From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Olsa Subject: Re: [PATCH v2]: perf/x86: expose user space frame-pointer value on a sample Date: Fri, 13 Apr 2018 14:43:02 +0200 Message-ID: <20180413124302.GC28241@krava> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Alexey Budankov Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel , linux-perf-users@vger.kernel.org List-Id: linux-perf-users.vger.kernel.org On Tue, Apr 10, 2018 at 06:40:04PM +0300, Alexey Budankov wrote: SNIP > Signed-off-by: Alexey Budankov > --- > Changes in v2: > - lifted restriction on frame pointer architecture so it's value is provided > as for i386 as for x86_64 processes > > MAINTAINERS file lacks references to appropriate folks for reviewing > changes at arch/x86/kernel/perf_regs.c so probably it makes sense to > update the file as well in this respect. > --- > arch/x86/kernel/perf_regs.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/perf_regs.c b/arch/x86/kernel/perf_regs.c > index e47b2dbbdef3..8d68658eff7f 100644 > --- a/arch/x86/kernel/perf_regs.c > +++ b/arch/x86/kernel/perf_regs.c > @@ -156,7 +156,13 @@ void perf_get_regs_user(struct perf_regs *regs_user, > * Most system calls don't save these registers, don't report them. > */ > regs_user_copy->bx = -1; > - regs_user_copy->bp = -1; > + /* > + * 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->r12 = -1; > regs_user_copy->r13 = -1; > regs_user_copy->r14 = -1; looks ok to me thanks, jirka