diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/thread/pthread_create.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index 55744155..250cd0a4 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -69,12 +69,25 @@ _Noreturn void __pthread_exit(void *result) __pthread_tsd_run_dtors(); + __block_app_sigs(&set); + + /* This atomic potentially competes with a concurrent pthread_detach + * call; the loser is responsible for freeing thread resources. */ + int state = a_cas(&self->detach_state, DT_JOINABLE, DT_EXITING); + + if (state==DT_DETACHED && self->map_base) { + /* Since __unmapself bypasses the normal munmap code path, + * explicitly wait for vmlock holders first. This must be + * done before any locks are taken, to avoid lock ordering + * issues that could lead to deadlock. */ + __vm_wait(); + } + /* Access to target the exiting thread with syscalls that use * its kernel tid is controlled by killlock. For detached threads, * any use past this point would have undefined behavior, but for * joinable threads it's a valid usage that must be handled. * Signals must be blocked since pthread_kill must be AS-safe. */ - __block_app_sigs(&set); LOCK(self->killlock); /* The thread list lock must be AS-safe, and thus depends on @@ -87,6 +100,7 @@ _Noreturn void __pthread_exit(void *result) if (self->next == self) { __tl_unlock(); UNLOCK(self->killlock); + self->detach_state = state; __restore_sigs(&set); exit(0); } @@ -125,10 +139,6 @@ _Noreturn void __pthread_exit(void *result) self->prev->next = self->next; self->prev = self->next = self; - /* This atomic potentially competes with a concurrent pthread_detach - * call; the loser is responsible for freeing thread resources. */ - int state = a_cas(&self->detach_state, DT_JOINABLE, DT_EXITING); - if (state==DT_DETACHED && self->map_base) { /* Detached threads must block even implementation-internal * signals, since they will not have a stack in their last @@ -140,10 +150,6 @@ _Noreturn void __pthread_exit(void *result) if (self->robust_list.off) __syscall(SYS_set_robust_list, 0, 3*sizeof(long)); - /* Since __unmapself bypasses the normal munmap code path, - * explicitly wait for vmlock holders first. */ - __vm_wait(); - /* The following call unmaps the thread's stack mapping * and then exits without touching the stack. */ __unmapself(self->map_base, self->map_size); |