linux-kernel - [tip:perf/core] perf symbols: Protect dso symbol loading using a mutex

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-4a936edc317005e8cd2b501e7865721bec104544@git.kernel.org>
Date:	Wed, 20 May 2015 05:25:02 -0700
From:	tip-bot for Namhyung Kim <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	mingo@...nel.org, linux-kernel@...r.kernel.org,
	a.p.zijlstra@...llo.nl, jolsa@...hat.com, andi@...stfloor.org,
	tglx@...utronix.de, eranian@...gle.com, hpa@...or.com,
	adrian.hunter@...el.com, namhyung@...nel.org, dsahern@...il.com,
	fweisbec@...il.com, acme@...hat.com
Subject: [tip:perf/core] perf symbols:
  Protect dso symbol loading using a mutex

Commit-ID:  4a936edc317005e8cd2b501e7865721bec104544
Gitweb:     http://git.kernel.org/tip/4a936edc317005e8cd2b501e7865721bec104544
Author:     Namhyung Kim <namhyung@...nel.org>
AuthorDate: Mon, 18 May 2015 09:30:40 +0900
Committer:  Arnaldo Carvalho de Melo <acme@...hat.com>
CommitDate: Mon, 18 May 2015 10:17:36 -0300

perf symbols: Protect dso symbol loading using a mutex

Add mutex to protect it from concurrent dso__load().

Signed-off-by: Namhyung Kim <namhyung@...nel.org>
Cc: Adrian Hunter <adrian.hunter@...el.com>
Cc: Andi Kleen <andi@...stfloor.org>
Cc: David Ahern <dsahern@...il.com>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Stephane Eranian <eranian@...gle.com>
Link: http://lkml.kernel.org/r/1431909055-21442-26-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/dso.c    |  2 ++
 tools/perf/util/dso.h    |  1 +
 tools/perf/util/symbol.c | 34 ++++++++++++++++++++++++----------
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 13d9ae0..482d602 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -936,6 +936,7 @@ struct dso *dso__new(const char *name)
 		RB_CLEAR_NODE(&dso->rb_node);
 		INIT_LIST_HEAD(&dso->node);
 		INIT_LIST_HEAD(&dso->data.open_entry);
+		pthread_mutex_init(&dso->lock, NULL);
 	}
 
 	return dso;
@@ -966,6 +967,7 @@ void dso__delete(struct dso *dso)
 	dso_cache__free(&dso->data.cache);
 	dso__free_a2l(dso);
 	zfree(&dso->symsrc_filename);
+	pthread_mutex_destroy(&dso->lock);
 	free(dso);
 }
 
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 3d79c74..b26ec3a 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -129,6 +129,7 @@ struct dsos {
 struct auxtrace_cache;
 
 struct dso {
+	pthread_mutex_t	 lock;
 	struct list_head node;
 	struct rb_node	 rb_node;	/* rbtree node sorted by long name */
 	struct rb_root	 symbols[MAP__NR_TYPES];
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 45ba48a..9ef8b89 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1383,12 +1383,22 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
 	bool kmod;
 
-	dso__set_loaded(dso, map->type);
+	pthread_mutex_lock(&dso->lock);
+
+	/* check again under the dso->lock */
+	if (dso__loaded(dso, map->type)) {
+		ret = 1;
+		goto out;
+	}
+
+	if (dso->kernel) {
+		if (dso->kernel == DSO_TYPE_KERNEL)
+			ret = dso__load_kernel_sym(dso, map, filter);
+		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
+			ret = dso__load_guest_kernel_sym(dso, map, filter);
 
-	if (dso->kernel == DSO_TYPE_KERNEL)
-		return dso__load_kernel_sym(dso, map, filter);
-	else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
-		return dso__load_guest_kernel_sym(dso, map, filter);
+		goto out;
+	}
 
 	if (map->groups && map->groups->machine)
 		machine = map->groups->machine;
@@ -1401,18 +1411,18 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 		struct stat st;
 
 		if (lstat(dso->name, &st) < 0)
-			return -1;
+			goto out;
 
 		if (st.st_uid && (st.st_uid != geteuid())) {
 			pr_warning("File %s not owned by current user or root, "
 				"ignoring it.\n", dso->name);
-			return -1;
+			goto out;
 		}
 
 		ret = dso__load_perf_map(dso, map, filter);
 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
 					     DSO_BINARY_TYPE__NOT_FOUND;
-		return ret;
+		goto out;
 	}
 
 	if (machine)
@@ -1420,7 +1430,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 
 	name = malloc(PATH_MAX);
 	if (!name)
-		return -1;
+		goto out;
 
 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
@@ -1501,7 +1511,11 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 out_free:
 	free(name);
 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
-		return 0;
+		ret = 0;
+out:
+	dso__set_loaded(dso, map->type);
+	pthread_mutex_unlock(&dso->lock);
+
 	return ret;
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/