Commit 20c9ccff authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

perf maps: Ensure kmap is set up for all inserts 



__maps__fixup_overlap_and_insert may split or directly insert a map,
when doing this the map may need to have a kmap set up for the sake of
the kmaps. The missing kmap set up fails the check_invariants test in
maps, later "Internal error" reports from map__kmap and ultimately
causes segfaults.

Similar fixes were added in commit e0e4e0b8 ("perf maps: Add
missing map__set_kmap_maps() when replacing a kernel map") and commit
25d9c030 ("perf maps: Set the kmaps for newly created/added kernel
maps") but they missed cases. To try to reduce the risk of this,
update the kmap directly following any manual insert. This identified
another problem in maps__copy_from.

Fixes: e0e4e0b8 ("perf maps: Add missing map__set_kmap_maps() when replacing a kernel map")
Fixes: 25d9c030 ("perf maps: Set the kmaps for newly created/added kernel maps")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 7947ad15

tools/perf/util/maps.c

+5 −4
Original line number Diff line number Diff line
@@ -477,6 +477,7 @@ static int __maps__insert(struct maps *maps, struct map *new) 
	}

	/* Insert the value at the end. */

	maps_by_address[nr_maps] = map__get(new);

	map__set_kmap_maps(new, maps);

	if (maps_by_name)

		maps_by_name[nr_maps] = map__get(new);
@@ -502,8 +503,6 @@ static int __maps__insert(struct maps *maps, struct map *new) 
	if (map__end(new) < map__start(new))

		RC_CHK_ACCESS(maps)->ends_broken = true;



	map__set_kmap_maps(new, maps);



	return 0;

}
@@ -891,6 +890,7 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new) 
		if (before) {

			map__put(maps_by_address[i]);

			maps_by_address[i] = before;

			map__set_kmap_maps(before, maps);



			if (maps_by_name) {

				map__put(maps_by_name[ni]);
@@ -918,6 +918,7 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new) 
			 */

			map__put(maps_by_address[i]);

			maps_by_address[i] = map__get(new);

			map__set_kmap_maps(new, maps);



			if (maps_by_name) {

				map__put(maps_by_name[ni]);
@@ -942,14 +943,13 @@ static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new) 
				 */

				map__put(maps_by_address[i]);

				maps_by_address[i] = map__get(new);

				map__set_kmap_maps(new, maps);



				if (maps_by_name) {

					map__put(maps_by_name[ni]);

					maps_by_name[ni] = map__get(new);

				}



				map__set_kmap_maps(new, maps);



				check_invariants(maps);

				return err;

			}
@@ -1019,6 +1019,7 @@ int maps__copy_from(struct maps *dest, struct maps *parent) 
				err = unwind__prepare_access(dest, new, NULL);

				if (!err) {

					dest_maps_by_address[i] = new;

					map__set_kmap_maps(new, dest);

					if (dest_maps_by_name)

						dest_maps_by_name[i] = map__get(new);

					RC_CHK_ACCESS(dest)->nr_maps = i + 1;