Commit-ID: 10b1105004fbd81058383537b67df35cc188ab62 Gitweb: https://git.kernel.org/tip/10b1105004fbd81058383537b67df35cc188ab62 Author: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx> AuthorDate: Thu, 24 May 2018 17:11:54 +0300 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Fri, 25 May 2018 08:11:12 +0200 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@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vince Weaver <vincent.weaver@xxxxxxxxx> Link: http://lkml.kernel.org/r/311d4a34-f81b-5535-3385-01427ac73b41@xxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/perf_regs.c | 10 ++++++---- 1 file 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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