sysdeps/unix/sysv/linux/tst-clone3.c

   1 /* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512)
   2    Copyright (C) 2017-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <string.h>
  20 #include <sched.h>
  21 #include <signal.h>
  22 #include <unistd.h>
  23 #include <sys/syscall.h>
  24 #include <sys/wait.h>
  25 #include <sys/types.h>
  26 #include <linux/futex.h>
  27
  28 #include <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
  29 #include <support/check.h>
  30
  31 /* Test if clone call with CLONE_THREAD does not call exit_group.  The 'f'
  32    function returns '1', which will be used by clone thread to call the
  33    'exit' syscall directly.  If _exit is used instead, exit_group will be
  34    used and thus the thread group will finish with return value of '1'
  35    (where '2' from main thread is expected.  */
  36
  37 static int
  38 f (void *a)
  39 {
  40   return 1;
  41 }
  42
  43 /* Futex wait for TID argument, similar to pthread_join internal
  44    implementation.  */
  45 #define wait_tid(tid) \
  46   do {                                  \
  47     __typeof (tid) __tid;               \
  48     while ((__tid = (tid)) != 0)        \
  49       futex_wait (&(tid), __tid);       \
  50   } while (0)
  51
  52 static inline int
  53 futex_wait (int *futexp, int val)
  54 {
  55   return syscall (__NR_futex, futexp, FUTEX_WAIT, val);
  56 }
  57
  58 static int
  59 do_test (void)
  60 {
  61   char st[1024] __attribute__ ((aligned));
  62   int clone_flags = CLONE_THREAD;
  63   /* Minimum required flags to used along with CLONE_THREAD.  */
  64   clone_flags |= CLONE_VM | CLONE_SIGHAND;
  65   /* We will used ctid to call on futex to wait for thread exit.  */
  66   clone_flags |= CLONE_CHILD_CLEARTID;
  67   pid_t ctid, tid;
  68
  69 #ifdef __ia64__
  70   extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base,
  71                        size_t __child_stack_size, int __flags,
  72                        void *__arg, ...);
  73   tid = __clone2 (f, st, sizeof (st), clone_flags, NULL, /* ptid */ NULL,
  74                   /* tls */ NULL, &ctid);
  75 #else
  76 #if _STACK_GROWS_DOWN
  77   tid = clone (f, st + sizeof (st), clone_flags, NULL, /* ptid */ NULL,
  78                /* tls */ NULL, &ctid);
  79 #elif _STACK_GROWS_UP
  80   tid = clone (f, st, clone_flags, NULL, /* ptid */ NULL, /* tls */ NULL,
  81                &ctid);
  82 #else
  83 #error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
  84 #endif
  85 #endif
  86   if (tid == -1)
  87     FAIL_EXIT1 ("clone failed: %m");
  88
  89   ctid = tid;
  90   wait_tid (ctid);
  91
  92   return 2;
  93 }
  94
  95 #define EXPECTED_STATUS 2
  96 #include <support/test-driver.c>