sysdeps/mach/hurd/powerpc/sigreturn.c

   1 /* Return from signal handler for Hurd.  PowerPC version.
   2    Copyright (C) 1996,97,98,2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <hurd.h>
  21 #include <hurd/signal.h>
  22 #include <hurd/threadvar.h>
  23 #include <stdlib.h>
  24
  25 int
  26 __sigreturn (struct sigcontext *scp)
  27 {
  28   struct hurd_sigstate *ss;
  29   mach_port_t *reply_port;
  30
  31   if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK))
  32     {
  33       errno = EINVAL;
  34       return -1;
  35     }
  36
  37   ss = _hurd_self_sigstate ();
  38   __spin_lock (&ss->lock);
  39
  40   /* Restore the set of blocked signals, and the intr_port slot.  */
  41   ss->blocked = scp->sc_mask;
  42   ss->intr_port = scp->sc_intr_port;
  43
  44   /* Check for pending signals that were blocked by the old set.  */
  45   if (ss->pending & ~ss->blocked)
  46     {
  47       /* There are pending signals that just became unblocked.  Wake up the
  48          signal thread to deliver them.  But first, squirrel away SCP where
  49          the signal thread will notice it if it runs another handler, and
  50          arrange to have us called over again in the new reality.  */
  51       ss->context = scp;
  52       __spin_unlock (&ss->lock);
  53       __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());
  54       /* If a pending signal was handled, sig_post never returned.  */
  55       __spin_lock (&ss->lock);
  56       ss->context = NULL;
  57     }
  58
  59   if (scp->sc_onstack)
  60     {
  61       ss->sigaltstack.ss_flags &= ~SS_ONSTACK; /* XXX threadvars */
  62       /* XXX cannot unlock until off sigstack */
  63       abort ();
  64     }
  65   else
  66     __spin_unlock (&ss->lock);
  67
  68   /* Destroy the MiG reply port used by the signal handler, and restore the
  69      reply port in use by the thread when interrupted.  */
  70   reply_port =
  71     (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY);
  72   if (*reply_port)
  73     {
  74       mach_port_t port = *reply_port;
  75
  76       /* Assigning MACH_PORT_DEAD here tells libc's mig_get_reply_port not to
  77          get another reply port, but avoids mig_dealloc_reply_port trying to
  78          deallocate it after the receive fails (which it will, because the
  79          reply port will be bogus, whether we do this or not).  */
  80       *reply_port = MACH_PORT_DEAD;
  81
  82       __mach_port_destroy (__mach_task_self (), port);
  83     }
  84   *reply_port = scp->sc_reply_port;
  85
  86   /* Restore FPU state.  */
  87 #define restore_fpr(n) \
  88   asm volatile ("lfd " #n ",%0(31)" : : "i" (n * 4))
  89
  90   asm volatile ("mr 31,%0" : : "r" (scp->sc_fprs));
  91
  92   /* Restore the floating-point control/status register.  */
  93   asm volatile ("lfd 0,256(31)");
  94   asm volatile ("mtfsf 0xff,0");
  95
  96   /* Restore floating-point registers. */
  97   restore_fpr (0);
  98   restore_fpr (1);
  99   restore_fpr (2);
 100   restore_fpr (3);
 101   restore_fpr (4);
 102   restore_fpr (5);
 103   restore_fpr (6);
 104   restore_fpr (7);
 105   restore_fpr (8);
 106   restore_fpr (9);
 107   restore_fpr (10);
 108   restore_fpr (11);
 109   restore_fpr (12);
 110   restore_fpr (13);
 111   restore_fpr (14);
 112   restore_fpr (15);
 113   restore_fpr (16);
 114   restore_fpr (17);
 115   restore_fpr (18);
 116   restore_fpr (19);
 117   restore_fpr (20);
 118   restore_fpr (21);
 119   restore_fpr (22);
 120   restore_fpr (23);
 121   restore_fpr (24);
 122   restore_fpr (25);
 123   restore_fpr (26);
 124   restore_fpr (27);
 125   restore_fpr (28);
 126   restore_fpr (29);
 127   restore_fpr (30);
 128   restore_fpr (31);
 129
 130   /* Load all the registers from the sigcontext.  */
 131 #define restore_gpr(n) \
 132   asm volatile ("lwz " #n ",%0(31)" : : "i" (n * 4))
 133
 134   asm volatile ("addi 31,31,-188");  /* r31 = scp->gprs */
 135
 136   /* Restore the special purpose registers.  */
 137   asm volatile ("lwz 0,128(31); mtcr 0");
 138   asm volatile ("lwz 0,132(31); mtxer 0");
 139   asm volatile ("lwz 0,136(31); mtlr 0");
 140   asm volatile ("lwz 0,-8(31); mtctr 0");  /* XXX this is the PC */
 141 #if 0
 142   asm volatile ("lwz 0,144(31); mtmq %0");  /* PPC601 only */
 143 #endif
 144
 145   /* Restore the normal registers.  */
 146   restore_gpr (0);
 147   restore_gpr (1);
 148   restore_gpr (2);
 149   restore_gpr (3);
 150   restore_gpr (4);
 151   restore_gpr (5);
 152   restore_gpr (6);
 153   restore_gpr (7);
 154   restore_gpr (8);
 155   restore_gpr (9);
 156   restore_gpr (10);
 157   restore_gpr (11);
 158   restore_gpr (12);
 159   restore_gpr (13);
 160   restore_gpr (14);
 161   restore_gpr (15);
 162   restore_gpr (16);
 163   restore_gpr (17);
 164   restore_gpr (18);
 165   restore_gpr (19);
 166   restore_gpr (20);
 167   restore_gpr (21);
 168   restore_gpr (22);
 169   restore_gpr (23);
 170   restore_gpr (24);
 171   restore_gpr (25);
 172   restore_gpr (26);
 173   restore_gpr (27);
 174   restore_gpr (28);
 175   restore_gpr (29);
 176   restore_gpr (30);
 177   restore_gpr (31);
 178
 179   /* Return. */
 180   asm volatile ("bctr");  /* XXX CTR is not restored! */
 181
 182   /* NOTREACHED */
 183   return -1;
 184 }
 185
 186 weak_alias (__sigreturn, sigreturn)