USHRT_MAX)
+ ret = -EINVAL;
+ else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
+ ret = -EINVAL;
+ }
out:
return ret;
--
1.7.7.6
Introducing PERF_SAMPLE_REGS_USER sample type bit to trigger
the dump of user level registers on sample. Registers we want
to dump are specified by sample_regs_user bitmask.
Only user level registers are dumped at the moment. Meaning the
register values of the user space context as it was before the
user entered the kernel for whatever reason (syscall, irq,
exception, or a PMI happening in userspace).
The layout of the sample_regs_user bitmap is described in
asm/perf_regs.h for archs that support register dump.
This is going to be useful to bring Dwarf CFI based stack
unwinding on top of samples.
Signed-off-by: Jiri Olsa <[email protected]>
Original-patch-by: Frederic Weisbecker <[email protected]>
[ Dump registers ABI specification. ]
Suggested-by: Stephane Eranian <[email protected]>
---
arch/x86/kernel/perf_regs.c | 15 ++++++++++
include/linux/perf_event.h | 35 +++++++++++++++++++++--
include/linux/perf_regs.h | 6 ++++
kernel/events/core.c | 66 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 119 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
index c00c92a..83cf975 100644
--- a/arch/x86/kernel/perf_regs.c
+++ b/arch/x86/kernel/perf_regs.c
@@ -1,5 +1,7 @@
#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_event.h>
#include <linux/bug.h>
#include <linux/stddef.h>
#include <asm/perf_regs.h>
@@ -71,6 +73,11 @@ int perf_reg_validate(u64 mask)
return 0;
}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+ return PERF_SAMPLE_REGS_ABI_32;
+}
#else /* CONFIG_X86_64 */
#define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
(1ULL << PERF_REG_X86_ES) | \
@@ -87,4 +94,12 @@ int perf_reg_validate(u64 mask)
return 0;
}
+
+u64 perf_reg_abi(struct task_struct *task)
+{
+ if (test_tsk_thread_flag(task, TIF_IA32))
+ return PERF_SAMPLE_REGS_ABI_32;
+ else
+ return PERF_SAMPLE_REGS_ABI_64;
+}
#endif /* CONFIG_X86_32 */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7602ccb..3d4d847 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -130,8 +130,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_STREAM_ID = 1U << 9,
PERF_SAMPLE_RAW = 1U << 10,
PERF_SAMPLE_BRANCH_STACK = 1U << 11,
+ PERF_SAMPLE_REGS_USER = 1U << 12,
- PERF_SAMPLE_MAX = 1U << 12, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 13, /* non-ABI */
};
/*
@@ -163,6 +164,15 @@ enum perf_branch_sample_type {
PERF_SAMPLE_BRANCH_HV)
/*
+ * Values to determine ABI of the registers dump.
+ */
+enum perf_sample_regs_abi {
+ PERF_SAMPLE_REGS_ABI_NONE = 0,
+ PERF_SAMPLE_REGS_ABI_32 = 1,
+ PERF_SAMPLE_REGS_ABI_64 = 2,
+};
+
+/*
* The format of the data returned by read() on a perf event fd,
* as specified by attr.read_format:
*
@@ -194,6 +204,7 @@ enum perf_event_read_format {
#define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */
#define PERF_ATTR_SIZE_VER1 72 /* add: config2 */
#define PERF_ATTR_SIZE_VER2 80 /* add: branch_sample_type */
+#define PERF_ATTR_SIZE_VER3 88 /* add: sample_regs_user */
/*
* Hardware event_id to monitor via a performance monitoring event:
@@ -271,7 +282,13 @@ struct perf_event_attr {
__u64 bp_len;
__u64 config2; /* extension of config1 */
};
- __u64 branch_sample_type; /* enum branch_sample_type */
+ __u64 branch_sample_type; /* enum perf_branch_sample_type */
+
+ /*
+ * Defines set of user regs to dump on samples.
+ * See asm/perf_regs.h for details.
+ */
+ __u64 sample_regs_user;
};
/*
@@ -548,6 +565,9 @@ enum perf_event_type {
* char data[size];}&& PERF_SAMPLE_RAW
*
* { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
+ *
+ * { u64 abi; # enum perf_sample_regs_abi
+ * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER
* };
*/
PERF_RECORD_SAMPLE = 9,
@@ -609,6 +629,7 @@ struct perf_guest_info_callbacks {
#include <linux/static_key.h>
#include <linux/atomic.h>
#include <linux/sysfs.h>
+#include <linux/perf_regs.h>
#include <asm/local.h>
struct perf_callchain_entry {
@@ -654,6 +675,11 @@ struct perf_branch_stack {
struct perf_branch_entry entries[0];
};
+struct perf_regs_user {
+ __u64 abi;
+ struct pt_regs *regs;
+};
+
struct task_struct;
/*
@@ -1133,6 +1159,7 @@ struct perf_sample_data {
struct perf_callchain_entry *callchain;
struct perf_raw_record *raw;
struct perf_branch_stack *br_stack;
+ struct perf_regs_user regs_user;
};
static inline void perf_sample_data_init(struct perf_sample_data *data,
@@ -1142,7 +1169,9 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
data->addr = addr;
data->raw = NULL;
data->br_stack = NULL;
- data->period = period;
+ data->period = period;
+ data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE;
+ data->regs_user.regs = NULL;
}
extern void perf_output_sample(struct perf_output_handle *handle,
diff --git a/include/linux/perf_regs.h b/include/linux/perf_regs.h
index a2f1a98..3c73d5f 100644
--- a/include/linux/perf_regs.h
+++ b/include/linux/perf_regs.h
@@ -5,6 +5,7 @@
#include <asm/perf_regs.h>
u64 perf_reg_value(struct pt_regs *regs, int idx);
int perf_reg_validate(u64 mask);
+u64 perf_reg_abi(struct task_struct *task);
#else
static inline u64 perf_reg_value(struct pt_regs *regs, int idx)
{
@@ -15,5 +16,10 @@ static inline int perf_reg_validate(u64 mask)
{
return mask ? -ENOSYS : 0;
}
+
+static inline u64 perf_reg_abi(struct task_struct *task)
+{
+ return PERF_SAMPLE_REGS_ABI_NONE;
+}
#endif /* CONFIG_HAVE_PERF_REGS */
#endif /* _LINUX_PERF_REGS_H */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b7935fc..d3ce975 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3756,6 +3756,37 @@ int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
+static void
+perf_output_sample_regs(struct perf_output_handle *handle,
+ struct pt_regs *regs, u64 mask)
+{
+ int bit;
+
+ for_each_set_bit(bit, (const unsigned long *) &mask,
+ sizeof(mask) * BITS_PER_BYTE) {
+ u64 val;
+
+ val = perf_reg_value(regs, bit);
+ perf_output_put(handle, val);
+ }
+}
+
+static void perf_sample_regs_user(struct perf_regs_user *regs_user,
+ struct pt_regs *regs)
+{
+ if (!user_mode(regs)) {
+ if (current->mm)
+ regs = task_pt_regs(current);
+ else
+ regs = NULL;
+ }
+
+ if (regs) {
+ regs_user->regs = regs;
+ regs_user->abi = perf_reg_abi(current);
+ }
+}
+
static void __perf_event_header__init_id(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event)
@@ -4016,6 +4047,23 @@ void perf_output_sample(struct perf_output_handle *handle,
perf_output_put(handle, nr);
}
}
+
+ if (sample_type & PERF_SAMPLE_REGS_USER) {
+ u64 abi = data->regs_user.abi;
+
+ /*
+ * If there are no regs to dump, notice it through
+ * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
+ */
+ perf_output_put(handle, abi);
+
+ if (abi) {
+ u64 mask = event->attr.sample_regs_user;
+ perf_output_sample_regs(handle,
+ data->regs_user.regs,
+ mask);
+ }
+ }
}
void perf_prepare_sample(struct perf_event_header *header,
@@ -4067,6 +4115,20 @@ void perf_prepare_sample(struct perf_event_header *header,
}
header->size += size;
}
+
+ if (sample_type & PERF_SAMPLE_REGS_USER) {
+ /* regs dump ABI info */
+ int size = sizeof(u64);
+
+ perf_sample_regs_user(&data->regs_user, regs);
+
+ if (data->regs_user.regs) {
+ u64 mask = event->attr.sample_regs_user;
+ size += hweight64(mask) * sizeof(u64);
+ }
+
+ header->size += size;
+ }
}
static void perf_event_output(struct perf_event *event,
@@ -6142,6 +6204,10 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
attr->branch_sample_type = mask;
}
}
+
+ if (attr->sample_type & PERF_SAMPLE_REGS_USER)
+ ret = perf_reg_validate(attr->sample_regs_user);
+
out:
return ret;
--
1.7.7.6
On 8/1/12 4:11 AM, Jiri Olsa wrote:
> +static int
> +parse_callchain_opt(const struct option *opt __used, const char *arg,
> + int unset)
> +{
> + struct perf_record *rec = (struct perf_record *)opt->value;
> + char *tok, *name, *saveptr = NULL;
> + char buf[20];
> + int ret = -1;
> +
> + /* --no-call-graph */
> + if (unset)
> + return 0;
> +
> + /* We specified default option if none is provided. */
> + BUG_ON(!arg);
> +
> + /* We need buffer that we know we can write to. */
> + snprintf(buf, 20, "%s", arg);
Isn't arg the user supplied string? What if the user messes up and
passes in 20+ characters to -g argument?
David
On Wed, Aug 01, 2012 at 08:26:11AM -0600, David Ahern wrote:
> On 8/1/12 4:11 AM, Jiri Olsa wrote:
> >+static int
> >+parse_callchain_opt(const struct option *opt __used, const char *arg,
> >+ int unset)
> >+{
> >+ struct perf_record *rec = (struct perf_record *)opt->value;
> >+ char *tok, *name, *saveptr = NULL;
> >+ char buf[20];
> >+ int ret = -1;
> >+
> >+ /* --no-call-graph */
> >+ if (unset)
> >+ return 0;
> >+
> >+ /* We specified default option if none is provided. */
> >+ BUG_ON(!arg);
> >+
> >+ /* We need buffer that we know we can write to. */
> >+ snprintf(buf, 20, "%s", arg);
>
> Isn't arg the user supplied string? What if the user messes up and
> passes in 20+ characters to -g argument?
[jolsa@dhcp-26-214 perf]$ ./perf record -g dwarf123213214321432143214321432143214321432143214321 ls
callchain: Unknown -g option value: dwarf12321321432143
...
hm, but if user specified it like this:
[jolsa@dhcp-26-214 perf]$ ./perf record -vg 'dwarf, 50000' ls
callchain: Incorrect stack dump size (max 65528):
then we're in trouble.. I'll send a fix
thanks,
jirka
On Wed, Aug 01, 2012 at 02:10:59PM +0400, Jiri Olsa wrote:
> From: Frederic Weisbecker <[email protected]>
>
> Introducing following bits to the the perf_event_attr struct:
> - exclude_callchain_kernel to filter out kernel callchain
> from the sample dump
> - exclude_callchain_user to filter out user callchain
> from the sample dump
>
> We need to be able to disable standard user callchain dump
> when we use the dwarf cfi callchain mode, because frame
> pointer based user callchains are useless in this mode.
>
> Implementing also exclude_callchain_kernel to have complete
> set of options.
>
> Signed-off-by: Frederic Weisbecker <[email protected]>
> [ Added kernel callchains filtering ]
> Signed-off-by: Jiri Olsa <[email protected]>
> CC: Andrew Vagin <[email protected]>
Acked-by: Andrew Vagin <[email protected]>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index c4582bb..0902d4a 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -4130,8 +4130,12 @@ void perf_prepare_sample(struct perf_event_header *header,
>
> if (sample_type & PERF_SAMPLE_CALLCHAIN) {
> int size = 1;
> + int kernel = !event->attr.exclude_callchain_kernel;
> + int user = !event->attr.exclude_callchain_user;
>
> - data->callchain = perf_callchain(event, regs);
> + if (kernel || user)
> + data->callchain = perf_callchain(event, regs,
> + kernel, user);
I am not sure, that we need two arguments kernel and user here,
we can get them from event inside perf_callchain...
>
> if (data->callchain)
> size += data->callchain->nr;
> diff --git a/kernel/events/internal.h b/kernel/events/internal.h
> index ce7bdfc..95d0215 100644
> --- a/kernel/events/internal.h
> +++ b/kernel/events/internal.h
> @@ -126,7 +126,8 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
>
> /* Callchain handling */
> extern struct perf_callchain_entry *
> -perf_callchain(struct perf_event *event, struct pt_regs *regs);
> +perf_callchain(struct perf_event *event, struct pt_regs *regs,
> + int kernel, int user);
> extern int get_callchain_buffers(void);
> extern void put_callchain_buffers(void);
>
> --
> 1.7.7.6
>
On Thu, Aug 02, 2012 at 11:38:26AM +0400, Andrew Vagin wrote:
> On Wed, Aug 01, 2012 at 02:10:59PM +0400, Jiri Olsa wrote:
> > From: Frederic Weisbecker <[email protected]>
> >
> > Introducing following bits to the the perf_event_attr struct:
> > - exclude_callchain_kernel to filter out kernel callchain
> > from the sample dump
> > - exclude_callchain_user to filter out user callchain
> > from the sample dump
> >
> > We need to be able to disable standard user callchain dump
> > when we use the dwarf cfi callchain mode, because frame
> > pointer based user callchains are useless in this mode.
> >
> > Implementing also exclude_callchain_kernel to have complete
> > set of options.
> >
> > Signed-off-by: Frederic Weisbecker <[email protected]>
> > [ Added kernel callchains filtering ]
> > Signed-off-by: Jiri Olsa <[email protected]>
> > CC: Andrew Vagin <[email protected]>
>
> Acked-by: Andrew Vagin <[email protected]>
>
>
> > diff --git a/kernel/events/core.c b/kernel/events/core.c
> > index c4582bb..0902d4a 100644
> > --- a/kernel/events/core.c
> > +++ b/kernel/events/core.c
> > @@ -4130,8 +4130,12 @@ void perf_prepare_sample(struct perf_event_header *header,
> >
> > if (sample_type & PERF_SAMPLE_CALLCHAIN) {
> > int size = 1;
> > + int kernel = !event->attr.exclude_callchain_kernel;
> > + int user = !event->attr.exclude_callchain_user;
> >
> > - data->callchain = perf_callchain(event, regs);
> > + if (kernel || user)
> > + data->callchain = perf_callchain(event, regs,
> > + kernel, user);
> I am not sure, that we need two arguments kernel and user here,
> we can get them from event inside perf_callchain...
right.. I'll send an update with other fixies
thanks
jirka