[BUG] perf/inject: crash in pipe mode

From: Stephane Eranian
Date: Fri May 25 2018 - 20:20:15 EST


Hi,


With the latest tip.git perf, if you run

$ perf record -a -o - sleep 2 | perf inject -b -i - | perf buildid-list -i -
SEGFAULT in perf inject:
free_dup_event (oe=0x555555d25b88, oe=0x555555d25b88,
event=0x3030310931303031) at util/ordered-events.c:86
86 oe->cur_alloc_size -= event->header.size;
(gdb) bt
#0 free_dup_event (oe=0x555555d25b88, oe=0x555555d25b88,
event=0x3030310931303031) at util/ordered-events.c:86
#1 ordered_events__free (oe=oe@entry=0x555555d25b88) at
util/ordered-events.c:310
#2 0x00005555557964f8 in __perf_session__process_pipe_events
(session=0x555555d1f910) at util/session.c:1778
#3 perf_session__process_events (session=session@entry=0x555555d1f910) at
util/session.c:1958
#4 0x00005555556ef9b2 in __cmd_inject (inject=0x7fffffffda40) at
builtin-inject.c:697
#5 cmd_inject (argc=<optimized out>, argv=<optimized out>) at
builtin-inject.c:871
#6 0x000055555572e8b1 in run_builtin (p=0x555555be8f98 <commands+600>,
argc=4, argv=0x7fffffffe460) at perf.c:303
#7 0x000055555572ebae in handle_internal_command (argc=4,
argv=0x7fffffffe460) at perf.c:355
#8 0x00005555556ae1e1 in run_argv (argcp=<synthetic pointer>,
argv=<synthetic pointer>) at perf.c:399
#9 main (argc=<optimized out>, argv=0x7fffffffe460) at perf.c:521

In general I think the pipe mode is not very well tested. I think it could
be made the default file format. I believe perf can
autodetect file vs. pipe mode perf.data using the header.size field. This
would simplify a few things inside perf and ensure
the pipe mode format is well tested.