[PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat

[PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat

[kan.liang]

From: Kan Liang <kan.liang@intel.com>

Perf will core dump if --per-socket/core -a are applied for perf stat.

The root cause is that cpu_map__build_map set refcnt of evlist's cpu_map
to 1.
It should set refcnt for the newly created cpu_map, not evlist's
cpu_map.

Here is the example:

perf stat -e cycles --per-socket -a sleep 1

 Performance counter stats for 'system wide':

S0       36         30,196,257      cycles
S1       28         15,823,536      cycles

       1.001126828 seconds time elapsed

*** Error in `./perf': corrupted double-linked list: 0x00000000021f9090
***
======= Backtrace: =========
/lib64/libc.so.6[0x3002e7bbe7]
/lib64/libc.so.6[0x3002e7d2b5]
./perf(perf_evsel__delete+0x28)[0x485bdd]
./perf[0x4800e8]
./perf(perf_evlist__delete+0x5e)[0x482cd5]
./perf(cmd_stat+0xf25)[0x432328]
./perf[0x4768e0]
./perf[0x476ad6]
./perf[0x476b41]
./perf(main+0x1d0)[0x476db2]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45]
./perf[0x4202c5]

Signed-off-by: Kan Liang <kan.liang@intel.com>
---
 tools/perf/util/cpumap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index c51c29f..dfc1f0b 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -284,7 +284,7 @@ static int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res,
 	/* ensure we process id in increasing order */
 	qsort(c->map, c->nr, sizeof(int), cmp_ids);
 
-	atomic_set(&cpus->refcnt, 1);
+	atomic_set(&c->refcnt, 1);
 	*res = c;
 	return 0;
 }
-- 
1.8.3.1

Re: [PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat

[Jiri Olsa]

On Fri, Oct 09, 2015 at 06:59:23AM -0400, kan.liang@intel.com wrote:
> From: Kan Liang <kan.liang@intel.com>
> 
> Perf will core dump if --per-socket/core -a are applied for perf stat.
> 
> The root cause is that cpu_map__build_map set refcnt of evlist's cpu_map
> to 1.
> It should set refcnt for the newly created cpu_map, not evlist's
> cpu_map.
> 
> Here is the example:
> 
> perf stat -e cycles --per-socket -a sleep 1
> 
>  Performance counter stats for 'system wide':
> 
> S0       36         30,196,257      cycles
> S1       28         15,823,536      cycles
> 
>        1.001126828 seconds time elapsed
> 
> *** Error in `./perf': corrupted double-linked list: 0x00000000021f9090
> ***
> ======= Backtrace: =========
> /lib64/libc.so.6[0x3002e7bbe7]
> /lib64/libc.so.6[0x3002e7d2b5]
> ./perf(perf_evsel__delete+0x28)[0x485bdd]
> ./perf[0x4800e8]
> ./perf(perf_evlist__delete+0x5e)[0x482cd5]
> ./perf(cmd_stat+0xf25)[0x432328]
> ./perf[0x4768e0]
> ./perf[0x476ad6]
> ./perf[0x476b41]
> ./perf(main+0x1d0)[0x476db2]
> /lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45]
> ./perf[0x4202c5]
> 
> Signed-off-by: Kan Liang <kan.liang@intel.com>
> ---
>  tools/perf/util/cpumap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
> index c51c29f..dfc1f0b 100644
> --- a/tools/perf/util/cpumap.c
> +++ b/tools/perf/util/cpumap.c
> @@ -284,7 +284,7 @@ static int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res,
>  	/* ensure we process id in increasing order */
>  	qsort(c->map, c->nr, sizeof(int), cmp_ids);
>  
> -	atomic_set(&cpus->refcnt, 1);
> +	atomic_set(&c->refcnt, 1);

ouch ;-) 

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

RE: [PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat

[Liang, Kan]

Hi Arnaldo

Here is one more fix for perf/core need to be pulled.

Thanks,
Kan

> 
> On Fri, Oct 09, 2015 at 06:59:23AM -0400, kan.liang@intel.com wrote:
> > From: Kan Liang <kan.liang@intel.com>
> >
> > Perf will core dump if --per-socket/core -a are applied for perf stat.
> >
> > The root cause is that cpu_map__build_map set refcnt of evlist's
> > cpu_map to 1.
> > It should set refcnt for the newly created cpu_map, not evlist's
> > cpu_map.
> >
> > Here is the example:
> >
> > perf stat -e cycles --per-socket -a sleep 1
> >
> >  Performance counter stats for 'system wide':
> >
> > S0       36         30,196,257      cycles
> > S1       28         15,823,536      cycles
> >
> >        1.001126828 seconds time elapsed
> >
> > *** Error in `./perf': corrupted double-linked list:
> > 0x00000000021f9090
> > ***
> > ======= Backtrace: =========
> > /lib64/libc.so.6[0x3002e7bbe7]
> > /lib64/libc.so.6[0x3002e7d2b5]
> > ./perf(perf_evsel__delete+0x28)[0x485bdd]
> > ./perf[0x4800e8]
> > ./perf(perf_evlist__delete+0x5e)[0x482cd5]
> > ./perf(cmd_stat+0xf25)[0x432328]
> > ./perf[0x4768e0]
> > ./perf[0x476ad6]
> > ./perf[0x476b41]
> > ./perf(main+0x1d0)[0x476db2]
> > /lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45]
> > ./perf[0x4202c5]
> >
> > Signed-off-by: Kan Liang <kan.liang@intel.com>
> > ---
> >  tools/perf/util/cpumap.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index
> > c51c29f..dfc1f0b 100644
> > --- a/tools/perf/util/cpumap.c
> > +++ b/tools/perf/util/cpumap.c
> > @@ -284,7 +284,7 @@ static int cpu_map__build_map(struct cpu_map
> *cpus, struct cpu_map **res,
> >  	/* ensure we process id in increasing order */
> >  	qsort(c->map, c->nr, sizeof(int), cmp_ids);
> >
> > -	atomic_set(&cpus->refcnt, 1);
> > +	atomic_set(&c->refcnt, 1);
> 
> ouch ;-)
> 
> Acked-by: Jiri Olsa <jolsa@kernel.org>
> 
> thanks,
> jirka

Re: [PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat

[Arnaldo Carvalho de Melo]

Em Mon, Oct 19, 2015 at 10:22:51PM +0000, Liang, Kan escreveu:
> Hi Arnaldo
> 
> Here is one more fix for perf/core need to be pulled.

Thanks for the reminder, tried to reproduce on a two socket system,
couldn't, but the fix is obvious enough, thanks, applied.

- Arnaldo
 
> Thanks,
> Kan
> 
> > 
> > On Fri, Oct 09, 2015 at 06:59:23AM -0400, kan.liang@intel.com wrote:
> > > From: Kan Liang <kan.liang@intel.com>
> > >
> > > Perf will core dump if --per-socket/core -a are applied for perf stat.
> > >
> > > The root cause is that cpu_map__build_map set refcnt of evlist's
> > > cpu_map to 1.
> > > It should set refcnt for the newly created cpu_map, not evlist's
> > > cpu_map.
> > >
> > > Here is the example:
> > >
> > > perf stat -e cycles --per-socket -a sleep 1
> > >
> > >  Performance counter stats for 'system wide':
> > >
> > > S0       36         30,196,257      cycles
> > > S1       28         15,823,536      cycles
> > >
> > >        1.001126828 seconds time elapsed
> > >
> > > *** Error in `./perf': corrupted double-linked list:
> > > 0x00000000021f9090
> > > ***
> > > ======= Backtrace: =========
> > > /lib64/libc.so.6[0x3002e7bbe7]
> > > /lib64/libc.so.6[0x3002e7d2b5]
> > > ./perf(perf_evsel__delete+0x28)[0x485bdd]
> > > ./perf[0x4800e8]
> > > ./perf(perf_evlist__delete+0x5e)[0x482cd5]
> > > ./perf(cmd_stat+0xf25)[0x432328]
> > > ./perf[0x4768e0]
> > > ./perf[0x476ad6]
> > > ./perf[0x476b41]
> > > ./perf(main+0x1d0)[0x476db2]
> > > /lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45]
> > > ./perf[0x4202c5]
> > >
> > > Signed-off-by: Kan Liang <kan.liang@intel.com>
> > > ---
> > >  tools/perf/util/cpumap.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c index
> > > c51c29f..dfc1f0b 100644
> > > --- a/tools/perf/util/cpumap.c
> > > +++ b/tools/perf/util/cpumap.c
> > > @@ -284,7 +284,7 @@ static int cpu_map__build_map(struct cpu_map
> > *cpus, struct cpu_map **res,
> > >  	/* ensure we process id in increasing order */
> > >  	qsort(c->map, c->nr, sizeof(int), cmp_ids);
> > >
> > > -	atomic_set(&cpus->refcnt, 1);
> > > +	atomic_set(&c->refcnt, 1);
> > 
> > ouch ;-)
> > 
> > Acked-by: Jiri Olsa <jolsa@kernel.org>
> > 
> > thanks,
> > jirka

[tip:perf/core] perf cpu_map: Fix core dump caused by per-socket/ core system-wide stat

[tip-bot for Kan Liang]

Commit-ID:  bc1d03687b9be3a30aab8e8d78c7884449b6e511
Gitweb:     http://git.kernel.org/tip/bc1d03687b9be3a30aab8e8d78c7884449b6e511
Author:     Kan Liang <kan.liang@intel.com>
AuthorDate: Fri, 9 Oct 2015 06:59:23 -0400
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 20 Oct 2015 15:54:20 -0300

perf cpu_map: Fix core dump caused by per-socket/core system-wide stat

Perf will core dump if --per-socket/core -a are applied for perf stat.

The root cause is that cpu_map__build_map set refcnt of evlist's cpu_map
to 1.  It should set refcnt for the newly created cpu_map, not evlist's
cpu_map.

Here is the example:

  # perf stat -e cycles --per-socket -a sleep 1

   Performance counter stats for 'system wide':

  S0       36         30,196,257      cycles
  S1       28         15,823,536      cycles

       1.001126828 seconds time elapsed

  *** Error in `./perf': corrupted double-linked list: 0x00000000021f9090 ***
  ======= Backtrace: =========
  /lib64/libc.so.6[0x3002e7bbe7]
  /lib64/libc.so.6[0x3002e7d2b5]
  ./perf(perf_evsel__delete+0x28)[0x485bdd]
  ./perf[0x4800e8]
  ./perf(perf_evlist__delete+0x5e)[0x482cd5]
  ./perf(cmd_stat+0xf25)[0x432328]
  ./perf[0x4768e0]
  ./perf[0x476ad6]
  ./perf[0x476b41]
  ./perf(main+0x1d0)[0x476db2]
  /lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45]
  ./perf[0x4202c5]

Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1444388363-35936-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/cpumap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index b368453..aa6b490 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -285,7 +285,7 @@ int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res,
 	/* ensure we process id in increasing order */
 	qsort(c->map, c->nr, sizeof(int), cmp_ids);
 
-	atomic_set(&cpus->refcnt, 1);
+	atomic_set(&c->refcnt, 1);
 	*res = c;
 	return 0;
 }