On Wed, Jan 16, 2019 at 1:53 PM Song Liu <liu.song....@gmail.com> wrote: > > Thanks Jiri! > > On Wed, Jan 16, 2019 at 1:34 PM Jiri Olsa <jo...@redhat.com> wrote: > > > > On Wed, Jan 16, 2019 at 10:57:49AM -0800, Song Liu wrote: > > > Hi, > > > > > > We are debugging a segfault of perf in ordered_events__free(). > > > > hi, > > any backtrace or info on how to reproduce it? > > Here is the backtrace: > > #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 ()" > > > > > > Disassemble shows the segfault was caused by oe->buff == NULL > > > in the following line: > > > > > > /* > > > * Current buffer might not have all the events allocated > > > * yet, we need to free only allocated ones ... > > > */ > > > list_del(&oe->buffer->list); > > > > > > After poking around the code, I suspect it is caused by the following > > > condition in alloc_event(): > > > > > > } else if (oe->buffer) { > > > new = &oe->buffer->event[oe->buffer_idx]; > > > if (++oe->buffer_idx == MAX_SAMPLE_BUFFER) > > > oe->buffer = NULL; > > > > > > argh.. yea, we need to check oe->buffer in ordered_events__free > > > > would attached change fix it for you? > > Let me try roll a fixed version to confirm.
Yes, the patch fixes this segfault. Please CC me on the official patch to back port the official version. Thanks, Song