Messages in this thread | | | Date | Wed, 29 Apr 2015 15:11:32 +0300 | From | Adrian Hunter <> | Subject | Re: [PATCH V3 04/25] perf tools: Add AUX area tracing index |
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On 28/04/15 15:32, Jiri Olsa wrote: > On Fri, Apr 24, 2015 at 10:29:46PM +0300, Adrian Hunter wrote: > > SNIP > >> --- a/tools/perf/util/auxtrace.c >> +++ b/tools/perf/util/auxtrace.c >> @@ -344,6 +344,33 @@ out_err: >> return err; >> } >> >> +static int auxtrace_queues__add_indexed_event(struct auxtrace_queues *queues, >> + struct perf_session *session, >> + off_t file_offset, size_t sz) >> +{ >> + union perf_event *event; >> + int err; >> + char buf[PERF_SAMPLE_MAX_SIZE]; >> + >> + err = perf_session__peek_event(session, file_offset, buf, >> + PERF_SAMPLE_MAX_SIZE, &event, NULL); >> + if (err) >> + return err; >> + >> + if (event->header.type == PERF_RECORD_AUXTRACE) { >> + if (event->header.size != sizeof(struct auxtrace_event) || >> + event->header.size != sz) { >> + err = -EINVAL; > > getting lost in here > > as per auxtrace_mmap__read it looks like we store PERF_RECORD_AUXTRACE event with: > ev.auxtrace.header.size = sizeof(ev.auxtrace); > > and it's followed with more data with size: > ev.auxtrace.size = size + padding; > > so why the check for 'event->header.size != sz' ?
It checks the consistency of the file structure.
But it seems to me that the previous check could be:
event->header.size < sizeof(struct auxtrace_event)
which would allow for the event being made bigger in a backward compatible way.
> > jirka > >> + goto out; >> + } >> + file_offset += event->header.size; >> + err = auxtrace_queues__add_event(queues, session, event, >> + file_offset, NULL); >> + } >> +out: >> + return err; >> +} > > SNIP > >
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