cut out a syscall on thread creation in the case where guard size is 0

[musl] / src / thread / sem_open.c

diff --git a/src/thread/sem_open.c b/src/thread/sem_open.c
index 6fff71a..809925d 100644 (file)
--- a/src/thread/sem_open.c
+++ b/src/thread/sem_open.c
@@ -100,7 +100,7 @@ sem_t *sem_open(const char *name, int flags, ...)
                                        close(tfd);
                                        unlink(tmp);
                                }
-                               if (fstat(fd, &st) < 0) {
+                               if (fd >= 0 && fstat(fd, &st) < 0) {
                                        close(fd);
                                        fd = -1;
                                }
@@ -118,6 +118,10 @@ sem_t *sem_open(const char *name, int flags, ...)
                                break;
                        }
                }
+               if (!(flags & O_CREAT)) {
+                       pthread_spin_unlock(&lock);
+                       return SEM_FAILED;
+               }
                if (!linkat(AT_FDCWD, tmp, dir, name, 0)) {
                        fd = tfd;
                        close(dir);