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

   1 /* POSIX.1 sigaction call for Linux/SPARC.
   2    Copyright (C) 1997-2000,2002,2003,2005,2012 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, struct sigaction *oact)
  37 {
  38   struct old_kernel_sigaction k_sigact, k_osigact;
  39   int ret;
  40
  41 #ifdef __NR_rt_sigaction
  42   /* First try the RT signals.  */
  43   if (!__libc_missing_rt_sigs)
  44     {
  45       struct kernel_sigaction kact, koact;
  46       unsigned long stub = 0;
  47       int saved_errno = errno;
  48
  49       if (act)
  50         {
  51           kact.k_sa_handler = act->sa_handler;
  52           memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
  53           if (((kact.sa_flags = act->sa_flags) & SA_SIGINFO) != 0)
  54             stub = (unsigned long) &__rt_sigreturn_stub;
  55           else
  56             stub = (unsigned long) &__sigreturn_stub;
  57           stub -= 8;
  58           kact.sa_restorer = NULL;
  59         }
  60
  61       /* XXX The size argument hopefully will have to be changed to the
  62          real size of the user-level sigset_t.  */
  63       ret = INLINE_SYSCALL (rt_sigaction, 5, sig, act ? &kact : 0,
  64                             oact ? &koact : 0, stub, _NSIG / 8);
  65
  66       if (ret >= 0 || errno != ENOSYS)
  67         {
  68           if (oact && ret >= 0)
  69             {
  70               oact->sa_handler = koact.k_sa_handler;
  71               memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
  72               oact->sa_flags = koact.sa_flags;
  73               oact->sa_restorer = koact.sa_restorer;
  74             }
  75           return ret;
  76         }
  77
  78       __set_errno (saved_errno);
  79       __libc_missing_rt_sigs = 1;
  80     }
  81 #endif
  82
  83   /* Magic to tell the kernel we are using "new-style" signals, in that
  84      the signal table is not kept in userspace.  Not the same as the
  85      really-new-style rt signals.  */
  86   sig = -sig;
  87
  88   if (act)
  89     {
  90       k_sigact.k_sa_handler = act->sa_handler;
  91       k_sigact.sa_mask = act->sa_mask.__val[0];
  92       k_sigact.sa_flags = act->sa_flags;
  93       k_sigact.sa_restorer = NULL;
  94     }
  95
  96   {
  97     register int r_syscallnr __asm__("%g1") = __NR_sigaction;
  98     register int r_sig __asm__("%o0") = sig;
  99     register struct old_kernel_sigaction *r_act __asm__("%o1");
 100     register struct old_kernel_sigaction *r_oact __asm__("%o2");
 101
 102     r_act = act ? &k_sigact : NULL;
 103     r_oact = oact ? &k_osigact : NULL;
 104
 105     __asm__ __volatile__("t 0x10\n\t"
 106                          "bcc 1f\n\t"
 107                          " nop\n\t"
 108                          "sub %%g0,%%o0,%%o0\n"
 109                          "1:"
 110                          : "=r"(r_sig)
 111                          : "r"(r_syscallnr), "r"(r_act), "r"(r_oact),
 112                            "0"(r_sig));
 113
 114     ret = r_sig;
 115   }
 116
 117   if (ret >= 0)
 118     {
 119       if (oact)
 120         {
 121           oact->sa_handler = k_osigact.k_sa_handler;
 122           oact->sa_mask.__val[0] = k_osigact.sa_mask;
 123           oact->sa_flags = k_osigact.sa_flags;
 124           oact->sa_restorer = NULL;
 125         }
 126       return ret;
 127     }
 128
 129   __set_errno (-ret);
 130   return -1;
 131 }
 132 libc_hidden_def (__libc_sigaction)
 133
 134 #ifdef WRAPPER_INCLUDE
 135 # include WRAPPER_INCLUDE
 136 #endif
 137
 138 #ifndef LIBC_SIGACTION
 139 weak_alias (__libc_sigaction, __sigaction);
 140 libc_hidden_weak (__sigaction)
 141 weak_alias (__libc_sigaction, sigaction);
 142 #endif
 143
 144 static void
 145 __rt_sigreturn_stub (void)
 146 {
 147   __asm__ ("mov %0, %%g1\n\t"
 148            "ta  0x10\n\t"
 149            : /* no outputs */
 150            : "i" (__NR_rt_sigreturn));
 151 }
 152
 153 static void
 154 __sigreturn_stub (void)
 155 {
 156   __asm__ ("mov %0, %%g1\n\t"
 157            "ta  0x10\n\t"
 158            : /* no outputs */
 159            : "i" (__NR_sigreturn));
 160 }