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authorAlexey Budankov2018-05-24 17:11:54 +0300
committerIngo Molnar2018-05-25 08:11:12 +0200
commit10b1105004fbd81058383537b67df35cc188ab62 (patch)
tree8c05509acc2d41d1a7139352958edebff0ce4f16 /arch
parent82489c5fe5f99ca95f708fecae9f2c8aa99398bb (diff)
perf/x86: Store user space frame-pointer value on a sample
Store user space frame-pointer value (BP register) into the perf trace on a sample for a process so the value becomes available when unwinding call stacks for functions gaining event samples. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/311d4a34-f81b-5535-3385-01427ac73b41@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/perf_regs.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c
index e47b2dbbdef3..c06c4c16c6b6 100644
--- a/arch/x86/kernel/perf_regs.c
+++ b/arch/x86/kernel/perf_regs.c
@@ -151,17 +151,19 @@ void perf_get_regs_user(struct perf_regs *regs_user,
regs_user_copy->sp = user_regs->sp;
regs_user_copy->cs = user_regs->cs;
regs_user_copy->ss = user_regs->ss;
-
/*
- * Most system calls don't save these registers, don't report them.
+ * Store user space frame-pointer value on sample
+ * to facilitate stack unwinding for cases when
+ * user space executable code has such support
+ * enabled at compile time:
*/
+ regs_user_copy->bp = user_regs->bp;
+
regs_user_copy->bx = -1;
- regs_user_copy->bp = -1;
regs_user_copy->r12 = -1;
regs_user_copy->r13 = -1;
regs_user_copy->r14 = -1;
regs_user_copy->r15 = -1;
-
/*
* For this to be at all useful, we need a reasonable guess for
* the ABI. Be careful: we're in NMI context, and we're