perf maps: Get map before returning in maps__find_by_name

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. Also fix some reference counted pointer comparisons.

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/20240210031746.4057262-4-irogers@google.com
This commit is contained in:
Ian Rogers
2024-02-09 19:17:43 -08:00
committed by Namhyung Kim
parent 42fd623b58
commit 107ef66cb0
6 changed files with 25 additions and 15 deletions

View File

@@ -131,9 +131,10 @@ static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data)
struct map *pair = maps__find_by_name(args->kallsyms.kmaps,
(dso->kernel ? dso->short_name : dso->name));
if (pair)
if (pair) {
map__set_priv(pair, 1);
else {
map__put(pair);
} else {
if (!args->header_printed) {
pr_info("WARN: Maps only in vmlinux:\n");
args->header_printed = true;