sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c

   1 /* POSIX.1 sigaction call for Linux/SPARC.
   2    Copyright (C) 1997-2000,2002,2003,2005 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Miguel de Icaza (miguel@nuclecu.unam.mx), 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <string.h>
  22 #include <syscall.h>
  23 #include <sys/signal.h>
  24 #include <errno.h>
  25 #include <kernel_sigaction.h>
  26 #include <sysdep.h>
  27
  28 static void __rt_sigreturn_stub (void);
  29 static void __sigreturn_stub (void);
  30
  31 /* The variable is shared between all wrappers around signal handling
  32    functions which have RT equivalents.  */
  33 int __libc_missing_rt_sigs;
  34
  35 int
  36 __libc_sigaction (int sig, __const struct sigaction *act,
  37                   struct sigaction *oact)
  38 {
  39   struct old_kernel_sigaction k_sigact, k_osigact;
  40   int ret;
  41
  42 #ifdef __NR_rt_sigaction
  43   /* First try the RT signals.  */
  44   if (!__libc_missing_rt_sigs)
  45     {
  46       struct kernel_sigaction kact, koact;
  47       unsigned long stub = 0;
  48       int saved_errno = errno;
  49
  50       if (act)
  51         {
  52           kact.k_sa_handler = act->sa_handler;
  53           memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  54           if (((kact.sa_flags = act->sa_flags) & SA_SIGINFO) != 0)
  55             stub = (unsigned long) &__rt_sigreturn_stub;
  56           else
  57             stub = (unsigned long) &__sigreturn_stub;
  58           stub -= 8;
  59           kact.sa_restorer = NULL;
  60         }
  61
  62       /* XXX The size argument hopefully will have to be changed to the
  63          real size of the user-level sigset_t.  */
  64       ret = INLINE_SYSCALL (rt_sigaction, 5, sig, act ? &kact : 0,
  65                             oact ? &koact : 0, stub, _NSIG / 8);
  66
  67       if (ret >= 0 || errno != ENOSYS)
  68         {
  69           if (oact && ret >= 0)
  70             {
  71               oact->sa_handler = koact.k_sa_handler;
  72               memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  73               oact->sa_flags = koact.sa_flags;
  74               oact->sa_restorer = koact.sa_restorer;
  75             }
  76           return ret;
  77         }
  78
  79       __set_errno (saved_errno);
  80       __libc_missing_rt_sigs = 1;
  81     }
  82 #endif
  83
  84   /* Magic to tell the kernel we are using "new-style" signals, in that
  85      the signal table is not kept in userspace.  Not the same as the
  86      really-new-style rt signals.  */
  87   sig = -sig;
  88
  89   if (act)
  90     {
  91       k_sigact.k_sa_handler = act->sa_handler;
  92       k_sigact.sa_mask = act->sa_mask.__val[0];
  93       k_sigact.sa_flags = act->sa_flags;
  94       k_sigact.sa_restorer = NULL;
  95     }
  96
  97   {
  98     register int r_syscallnr __asm__("%g1") = __NR_sigaction;
  99     register int r_sig __asm__("%o0") = sig;
 100     register struct old_kernel_sigaction *r_act __asm__("%o1");
 101     register struct old_kernel_sigaction *r_oact __asm__("%o2");
 102
 103     r_act = act ? &k_sigact : NULL;
 104     r_oact = oact ? &k_osigact : NULL;
 105
 106     __asm__ __volatile__("t 0x10\n\t"
 107                          "bcc 1f\n\t"
 108                          " nop\n\t"
 109                          "sub %%g0,%%o0,%%o0\n"
 110                          "1:"
 111                          : "=r"(r_sig)
 112                          : "r"(r_syscallnr), "r"(r_act), "r"(r_oact),
 113                            "0"(r_sig));
 114
 115     ret = r_sig;
 116   }
 117
 118   if (ret >= 0)
 119     {
 120       if (oact)
 121         {
 122           oact->sa_handler = k_osigact.k_sa_handler;
 123           oact->sa_mask.__val[0] = k_osigact.sa_mask;
 124           oact->sa_flags = k_osigact.sa_flags;
 125           oact->sa_restorer = NULL;
 126         }
 127       return ret;
 128     }
 129
 130   __set_errno (-ret);
 131   return -1;
 132 }
 133 libc_hidden_def (__libc_sigaction)
 134
 135 #ifdef WRAPPER_INCLUDE
 136 # include WRAPPER_INCLUDE
 137 #endif
 138
 139 #ifndef LIBC_SIGACTION
 140 weak_alias (__libc_sigaction, __sigaction);
 141 libc_hidden_weak (__sigaction)
 142 weak_alias (__libc_sigaction, sigaction);
 143 #endif
 144
 145 static void
 146 __rt_sigreturn_stub (void)
 147 {
 148   __asm__ ("mov %0, %%g1\n\t"
 149            "ta  0x10\n\t"
 150            : /* no outputs */
 151            : "i" (__NR_rt_sigreturn));
 152 }
 153
 154 static void
 155 __sigreturn_stub (void)
 156 {
 157   __asm__ ("mov %0, %%g1\n\t"
 158            "ta  0x10\n\t"
 159            : /* no outputs */
 160            : "i" (__NR_sigreturn));
 161 }