[PATCH 3/4] perf tools: Fix double free and memory leak in kvm_events_record()

[Michalis Niarchos via B4 Relay <devnull+michael.niarchos.gmail.com@kernel.org>]

From: Michalis Niarchos <michael.niarchos@gmail.com>

cmd_record() reorders the contents of the rec_argv pointer array, so
its entry order no longer matches the order in which the caller
originally allocated them. Freeing the contents of rec_argv by
iterating the reordered array results in some pointers being freed
twice and others never freed.

All the entries of rec_argv come from literals or pointers that are
valid for the lifetime of this call. Reference them directly instead
of duplicating to remove the need to individually track and free each
entry.

Signed-off-by: Michalis Niarchos <michael.niarchos@gmail.com>
---
 tools/perf/builtin-kvm.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 1a013698cae3..189ef3576e34 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -1681,18 +1681,18 @@ kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv)
 		return -ENOMEM;
 
 	for (i = 0; i < ARRAY_SIZE(record_args); i++)
-		rec_argv[i] = STRDUP_FAIL_EXIT(record_args[i]);
+		rec_argv[i] = record_args[i];
 
 	for (j = 0; j < events_tp_size; j++) {
-		rec_argv[i++] = STRDUP_FAIL_EXIT("-e");
-		rec_argv[i++] = STRDUP_FAIL_EXIT(kvm_events_tp(e_machine)[j]);
+		rec_argv[i++] = "-e";
+		rec_argv[i++] = kvm_events_tp(e_machine)[j];
 	}
 
-	rec_argv[i++] = STRDUP_FAIL_EXIT("-o");
-	rec_argv[i++] = STRDUP_FAIL_EXIT(kvm->file_name);
+	rec_argv[i++] = "-o";
+	rec_argv[i++] = kvm->file_name;
 
 	for (j = 1; j < (unsigned int)argc; j++, i++)
-		rec_argv[i] = STRDUP_FAIL_EXIT(argv[j]);
+		rec_argv[i] = argv[j];
 
 	set_option_flag(record_options, 'e', "event", PARSE_OPT_HIDDEN);
 	set_option_flag(record_options, 0, "filter", PARSE_OPT_HIDDEN);
@@ -1717,9 +1717,6 @@ kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv)
 	record_usage = kvm_stat_record_usage;
 	ret = cmd_record(i, rec_argv);
 
-EXIT:
-	for (i = 0; i < rec_argc; i++)
-		free((void *)rec_argv[i]);
 	free(rec_argv);
 	return ret;
 }

-- 
2.55.0