+2019-02-18 Stefan Liebler <stli@linux.ibm.com>
+
+ * sysdeps/unix/sysv/linux/tst-clone3.c (do_test):
+ Initialize ctid with a known value and remove update of ctid
+ after clone.
+ (wait_tid): Adjust arguments and call futex_wait with ctid_val
+ as assumed current value of ctid_ptr.
+
2019-02-15 Florian Weimer <fweimer@redhat.com>
Check that non-sysdeps headers have wrapper headers.
#include <stackinfo.h> /* For _STACK_GROWS_{UP,DOWN}. */
#include <support/check.h>
+#include <stdatomic.h>
/* Test if clone call with CLONE_THREAD does not call exit_group. The 'f'
function returns '1', which will be used by clone thread to call the
/* Futex wait for TID argument, similar to pthread_join internal
implementation. */
-#define wait_tid(tid) \
- do { \
- __typeof (tid) __tid; \
- while ((__tid = (tid)) != 0) \
- futex_wait (&(tid), __tid); \
+#define wait_tid(ctid_ptr, ctid_val) \
+ do { \
+ __typeof (*(ctid_ptr)) __tid; \
+ /* We need acquire MO here so that we synchronize with the \
+ kernel's store to 0 when the clone terminates. */ \
+ while ((__tid = atomic_load_explicit (ctid_ptr, \
+ memory_order_acquire)) != 0) \
+ futex_wait (ctid_ptr, ctid_val); \
} while (0)
static inline int
clone_flags |= CLONE_VM | CLONE_SIGHAND;
/* We will used ctid to call on futex to wait for thread exit. */
clone_flags |= CLONE_CHILD_CLEARTID;
- pid_t ctid, tid;
+ /* Initialize with a known value. ctid is set to zero by the kernel after the
+ cloned thread has exited. */
+#define CTID_INIT_VAL 1
+ pid_t ctid = CTID_INIT_VAL;
+ pid_t tid;
#ifdef __ia64__
extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base,
if (tid == -1)
FAIL_EXIT1 ("clone failed: %m");
- ctid = tid;
- wait_tid (ctid);
+ wait_tid (&ctid, CTID_INIT_VAL);
return 2;
}