>From 382009435fd6bf61df8f7c94dd44ea0ddd42f749 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 11 Feb 2023 09:54:12 -0500 Subject: [PATCH 1/4] fix pthred_detach inadvertently acting as cancellation point in race case disabling cancellation around the pthread_join call seems to be the safest and logically simplest fix. i believe it would also be possible to just perform the unmap directly here after __tl_sync, removing the dependency on pthread_join, but such an approach duplicately encodes a lot more implementation assumptions. --- src/thread/pthread_detach.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/thread/pthread_detach.c b/src/thread/pthread_detach.c index 77772af2..ac9c1035 100644 --- a/src/thread/pthread_detach.c +++ b/src/thread/pthread_detach.c @@ -5,8 +5,12 @@ static int __pthread_detach(pthread_t t) { /* If the cas fails, detach state is either already-detached * or exiting/exited, and pthread_join will trap or cleanup. */ - if (a_cas(&t->detach_state, DT_JOINABLE, DT_DETACHED) != DT_JOINABLE) + if (a_cas(&t->detach_state, DT_JOINABLE, DT_DETACHED) != DT_JOINABLE) { + int cs; + __pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); return __pthread_join(t, 0); + __pthread_setcancelstate(cs, 0); + } return 0; } -- 2.21.0