diff options
| author | Kan Liang <kan.liang@linux.intel.com> | 2018-03-26 09:42:09 -0400 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-03-27 13:13:38 -0300 |
| commit | f58385f629c87a9e210108b39c1f4950d0363ad2 (patch) | |
| tree | 532b5e34e645af4984155e187d2737e38a57f2fc | |
| parent | b4c786e5aa69c5a75ac3932f81fdf8e8c120c03b (diff) | |
perf mmap: Fix accessing unmapped mmap in perf_mmap__read_done()
There is a segmentation fault when running 'perf trace'. For example:
[root@jouet e]# perf trace -e *chdir -o /tmp/bla perf report --ignore-vmlinux -i ../perf.data
The perf_mmap__consume() could unmap the mmap. It needs to check the
refcnt in perf_mmap__read_done().
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: ee023de05f35 ("perf mmap: Introduce perf_mmap__read_done()")
Link: http://lkml.kernel.org/r/1522071729-16776-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/mmap.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index 38ca3ffb9d61..f6cfc52ff1fe 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -317,5 +317,11 @@ out: */ void perf_mmap__read_done(struct perf_mmap *map) { + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!refcount_read(&map->refcnt)) + return; + map->prev = perf_mmap__read_head(map); } |