[PATCH v2] perf session: check for null pointer before derefernce

From: Ameer Hamza
Date: Tue Jan 25 2022 - 07:17:57 EST


Move null pointer check before dereferncing the variable

Addresses-Coverity: 1497622 ("Derereference before null check")

Reviewed-by: James Clark <james.clark@xxxxxxx>

Signed-off-by: Ameer Hamza <amhamza.mgc@xxxxxxxxx>

---
v1 -> v2: It should be possible to dump stuff if machine is NULL.
---
tools/perf/util/session.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index f19348dddd55..210eeee3dd70 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1503,11 +1503,12 @@ static int machines__deliver_event(struct machines *machines,
++evlist->stats.nr_unknown_id;
return 0;
}
- dump_sample(evsel, event, sample, perf_env__arch(machine->env));
if (machine == NULL) {
++evlist->stats.nr_unprocessable_samples;
+ dump_sample(evsel, event, sample, perf_env__arch(NULL));
return 0;
}
+ dump_sample(evsel, event, sample, perf_env__arch(machine->env));
return evlist__deliver_sample(evlist, tool, event, sample, evsel, machine);
case PERF_RECORD_MMAP:
return tool->mmap(tool, event, sample, machine);
--
2.25.1