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From:   Ameer Hamza <amhamza.mgc@gmail.com>
To:     mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        jolsa@redhat.com, namhyung@kernel.org
Cc:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        rickyman7@gmail.com, alexey.v.bayduraev@linux.intel.com,
        adrian.hunter@intel.com, leo.yan@linaro.org, german.gomez@arm.com,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        amhamza.mgc@gmail.com, James Clark <james.clark@arm.com>
Subject: [PATCH v2] perf session: check for null pointer before derefernce
Date:   Tue, 25 Jan 2022 17:11:41 +0500
Message-Id: <20220125121141.18347-1-amhamza.mgc@gmail.com>
In-Reply-To: <8983b963-2139-ecb3-3a31-b5e225db389c@arm.com>
References: <8983b963-2139-ecb3-3a31-b5e225db389c@arm.com>
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Move null pointer check before dereferncing the variable

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

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

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

---
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