diff options
Diffstat (limited to 'sysdeps/mach/hurd/mips/trampoline.c')
| -rw-r--r-- | sysdeps/mach/hurd/mips/trampoline.c | 217 |
1 files changed, 137 insertions, 80 deletions
diff --git a/sysdeps/mach/hurd/mips/trampoline.c b/sysdeps/mach/hurd/mips/trampoline.c index 03e3d1da6f..fbb7df508f 100644 --- a/sysdeps/mach/hurd/mips/trampoline.c +++ b/sysdeps/mach/hurd/mips/trampoline.c @@ -1,56 +1,58 @@ /* Set thread_state for sighandler, and sigcontext to recover. MIPS version. -Copyright (C) 1994, 1995 Free Software Foundation, Inc. -This file is part of the GNU C Library. + Copyright (C) 1996, 1997 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 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. + 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. */ + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ #include <hurd/signal.h> +#include <hurd/userlink.h> #include "thread_state.h" - - -struct mach_msg_trap_args - { - /* This is the order of arguments to mach_msg_trap. */ - mach_msg_header_t *msg; - mach_msg_option_t option; - mach_msg_size_t send_size; - mach_msg_size_t rcv_size; - mach_port_t rcv_name; - mach_msg_timeout_t timeout; - mach_port_t notify; - }; +#include <assert.h> +#include <errno.h> +#include "hurdfault.h" +#include "intr-msg.h" struct sigcontext * _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, - int signo, long int sigcode, - int rpc_wait, + int signo, struct hurd_signal_detail *detail, + volatile int rpc_wait, struct machine_thread_all_state *state) { - - __label__ trampoline, rpc_wait_trampoline; - void *sigsp; + __label__ trampoline, rpc_wait_trampoline, firewall; + void *volatile sigsp; struct sigcontext *scp; + struct + { + int signo; + long int sigcode; + struct sigcontext *scp; /* Points to ctx, below. */ + void *sigreturn_addr; + void *sigreturn_returns_here; + struct sigcontext *return_scp; /* Same; arg to sigreturn. */ + struct sigcontext ctx; + struct hurd_userlink link; + } *stackframe; if (ss->context) { /* We have a previous sigcontext that sigreturn was about to restore when another signal arrived. We will just base our setup on that. */ - if (! setjmp (_hurd_sigthread_fault_env)) + if (! _hurdsig_catch_memory_fault (ss->context)) { memcpy (&state->basic, &ss->context->sc_mips_thread_state, sizeof (state->basic)); @@ -63,24 +65,17 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, sizeof (state->fpu)); state->set |= (1 << MIPS_FLOAT_STATE); } - assert (! rpc_wait); - /* The intr_port slot was cleared before sigreturn sent us the - sig_post that made us notice this pending signal, so - _hurd_internal_post_signal wouldn't do interrupt_operation. - After we return, our caller will set SCP->sc_intr_port (in the - new context) from SS->intr_port and clear SS->intr_port. Now - that we are restoring this old context recorded by sigreturn, - we want to restore its intr_port too; so store it in - SS->intr_port now, so it will end up in SCP->sc_intr_port - later. */ - ss->intr_port = ss->context->sc_intr_port; } - /* If the sigreturn context was bogus, just ignore it. */ - ss->context = NULL; } - else if (! machine_get_basic_state (ss->thread, state)) + + if (! machine_get_basic_state (ss->thread, state)) return NULL; + /* Save the original SP in the gratuitous s0 ($16) slot. + We may need to reset the SP (the `r29' slot) to avoid clobbering an + interrupted RPC frame. */ + state->basic.r16 = state->basic.r29; + if ((ss->actions[signo].sa_flags & SA_ONSTACK) && !(ss->sigaltstack.ss_flags & (SA_DISABLE|SA_ONSTACK))) { @@ -92,13 +87,46 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, else sigsp = (char *) state->basic.r29; - /* Set up the sigcontext structure on the stack. This is all the stack - needs, since the args are passed in registers (below). */ - sigsp -= sizeof (*scp); - scp = sigsp; + /* Push the arguments to call `trampoline' on the stack. */ + sigsp -= sizeof (*stackframe); + stackframe = sigsp; - if (! setjmp (_hurd_sigthread_fault_env)) + if (_hurdsig_catch_memory_fault (stackframe)) { + /* We got a fault trying to write the stack frame. + We cannot set up the signal handler. + Returning NULL tells our caller, who will nuke us with a SIGILL. */ + return NULL; + } + else + { + int ok; + + extern void _hurdsig_longjmp_from_handler (void *, jmp_buf, int); + + /* Add a link to the thread's active-resources list. We mark this as + the only user of the "resource", so the cleanup function will be + called by any longjmp which is unwinding past the signal frame. + The cleanup function (in sigunwind.c) will make sure that all the + appropriate cleanups done by sigreturn are taken care of. */ + stackframe->link.cleanup = &_hurdsig_longjmp_from_handler; + stackframe->link.cleanup_data = &stackframe->ctx; + stackframe->link.resource.next = NULL; + stackframe->link.resource.prevp = NULL; + stackframe->link.thread.next = ss->active_resources; + stackframe->link.thread.prevp = &ss->active_resources; + if (stackframe->link.thread.next) + stackframe->link.thread.next->thread.prevp + = &stackframe->link.thread.next; + ss->active_resources = &stackframe->link; + + /* Set up the arguments for the signal handler. */ + stackframe->signo = signo; + stackframe->sigcode = detail->code; + stackframe->scp = stackframe->return_scp = scp = &stackframe->ctx; + stackframe->sigreturn_addr = &__sigreturn; + stackframe->sigreturn_returns_here = &&firewall; /* Crash on return. */ + /* Set up the sigcontext from the current state of the thread. */ scp->sc_onstack = ss->sigaltstack.ss_flags & SA_ONSTACK ? 1 : 0; @@ -110,24 +138,23 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, /* struct sigcontext is laid out so that starting at sc_cause mimics a struct mips_exc_state. */ - if (! machine_get_state (ss->thread, state, MIPS_EXC_STATE, - &state->exc, &scp->sc_cause, - sizeof (state->exc))) - return NULL; - if ((scp->sc_coproc_used & SC_COPROC_USE_FPU) && - /* struct sigcontext is laid out so that starting at sc_fpr - mimics a struct mips_float_state. This state - is only meaningful if the coprocessor was used. */ - ! machine_get_state (ss->thread, state, MIPS_FLOAT_STATE, - &state->fpu, - &scp->sc_mips_float_state, sizeof (state->fpu))) + ok = machine_get_state (ss->thread, state, MIPS_EXC_STATE, + &state->exc, &scp->sc_cause, + sizeof (state->exc)); + + if (ok && (scp->sc_coproc_used & SC_COPROC_USE_FPU)) + /* struct sigcontext is laid out so that starting at sc_fpr + mimics a struct mips_float_state. This state + is only meaningful if the coprocessor was used. */ + ok = machine_get_state (ss->thread, state, MIPS_FLOAT_STATE, + &state->fpu, &scp->sc_mips_float_state, + sizeof (state->fpu)); + + _hurdsig_end_catch_fault (); + + if (! ok) return NULL; } - else - /* We got a fault trying to write the stack frame. - We cannot set up the signal handler. - Returning NULL tells our caller, who will nuke us with a SIGILL. */ - return NULL; /* Modify the thread state to call the trampoline code on the new stack. */ if (rpc_wait) @@ -145,6 +172,12 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, starting with a0 ($4). */ struct mach_msg_trap_args *args = (void *) &state->basic.r4; + if (_hurdsig_catch_memory_fault (args)) + { + /* Faulted accessing ARGS. Bomb. */ + return NULL; + } + assert (args->option & MACH_RCV_MSG); /* Disable the message-send, since it has already completed. The calls we retry need only wait to receive the reply message. */ @@ -156,17 +189,22 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, args->option |= MACH_RCV_TIMEOUT; args->timeout = _hurd_interrupted_rpc_timeout; + _hurdsig_end_catch_fault (); + state->basic.pc = (int) &&rpc_wait_trampoline; - state->basic.r29 = (int) sigsp; /* $29 is the stack pointer register. */ + /* The reply-receiving trampoline code runs initially on the original + user stack. We pass it the signal stack pointer in s4 ($20). */ + state->basic.r29 = state->basic.r16; /* Restore mach_msg syscall SP. */ + state->basic.r20 = (int) sigsp; /* After doing the message receive, the trampoline code will need to update the v0 ($2) value to be restored by sigreturn. To simplify the assembly code, we pass the address of its slot in SCP to the - trampoline code in v1 ($3). */ - state->basic.r3 = (int) &scp->sc_gpr[1]; + trampoline code in s5 ($21). */ + state->basic.r21 = (int) &scp->sc_gpr[1]; /* We must preserve the mach_msg_trap args in a0..t2 ($4..$10). Pass the handler args to the trampoline code in s1..s3 ($17..$19). */ state->basic.r17 = signo; - state->basic.r18 = sigcode; + state->basic.r18 = detail->code; state->basic.r19 = (int) scp; } else @@ -174,12 +212,12 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, state->basic.pc = (int) &&trampoline; state->basic.r29 = (int) sigsp; state->basic.r4 = signo; - state->basic.r5 = sigcode; + state->basic.r5 = detail->code; state->basic.r6 = (int) scp; } - /* We pass the handler function to the trampoline code in at ($1). */ - state->basic.r1 = (int) handler; + /* We pass the handler function to the trampoline code in s6 ($22). */ + state->basic.r22 = (int) handler; /* In the callee-saved register s0 ($16), we save the SCP value to pass to __sigreturn after the handler returns. */ state->basic.r16 = (int) scp; @@ -197,21 +235,31 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, asm volatile (".set noat; .set noreorder; .set nomacro\n" /* Retry the interrupted mach_msg system call. */ +#ifdef __mips64 + "dli $2, -25\n" /* mach_msg_trap */ +#else "li $2, -25\n" /* mach_msg_trap */ +#endif "syscall\n" /* When the sigcontext was saved, v0 was MACH_RCV_INTERRUPTED. But now the message receive has completed and the original caller of the RPC (i.e. the code running when the signal arrived) needs to see the final return value of the message receive in v0. So store the new v0 value into the sc_gpr[1] member of the sigcontext - (whose address is in v1 to make this code simpler). */ - "sw $2, ($3)\n" + (whose address is in s5 to make this code simpler). */ +#ifdef __mips64 + "sd $2, ($21)\n" +#else + "sw $2, ($21)\n" +#endif /* Since the argument registers needed to have the mach_msg_trap arguments, we've stored the arguments to the handler function in registers s1..s3 ($17..$19). */ "move $4, $17\n" "move $5, $18\n" - "move $6, $19\n"); + "move $6, $19\n" + /* Switch to the signal stack. */ + "move $29, $20\n"); trampoline: /* Entry point for running the handler normally. The arguments to the @@ -222,14 +270,23 @@ _hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler, a2 SCP */ asm volatile - ("jal $1; nop\n" /* Call the handler function. */ + ("move $25, $22\n" /* Copy s6 to t9 for MIPS ABI. */ + "jal $25; nop\n" /* Call the handler function. */ /* Call __sigreturn (SCP); this cannot return. */ - "j %0\n" +#ifdef __mips64 + "dla $1,%0\n" +#else + "la $1,%0\n" +#endif + "j $1\n" "move $4, $16" /* Set up arg from saved SCP in delay slot. */ : : "i" (&__sigreturn)); /* NOTREACHED */ asm volatile (".set reorder; .set at; .set macro"); + firewall: + asm volatile ("hlt: j hlt"); + return NULL; } |