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* sysdeps/mach/hurd/alpha/trampoline.c: Don't include <mach/machine/alpha_instruction.h>. (_hurd_setup_sighandler): Take proper arguments for current decls. Update code to use _hurdsig_catch_fault. Use `callsys' instruction instead of `call_pal'. * sysdeps/mach/hurd/alpha/intr-msg.h: New file.
250 lines
9.4 KiB
C
250 lines
9.4 KiB
C
/* Set thread_state for sighandler, and sigcontext to recover. Alpha version.
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Copyright (C) 1994,95,97,98,2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <hurd/signal.h>
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#include "thread_state.h"
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#include "hurdfault.h"
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#include <assert.h>
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struct mach_msg_trap_args
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{
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/* This is the order of arguments to mach_msg_trap. */
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mach_msg_header_t *msg;
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mach_msg_option_t option;
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mach_msg_size_t send_size;
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mach_msg_size_t rcv_size;
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mach_port_t rcv_name;
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mach_msg_timeout_t timeout;
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mach_port_t notify;
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};
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struct sigcontext *
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_hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
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int signo, struct hurd_signal_detail *detail,
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int rpc_wait, struct machine_thread_all_state *state)
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{
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__label__ trampoline, rpc_wait_trampoline;
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void *sigsp;
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struct sigcontext *scp;
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if (ss->context)
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{
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/* We have a previous sigcontext that sigreturn was about
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to restore when another signal arrived. We will just base
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our setup on that. */
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if (! _hurdsig_catch_memory_fault (ss->context))
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{
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memcpy (&state->basic, &ss->context->sc_alpha_thread_state,
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sizeof (state->basic));
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memcpy (&state->exc, &ss->context->sc_alpha_exc_state,
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sizeof (state->exc));
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state->set = (1 << ALPHA_THREAD_STATE) | (1 << ALPHA_EXC_STATE);
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if (state->exc.used_fpa)
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{
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memcpy (&state->fpu, &ss->context->sc_alpha_float_state,
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sizeof (state->fpu));
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state->set |= (1 << ALPHA_FLOAT_STATE);
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}
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assert (! rpc_wait);
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/* The intr_port slot was cleared before sigreturn sent us the
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sig_post that made us notice this pending signal, so
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_hurd_internal_post_signal wouldn't do interrupt_operation.
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After we return, our caller will set SCP->sc_intr_port (in the
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new context) from SS->intr_port and clear SS->intr_port. Now
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that we are restoring this old context recorded by sigreturn,
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we want to restore its intr_port too; so store it in
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SS->intr_port now, so it will end up in SCP->sc_intr_port
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later. */
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ss->intr_port = ss->context->sc_intr_port;
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}
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_hurdsig_end_catch_fault ();
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/* If the sigreturn context was bogus, just ignore it. */
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ss->context = NULL;
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}
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else if (! machine_get_basic_state (ss->thread, state))
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return NULL;
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if ((ss->actions[signo].sa_flags & SA_ONSTACK) &&
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!(ss->sigaltstack.ss_flags & (SS_DISABLE|SS_ONSTACK)))
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{
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sigsp = ss->sigaltstack.ss_sp + ss->sigaltstack.ss_size;
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ss->sigaltstack.ss_flags |= SS_ONSTACK;
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/* XXX need to set up base of new stack for
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per-thread variables, cthreads. */
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}
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else
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sigsp = (char *) state->basic.SP;
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/* Set up the sigcontext structure on the stack. This is all the stack
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needs, since the args are passed in registers (below). */
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sigsp -= sizeof (*scp);
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scp = sigsp;
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if (_hurdsig_catch_memory_fault (scp))
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{
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/* We got a fault trying to write the stack frame.
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We cannot set up the signal handler.
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Returning NULL tells our caller, who will nuke us with a SIGILL. */
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return NULL;
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}
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else
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{
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/* Set up the sigcontext from the current state of the thread. */
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scp->sc_onstack = ss->sigaltstack.ss_flags & SS_ONSTACK ? 1 : 0;
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/* struct sigcontext is laid out so that starting at sc_regs
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mimics a struct alpha_thread_state. */
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memcpy (&scp->sc_alpha_thread_state,
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&state->basic, sizeof (state->basic));
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/* struct sigcontext is laid out so that starting at sc_badvaddr
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mimics a struct mips_exc_state. */
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if (! machine_get_state (ss->thread, state, ALPHA_EXC_STATE,
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&state->exc, &scp->sc_alpha_exc_state,
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sizeof (state->exc)))
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return NULL;
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if (state->exc.used_fpa &&
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/* struct sigcontext is laid out so that starting at sc_fpregs
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mimics a struct alpha_float_state. This state
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is only meaningful if the coprocessor was used. */
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! machine_get_state (ss->thread, state, ALPHA_FLOAT_STATE,
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&state->fpu,
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&scp->sc_alpha_float_state,
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sizeof (state->fpu)))
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return NULL;
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_hurdsig_end_catch_fault ();
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}
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/* Modify the thread state to call the trampoline code on the new stack. */
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if (rpc_wait)
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{
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/* The signalee thread was blocked in a mach_msg_trap system call,
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still waiting for a reply. We will have it run the special
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trampoline code which retries the message receive before running
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the signal handler.
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To do this we change the OPTION argument in its registers to
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enable only message reception, since the request message has
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already been sent. */
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/* The system call arguments are stored in consecutive registers
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starting with a0 ($16). */
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struct mach_msg_trap_args *args = (void *) &state->basic.r16;
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assert (args->option & MACH_RCV_MSG);
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/* Disable the message-send, since it has already completed. The
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calls we retry need only wait to receive the reply message. */
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args->option &= ~MACH_SEND_MSG;
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/* Limit the time to receive the reply message, in case the server
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claimed that `interrupt_operation' succeeded but in fact the RPC
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is hung. */
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args->option |= MACH_RCV_TIMEOUT;
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args->timeout = _hurd_interrupted_rpc_timeout;
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state->basic.pc = (long int) &&rpc_wait_trampoline;
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/* After doing the message receive, the trampoline code will need to
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update the v0 ($0) value to be restored by sigreturn. To simplify
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the assembly code, we pass the address of its slot in SCP to the
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trampoline code in at ($28). */
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state->basic.r28 = (long int) &scp->sc_regs[0];
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/* We must preserve the mach_msg_trap args in a0..a5 and t0
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($16..$21, $1). Pass the handler args to the trampoline code in
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t8..t10 ($22.$24). */
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state->basic.r22 = signo;
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state->basic.r23 = detail->code;
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state->basic.r24 = (long int) scp;
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}
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else
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{
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state->basic.pc = (long int) &&trampoline;
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state->basic.r16 = signo;
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state->basic.r17 = detail->code;
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state->basic.r18 = (long int) scp;
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}
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state->basic.r30 = (long int) sigsp; /* $30 is the stack pointer. */
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/* We pass the handler function to the trampoline code in ra ($26). */
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state->basic.r26 = (long int) handler;
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/* In the callee-saved register t12/pv ($27), we store the
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address of __sigreturn itself, for the trampoline code to use. */
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state->basic.r27 = (long int) &__sigreturn;
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/* In the callee-saved register t11/ai ($25), we save the SCP value to pass
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to __sigreturn after the handler returns. */
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state->basic.r25 = (long int) scp;
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return scp;
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/* The trampoline code follows. This is not actually executed as part of
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this function, it is just convenient to write it that way. */
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rpc_wait_trampoline:
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/* This is the entry point when we have an RPC reply message to receive
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before running the handler. The MACH_MSG_SEND bit has already been
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cleared in the OPTION argument in our registers. For our convenience,
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at ($28) points to the sc_regs[0] member of the sigcontext (saved v0
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($0)). */
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asm volatile
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(/* Retry the interrupted mach_msg system call. */
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"lda $0, -25($31)\n" /* mach_msg_trap */
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"callsys\n" /* Magic system call instruction. */
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/* When the sigcontext was saved, v0 was MACH_RCV_INTERRUPTED. But
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now the message receive has completed and the original caller of
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the RPC (i.e. the code running when the signal arrived) needs to
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see the final return value of the message receive in v0. So
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store the new v0 value into the sc_regs[0] member of the sigcontext
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(whose address is in at to make this code simpler). */
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"stq $0, 0($28)\n"
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/* Since the argument registers needed to have the mach_msg_trap
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arguments, we've stored the arguments to the handler function
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in registers t8..t10 ($22..$24). */
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"mov $22, $16\n"
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"mov $23, $17\n"
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"mov $24, $18\n");
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trampoline:
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/* Entry point for running the handler normally. The arguments to the
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handler function are already in the standard registers:
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a0 SIGNO
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a1 SIGCODE
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a2 SCP
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t12 also contains SCP; this value is callee-saved (and so should not get
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clobbered by running the handler). We use this saved value to pass to
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__sigreturn, so the handler can clobber the argument registers if it
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likes. */
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/* Call the handler function, saving return address in ra ($26). */
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asm volatile ("jsr $26, ($26)");
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/* Reset gp ($29) from the return address (here) in ra ($26). */
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asm volatile ("ldgp $29, 0($26)");
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asm volatile ("mov $25, $16"); /* Move saved SCP to argument register. */
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/* Call __sigreturn (SCP); this cannot return. */
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asm volatile ("jmp $31, ($27)");
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/* NOTREACHED */
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return NULL;
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}
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