if pthread_create fails, it must not attempt mmap if there is no mapping

this bug was introduced when support for application-provided stacks
was originally added.

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 4c1decaa7ce5f660ace954a032fcd88751e603d6..1e55a6f944a26987f783a5cdef19454655b02c7b 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -188,7 +188,7 @@ int pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp
 
        if (ret < 0) {
                a_dec(&libc.threads_minus_1);
-               munmap(map, size);
+               if (map) munmap(map, size);
                return EAGAIN;
        }