libc/signal/sigaction.c

   1 /* Copyright (C) 1997-2000,2002,2003,2005,2006 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 <signal.h>
  19 #include <sys/syscall.h>
  20
  21 #if defined __NR_rt_sigaction
  22
  23 /* If ACT is not NULL, change the action for SIG to *ACT.
  24    If OACT is not NULL, put the old action for SIG in *OACT.  */
  25 int
  26 __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
  27 {
  28         /* NB: kernel (as of 2.6.25) will return EINVAL
  29          * if sizeof(act->sa_mask) does not match kernel's sizeof(sigset_t).
  30          * Try to catch this problem at uclibc build time:  */
  31         struct BUG_sigset_size {
  32                 int BUG_sigset_size
  33                         [sizeof(act->sa_mask) == _NSIG / 8 ? 1 : -1];
  34         };
  35         return __syscall_rt_sigaction(sig, act, oact, sizeof(act->sa_mask));
  36 }
  37
  38 #else
  39 # define __need_NULL
  40 # include <stddef.h>
  41 # include <bits/kernel_sigaction.h>
  42
  43 /* If ACT is not NULL, change the action for SIG to *ACT.
  44    If OACT is not NULL, put the old action for SIG in *OACT.  */
  45 int
  46 __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
  47 {
  48         int result;
  49         struct old_kernel_sigaction kact, koact;
  50
  51         if (act) {
  52                 kact.k_sa_handler = act->sa_handler;
  53                 kact.sa_mask = act->sa_mask.__val[0];
  54                 kact.sa_flags = act->sa_flags;
  55 # ifdef HAVE_SA_RESTORER
  56                 kact.sa_restorer = act->sa_restorer;
  57 # endif
  58         }
  59         result = __syscall_sigaction(sig,
  60                         act ? &kact : NULL,
  61                         oact ? &koact : NULL);
  62         if (oact && result >= 0) {
  63                 oact->sa_handler = koact.k_sa_handler;
  64                 oact->sa_mask.__val[0] = koact.sa_mask;
  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
  73 #endif
  74
  75
  76 #ifndef LIBC_SIGACTION
  77 # ifndef __UCLIBC_HAS_THREADS__
  78 strong_alias(__libc_sigaction,sigaction)
  79 libc_hidden_def(sigaction)
  80 # else
  81 weak_alias(__libc_sigaction,sigaction)
  82 libc_hidden_weak(sigaction)
  83 # endif
  84 #endif