[PATCH] perf tools: arm-spe: Fix uninitialized record error variable

[PATCH] perf tools: arm-spe: Fix uninitialized record error variable

[Kim Phillips]

The auxtrace init variable 'err' was not being initialized, leading
perf to abort early in an SPE record command when there was no explicit
error, rather only based whatever memory contents were on the stack.
Initialize it explicitly on getting an SPE successfully, the same way
cs-etm does.

Signed-off-by: Kim Phillips <kim.phillips@arm.com>
---
Hi Arnaldo, please apply to perf/urgent / stable series if at all
possible.  Thank you.

 tools/perf/arch/arm64/util/arm-spe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 1120e39c1b00..5ccfce87e693 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -194,6 +194,7 @@ struct auxtrace_record *arm_spe_recording_init(int *err,
 	sper->itr.read_finish = arm_spe_read_finish;
 	sper->itr.alignment = 0;
 
+	*err = 0;
 	return &sper->itr;
 }
 
-- 
2.17.1

Re: [PATCH] perf tools: arm-spe: Fix uninitialized record error variable

[Arnaldo Carvalho de Melo]

Em Fri, Aug 10, 2018 at 05:45:12PM -0500, Kim Phillips escreveu:
> The auxtrace init variable 'err' was not being initialized, leading
> perf to abort early in an SPE record command when there was no explicit
> error, rather only based whatever memory contents were on the stack.
> Initialize it explicitly on getting an SPE successfully, the same way
> cs-etm does.
> 
> Signed-off-by: Kim Phillips <kim.phillips@arm.com>
> ---
> Hi Arnaldo, please apply to perf/urgent / stable series if at all
> possible.  Thank you.

In such cases the best thing is to have a "Fixes: ..." so that this gets
automatically picked by the stabe trees, I'll try to find out what was
the patch that introduced this problem.

- Arnaldo

Re: [PATCH] perf tools: arm-spe: Fix uninitialized record error variable

[Arnaldo Carvalho de Melo]

Em Mon, Aug 13, 2018 at 03:55:11PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Fri, Aug 10, 2018 at 05:45:12PM -0500, Kim Phillips escreveu:
> > The auxtrace init variable 'err' was not being initialized, leading
> > perf to abort early in an SPE record command when there was no explicit
> > error, rather only based whatever memory contents were on the stack.
> > Initialize it explicitly on getting an SPE successfully, the same way
> > cs-etm does.
> > 
> > Signed-off-by: Kim Phillips <kim.phillips@arm.com>
> > ---
> > Hi Arnaldo, please apply to perf/urgent / stable series if at all
> > possible.  Thank you.
> 
> In such cases the best thing is to have a "Fixes: ..." so that this gets
> automatically picked by the stabe trees, I'll try to find out what was
> the patch that introduced this problem.

This one was easy, there is just one cset for this file prior to this
fix, so:

Fixes: ffd3d18c20b8 ("perf tools: Add ARM Statistical Profiling Extensions (SPE) support")

- Arnaldo

[tip:perf/urgent] perf arm spe: Fix uninitialized record error variable

[tip-bot for Kim Phillips]

Commit-ID:  344353366591acf659a0d0dea498611da78d67e2
Gitweb:     https://git.kernel.org/tip/344353366591acf659a0d0dea498611da78d67e2
Author:     Kim Phillips <kim.phillips@arm.com>
AuthorDate: Fri, 10 Aug 2018 17:45:12 -0500
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 14 Aug 2018 15:10:44 -0300

perf arm spe: Fix uninitialized record error variable

The auxtrace init variable 'err' was not being initialized, leading perf
to abort early in an SPE record command when there was no explicit
error, rather only based whatever memory contents were on the stack.
Initialize it explicitly on getting an SPE successfully, the same way
cs-etm does.

Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Dongjiu Geng <gengdongjiu@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: ffd3d18c20b8 ("perf tools: Add ARM Statistical Profiling Extensions (SPE) support")
Link: http://lkml.kernel.org/r/20180810174512.52900813e57cbccf18ce99a2@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/arm64/util/arm-spe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c
index 1120e39c1b00..5ccfce87e693 100644
--- a/tools/perf/arch/arm64/util/arm-spe.c
+++ b/tools/perf/arch/arm64/util/arm-spe.c
@@ -194,6 +194,7 @@ struct auxtrace_record *arm_spe_recording_init(int *err,
 	sper->itr.read_finish = arm_spe_read_finish;
 	sper->itr.alignment = 0;
 
+	*err = 0;
 	return &sper->itr;
 }