libc/sysdeps/linux/arc/sigaction.c

   1 /*
   2  * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
   5  */
   6
   7 #include <errno.h>
   8 #include <signal.h>
   9 #include <string.h>
  10 #include <sys/syscall.h>
  11 #include <bits/kernel_sigaction.h>
  12
  13 /*
  14  * Default sigretrun stub if user doesn't specify SA_RESTORER
  15  */
  16 static void attribute_optimize("Os") __attribute_noinline__
  17 __default_rt_sa_restorer(void)
  18 {
  19         INTERNAL_SYSCALL_NCS(__NR_rt_sigreturn, , 0);
  20 }
  21
  22 #define SA_RESTORER     0x04000000
  23
  24 /* If @act is not NULL, change the action for @sig to @act.
  25    If @oact is not NULL, put the old action for @sig in @oact.  */
  26 int
  27 __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
  28 {
  29         struct sigaction kact;
  30
  31         /*
  32          * SA_RESTORER is only relevant for act != NULL case
  33          * (!act means caller only wants to know @oact)
  34          */
  35         if (act && !(act->sa_flags & SA_RESTORER)) {
  36                 kact.sa_restorer = __default_rt_sa_restorer;
  37                 kact.sa_flags = act->sa_flags | SA_RESTORER;
  38
  39                 kact.sa_handler = act->sa_handler;
  40                 kact.sa_mask = act->sa_mask;
  41
  42                 act = &kact;
  43         }
  44
  45         return INLINE_SYSCALL(rt_sigaction, 4,
  46                         sig, act, oact, sizeof(act->sa_mask));
  47 }
  48
  49 #ifndef LIBC_SIGACTION
  50 # ifndef __UCLIBC_HAS_THREADS__
  51 strong_alias(__libc_sigaction,sigaction)
  52 libc_hidden_def(sigaction)
  53 # else
  54 weak_alias(__libc_sigaction,sigaction)
  55 libc_hidden_weak(sigaction)
  56 # endif
  57 #endif