POSIX says if a thread is in sigwait state, although a signal may not in

its waitset, but if the signal is not masked by the thread, the signal
can interrupt the thread and signal action can be invoked by the thread,
sigwait should return with errno set to EINTR.
Also save and restore thread internal state(timeout and interrupted)
around signal handler invoking.

2 files changed, 29 insertions, 11 deletions

diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c
index 6e95cdd..cef8399 100644
--- a/lib/libpthread/thread/thr_sig.c
+++ b/lib/libpthread/thread/thr_sig.c
@@ -217,7 +217,10 @@ _thr_sig_dispatch(struct kse *curkse, int sig, siginfo_t *info)
 		    THR_IS_EXITING(thread) || THR_IS_SUSPENDED(thread)) {
 			KSE_SCHED_UNLOCK(curkse, thread->kseg);
 			_thr_ref_delete(NULL, thread);
-		} else if (SIGISMEMBER(thread->sigmask, sig)) {
+		} else if ((thread->state == PS_SIGWAIT &&
+			    SIGISMEMBER(thread->oldsigmask, sig)) ||
+			   (thread->state != PS_SIGWAIT &&
+			    SIGISMEMBER(thread->sigmask, sig))) {
 			KSE_SCHED_UNLOCK(curkse, thread->kseg);
 			_thr_ref_delete(NULL, thread);
 		} else {
@@ -415,10 +418,10 @@ thr_sig_find(struct kse *curkse, int sig, siginfo_t *info)
 		if ((pthread->state == PS_DEAD)		||
 		    (pthread->state == PS_DEADLOCK)	||
 		    THR_IS_EXITING(pthread)		||
-		    THR_IS_SUSPENDED(pthread)		||
-		    SIGISMEMBER(pthread->sigmask, sig)) {
+		    THR_IS_SUSPENDED(pthread)) {
 			; /* Skip this thread. */
-		} else if (pthread->state == PS_SIGWAIT) {
+		} else if (pthread->state == PS_SIGWAIT &&
+			   !SIGISMEMBER(pthread->sigmask, sig)) {
 			/*
 			 * retrieve signal from kernel, if it is job control
 			 * signal, and sigaction is SIG_DFL, then we will
@@ -447,7 +450,9 @@ thr_sig_find(struct kse *curkse, int sig, siginfo_t *info)
 			 */
 			KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
 			return (NULL);
-		} else  {
+		} else if (!SIGISMEMBER(pthread->sigmask, sig) ||
+			(!SIGISMEMBER(pthread->oldsigmask, sig) &&
+			 pthread->state == PS_SIGWAIT)) {
 			if (pthread->state == PS_SIGSUSPEND) {
 				if (suspended_thread == NULL) {
 					suspended_thread = pthread;
@@ -490,6 +495,8 @@ void
 _thr_sig_rundown(struct pthread *curthread, ucontext_t *ucp,
     struct pthread_sigframe *psf)
 {
+	int interrupted = curthread->interrupted;
+	int timeout = curthread->timeout;
 	siginfo_t siginfo;
 	int i;
 	kse_critical_t crit;
@@ -563,6 +570,9 @@ _thr_sig_rundown(struct pthread *curthread, ucontext_t *ucp,
 	KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
 	_kse_critical_leave(&curthread->tmbx);
 
+	curthread->interrupted = interrupted;
+	curthread->timeout = timeout;
+
 	DBG_MSG("<<< thr_sig_rundown %p\n", curthread);
 }
 
@@ -659,7 +669,8 @@ _thr_sig_add(struct pthread *pthread, int sig, siginfo_t *info)
 #endif
 
 	if (pthread->curframe == NULL ||
-	    SIGISMEMBER(pthread->sigmask, sig) ||
+	    (pthread->state != PS_SIGWAIT &&
+	    SIGISMEMBER(pthread->sigmask, sig)) ||
 	    THR_IN_CRITICAL(pthread)) {
 		/* thread is running or signal was being masked */
 		if (!fromproc) {
@@ -760,6 +771,9 @@ _thr_sig_add(struct pthread *pthread, int sig, siginfo_t *info)
 				/* Increment the pending signal count. */
 				SIGADDSET(pthread->sigpend, sig);
 				pthread->check_pending = 1;
+				pthread->interrupted = 1;
+				pthread->sigmask = pthread->oldsigmask;
+				_thr_setrunnable_unlocked(pthread);
 			}
 		
 			return;
@@ -823,6 +837,9 @@ thr_sig_check_state(struct pthread *pthread, int sig)
 			/* Increment the pending signal count. */
 			SIGADDSET(pthread->sigpend, sig);
 			pthread->check_pending = 1;
+			pthread->interrupted = 1;
+			pthread->sigmask = pthread->oldsigmask;
+			_thr_setrunnable_unlocked(pthread);
 		}
 		break;
 
diff --git a/lib/libpthread/thread/thr_sigwait.c b/lib/libpthread/thread/thr_sigwait.c
index ac44972..46dac92 100644
--- a/lib/libpthread/thread/thr_sigwait.c
+++ b/lib/libpthread/thread/thr_sigwait.c
@@ -123,6 +123,7 @@ lib_sigtimedwait(const sigset_t *set, siginfo_t *info,
 			}
 		}
 		curthread->timeout = 0;
+		curthread->interrupted = 0;
 		_thr_set_timeout(timeout);
 		/* Wait for a signal: */
 		curthread->oldsigmask = curthread->sigmask;
@@ -134,18 +135,18 @@ lib_sigtimedwait(const sigset_t *set, siginfo_t *info,
 		_thr_sched_switch_unlocked(curthread);
 		/*
 		 * Return the signal number to the caller:
-		 * XXX Here is race, how about a signal come in before
-		 * we reach here? so we might got an incorrect timeout
-		 * status.
 		 */
 		if (siginfo.si_signo > 0) {
 			ret = siginfo.si_signo;
 		} else {
-			if (curthread->timeout)
+			if (curthread->interrupted)
+				errno = EINTR;
+			else if (curthread->timeout)
 				errno = EAGAIN;
 			ret = -1;
 		}
-
+		curthread->timeout = 0;
+		curthread->interrupted = 0;
 		/*
 		 * Probably unnecessary, but since it's in a union struct
 		 * we don't know how it could be used in the future.