perf callchain: Fix segfault in thread__resolve_callchain_sample()

commit aceb98261ea7d9fe38f9c140c5531f0b13623832 upstream.

Do not dereference 'chain' when it is NULL.

  $ perf record -e intel_pt//u -e branch-misses:u uname
  $ perf report --itrace=l --branch-history
  perf: Segmentation fault

Fixes: e9024d519d ("perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}")
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Adrian Hunter 2019-11-14 16:25:38 +02:00 • committed by Greg Kroah-Hartman
commit 632a300260

View file

@ -2403,7 +2403,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
}
check_calls:
if (callchain_param.order != ORDER_CALLEE) {
if (chain && callchain_param.order != ORDER_CALLEE) {
err = find_prev_cpumode(chain, thread, cursor, parent, root_al,
&cpumode, chain->nr - first_call);
if (err)