The patch f9db0d0f1b ("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: f9db0d0f1b ("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>
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