sysdeps/unix/sysv/linux/sigaction.c

   1 /* Copyright (C) 1997-2019 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 /* New ports should not define the obsolete SA_RESTORER, however some
  26    architecture requires for compat mode and/or due old ABI.  */
  27 #include <kernel_sigaction.h>
  28
  29 #ifndef SA_RESTORER
  30 # define SET_SA_RESTORER(kact, act)
  31 # define RESET_SA_RESTORER(act, kact)
  32 #endif
  33
  34 /* SPARC passes the restore function as an argument to rt_sigaction.  */
  35 #ifndef STUB
  36 # define STUB(act, sigsetsize) (sigsetsize)
  37 #endif
  38
  39 /* If ACT is not NULL, change the action for SIG to *ACT.
  40    If OACT is not NULL, put the old action for SIG in *OACT.  */
  41 int
  42 __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
  43 {
  44   int result;
  45
  46   struct kernel_sigaction kact, koact;
  47
  48   if (act)
  49     {
  50       kact.k_sa_handler = act->sa_handler;
  51       memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  52       kact.sa_flags = act->sa_flags;
  53       SET_SA_RESTORER (&kact, act);
  54     }
  55
  56   /* XXX The size argument hopefully will have to be changed to the
  57      real size of the user-level sigset_t.  */
  58   result = INLINE_SYSCALL_CALL (rt_sigaction, sig,
  59                                 act ? &kact : NULL,
  60                                 oact ? &koact : NULL, STUB (act, _NSIG / 8));
  61
  62   if (oact && result >= 0)
  63     {
  64       oact->sa_handler = koact.k_sa_handler;
  65       memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  66       oact->sa_flags = koact.sa_flags;
  67       RESET_SA_RESTORER (oact, &koact);
  68     }
  69   return result;
  70 }
  71 libc_hidden_def (__libc_sigaction)
  72
  73 #include <nptl/sigaction.c>