sysdeps/unix/sysv/linux/raise.c

   1 /* Copyright (C) 2002-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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 <errno.h>
  20 #include <limits.h>
  21 #include <signal.h>
  22 #include <sysdep.h>
  23 #include <nptl/pthreadP.h>
  24
  25
  26 int
  27 raise (sig)
  28      int sig;
  29 {
  30   struct pthread *pd = THREAD_SELF;
  31   pid_t pid = THREAD_GETMEM (pd, pid);
  32   pid_t selftid = THREAD_GETMEM (pd, tid);
  33   if (selftid == 0)
  34     {
  35       /* This system call is not supposed to fail.  */
  36 #ifdef INTERNAL_SYSCALL
  37       INTERNAL_SYSCALL_DECL (err);
  38       selftid = INTERNAL_SYSCALL (gettid, err, 0);
  39 #else
  40       selftid = INLINE_SYSCALL (gettid, 0);
  41 #endif
  42       THREAD_SETMEM (pd, tid, selftid);
  43
  44       /* We do not set the PID field in the TID here since we might be
  45          called from a signal handler while the thread executes fork.  */
  46       pid = selftid;
  47     }
  48   else
  49     /* raise is an async-safe function.  It could be called while the
  50        fork/vfork function temporarily invalidated the PID field.  Adjust for
  51        that.  */
  52     if (__glibc_unlikely (pid <= 0))
  53       pid = (pid & INT_MAX) == 0 ? selftid : -pid;
  54
  55   return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
  56 }
  57 libc_hidden_def (raise)
  58 weak_alias (raise, gsignal)