sysdeps/unix/sysv/linux/arm/sigaction.c

   1 /* Copyright (C) 1997-2015 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 #define SA_RESTORER     0x04000000
  31
  32 extern void __default_sa_restorer (void);
  33 extern void __default_rt_sa_restorer (void);
  34
  35 /* When RT signals are in use we need to use a different return stub.  */
  36 #define choose_restorer(flags)                                  \
  37   (flags & SA_SIGINFO) ? __default_rt_sa_restorer               \
  38   : __default_sa_restorer
  39
  40 /* If ACT is not NULL, change the action for SIG to *ACT.
  41    If OACT is not NULL, put the old action for SIG in *OACT.  */
  42 int
  43 __libc_sigaction (sig, act, oact)
  44      int sig;
  45      const struct sigaction *act;
  46      struct sigaction *oact;
  47 {
  48   int result;
  49
  50   struct kernel_sigaction kact, koact;
  51
  52   if (act)
  53     {
  54       kact.k_sa_handler = act->sa_handler;
  55       memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  56       kact.sa_flags = act->sa_flags;
  57 #ifdef HAVE_SA_RESTORER
  58       if (kact.sa_flags & SA_RESTORER)
  59         kact.sa_restorer = act->sa_restorer;
  60       else
  61         {
  62           kact.sa_restorer = choose_restorer (kact.sa_flags);
  63           kact.sa_flags |= SA_RESTORER;
  64         }
  65 #endif
  66     }
  67
  68   /* XXX The size argument hopefully will have to be changed to the
  69      real size of the user-level sigset_t.  */
  70   result = INLINE_SYSCALL (rt_sigaction, 4, sig,
  71                            act ? &kact : NULL,
  72                            oact ? &koact : NULL, _NSIG / 8);
  73
  74   if (oact && result >= 0)
  75     {
  76       oact->sa_handler = koact.k_sa_handler;
  77       memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  78       oact->sa_flags = koact.sa_flags;
  79 #ifdef HAVE_SA_RESTORER
  80       oact->sa_restorer = koact.sa_restorer;
  81 #endif
  82     }
  83   return result;
  84 }
  85 libc_hidden_def (__libc_sigaction)
  86
  87 #include <nptl/sigaction.c>