perf maps: Get map before returning in maps__find

Finding a map is done under a lock, returning the map without a
reference count means it can be removed without notice and causing
uses after free. Grab a reference count to the map within the lock
region and return this. Fix up locations that need a map__put
following this.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Artem Savkov <asavkov@redhat.com>
Cc: bpf@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240210031746.4057262-3-irogers@google.com
This commit is contained in:
Ian Rogers
2024-02-09 19:17:42 -08:00
committed by Namhyung Kim
parent 659ad3492b
commit 42fd623b58
7 changed files with 26 additions and 27 deletions

View File

@@ -151,10 +151,8 @@ static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data)
u64 mem_end = map__unmap_ip(args->vmlinux_map, map__end(map));
pair = maps__find(args->kallsyms.kmaps, mem_start);
if (pair == NULL || map__priv(pair))
return 0;
if (map__start(pair) == mem_start) {
if (pair != NULL && !map__priv(pair) && map__start(pair) == mem_start) {
struct dso *dso = map__dso(map);
if (!args->header_printed) {
@@ -170,6 +168,7 @@ static int test__vmlinux_matches_kallsyms_cb2(struct map *map, void *data)
pr_info(" %s\n", dso->name);
map__set_priv(pair, 1);
}
map__put(pair);
return 0;
}