Re: [BUG] perf annotate: broken in pipe mode

[Namhyung Kim]

Hi Stephane,

On Fri, 1 Feb 2013 00:51:51 +0100, Stephane Eranian wrote:
> Hi,
>
> Looks like perf annotate in pipe mode is totally broken nowadays.
> I tried this from tip.git:
>
> $ perf record -o - noploop 5 >perf.data
> $ perf annotate -i i < perf.data
> Core dump
>
> Callstack looks as follows:
> 0x000000000049f9e4 in add_hist_entry (hists=0x809708,
> entry=0x7fffffffde60, al=0x7fffffffdff0, period=1) at util/hist.c:297
> 297 while (*p != NULL) {
> :t
> [Current thread is 1 (Thread 0x7ffff7fc9980 (LWP 13292))]
> (gdb) bt
> #0  0x000000000049f9e4 in add_hist_entry (hists=0x809708,
> entry=0x7fffffffde60, al=0x7fffffffdff0, period=1) at util/hist.c:297
> #1  0x000000000049fcca in __hists__add_entry (self=0x809708,
> al=0x7fffffffdff0, sym_parent=0x0, period=1) at util/hist.c:395
> #2  0x00000000004171b0 in perf_evsel__add_sample (evsel=0x809660,
> sample=0x7fffffffe0e0, al=0x7fffffffdff0, ann=0x7fffffffe750) at
> builtin-annotate.c:65
> #3  0x0000000000417394 in process_sample_event (tool=0x7fffffffe750,
> event=0x80af70, sample=0x7fffffffe0e0, evsel=0x809660,
> machine=0x8093c8) at builtin-annotate.c:102
> #4  0x000000000048c56d in perf_session_deliver_event
> (session=0x8092e0, event=0x80af70, sample=0x7fffffffe0e0,
> tool=0x7fffffffe750, file_offset=11688)
>     at util/session.c:870
> #5  0x000000000048cb20 in perf_session__process_event
> (session=0x8092e0, event=0x80af70, tool=0x7fffffffe750,
> file_offset=11688) at util/session.c:986
> #6  0x000000000048cf75 in __perf_session__process_pipe_events
> (self=0x8092e0, tool=0x7fffffffe750) at util/session.c:1120
>
> Looks like the session->evlist is not properly initialized in pipe
> mode or that evsel->hists
> is bogus because it crashes due to evsel->hists->entries_in == NULL.
> Don't know how
> you can get there.
>
> Anybody has a clue?

After some study I think I managed to figure out the root cause.  The
patch follows..


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