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1d20f33ff4
INTR_MSG_TRAP was tinkering with esp to make it point to _hurd_intr_rpc_mach_msg's parameters, and notably use (&msg)[-1] which is meaningless in C. Instead, just push the parameters on the stack, which also avoids leaving local variables of _hurd_intr_rpc_mach_msg below esp. We now also properly express that OPTION and TIMEOUT may be updated during the trap call.
153 lines
6.0 KiB
C
153 lines
6.0 KiB
C
/* Machine-dependent details of interruptible RPC messaging. i386 version.
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Copyright (C) 1995-2021 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, see
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<https://www.gnu.org/licenses/>. */
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/* Note that we must mark OPTION and TIMEOUT as outputs of this operation,
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to indicate that the signal thread might mutate them as part
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of sending us to a signal handler. */
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#define INTR_MSG_TRAP(msg, option, send_size, rcv_size, rcv_name, timeout, notify, cancel_p, intr_port_p) \
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({ \
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error_t err; \
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asm (".globl _hurd_intr_rpc_msg_about_to\n" \
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".globl _hurd_intr_rpc_msg_cx_sp\n" \
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".globl _hurd_intr_rpc_msg_do_trap\n" \
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".globl _hurd_intr_rpc_msg_in_trap\n" \
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".globl _hurd_intr_rpc_msg_sp_restored\n" \
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"_hurd_intr_rpc_msg_about_to:" \
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/* We need to make a last check of cancel, in case we got interrupted
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right before _hurd_intr_rpc_msg_about_to. */ \
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" cmpl $0, %5\n" \
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" jz _hurd_intr_rpc_msg_do\n" \
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/* We got interrupted, note so and return EINTR. */ \
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" movl $0, %3\n" \
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" movl %6, %%eax\n" \
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" jmp _hurd_intr_rpc_msg_sp_restored\n" \
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"_hurd_intr_rpc_msg_do:" \
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/* Ok, push the mach_msg_trap arguments. */ \
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" pushl 24(%4)\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl %2\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl 16(%4)\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl 12(%4)\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl 8(%4)\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl %1\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl (%4)\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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" pushl $0\n" \
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" .cfi_adjust_cfa_offset 4\n" \
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/* TODO: remove this ecx kludge, we don't need it any more */ \
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" movl %%esp, %%ecx\n" \
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"_hurd_intr_rpc_msg_cx_sp: movl $-25, %%eax\n" \
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"_hurd_intr_rpc_msg_do_trap: lcall $7, $0 # status in %0\n" \
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"_hurd_intr_rpc_msg_in_trap:" \
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/* Ok, clean the arguments and update OPTION and TIMEOUT. */ \
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" addl $8, %%esp\n" \
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" .cfi_adjust_cfa_offset -8\n" \
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" popl %1\n" \
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" .cfi_adjust_cfa_offset -4\n" \
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" addl $12, %%esp\n" \
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" .cfi_adjust_cfa_offset -12\n" \
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" popl %2\n" \
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" .cfi_adjust_cfa_offset -4\n" \
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" addl $4, %%esp\n" \
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" .cfi_adjust_cfa_offset -4\n" \
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"_hurd_intr_rpc_msg_sp_restored:" \
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: "=a" (err), "+r" (option), "+r" (timeout), "=m" (*intr_port_p) \
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: "r" (&msg), "m" (*cancel_p), "i" (EINTR) \
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: "ecx"); \
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err; \
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})
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static void inline
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INTR_MSG_BACK_OUT (struct i386_thread_state *state)
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{
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extern const void _hurd_intr_rpc_msg_cx_sp;
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if (state->eip >= (natural_t) &_hurd_intr_rpc_msg_cx_sp)
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state->uesp = state->ecx;
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else
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state->ecx = state->uesp;
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}
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#include "hurdfault.h"
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/* This cannot be an inline function because it calls setjmp. */
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#define SYSCALL_EXAMINE(state, callno) \
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({ \
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struct { unsigned int c[2]; } *p = (void *) ((state)->eip - 7); \
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int result; \
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if (_hurdsig_catch_memory_fault (p)) \
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return 0; \
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if (result = p->c[0] == 0x0000009a && (p->c[1] & 0x00ffffff) == 0x00000700) \
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/* The PC is just after an `lcall $7,$0' instruction. \
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This is a system call in progress; %eax holds the call number. */ \
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*(callno) = (state)->eax; \
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_hurdsig_end_catch_fault (); \
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result; \
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})
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struct mach_msg_trap_args
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{
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void *retaddr; /* Address mach_msg_trap will return to. */
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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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/* This cannot be an inline function because it calls setjmp. */
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#define MSG_EXAMINE(state, msgid, rcvname, send_name, opt, tmout) \
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({ \
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const struct mach_msg_trap_args *args = (const void *) (state)->uesp; \
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mach_msg_header_t *msg; \
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_hurdsig_catch_memory_fault (args) ? -1 : \
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({ \
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msg = args->msg; \
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*(opt) = args->option; \
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*(tmout) = args->timeout; \
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*(rcvname) = args->rcv_name; \
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_hurdsig_end_catch_fault (); \
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if (msg == 0) \
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{ \
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*(send_name) = MACH_PORT_NULL; \
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*(msgid) = 0; \
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} \
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else \
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{ \
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if (_hurdsig_catch_memory_fault (msg)) \
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return -1; \
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*(send_name) = msg->msgh_remote_port; \
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*(msgid) = msg->msgh_id; \
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_hurdsig_end_catch_fault (); \
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} \
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0; \
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}); \
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})
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