diff options
| author | Zhouyi Zhou <zhouzhouyi@gmail.com> | 2013-10-24 15:43:33 +0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2013-10-28 16:06:00 -0300 |
| commit | 8e50d384cc1d5afd2989cf0f7093756ed7164eb2 (patch) | |
| tree | 87e34b49783a32d8552eaad510d0b5fba94ee08e /tools/perf/util | |
| parent | ae779a630977d93fbebfa06216ea47df5b5c62c8 (diff) | |
perf tools: Fixup mmap event consumption
The tail position of the event buffer should only be modified after
actually use that event.
If not the event buffer could be invalid before use, and segment fault
occurs when invoking perf top -G.
Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Cc: David Ahern <dsahern@gmail.com>
Cc: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Link: http://lkml.kernel.org/r/1382600613-32177-1-git-send-email-zhouzhouyi@gmail.com
[ Simplified the logic using exit gotos and renamed write_tail method to mmap_consume ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util')
| -rw-r--r-- | tools/perf/util/evlist.c | 13 | ||||
| -rw-r--r-- | tools/perf/util/evlist.h | 2 | ||||
| -rw-r--r-- | tools/perf/util/python.c | 2 |
3 files changed, 14 insertions, 3 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index f9f77bee0b1b..e584cd30b0f2 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -545,12 +545,19 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) md->prev = old; - if (!evlist->overwrite) - perf_mmap__write_tail(md, old); - return event; } +void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx) +{ + if (!evlist->overwrite) { + struct perf_mmap *md = &evlist->mmap[idx]; + unsigned int old = md->prev; + + perf_mmap__write_tail(md, old); + } +} + static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx) { if (evlist->mmap[idx].base != NULL) { diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 880d7139d2fb..206d09339306 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -89,6 +89,8 @@ struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id); union perf_event *perf_evlist__mmap_read(struct perf_evlist *self, int idx); +void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx); + int perf_evlist__open(struct perf_evlist *evlist); void perf_evlist__close(struct perf_evlist *evlist); diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c index 71b5412bbbb9..2ac4bc92bb1f 100644 --- a/tools/perf/util/python.c +++ b/tools/perf/util/python.c @@ -822,6 +822,8 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist, PyObject *pyevent = pyrf_event__new(event); struct pyrf_event *pevent = (struct pyrf_event *)pyevent; + perf_evlist__mmap_consume(evlist, cpu); + if (pyevent == NULL) return PyErr_NoMemory(); |