perf tools: Fix map reference counting

By calling maps__insert() we assume to get 2 references on the map,
which we relese within maps__remove call.

However if there's already same map name, we currently don't bump the
reference and can crash, like:

  Program received signal SIGABRT, Aborted.
  0x00007ffff75e60f5 in raise () from /lib64/

  (gdb) bt
  #0  0x00007ffff75e60f5 in raise () from /lib64/
  #1  0x00007ffff75d0895 in abort () from /lib64/
  #2  0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/
  #3  0x00007ffff75de596 in __assert_fail () from /lib64/
  #4  0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131
  #5  refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148
  #6  map__put (map=0x1224df0) at util/map.c:299
  #7  0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953
  #8  maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959
  #9  0x00000000004f7d8a in map_groups__remove (map=<optimized out>, mg=<optimized out>) at util/map_groups.h:65
  #10 machine__process_ksymbol_unregister (sample=<optimized out>, event=0x7ffff7279670, machine=<optimized out>) at util/machine.c:728
  #11 machine__process_ksymbol (machine=<optimized out>, event=0x7ffff7279670, sample=<optimized out>) at util/machine.c:741
  #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362
  #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243
  #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=<optimized out>) at util/ordered-events.c:322
  #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8,

Add the map to the list and getting the reference event if we find the
map with same name.

Signed-off-by: Jiri Olsa <>
Cc: Adrian Hunter <>
Cc: Alexander Shishkin <>
Cc: Alexei Starovoitov <>
Cc: Andi Kleen <>
Cc: Daniel Borkmann <>
Cc: Eric Saint-Etienne <>
Cc: Namhyung Kim <>
Cc: Peter Zijlstra <>
Cc: Song Liu <>
Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section")
Signed-off-by: Arnaldo Carvalho de Melo <>
1 file changed