[PATCH 15/20] perf trace: free malloc'd trace fields on exit

From: Riccardo Mancini
Date: Thu Jul 15 2021 - 12:08:06 EST


ASan reports several memory leaks running the perf test
"88: Check open filename arg using perf trace + vfs_getname".
The first of these leaks is related to struct trace fields never being
deallocated.

This patch adds the function trace__exit, which is called at the end of
cmd_trace, replacing the existing deallocation, which is now moved
inside the new function.
This function deallocates:
- ev_qualifier
- ev_qualifier_ids.entries
- syscalls.table
- sctbl
- perfconfig_events

In order to prevent errors in case any of this field is never
initialized, this patch also adds initialization to NULL to these
fields.

Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
---
tools/perf/builtin-trace.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 7ec18ff57fc4ae35..fe26d87ca8ccc14d 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -4701,6 +4701,15 @@ static int trace__config(const char *var, const char *value, void *arg)
return err;
}

+static void trace__exit(struct trace *trace)
+{
+ strlist__delete(trace->ev_qualifier);
+ free(trace->ev_qualifier_ids.entries);
+ free(trace->syscalls.table);
+ syscalltbl__delete(trace->sctbl);
+ zfree(&trace->perfconfig_events);
+}
+
int cmd_trace(int argc, const char **argv)
{
const char *trace_usage[] = {
@@ -4731,6 +4740,12 @@ int cmd_trace(int argc, const char **argv)
.kernel_syscallchains = false,
.max_stack = UINT_MAX,
.max_events = ULONG_MAX,
+ .ev_qualifier = NULL,
+ .sctbl = NULL,
+ .ev_qualifier_ids = {
+ .entries = NULL,
+ .nr = 0,
+ },
};
const char *map_dump_str = NULL;
const char *output_name = NULL;
@@ -5135,6 +5150,6 @@ int cmd_trace(int argc, const char **argv)
if (output_name != NULL)
fclose(trace.output);
out:
- zfree(&trace.perfconfig_events);
+ trace__exit(&trace);
return err;
}
--
2.31.1