perf dso: Hold lock when accessing nsinfo

There may be threads racing to update dso->nsinfo:

https://lore.kernel.org/linux-perf-users/CAP-5=fWZH20L4kv-BwVtGLwR=[e-mail]/

Holding the dso->lock avoids use-after-free, memory leaks and other such
bugs. Apply the fix in:

https://lore.kernel.org/linux-perf-users/[e-mail]/

of there being a missing nsinfo__put now that the accesses are data race
free. Fixes test "Lookup mmap thread" when compiled with address
sanitizer.

Signed-off-by: Ian Rogers <[e-mail]>
Reviewed-by: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Alexandre Truong <[e-mail]>
Cc: Alexey Bayduraev <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Andres Freund <[e-mail]>
Cc: Andrii Nakryiko <[e-mail]>
Cc: André Almeida <[e-mail]>
Cc: Athira Jajeev <[e-mail]>
Cc: Christophe JAILLET <[e-mail]>
Cc: Colin Ian King <[e-mail]>
Cc: Dario Petrillo <[e-mail]>
Cc: Darren Hart <[e-mail]>
Cc: Dave Marchevsky <[e-mail]>
Cc: Davidlohr Bueso <[e-mail]>
Cc: Fangrui Song <[e-mail]>
Cc: Hewenliang <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jason Wang <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Kim Phillips <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Martin Liška <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: Nick Desaulniers <[e-mail]>
Cc: Pavithra Gurushankar <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Quentin Monnet <[e-mail]>
Cc: Ravi Bangoria <[e-mail]>
Cc: Remi Bernon <[e-mail]>
Cc: Riccardo Mancini <[e-mail]>
Cc: Song Liu <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Cc: Tom Rix <[e-mail]>
Cc: Weiguo Li <[e-mail]>
Cc: Wenyu Liu <[e-mail]>
Cc: William Cohen <[e-mail]>
Cc: Zechuan Chen <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: yaowenbin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-inject.c

···
 	}
 
 	if (dso) {
+		mutex_lock(&dso->lock);
 		nsinfo__put(dso->nsinfo);
 		dso->nsinfo = nsi;
+		mutex_unlock(&dso->lock);
 	} else
 		nsinfo__put(nsi);
 
···
 	if (dso->has_build_id)
 		return 0;
 
+	mutex_lock(&dso->lock);
 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
 	if (filename__read_build_id(dso->long_name, &dso->bid) > 0)
 		dso->has_build_id = true;
···
 		free(new_name);
 	}
 	nsinfo__mountns_exit(&nsc);
+	mutex_unlock(&dso->lock);
 
 	return dso->has_build_id ? 0 : -1;
 }

tools/perf/util/annotate.c

···
 		 */
 		__symbol__join_symfs(filename, filename_size, dso->long_name);
 
+		mutex_lock(&dso->lock);
 		if (access(filename, R_OK) && errno == ENOENT && dso->nsinfo) {
 			char *new_name = filename_with_chroot(dso->nsinfo->pid,
 							      filename);
···
 				free(new_name);
 			}
 		}
+		mutex_unlock(&dso->lock);
 	}
 
 	free(build_id_path);

tools/perf/util/build-id.c

···
 static bool dso__build_id_mismatch(struct dso *dso, const char *name)
 {
 	struct build_id bid;
+	bool ret = false;
 
-	if (filename__read_build_id_ns(name, &bid, dso->nsinfo) < 0)
-		return false;
+	mutex_lock(&dso->lock);
+	if (filename__read_build_id_ns(name, &bid, dso->nsinfo) >= 0)
+		ret = !dso__build_id_equal(dso, &bid);
 
-	return !dso__build_id_equal(dso, &bid);
+	mutex_unlock(&dso->lock);
+
+	return ret;
 }
 
 static int dso__cache_build_id(struct dso *dso, struct machine *machine,
···
 	if (!is_kallsyms && dso__build_id_mismatch(dso, name))
 		goto out_free;
 
+	mutex_lock(&dso->lock);
 	ret = build_id_cache__add_b(&dso->bid, name, dso->nsinfo,
 				    is_kallsyms, is_vdso, proper_name, root_dir);
+	mutex_unlock(&dso->lock);
 out_free:
 	free(allocated_name);
 	return ret;

tools/perf/util/dso.c

···
 	if (!name)
 		return -ENOMEM;
 
+	mutex_lock(&dso->lock);
 	if (machine)
 		root_dir = machine->root_dir;
 
···
 		unlink(name);
 
 out:
+	mutex_unlock(&dso->lock);
 	free(name);
 	return fd;
 }
···
 	int fd;
 	struct nscookie nsc;
 
-	if (dso->binary_type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
+	if (dso->binary_type != DSO_BINARY_TYPE__BUILD_ID_CACHE) {
+		mutex_lock(&dso->lock);
 		nsinfo__mountns_enter(dso->nsinfo, &nsc);
+		mutex_unlock(&dso->lock);
+	}
 	fd = __open_dso(dso, machine);
 	if (dso->binary_type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
 		nsinfo__mountns_exit(&nsc);

tools/perf/util/map.c

···
 			if (!(prot & PROT_EXEC))
 				dso__set_loaded(dso);
 		}
+		mutex_lock(&dso->lock);
+		nsinfo__put(dso->nsinfo);
 		dso->nsinfo = nsi;
+		mutex_unlock(&dso->lock);
 
 		if (build_id__is_defined(bid)) {
 			dso__set_build_id(dso, bid);

tools/perf/util/probe-event.c

···
 #include "color.h"
 #include "map.h"
 #include "maps.h"
+#include "mutex.h"
 #include "symbol.h"
 #include <api/fs/fs.h>
 #include "trace-event.h"	/* For __maybe_unused */
···
 
 		map = dso__new_map(target);
 		if (map && map->dso) {
+			mutex_lock(&map->dso->lock);
 			nsinfo__put(map->dso->nsinfo);
 			map->dso->nsinfo = nsinfo__get(nsi);
+			mutex_unlock(&map->dso->lock);
 		}
 		return map;
 	} else {

tools/perf/util/symbol.c

···
 	char newmapname[PATH_MAX];
 	const char *map_path = dso->long_name;
 
+	mutex_lock(&dso->lock);
 	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
 	if (perfmap) {
 		if (dso->nsinfo && (dso__find_perf_map(newmapname,
···
 	}
 
 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
-	mutex_lock(&dso->lock);
 
 	/* check again under the dso->lock */
 	if (dso__loaded(dso)) {