sysdeps/unix/sysv/linux/sigaction.c

   1 /* Copyright (C) 1997-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <signal.h>
  20 #include <string.h>
  21
  22 #include <sysdep.h>
  23 #include <sys/syscall.h>
  24
  25 #include <kernel-features.h>
  26
  27 /* The difference here is that the sigaction structure used in the
  28    kernel is not the same as we use in the libc.  Therefore we must
  29    translate it here.  */
  30 #include <kernel_sigaction.h>
  31
  32
  33 /* If ACT is not NULL, change the action for SIG to *ACT.
  34    If OACT is not NULL, put the old action for SIG in *OACT.  */
  35 int
  36 __libc_sigaction (sig, act, oact)
  37      int sig;
  38      const struct sigaction *act;
  39      struct sigaction *oact;
  40 {
  41   int result;
  42
  43   struct kernel_sigaction kact, koact;
  44
  45   if (act)
  46     {
  47       kact.k_sa_handler = act->sa_handler;
  48       memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  49       kact.sa_flags = act->sa_flags;
  50 #ifdef HAVE_SA_RESTORER
  51       kact.sa_restorer = act->sa_restorer;
  52 #endif
  53     }
  54
  55   /* XXX The size argument hopefully will have to be changed to the
  56      real size of the user-level sigset_t.  */
  57   result = INLINE_SYSCALL (rt_sigaction, 4, sig,
  58                            act ? &kact : NULL,
  59                            oact ? &koact : NULL, _NSIG / 8);
  60
  61   if (oact && result >= 0)
  62     {
  63       oact->sa_handler = koact.k_sa_handler;
  64       memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  65       oact->sa_flags = koact.sa_flags;
  66 #ifdef HAVE_SA_RESTORER
  67       oact->sa_restorer = koact.sa_restorer;
  68 #endif
  69     }
  70   return result;
  71 }
  72 libc_hidden_def (__libc_sigaction)
  73
  74 #ifdef WRAPPER_INCLUDE
  75 # include WRAPPER_INCLUDE
  76 #endif
  77
  78 #ifndef LIBC_SIGACTION
  79 weak_alias (__libc_sigaction, __sigaction)
  80 libc_hidden_weak (__sigaction)
  81 weak_alias (__libc_sigaction, sigaction)
  82 #endif