ensure debugger hook for dynamic linker does not point to a PLT slot

[musl] / src / thread / pthread_create.c

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 893773f..6963f0d 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -9,8 +9,6 @@
 void *__mmap(void *, size_t, int, int, int, off_t);
 int __munmap(void *, size_t);
 int __mprotect(void *, size_t, int);
-void __vm_lock_impl(int);
-void __vm_unlock_impl(void);
 
 static void dummy_0()
 {
@@ -77,7 +75,7 @@ _Noreturn void __pthread_exit(void *result)
        /* Process robust list in userspace to handle non-pshared mutexes
         * and the detached thread case where the robust list head will
         * be invalid when the kernel would process it. */
-       __vm_lock_impl(+1);
+       __vm_lock();
        volatile void *volatile *rp;
        while ((rp=self->robust_list.head) && rp != &self->robust_list.head) {
                pthread_mutex_t *m = (void *)((char *)rp
@@ -91,7 +89,7 @@ _Noreturn void __pthread_exit(void *result)
                if (cont < 0 || waiters)
                        __wake(&m->_m_lock, 1, priv);
        }
-       __vm_unlock_impl();
+       __vm_unlock();
 
        __do_orphaned_stdio_locks();
 
@@ -110,6 +108,10 @@ _Noreturn void __pthread_exit(void *result)
                if (self->robust_list.off)
                        __syscall(SYS_set_robust_list, 0, 3*sizeof(long));
 
+               /* Since __unmapself bypasses the normal munmap code path,
+                * explicitly wait for vmlock holders first. */
+               __vm_wait();
+
                /* The following call unmaps the thread's stack mapping
                 * and then exits without touching the stack. */
                __unmapself(self->map_base, self->map_size);
@@ -120,7 +122,6 @@ _Noreturn void __pthread_exit(void *result)
 
 void __do_cleanup_push(struct __ptcb *cb)
 {
-       if (!libc.has_thread_pointer) return;
        struct pthread *self = __pthread_self();
        cb->__next = self->cancelbuf;
        self->cancelbuf = cb;
@@ -128,7 +129,6 @@ void __do_cleanup_push(struct __ptcb *cb)
 
 void __do_cleanup_pop(struct __ptcb *cb)
 {
-       if (!libc.has_thread_pointer) return;
        __pthread_self()->cancelbuf = cb->__next;
 }
 
@@ -268,6 +268,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
                do_sched = new->startlock[0] = 1;
                __block_app_sigs(new->sigmask);
        }
+       new->robust_list.head = &new->robust_list.head;
        new->unblock_cancel = self->cancel;
        new->canary = self->canary;