From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/8584 Path: news.gmane.org!not-for-mail From: Bobby Bingham Newsgroups: gmane.linux.lib.musl.general Subject: [PATCH 1/2] pthread: add missing memory barrier Date: Mon, 28 Sep 2015 16:58:44 -0500 Message-ID: <1443477525-24743-1-git-send-email-koorogi@koorogi.info> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1443477557 3533 80.91.229.3 (28 Sep 2015 21:59:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 28 Sep 2015 21:59:17 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-8596-gllmg-musl=m.gmane.org@lists.openwall.com Mon Sep 28 23:59:16 2015 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1ZggS3-0003WE-TG for gllmg-musl@m.gmane.org; Mon, 28 Sep 2015 23:59:16 +0200 Original-Received: (qmail 23794 invoked by uid 550); 28 Sep 2015 21:59:13 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 23735 invoked from network); 28 Sep 2015 21:59:07 -0000 X-Mailer: git-send-email 2.5.3 Xref: news.gmane.org gmane.linux.lib.musl.general:8584 Archived-At: posix requires pthread_join to synchronize memory on success. in the case that we call __timedwait_cp, we can rely on its futex_wake call to synchronize memory, but we need a memory barrier for the case where we don't call it. --- src/thread/pthread_join.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/thread/pthread_join.c b/src/thread/pthread_join.c index 966b4ab..eb78e2f 100644 --- a/src/thread/pthread_join.c +++ b/src/thread/pthread_join.c @@ -11,7 +11,9 @@ int __pthread_join(pthread_t t, void **res) __pthread_testcancel(); __pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); if (cs == PTHREAD_CANCEL_ENABLE) __pthread_setcancelstate(cs, 0); - while ((tmp = t->tid)) __timedwait_cp(&t->tid, tmp, 0, 0, 0); + if (!(tmp = t->tid)) a_barrier(); + else do __timedwait_cp(&t->tid, tmp, 0, 0, 0); + while ((tmp = t->tid)); __pthread_setcancelstate(cs, 0); if (res) *res = t->result; if (t->map_base) __munmap(t->map_base, t->map_size); -- 2.5.3