diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/tst-clone3.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/tst-clone3.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/sysdeps/unix/sysv/linux/tst-clone3.c b/sysdeps/unix/sysv/linux/tst-clone3.c index 784ce18f53..76f8b08a69 100644 --- a/sysdeps/unix/sysv/linux/tst-clone3.c +++ b/sysdeps/unix/sysv/linux/tst-clone3.c @@ -1,5 +1,5 @@ /* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512) - Copyright (C) 2017-2018 Free Software Foundation, Inc. + Copyright (C) 2017-2019 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -14,7 +14,7 @@ You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ + <https://www.gnu.org/licenses/>. */ #include <string.h> #include <sched.h> @@ -27,6 +27,7 @@ #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 @@ -42,11 +43,14 @@ f (void *a) /* 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 @@ -64,7 +68,11 @@ do_test (void) 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, @@ -86,8 +94,7 @@ do_test (void) if (tid == -1) FAIL_EXIT1 ("clone failed: %m"); - ctid = tid; - wait_tid (ctid); + wait_tid (&ctid, CTID_INIT_VAL); return 2; } |