freebsd-skq/sys/amd64/ia32/ia32_exception.S
Konstantin Belousov 2c66cccab7 Save and restore segment registers on amd64 when entering and leaving
the kernel on amd64. Fill and read segment registers for mcontext and
signals. Handle traps caused by restoration of the
invalidated selectors.

Implement user-mode creation and manipulation of the process-specific
LDT descriptors for amd64, see sysarch(2).

Implement support for TSS i/o port access permission bitmap for amd64.

Context-switch LDT and TSS. Do not save and restore segment registers on
the context switch, that is handled by kernel enter/leave trampolines
now. Remove segment restore code from the signal trampolines for
freebsd/amd64, freebsd/ia32 and linux/i386 for the same reason.

Implement amd64-specific compat shims for sysarch.

Linuxolator (temporary ?) switched to use gsbase for thread_area pointer.

TODO:
Currently, gdb is not adapted to show segment registers from struct reg.
Also, no machine-depended ptrace command is added to set segment
registers for debugged process.

In collaboration with:	pho
Discussed with:	peter
Reviewed by:	jhb
Linuxolator tested by:	dchagin
2009-04-01 13:09:26 +00:00

73 lines
2.4 KiB
ArmAsm

/*-
* Copyright (c) 2003 Peter Wemm
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asmacros.h>
#include "assym.s"
.text
/*
* Call gate entry for FreeBSD ELF and Linux/NetBSD syscall (int 0x80)
*
* This is a SDT_SYSIDT entry point (unlike the i386 port) so that we
* can do a swapgs before enabling interrupts. This is critical because
* if we took an interrupt before swapgs, the interrupt code would see
* that it originated in supervisor mode and skip the swapgs.
*/
SUPERALIGN_TEXT
IDTVEC(int0x80_syscall)
swapgs
sti
pushq $2 /* sizeof "int 0x80" */
subq $TF_ERR,%rsp /* skip over tf_trapno */
movq %rdi,TF_RDI(%rsp)
movq %rsi,TF_RSI(%rsp)
movq %rdx,TF_RDX(%rsp)
movq %rcx,TF_RCX(%rsp)
movq %r8,TF_R8(%rsp)
movq %r9,TF_R9(%rsp)
movq %rax,TF_RAX(%rsp)
movq %rbx,TF_RBX(%rsp)
movq %rbp,TF_RBP(%rsp)
movq %r10,TF_R10(%rsp)
movq %r11,TF_R11(%rsp)
movq %r12,TF_R12(%rsp)
movq %r13,TF_R13(%rsp)
movq %r14,TF_R14(%rsp)
movq %r15,TF_R15(%rsp)
movw %fs,TF_FS(%rsp)
movw %gs,TF_GS(%rsp)
movw %es,TF_ES(%rsp)
movw %ds,TF_DS(%rsp)
movl $TF_HASSEGS,TF_FLAGS(%rsp)
FAKE_MCOUNT(TF_RIP(%rsp))
movq %rsp, %rdi
call ia32_syscall
MEXITCOUNT
jmp doreti