[GIT PULL 0/2] perf/urgent fix

[GIT PULL 0/2] perf/urgent fix

[Arnaldo Carvalho de Melo]

Hi Ingo,

	Please consider pulling, this one is already in perf/core,
but is needed for perf/urgent too, as reported by Will Cohen.

- Arnaldo

The following changes since commit 03fba21adb190fc0aec9c2556639c1c1b195aee7:

  Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2015-12-08 06:05:12 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo

for you to fetch changes up to fb202539e61b14bc63ac29af10fe5d758ecd880a:

  perf list: Robustify event printing routine (2015-12-16 16:43:10 -0300)

----------------------------------------------------------------
perf/urgent fix:

User visible changes:

  - Fix 'perf list' segfault due to lack of support for PERF_CONF_SW_BPF_OUTPUT
    in an array used just for printing available events, robustify the code
    involved (Arnaldo Carvalho de Melo)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

----------------------------------------------------------------
Arnaldo Carvalho de Melo (2):
      perf list: Add support for PERF_COUNT_SW_BPF_OUT
      perf list: Robustify event printing routine

 tools/perf/util/parse-events.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

[PATCH 1/2] perf list: Add support for PERF_COUNT_SW_BPF_OUT

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

When PERF_COUNT_SW_BPF_OUTPUT was added to the kernel we should've
added it to tools/perf, where it is used just to list events.

This ended up causing a segfault in commands like "perf list stall".

Fix it by adding that new software counter.

A patch to robustify perf to not segfault when the next counter gets
added in the kernel will follow this one.

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: William Cohen <wcohen@redhat.com>
Link: http://lkml.kernel.org/n/tip-uya354upi3eprsey6mi5962d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/parse-events.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index e48d9da75707..40ae92a8673c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -124,6 +124,10 @@ struct event_symbol event_symbols_sw[PERF_COUNT_SW_MAX] = {
 		.symbol = "dummy",
 		.alias  = "",
 	},
+	[PERF_COUNT_SW_BPF_OUTPUT] = {
+		.symbol = "bpf-output",
+		.alias  = "",
+	},
 };
 
 #define __PERF_EVENT_FIELD(config, name) \
-- 
2.1.0

[PATCH 2/2] perf list: Robustify event printing routine

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

When a43eec304259 ("bpf: introduce bpf_perf_event_output() helper") added
PERF_COUNT_SW_BPF_OUTPUT we ended up with a new entry in the event_symbols_sw
array that wasn't initialized, thus set to NULL, fix print_symbol_events()
to check for that case so that we don't crash if this happens again.

  (gdb) bt
  #0  __match_glob (ignore_space=false, pat=<optimized out>, str=<optimized out>) at util/string.c:198
  #1  strglobmatch (str=<optimized out>, pat=pat@entry=0x7fffffffe61d "stall") at util/string.c:252
  #2  0x00000000004993a5 in print_symbol_events (type=1, syms=0x872880 <event_symbols_sw+160>, max=11, name_only=false, event_glob=0x7fffffffe61d "stall")
      at util/parse-events.c:1615
  #3  print_events (event_glob=event_glob@entry=0x7fffffffe61d "stall", name_only=false) at util/parse-events.c:1675
  #4  0x000000000042c79e in cmd_list (argc=1, argv=0x7fffffffe390, prefix=<optimized out>) at builtin-list.c:68
  #5  0x00000000004788a5 in run_builtin (p=p@entry=0x871758 <commands+120>, argc=argc@entry=2, argv=argv@entry=0x7fffffffe390) at perf.c:370
  #6  0x0000000000420ab0 in handle_internal_command (argv=0x7fffffffe390, argc=2) at perf.c:429
  #7  run_argv (argv=0x7fffffffe110, argcp=0x7fffffffe11c) at perf.c:473
  #8  main (argc=2, argv=0x7fffffffe390) at perf.c:588
  (gdb) p event_symbols_sw[PERF_COUNT_SW_BPF_OUTPUT]
  $4 = {symbol = 0x0, alias = 0x0}
  (gdb)

A patch to robustify perf to not segfault when the next counter gets added in
the kernel will follow this one.

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: William Cohen <wcohen@redhat.com>
Link: http://lkml.kernel.org/n/tip-57wysblcjfrseb0zg5u7ek10@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/parse-events.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 40ae92a8673c..6fc8cd753e1a 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1883,7 +1883,7 @@ restart:
 
 	for (i = 0; i < max; i++, syms++) {
 
-		if (event_glob != NULL &&
+		if (event_glob != NULL && syms->symbol != NULL &&
 		    !(strglobmatch(syms->symbol, event_glob) ||
 		      (syms->alias && strglobmatch(syms->alias, event_glob))))
 			continue;
-- 
2.1.0

Re: [GIT PULL 0/2] perf/urgent fix

[Ingo Molnar]

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Hi Ingo,
> 
> 	Please consider pulling, this one is already in perf/core,
> but is needed for perf/urgent too, as reported by Will Cohen.
> 
> - Arnaldo
> 
> The following changes since commit 03fba21adb190fc0aec9c2556639c1c1b195aee7:
> 
>   Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2015-12-08 06:05:12 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-urgent-for-mingo
> 
> for you to fetch changes up to fb202539e61b14bc63ac29af10fe5d758ecd880a:
> 
>   perf list: Robustify event printing routine (2015-12-16 16:43:10 -0300)
> 
> ----------------------------------------------------------------
> perf/urgent fix:
> 
> User visible changes:
> 
>   - Fix 'perf list' segfault due to lack of support for PERF_CONF_SW_BPF_OUTPUT
>     in an array used just for printing available events, robustify the code
>     involved (Arnaldo Carvalho de Melo)
> 
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> ----------------------------------------------------------------
> Arnaldo Carvalho de Melo (2):
>       perf list: Add support for PERF_COUNT_SW_BPF_OUT
>       perf list: Robustify event printing routine
> 
>  tools/perf/util/parse-events.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Pulled, thanks a lot Arnaldo!

	Ingo