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

   1 /* POSIX.1 sigaction call for Linux/SPARC.
   2    Copyright (C) 1997, 1998, 1999, 2000 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 Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 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
  27 extern int __syscall_rt_sigaction (int, const struct kernel_sigaction *,
  28                                    struct kernel_sigaction *, unsigned long,
  29                                    size_t);
  30
  31 static void __rt_sigreturn_stub (void);
  32 static void __sigreturn_stub (void);
  33
  34 /* The variable is shared between all wrappers around signal handling
  35    functions which have RT equivalents.  */
  36 int __libc_missing_rt_sigs;
  37
  38 int
  39 __libc_sigaction (int sig, __const struct sigaction *act,
  40                   struct sigaction *oact)
  41 {
  42   struct old_kernel_sigaction k_sigact, k_osigact;
  43   int ret;
  44
  45 #ifdef __NR_rt_sigaction
  46   /* First try the RT signals.  */
  47   if (!__libc_missing_rt_sigs)
  48     {
  49       struct kernel_sigaction kact, koact;
  50       unsigned long stub = 0;
  51       int saved_errno = errno;
  52
  53       if (act)
  54         {
  55           kact.k_sa_handler = act->sa_handler;
  56           memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  57           if (((kact.sa_flags = act->sa_flags) & SA_SIGINFO) != 0)
  58             stub = (unsigned long) &__rt_sigreturn_stub;
  59           else
  60             stub = (unsigned long) &__sigreturn_stub;
  61           stub -= 8;
  62           kact.sa_restorer = NULL;
  63         }
  64
  65       /* XXX The size argument hopefully will have to be changed to the
  66          real size of the user-level sigset_t.  */
  67       ret = __syscall_rt_sigaction (sig, act ? &kact : 0,
  68                                     oact ? &koact : 0,
  69                                     stub, _NSIG / 8);
  70
  71       if (ret >= 0 || errno != ENOSYS)
  72         {
  73           if (oact && ret >= 0)
  74             {
  75               oact->sa_handler = koact.k_sa_handler;
  76               memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  77               oact->sa_flags = koact.sa_flags;
  78               oact->sa_restorer = koact.sa_restorer;
  79             }
  80           return ret;
  81         }
  82
  83       __set_errno (saved_errno);
  84       __libc_missing_rt_sigs = 1;
  85     }
  86 #endif
  87
  88   /* Magic to tell the kernel we are using "new-style" signals, in that
  89      the signal table is not kept in userspace.  Not the same as the
  90      really-new-style rt signals.  */
  91   sig = -sig;
  92
  93   if (act)
  94     {
  95       k_sigact.k_sa_handler = act->sa_handler;
  96       k_sigact.sa_mask = act->sa_mask.__val[0];
  97       k_sigact.sa_flags = act->sa_flags;
  98       k_sigact.sa_restorer = NULL;
  99     }
 100
 101   {
 102     register int r_syscallnr __asm__("%g1") = __NR_sigaction;
 103     register int r_sig __asm__("%o0") = sig;
 104     register struct old_kernel_sigaction *r_act __asm__("%o1");
 105     register struct old_kernel_sigaction *r_oact __asm__("%o2");
 106
 107     r_act = act ? &k_sigact : NULL;
 108     r_oact = oact ? &k_osigact : NULL;
 109
 110     __asm__ __volatile__("t 0x10\n\t"
 111                          "bcc 1f\n\t"
 112                          " nop\n\t"
 113                          "sub %%g0,%%o0,%%o0\n"
 114                          "1:"
 115                          : "=r"(r_sig)
 116                          : "r"(r_syscallnr), "r"(r_act), "r"(r_oact),
 117                            "0"(r_sig));
 118
 119     ret = r_sig;
 120   }
 121
 122   if (ret >= 0)
 123     {
 124       if (oact)
 125         {
 126           oact->sa_handler = k_osigact.k_sa_handler;
 127           oact->sa_mask.__val[0] = k_osigact.sa_mask;
 128           oact->sa_flags = k_osigact.sa_flags;
 129           oact->sa_restorer = NULL;
 130         }
 131       return ret;
 132     }
 133
 134   __set_errno (-ret);
 135   return -1;
 136 }
 137
 138 strong_alias (__libc_sigaction, __sigaction);
 139 weak_alias (__libc_sigaction, sigaction);
 140
 141 static void
 142 __rt_sigreturn_stub (void)
 143 {
 144   __asm__ ("mov %0, %%g1\n\t"
 145            "ta  0x10\n\t"
 146            : /* no outputs */
 147            : "i" (__NR_rt_sigreturn));
 148 }
 149
 150 static void
 151 __sigreturn_stub (void)
 152 {
 153   __asm__ ("mov %0, %%g1\n\t"
 154            "ta  0x10\n\t"
 155            : /* no outputs */
 156            : "i" (__NR_sigreturn));
 157 }