sysdeps/unix/sysv/linux/sigaction.c

   1 /* Copyright (C) 1997-2018 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 /* The difference here is that the sigaction structure used in the
  26    kernel is not the same as we use in the libc.  Therefore we must
  27    translate it here.  */
  28 #include <kernel_sigaction.h>
  29
  30
  31 /* If ACT is not NULL, change the action for SIG to *ACT.
  32    If OACT is not NULL, put the old action for SIG in *OACT.  */
  33 int
  34 __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
  35 {
  36   int result;
  37
  38   struct kernel_sigaction kact, koact;
  39
  40   if (act)
  41     {
  42       kact.k_sa_handler = act->sa_handler;
  43       memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  44       kact.sa_flags = act->sa_flags;
  45 #ifdef HAVE_SA_RESTORER
  46       kact.sa_restorer = act->sa_restorer;
  47 #endif
  48     }
  49
  50   /* XXX The size argument hopefully will have to be changed to the
  51      real size of the user-level sigset_t.  */
  52   result = INLINE_SYSCALL (rt_sigaction, 4, sig,
  53                            act ? &kact : NULL,
  54                            oact ? &koact : NULL, _NSIG / 8);
  55
  56   if (oact && result >= 0)
  57     {
  58       oact->sa_handler = koact.k_sa_handler;
  59       memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  60       oact->sa_flags = koact.sa_flags;
  61 #ifdef HAVE_SA_RESTORER
  62       oact->sa_restorer = koact.sa_restorer;
  63 #endif
  64     }
  65   return result;
  66 }
  67 libc_hidden_def (__libc_sigaction)
  68
  69 #include <nptl/sigaction.c>