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.

1 files changed, 6 insertions, 5 deletions

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.