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 e0e4e0b8b7fa ("perf maps: Add
missing map__set_kmap_maps() when replacing a kernel map") and commit
25d9c0301d36 ("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: e0e4e0b8b7fa ("perf maps: Add missing map__set_kmap_maps() when replacing a kernel map")
Fixes: 25d9c0301d36 ("perf maps: Set the kmaps for newly created/added kernel maps")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 85b2a93a59ac6580505c6a960f52198a40a45202..779f6230130af22735dd5d6ba5e9ac6c80e7d554 100644 (file)
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -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;