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authorRich Felker <dalias@aerifal.cx>2012-07-11 23:36:46 -0400
committerRich Felker <dalias@aerifal.cx>2012-07-11 23:36:46 -0400
commit92f8396b0c8e4f146563b87f46137484cfb36e31 (patch)
tree62bd8daab801d7127114a33a83db28f591e01669 /src/thread/pthread_detach.c
parenta03f69d4456d3ac5120cc07a22af8ecb631444bb (diff)
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fix potential race condition in detached threads
after the thread unmaps its own stack/thread structure, the kernel, performing child tid clear and futex wake, could clobber a new mapping made at the same location as the just-removed thread's tid field. disable kernel clearing of child tid to prevent this.
Diffstat (limited to 'src/thread/pthread_detach.c')
-rw-r--r--src/thread/pthread_detach.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/src/thread/pthread_detach.c b/src/thread/pthread_detach.c
index 8ef03d51..e8032398 100644
--- a/src/thread/pthread_detach.c
+++ b/src/thread/pthread_detach.c
@@ -5,7 +5,7 @@ int pthread_detach(pthread_t t)
/* Cannot detach a thread that's already exiting */
if (a_swap(&t->exitlock, 1))
return pthread_join(t, 0);
- t->detached = 1;
- t->exitlock = 0;
+ t->detached = 2;
+ a_store(&t->exitlock, 0);
return 0;
}