libperf evsel: Open shouldn't leak fd on failure

If perf_event_open() fails the fd is opened but it is only freed by
closing (not by delete).

Typically when an open fails you don't call close and so this results in
a memory leak. To avoid this, add a close when open fails.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-By: Kajol Jain <kjain@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20220609052355.1300162-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/perf/evsel.c

@@ -149,23 +149,30 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
 			int fd, group_fd, *evsel_fd;
 
 			evsel_fd = FD(evsel, idx, thread);
-			if (evsel_fd == NULL)
-				return -EINVAL;
+			if (evsel_fd == NULL) {
+				err = -EINVAL;
+				goto out;
+			}
 
 			err = get_group_fd(evsel, idx, thread, &group_fd);
 			if (err < 0)
-				return err;
+				goto out;
 
 			fd = sys_perf_event_open(&evsel->attr,
 						 threads->map[thread].pid,
 						 cpu, group_fd, 0);
 
-			if (fd < 0)
-				return -errno;
+			if (fd < 0) {
+				err = -errno;
+				goto out;
+			}
 
 			*evsel_fd = fd;
 		}
 	}
+out:
+	if (err)
+		perf_evsel__close(evsel);
 
 	return err;
 }