perf-tools fixes for v6.17-rc7

A small set of fixes for crashes in different commands and conditions.
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Namhyung Kim:
 "A small set of fixes for crashes in different commands and conditions"

* tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf maps: Ensure kmap is set up for all inserts
  perf lock: Provide a host_env for session new
  perf subcmd: avoid crash in exclude_cmds when excludes is empty

tools/lib/subcmd/help.c

@@ -75,6 +75,9 @@ void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
 	size_t ci, cj, ei;
 	int cmp;
 
+	if (!excludes->cnt)
+		return;
+
 	ci = cj = ei = 0;
 	while (ci < cmds->cnt && ei < excludes->cnt) {
 		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);

tools/perf/builtin-lock.c

@@ -2009,6 +2009,7 @@ static int __cmd_contention(int argc, const char **argv)
 		.owner = show_lock_owner,
 		.cgroups = RB_ROOT,
 	};
+	struct perf_env host_env;
 
 	lockhash_table = calloc(LOCKHASH_SIZE, sizeof(*lockhash_table));
 	if (!lockhash_table)
@@ -2024,7 +2025,10 @@ static int __cmd_contention(int argc, const char **argv)
 	eops.mmap		 = perf_event__process_mmap;
 	eops.tracing_data	 = perf_event__process_tracing_data;
 
-	session = perf_session__new(use_bpf ? NULL : &data, &eops);
+	perf_env__init(&host_env);
+	session = __perf_session__new(use_bpf ? NULL : &data, &eops,
+				/*trace_event_repipe=*/false, &host_env);
+
 	if (IS_ERR(session)) {
 		pr_err("Initializing perf session failed\n");
 		err = PTR_ERR(session);
@@ -2142,6 +2146,7 @@ static int __cmd_contention(int argc, const char **argv)
 	evlist__delete(con.evlist);
 	lock_contention_finish(&con);
 	perf_session__delete(session);
+	perf_env__exit(&host_env);
 	zfree(&lockhash_table);
 	return err;
 }

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;