On Thu, Jan 17, 2019 at 3:54 AM Jiri Olsa <[email protected]> wrote: > > Song Liu reported crash in perf record: > > > #0 0x0000000000500055 in ordered_events(float, long double,...)(...) () > > #1 0x0000000000500196 in ordered_events.reinit () > > #2 0x00000000004fe413 in perf_session.process_events () > > #3 0x0000000000440431 in cmd_record () > > #4 0x00000000004a439f in run_builtin () > > #5 0x000000000042b3e5 in main ()" > > This can happen when we get out of the buffers during > event processing. The subsequent ordered_events__free > assumes the oe->buffer != NULL and crashes. Adding > the check to prevent that. > > Cc: Stephane Eranian <[email protected]> > Fixes: d5ceb62b3654 ("perf ordered_events: Add 'struct ordered_events_buffer' > layer") > Reported-by: Song Liu <[email protected]> > Link: http://lkml.kernel.org/n/[email protected] > Signed-off-by: Jiri Olsa <[email protected]>
Reviewed-and-tested-by: Song Liu <[email protected]> Thanks again for the fix! Song > --- > tools/perf/util/ordered-events.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/ordered-events.c > b/tools/perf/util/ordered-events.c > index 897589507d97..ea523d3b248f 100644 > --- a/tools/perf/util/ordered-events.c > +++ b/tools/perf/util/ordered-events.c > @@ -391,8 +391,10 @@ void ordered_events__free(struct ordered_events *oe) > * Current buffer might not have all the events allocated > * yet, we need to free only allocated ones ... > */ > - list_del(&oe->buffer->list); > - ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe); > + if (oe->buffer) { > + list_del(&oe->buffer->list); > + ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe); > + } > > /* ... and continue with the rest */ > list_for_each_entry_safe(buffer, tmp, &oe->to_free, list) { > -- > 2.17.2 >
