sysdeps/unix/sysv/linux/raise.c

   1 /* Copyright (C) 2002-2016 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 <signal.h>
  20 #include <sysdep.h>
  21 #include <errno.h>
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24 #include <nptl-signals.h>
  25
  26 int
  27 raise (int sig)
  28 {
  29   /* raise is an async-safe function so it could be called while the
  30      fork/vfork function temporarily invalidated the PID field.  To avoid
  31      relying on cached value we block all user-defined signal handler
  32      (which might call fork/vfork) and issue the getpid and gettid
  33      syscalls directly.  */
  34
  35
  36   /* rt_sigprocmask may fail if:
  37
  38      1. sigsetsize != sizeof (sigset_t) (EINVAL)
  39      2. a failure in copy from/to user space (EFAULT)
  40      3. an invalid 'how' operation (EINVAL)
  41
  42      The first case is already handle in glibc syscall call by using the arch
  43      defined _NSIG.  Second case is handled by using a stack allocated mask.
  44      The last one should be handled by the block/unblock functions.  */
  45
  46   sigset_t set;
  47   __libc_signal_block_app (&set);
  48
  49   INTERNAL_SYSCALL_DECL (err);
  50   pid_t pid = INTERNAL_SYSCALL (getpid, err, 0);
  51   pid_t tid = INTERNAL_SYSCALL (gettid, err, 0);
  52
  53   int ret = INLINE_SYSCALL (tgkill, 3, pid, tid, sig);
  54
  55   __libc_signal_restore_set (&set);
  56
  57   return ret;
  58 }
  59 libc_hidden_def (raise)
  60 weak_alias (raise, gsignal)