| Message ID | 20190428083228.20246-1-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | 35bb59c10a6d0578806dd500477dae9cb4be344e |
| Headers | show |
| Series | [v1,1/2] perf cs-etm: Always allocate memory for cs_etm_queue::prev_packet | expand |
Hi, On 28/04/2019 09:32, Leo Yan wrote: > 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> > Fixes: 7100b12cf474 ("perf cs-etm: Generate branch sample for exception packet") > Fixes: 24fff5eb2b93 ("perf cs-etm: Avoid stale branch samples when flush packet") > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/cs-etm.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) I've tested these with the trace from the HiKey960 and the segfault no longer occurs Tested-by: Robert Walker <robert.walker@arm.com> Regards Rob > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index 110804936fc3..054b480aab04 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -422,11 +422,9 @@ 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);
Em Sun, Apr 28, 2019 at 04:32:27PM +0800, Leo Yan escreveu: > 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> > Fixes: 7100b12cf474 ("perf cs-etm: Generate branch sample for exception packet") Thanks, applied both to perf/urgent, testing them now in the containers. - Arnaldo > Fixes: 24fff5eb2b93 ("perf cs-etm: Avoid stale branch samples when flush packet") > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/cs-etm.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index 110804936fc3..054b480aab04 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -422,11 +422,9 @@ 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); > -- > 2.17.1
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 110804936fc3..054b480aab04 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -422,11 +422,9 @@ 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);
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> Fixes: 7100b12cf474 ("perf cs-etm: Generate branch sample for exception packet") Fixes: 24fff5eb2b93 ("perf cs-etm: Avoid stale branch samples when flush packet") Signed-off-by: Leo Yan <leo.yan@linaro.org> --- tools/perf/util/cs-etm.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)