perf report: Fix a bug on "--call-graph none" option
authorNamhyung Kim <namhyung@kernel.org>
Wed, 30 Sep 2015 04:34:00 +0000 (13:34 +0900)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 1 Oct 2015 12:54:33 +0000 (09:54 -0300)
commit208e7607459477432d3df52c32d4b961a96d4a94
treeee8d95e7b684cdddd44620b024889c73d04508e5
parentc53d138d41a7f33cf085762c64b4b61e8d223e1c
perf report: Fix a bug on "--call-graph none" option

The patch f9db0d0f1b2c ("perf callchain: Allow disabling call graphs
per event") added an ability to enable/disable callchain recording per
event.  But it had a problem when the enablement setting is changed at
'perf report' time using -g/--call-graph option.

For example, the following scenario will get a segfault.

  $ perf record -ag sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.500 MB perf.data (2555 samples) ]

  $ perf report -g none
  perf: Segmentation fault
  -------- backtrace --------
  perf[0x53a98a]
  /usr/lib/libc.so.6(+0x335af)[0x7f4e91df95af]

This is because callchain_param.sort() callback was not set but it
tried to call the function as it had the PERF_SAMPLE_CALLCHAIN bit.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: f9db0d0f1b2c ("perf callchain: Allow disabling call graphs per event")
Link: http://lkml.kernel.org/r/1443587640-24242-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/hist.c