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| author | Adrian Hunter <adrian.hunter@intel.com> | 2015-08-19 17:29:19 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-08-19 14:15:09 -0300 |
| commit | 0d7e7acc47133e82911e24758178815cfee309e9 (patch) | |
| tree | c95e7817da85ba9a8bf711d58600add03b7a16df /tools | |
| parent | d7a702f0b1033cf402fef65bd6395072738f0844 (diff) | |
| download | lwn-0d7e7acc47133e82911e24758178815cfee309e9.tar.gz lwn-0d7e7acc47133e82911e24758178815cfee309e9.zip | |
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>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/thread.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 28c4b746baa1..0a9ae8014729 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) |