Date: Wed, 4 Apr 2007 17:14:57 -0400 From: "Ed Maste" <ed.maste@gmail.com> To: freebsd-threads@freebsd.org Subject: [PATCH] libthr - pthread_set_name_np crash Message-ID: <88607eb20704041414s6bda8765u6782a0460372407f@mail.gmail.com>
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It seems there is a bug in pthread_set_name_np for the thread != curthread
case. That is, pthread_set_name_np called from outside of the thread
being named, as in the following example:
pthread_create(&pt, 0, t_spin, (void *)1);
[...]
pthread_set_name_np(pt, "t1");
The bug is a race condition that leads to thread->locklevel being
incorrect. Based on the other cases of locking a not-curthread thread,
I think the patch below is the fix. Can a libthr expert comment?
Thanks,
Ed
Index: thr_info.c
===================================================================
RCS file: /usr/cvs/src/lib/libthr/thread/thr_info.c,v
retrieving revision 1.9
diff -u -r1.9 thr_info.c
--- thr_info.c 12 Jan 2007 07:26:20 -0000 1.9
+++ thr_info.c 23 Mar 2007 14:56:13 -0000
@@ -52,12 +52,12 @@
ret = errno;
} else {
if (_thr_ref_add(curthread, thread, 0) == 0) {
- THR_LOCK(thread);
+ THR_THREAD_LOCK(curthread, thread);
if (thread->state != PS_DEAD) {
if (thr_set_name(thread->tid, name))
ret = errno;
}
- THR_UNLOCK(thread);
+ THR_THREAD_UNLOCK(curthread, thread);
_thr_ref_delete(curthread, thread);
} else {
ret = ESRCH;
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