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authorLeo Yan <leo.yan@linaro.org>2019-04-28 16:32:27 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-25 18:22:30 +0200
commit58d1e074c74287b9f92e8ef357372e6189ccf0a7 (patch)
tree2a5008213517471f5b48576c3dd535f89d283480
parentcd448c27b08eabae019f7d933f6313768617ad0d (diff)
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perf cs-etm: Always allocate memory for cs_etm_queue::prev_packet
[ Upstream commit 35bb59c10a6d0578806dd500477dae9cb4be344e ] Robert Walker reported a segmentation fault is observed when process CoreSight trace data; this issue can be easily reproduced by the command 'perf report --itrace=i1000i' for decoding tracing data. If neither the 'b' flag (synthesize branches events) nor 'l' flag (synthesize last branch entries) are specified to option '--itrace', cs_etm_queue::prev_packet will not been initialised. After merging the code to support exception packets and sample flags, there introduced a number of uses of cs_etm_queue::prev_packet without checking whether it is valid, for these cases any accessing to uninitialised prev_packet will cause crash. As cs_etm_queue::prev_packet is used more widely now and it's already hard to follow which functions have been called in a context where the validity of cs_etm_queue::prev_packet has been checked, this patch always allocates memory for cs_etm_queue::prev_packet. Reported-by: Robert Walker <robert.walker@arm.com> Suggested-by: Robert Walker <robert.walker@arm.com> Signed-off-by: Leo Yan <leo.yan@linaro.org> Tested-by: Robert Walker <robert.walker@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Suzuki K Poulouse <suzuki.poulose@arm.com> Cc: linux-arm-kernel@lists.infradead.org Fixes: 7100b12cf474 ("perf cs-etm: Generate branch sample for exception packet") Fixes: 24fff5eb2b93 ("perf cs-etm: Avoid stale branch samples when flush packet") Link: http://lkml.kernel.org/r/20190428083228.20246-1-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--tools/perf/util/cs-etm.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 27a374ddf661..947f1bb2fbdf 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -345,11 +345,9 @@ static struct cs_etm_queue *cs_etm__alloc_queue(struct cs_etm_auxtrace *etm,
if (!etmq->packet)
goto out_free;
- if (etm->synth_opts.last_branch || etm->sample_branches) {
- etmq->prev_packet = zalloc(szp);
- if (!etmq->prev_packet)
- goto out_free;
- }
+ etmq->prev_packet = zalloc(szp);
+ if (!etmq->prev_packet)
+ goto out_free;
if (etm->synth_opts.last_branch) {
size_t sz = sizeof(struct branch_stack);