1 files changed, 3 insertions, 2 deletions
diff --git a/libc/bionic/semaphore.c b/libc/bionic/semaphore.c
index 0c94600..84b9314 100644
--- a/libc/bionic/semaphore.c
+++ b/libc/bionic/semaphore.c
@@ -180,7 +180,7 @@ int sem_post(sem_t *sem)
     if (sem == NULL)
         return EINVAL;
 
-    if (__atomic_inc((volatile int*)&sem->count) == 0)
+    if (__atomic_inc((volatile int*)&sem->count) >= 0)
         __futex_wake(&sem->count, 1);
 
     return 0;
@@ -196,7 +196,8 @@ int  sem_trywait(sem_t *sem)
     if (__atomic_dec_if_positive(&sem->count) > 0) {
         return 0;
     } else {
-        return EAGAIN;
+        errno = EAGAIN;
+        return -1;
     }
 }