nptl/sysdeps/unix/sysv/linux/raise.c

   1 /* Copyright (C) 2002, 2003, 2004 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <signal.h>
  23 #include <sysdep.h>
  24 #include <nptl/pthreadP.h>
  25 #include <kernel-features.h>
  26
  27
  28 int
  29 raise (sig)
  30      int sig;
  31 {
  32   struct pthread *pd = THREAD_SELF;
  33 #if __ASSUME_TGKILL || defined __NR_tgkill
  34   pid_t pid = THREAD_GETMEM (pd, pid);
  35 #endif
  36   pid_t selftid = THREAD_GETMEM (pd, tid);
  37   if (selftid == 0)
  38     {
  39       /* This system call is not supposed to fail.  */
  40 #ifdef INTERNAL_SYSCALL
  41       INTERNAL_SYSCALL_DECL (err);
  42       selftid = INTERNAL_SYSCALL (gettid, err, 0);
  43 #else
  44       selftid = INLINE_SYSCALL (gettid, 0);
  45 #endif
  46       THREAD_SETMEM (pd, tid, selftid);
  47
  48 #if __ASSUME_TGKILL || defined __NR_tgkill
  49       /* We do not set the PID field in the TID here since we might be
  50          called from a signal handler while the thread executes fork.  */
  51       pid = selftid;
  52 #endif
  53     }
  54 #if __ASSUME_TGKILL || defined __NR_tgkill
  55   else
  56     /* raise is an async-safe function.  It could be called while the
  57        fork/vfork function temporarily invalidated the PID field.  Adjust for
  58        that.  */
  59     if (__builtin_expect (pid <= 0, 0))
  60       pid = (pid & INT_MAX) == 0 ? selftid : -pid;
  61 #endif
  62
  63 #if __ASSUME_TGKILL
  64   return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
  65 #else
  66 # ifdef __NR_tgkill
  67   int res = INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
  68   if (res != -1 || errno != ENOSYS)
  69     return res;
  70 # endif
  71   return INLINE_SYSCALL (tkill, 2, selftid, sig);
  72 #endif
  73 }
  74 libc_hidden_def (raise)
  75 weak_alias (raise, gsignal)