ports/sysdeps/unix/sysv/linux/arm/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 #include <kernel-features.h>
  25
  26 /* The difference here is that the sigaction structure used in the
  27    kernel is not the same as we use in the libc.  Therefore we must
  28    translate it here.  */
  29 #include <kernel_sigaction.h>
  30
  31 #define SA_RESTORER     0x04000000
  32
  33 extern void __default_sa_restorer_v1(void);
  34 extern void __default_sa_restorer_v2(void);
  35 extern void __default_rt_sa_restorer_v1(void);
  36 extern void __default_rt_sa_restorer_v2(void);
  37 #ifdef __ASSUME_SIGFRAME_V2
  38 # define __default_sa_restorer __default_sa_restorer_v2
  39 # define __default_rt_sa_restorer __default_rt_sa_restorer_v2
  40 #else
  41 # include <ldsodefs.h>
  42 # define __default_sa_restorer (GLRO(dl_osversion) >= 0x020612  \
  43                                  ? __default_sa_restorer_v2     \
  44                                  : __default_sa_restorer_v1)
  45 # define __default_rt_sa_restorer (GLRO(dl_osversion) >= 0x020612       \
  46                                     ? __default_rt_sa_restorer_v2       \
  47                                     : __default_rt_sa_restorer_v1)
  48 #endif
  49
  50 /* When RT signals are in use we need to use a different return stub.  */
  51 #define choose_restorer(flags)                                  \
  52   (flags & SA_SIGINFO) ? __default_rt_sa_restorer               \
  53   : __default_sa_restorer
  54
  55 /* If ACT is not NULL, change the action for SIG to *ACT.
  56    If OACT is not NULL, put the old action for SIG in *OACT.  */
  57 int
  58 __libc_sigaction (sig, act, oact)
  59      int sig;
  60      const struct sigaction *act;
  61      struct sigaction *oact;
  62 {
  63   int result;
  64
  65   struct kernel_sigaction kact, koact;
  66
  67   if (act)
  68     {
  69       kact.k_sa_handler = act->sa_handler;
  70       memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  71       kact.sa_flags = act->sa_flags;
  72 #ifdef HAVE_SA_RESTORER
  73       if (kact.sa_flags & SA_RESTORER)
  74         kact.sa_restorer = act->sa_restorer;
  75       else
  76         {
  77           kact.sa_restorer = choose_restorer (kact.sa_flags);
  78           kact.sa_flags |= SA_RESTORER;
  79         }
  80 #endif
  81     }
  82
  83   /* XXX The size argument hopefully will have to be changed to the
  84      real size of the user-level sigset_t.  */
  85   result = INLINE_SYSCALL (rt_sigaction, 4, sig,
  86                            act ? &kact : NULL,
  87                            oact ? &koact : NULL, _NSIG / 8);
  88
  89   if (oact && result >= 0)
  90     {
  91       oact->sa_handler = koact.k_sa_handler;
  92       memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  93       oact->sa_flags = koact.sa_flags;
  94 #ifdef HAVE_SA_RESTORER
  95       oact->sa_restorer = koact.sa_restorer;
  96 #endif
  97     }
  98   return result;
  99 }
 100 libc_hidden_def (__libc_sigaction)
 101
 102 #ifdef WRAPPER_INCLUDE
 103 # include WRAPPER_INCLUDE
 104 #endif
 105
 106 #ifndef LIBC_SIGACTION
 107 weak_alias (__libc_sigaction, __sigaction)
 108 libc_hidden_weak (__sigaction)
 109 weak_alias (__libc_sigaction, sigaction)
 110 #endif