Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1209851 > unrolled thread

[PATCH 1/3] perf tools: Avoid deadlock when map_groups are broken

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 1/3] perf tools: Avoid deadlock when map_groups are broken Adrian Hunter <adrian.hunter@intel.com> - 2015-08-19 16:40 +0200
    [tip:perf/core] perf tools:   Avoid deadlock when map_groups are broken tip-bot for Adrian Hunter <tipbot@zytor.com> - 2015-08-20 12:10 +0200

#1209851 — [PATCH 1/3] perf tools: Avoid deadlock when map_groups are broken

Attempting to clone map groups onto themselves will deadlock.
It only happens because of other bugs, but the code should
protect itself anyway.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/util/thread.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 28c4b746baa1..471102554a78 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -191,6 +191,12 @@ static int thread__clone_map_groups(struct thread *thread,
 	if (thread->pid_ == parent->pid_)
 		return 0;
 
+	if (thread->mg == parent->mg) {
+		dump_printf("broken map groups on thread %d/%d parent %d/%d\n",
+			    thread->pid_, thread->tid, parent->pid_, parent->tid);
+		return 0;
+	}
+
 	/* But this one is new process, copy maps. */
 	for (i = 0; i < MAP__NR_TYPES; ++i)
 		if (map_groups__clone(thread->mg, parent->mg, i) < 0)
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1210387 — [tip:perf/core] perf tools: Avoid deadlock when map_groups are broken

Commit-ID:  0d7e7acc47133e82911e24758178815cfee309e9
Gitweb:     http://git.kernel.org/tip/0d7e7acc47133e82911e24758178815cfee309e9
Author:     Adrian Hunter <adrian.hunter@intel.com>
AuthorDate: Wed, 19 Aug 2015 17:29:19 +0300
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 19 Aug 2015 14:15:09 -0300

perf tools: Avoid deadlock when map_groups are broken

Attempting to clone map groups onto themselves will deadlock.

It only happens because of other bugs, but the code should protect
itself anyway.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1439994561-27436-2-git-send-email-adrian.hunter@intel.com
[ Use pr_debug() instead of dump_fprintf() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/thread.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 28c4b74..0a9ae80 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -191,6 +191,12 @@ static int thread__clone_map_groups(struct thread *thread,
 	if (thread->pid_ == parent->pid_)
 		return 0;
 
+	if (thread->mg == parent->mg) {
+		pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
+			 thread->pid_, thread->tid, parent->pid_, parent->tid);
+		return 0;
+	}
+
 	/* But this one is new process, copy maps. */
 	for (i = 0; i < MAP__NR_TYPES; ++i)
 		if (map_groups__clone(thread->mg, parent->mg, i) < 0)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web