Commit-ID:  f9a5978ac4ede901fa73d7c28ae1c5d89bc2a46a
Gitweb:     http://git.kernel.org/tip/f9a5978ac4ede901fa73d7c28ae1c5d89bc2a46a
Author:     Jiri Olsa <[email protected]>
AuthorDate: Thu, 3 Mar 2016 10:53:48 +0100
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 3 Mar 2016 11:04:54 -0300

perf tools: Fix locale handling in pmu parsing

Ingo reported regression on display format of big numbers, which is
missing separators (in default perf stat output).

 triton:~/tip> perf stat -a sleep 1
         ...
         127008602      cycles                    #    0.011 GHz
         279538533      stalled-cycles-frontend   #  220.09% frontend cycles 
idle
         119213269      instructions              #    0.94  insn per cycle

This is caused by recent change:

  perf stat: Check existence of frontend/backed stalled cycles

that added call to pmu_have_event, that subsequently calls
perf_pmu__parse_scale, which has a bug in locale handling.

The lc string returned from setlocale, that we use to store old locale
value, may be allocated in static storage. Getting a dynamic copy to
make it survive another setlocale call.

  $ perf stat ls
         ...
         2,360,602      cycles                    #    3.080 GHz
         2,703,090      instructions              #    1.15  insn per cycle
           546,031      branches                  #  712.511 M/sec

Committer note:

Since the patch introducing the regression didn't made to perf/core,
move it to just before where the regression was introduced, so that we
don't break bisection for this feature.

Reported-by: Ingo Molnar <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/pmu.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index ce61f79..d8cd038 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -124,6 +124,17 @@ static int perf_pmu__parse_scale(struct perf_pmu_alias 
*alias, char *dir, char *
        lc = setlocale(LC_NUMERIC, NULL);
 
        /*
+        * The lc string may be allocated in static storage,
+        * so get a dynamic copy to make it survive setlocale
+        * call below.
+        */
+       lc = strdup(lc);
+       if (!lc) {
+               ret = -ENOMEM;
+               goto error;
+       }
+
+       /*
         * force to C locale to ensure kernel
         * scale string is converted correctly.
         * kernel uses default C locale.
@@ -135,6 +146,8 @@ static int perf_pmu__parse_scale(struct perf_pmu_alias 
*alias, char *dir, char *
        /* restore locale */
        setlocale(LC_NUMERIC, lc);
 
+       free((char *) lc);
+
        ret = 0;
 error:
        close(fd);

Reply via email to