libperf: Add NULL pointer check for cpu_map iteration and NULL assignment for all_cpus.

A NULL pointer may be passed to perf_cpu_map__cpu and then cause a
crash, such as the one commit cb71f7d43e ("libperf: Setup initial
evlist::all_cpus value") fix.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kyle Meyer <meyerk@hpe.com>
Link: http://lore.kernel.org/lkml/1583665157-349023-1-git-send-email-zhe.he@windriver.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
He Zhe 2020-03-08 18:59:17 +08:00 committed by Arnaldo Carvalho de Melo
parent 23cbb41c93
commit 44d041b7b2
2 changed files with 2 additions and 1 deletions

View File

@ -247,7 +247,7 @@ out:
int perf_cpu_map__cpu(const struct perf_cpu_map *cpus, int idx)
{
if (idx < cpus->nr)
if (cpus && idx < cpus->nr)
return cpus->map[idx];
return -1;

View File

@ -125,6 +125,7 @@ void perf_evlist__exit(struct perf_evlist *evlist)
perf_cpu_map__put(evlist->cpus);
perf_thread_map__put(evlist->threads);
evlist->cpus = NULL;
evlist->all_cpus = NULL;
evlist->threads = NULL;
fdarray__exit(&evlist->pollfd);
}