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authorJiri Olsa <jolsa@redhat.com>2013-10-02 15:46:39 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-10-11 12:17:40 -0300
commita65cb4b9f8a777a715371c63c0525408048cea3e (patch)
tree283b133e3f2e10fb308d668695806f5d1bdf3e3f /tools/perf/util/event.h
parentb81a48ea877e1a104dace1392d92f708ff208f97 (diff)
perf evlist: Fix perf_evlist__mmap_read event overflow
The perf_evlist__mmap_read used 'union perf_event' as a placeholder for event crossing the mmap boundary. This is ok for sample shorter than ~PATH_MAX. However we could grow up to the maximum sample size which is 16 bits max. I hit this overflow issue when using 'perf top -G dwarf' which produces sample with the size around 8192 bytes. We could configure any valid sample size here using: '-G dwarf,size'. Using array with sample max size instead for the event placeholder. Also adding another safe check for the dynamic size of the user stack. TODO: The 'struct perf_mmap' is quite big now, maybe we could use some lazy allocation for event_copy size. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1380721599-24285-1-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/event.h')
-rw-r--r--tools/perf/util/event.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 9b7d4d333111..752709ccfb00 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -75,6 +75,9 @@ struct throttle_event {
PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD | \
PERF_SAMPLE_IDENTIFIER)
+/* perf sample has 16 bits size limit */
+#define PERF_SAMPLE_MAX_SIZE (1 << 16)
+
struct sample_event {
struct perf_event_header header;
u64 array[];