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- /* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If
- not, write to the Free Software Foundation, Inc., 675 Mass Ave,
- Cambridge, MA 02139, USA. */
-
- #include <hurd.h>
- #include <hurd/signal.h>
- #include <hurd/threadvar.h>
- #include <stdlib.h>
-
- int
- __sigreturn (struct sigcontext *scp)
- {
- struct hurd_sigstate *ss;
- mach_port_t *reply_port;
-
- if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK))
- {
- errno = EINVAL;
- return -1;
- }
-
- ss = _hurd_self_sigstate (); /* SS->lock now locked. */
-
- /* Restore the set of blocked signals, and the intr_port slot. */
- ss->blocked = scp->sc_mask;
- ss->intr_port = scp->sc_intr_port;
-
- /* Check for pending signals that were blocked by the old set. */
- if (ss->pending & ~ss->blocked)
- {
- /* There are pending signals that just became unblocked. Wake up the
- signal thread to deliver them. But first, squirrel away SCP where
- the signal thread will notice it if it runs another handler, and
- arrange to have us called over again in the new reality. */
- ss->context = scp;
- /* Clear the intr_port slot, since we are not in fact doing
- an interruptible RPC right now. If SS->intr_port is not null,
- the SCP context is doing an interruptible RPC, but the signal
- thread will examine us while we are blocked in the sig_post RPC. */
- ss->intr_port = MACH_PORT_NULL;
- __mutex_unlock (&ss->lock);
- __sig_post (_hurd_msgport, 0, __mach_task_self ());
- /* If a pending signal was handled, sig_post never returned. */
- __mutex_lock (&ss->lock);
- }
-
- if (scp->sc_onstack)
- {
- ss->sigaltstack.ss_flags &= ~SA_ONSTACK; /* XXX threadvars */
- /* XXX cannot unlock until off sigstack */
- abort ();
- }
- else
- __mutex_unlock (&ss->lock);
-
- /* Destroy the MiG reply port used by the signal handler, and restore the
- reply port in use by the thread when interrupted. */
- reply_port =
- (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY);
- if (*reply_port)
- __mach_port_destroy (__mach_task_self (), *reply_port);
- *reply_port = scp->sc_reply_port;
-
- if (scp->sc_coproc_used & SC_COPROC_USE_FPU)
- {
- /* Restore FPU state. */
- #define restore_fpr(n) \
- asm volatile ("l.d $f" #n ",%0" : : "m" (scp->sc_fpr[n]))
-
- /* Restore floating-point registers. */
- restore_fpr (0);
- restore_fpr (2);
- restore_fpr (4);
- restore_fpr (6);
- restore_fpr (8);
- restore_fpr (10);
- restore_fpr (12);
- restore_fpr (14);
- restore_fpr (16);
- restore_fpr (18);
- restore_fpr (20);
- restore_fpr (22);
- restore_fpr (24);
- restore_fpr (26);
- restore_fpr (28);
- restore_fpr (30);
-
- /* Restore the floating-point control/status register ($f31). */
- asm volatile ("ctc1 %0,$f31" : : "r" (scp->sc_fpcsr));
- }
-
- /* Load all the registers from the sigcontext. */
- #define restore_gpr(n) \
- asm volatile ("lw $" #n ",%0" : : "m" (scpreg->sc_gpr[n - 1]))
-
- {
- register const struct sigcontext *const scpreg asm ("$1") = scp;
- register int *at asm ("$1");
-
- /* First restore the multiplication result registers. The compiler
- will use some temporary registers, so we do this before restoring
- the general registers. */
- asm volatile ("mtlo %0" : : "r" (scpreg->sc_mdlo));
- asm volatile ("mthi %0" : : "r" (scpreg->sc_mdhi));
-
- /* In the word after the saved PC, store the saved $1 value. */
- (&scpreg->sc_pc)[1] = scpreg->sc_gpr[0];
-
- asm volatile (".set noreorder; .set noat;");
-
- /* Restore the normal registers. */
- restore_gpr (2);
- restore_gpr (3);
- restore_gpr (4);
- restore_gpr (5);
- restore_gpr (6);
- restore_gpr (7);
- restore_gpr (8);
- restore_gpr (9);
- restore_gpr (10);
- restore_gpr (11);
- restore_gpr (12);
- restore_gpr (13);
- restore_gpr (14);
- restore_gpr (15);
- restore_gpr (16);
- restore_gpr (17);
- restore_gpr (18);
- restore_gpr (19);
- restore_gpr (20);
- restore_gpr (21);
- restore_gpr (22);
- restore_gpr (23);
- restore_gpr (24);
- restore_gpr (25);
- /* Registers 26-27 are kernel-only. */
- restore_gpr (28);
- restore_gpr (29); /* Stack pointer. */
- restore_gpr (30); /* Frame pointer. */
- restore_gpr (31); /* Return address. */
-
- at = &scpreg->sc_pc;
- /* This is an emulated instruction that will find at the address in $1
- two words: the PC value to restore, and the $1 value to restore. */
- asm volatile (".word op_sigreturn");
-
- asm volatile (".set reorder; .set at;");
- }
-
- /* NOTREACHED */
- return -1;
- }
-