Let _umtx_op directly return error code rather than from errno because

errno can be tampered potentially by nested signal handle.
Now all error codes are returned in negative value, positive value are
reserved for future expansion.

1 files changed, 23 insertions, 12 deletions

diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c
index 158210c..bcdddab 100644
--- a/sys/kern/kern_umtx.c
+++ b/sys/kern/kern_umtx.c
@@ -679,7 +679,6 @@ do_wake(struct thread *td, void *uaddr, int n_wake)
 	ret = umtxq_signal(&key, n_wake);
 	umtxq_unlock(&key);
 	umtx_key_release(&key);
-	td->td_retval[0] = ret;
 	return (0);
 }
 
@@ -712,15 +711,20 @@ _umtx_op(struct thread *td, struct _umtx_op_args *uap)
 		else {
 			error = copyin(uap->uaddr2, &abstime, sizeof(abstime));
 			if (error != 0)
-				return (error);
+				break;
+			printf("uap->abstime: %d.%ld\n", abstime.tv_sec, abstime.tv_nsec);	
 			if (abstime.tv_nsec >= 1000000000 ||
-			    abstime.tv_nsec < 0)
-				return (EINVAL);
+			    abstime.tv_nsec < 0) {
+				error = EINVAL;
+				break;
+			}
 			ts = &abstime;
 		}
-		return do_lock(td, uap->umtx, uap->id, ts);
+		error = do_lock(td, uap->umtx, uap->id, ts);
+		break;
 	case UMTX_OP_UNLOCK:
-		return do_unlock(td, uap->umtx, uap->id);
+		error = do_unlock(td, uap->umtx, uap->id);
+		break;
 	case UMTX_OP_WAIT:
 		/* Allow a null timespec (wait forever). */
 		if (uap->uaddr2 == NULL)
@@ -728,16 +732,23 @@ _umtx_op(struct thread *td, struct _umtx_op_args *uap)
 		else {
 			error = copyin(uap->uaddr2, &abstime, sizeof(abstime));
 			if (error != 0)
-				return (error);
+				break;
 			if (abstime.tv_nsec >= 1000000000 ||
-			    abstime.tv_nsec < 0)
-				return (EINVAL);
+			    abstime.tv_nsec < 0) {
+				error = EINVAL;
+				break;
+			}
 			ts = &abstime;
 		}
-		return do_wait(td, uap->umtx, uap->id, ts);
+		error = do_wait(td, uap->umtx, uap->id, ts);
+		break;
 	case UMTX_OP_WAKE:
-		return do_wake(td, uap->umtx, uap->id);
+		error = do_wake(td, uap->umtx, uap->id);
+		break;
 	default:
-		return (EINVAL);
+		error = EINVAL;
+		break;
 	}
+	td->td_retval[0] = -error;
+	return (0);
 }