diff options
Diffstat (limited to 'sysdeps/mach/hurd/i386/trampoline.c')
| -rw-r--r-- | sysdeps/mach/hurd/i386/trampoline.c | 265 |
1 files changed, 0 insertions, 265 deletions
diff --git a/sysdeps/mach/hurd/i386/trampoline.c b/sysdeps/mach/hurd/i386/trampoline.c deleted file mode 100644 index 002415929c..0000000000 --- a/sysdeps/mach/hurd/i386/trampoline.c +++ /dev/null @@ -1,265 +0,0 @@ -/* Set thread_state for sighandler, and sigcontext to recover. i386 version. - Copyright (C) 1994-2017 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 Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <hurd/signal.h> -#include <hurd/userlink.h> -#include <thread_state.h> -#include <mach/machine/eflags.h> -#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, struct hurd_signal_detail *detail, - volatile int rpc_wait, - struct machine_thread_all_state *state) -{ - void trampoline (void); - void rpc_wait_trampoline (void); - void firewall (void); - extern const void _hurd_intr_rpc_msg_cx_sp; - extern const void _hurd_intr_rpc_msg_sp_restored; - 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 (! _hurdsig_catch_memory_fault (ss->context)) - { - memcpy (&state->basic, &ss->context->sc_i386_thread_state, - sizeof (state->basic)); - memcpy (&state->fpu, &ss->context->sc_i386_float_state, - sizeof (state->fpu)); - state->set |= (1 << i386_THREAD_STATE) | (1 << i386_FLOAT_STATE); - } - } - - if (! machine_get_basic_state (ss->thread, state)) - return NULL; - - /* Save the original SP in the gratuitous `esp' slot. - We may need to reset the SP (the `uesp' slot) to avoid clobbering an - interrupted RPC frame. */ - state->basic.esp = state->basic.uesp; - - if ((ss->actions[signo].sa_flags & SA_ONSTACK) && - !(ss->sigaltstack.ss_flags & (SS_DISABLE|SS_ONSTACK))) - { - sigsp = ss->sigaltstack.ss_sp + ss->sigaltstack.ss_size; - ss->sigaltstack.ss_flags |= SS_ONSTACK; - /* XXX need to set up base of new stack for - per-thread variables, cthreads. */ - } - /* This code has intimate knowledge of the special mach_msg system call - done in intr-msg.c; that code does (see intr-msg.h): - movl %esp, %ecx - leal ARGS, %esp - _hurd_intr_rpc_msg_cx_sp: movl $-25, %eax - _hurd_intr_rpc_msg_do_trap: lcall $7, $0 - _hurd_intr_rpc_msg_in_trap: movl %ecx, %esp - _hurd_intr_rpc_msg_sp_restored: - We must check for the window during which %esp points at the - mach_msg arguments. The space below until %ecx is used by - the _hurd_intr_rpc_mach_msg frame, and must not be clobbered. */ - else if (state->basic.eip >= (int) &_hurd_intr_rpc_msg_cx_sp && - state->basic.eip < (int) &_hurd_intr_rpc_msg_sp_restored) - /* The SP now points at the mach_msg args, but there is more stack - space used below it. The real SP is saved in %ecx; we must push the - new frame below there, and restore that value as the SP on - sigreturn. */ - sigsp = (char *) (state->basic.uesp = state->basic.ecx); - else - sigsp = (char *) state->basic.uesp; - - /* Push the arguments to call `trampoline' on the stack. */ - sigsp -= sizeof (*stackframe); - stackframe = sigsp; - - 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 & SS_ONSTACK ? 1 : 0; - - /* struct sigcontext is laid out so that starting at sc_gs mimics a - struct i386_thread_state. */ - memcpy (&scp->sc_i386_thread_state, - &state->basic, sizeof (state->basic)); - - /* struct sigcontext is laid out so that starting at sc_fpkind mimics - a struct i386_float_state. */ - ok = machine_get_state (ss->thread, state, i386_FLOAT_STATE, - &state->fpu, &scp->sc_i386_float_state, - sizeof (state->fpu)); - - _hurdsig_end_catch_fault (); - - if (! ok) - return NULL; - } - - /* Modify the thread state to call the trampoline code on the new stack. */ - if (rpc_wait) - { - /* The signalee thread was blocked in a mach_msg_trap system call, - still waiting for a reply. We will have it run the special - trampoline code which retries the message receive before running - the signal handler. - - To do this we change the OPTION argument on its stack to enable only - message reception, since the request message has already been - sent. */ - - struct mach_msg_trap_args *args = (void *) state->basic.esp; - - 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. */ - args->option &= ~MACH_SEND_MSG; - - /* Limit the time to receive the reply message, in case the server - claimed that `interrupt_operation' succeeded but in fact the RPC - is hung. */ - args->option |= MACH_RCV_TIMEOUT; - args->timeout = _hurd_interrupted_rpc_timeout; - - _hurdsig_end_catch_fault (); - - state->basic.eip = (int) rpc_wait_trampoline; - /* The reply-receiving trampoline code runs initially on the original - user stack. We pass it the signal stack pointer in %ebx. */ - state->basic.uesp = state->basic.esp; /* Restore mach_msg syscall SP. */ - state->basic.ebx = (int) sigsp; - /* After doing the message receive, the trampoline code will need to - update the %eax 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 %ecx. */ - state->basic.ecx = (int) &scp->sc_eax; - } - else - { - state->basic.eip = (int) trampoline; - state->basic.uesp = (int) sigsp; - } - /* We pass the handler function to the trampoline code in %edx. */ - state->basic.edx = (int) handler; - - /* The x86 ABI says the DF bit is clear on entry to any function. */ - state->basic.efl &= ~EFL_DF; - - return scp; -} - -/* The trampoline code follows. This used to be located inside - _hurd_setup_sighandler, but was optimized away by gcc 2.95. */ - -asm ("rpc_wait_trampoline:\n"); - /* This is the entry point when we have an RPC reply message to receive - before running the handler. The MACH_MSG_SEND bit has already been - cleared in the OPTION argument on our stack. The interrupted user - stack pointer has not been changed, so the system call can find its - arguments; the signal stack pointer is in %ebx. For our convenience, - %ecx points to the sc_eax member of the sigcontext. */ -asm (/* Retry the interrupted mach_msg system call. */ - "movl $-25, %eax\n" /* mach_msg_trap */ - "lcall $7, $0\n" - /* When the sigcontext was saved, %eax 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 %eax. So - store the new %eax value into the sc_eax member of the sigcontext - (whose address is in %ecx to make this code simpler). */ - "movl %eax, (%ecx)\n" - /* Switch to the signal stack. */ - "movl %ebx, %esp\n"); - - asm ("trampoline:\n"); - /* Entry point for running the handler normally. The arguments to the - handler function are already on the top of the stack: - - 0(%esp) SIGNO - 4(%esp) SIGCODE - 8(%esp) SCP - */ -asm ("call *%edx\n" /* Call the handler function. */ - "addl $12, %esp\n" /* Pop its args. */ - /* The word at the top of stack is &__sigreturn; following are a dummy - word to fill the slot for the address for __sigreturn to return to, - and a copy of SCP for __sigreturn's argument. "Return" to calling - __sigreturn (SCP); this call never returns. */ - "ret"); - -asm ("firewall:\n" - "hlt"); |