Files
ftmemsim-valgrind/coregrind/amd64-linux/syscall.S
Nicholas Nethercote 244787cc7f Get AMD64 slightly further before dying:
- implemented VG_(do_syscall)()
- fixed a problem in ume.c with mapping when loading, which was causing
  stage2's memory to be trashed
- fixed stage2.lds substitution so stage2 goes in the right address



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3156
2004-11-30 11:40:24 +00:00

85 lines
2.7 KiB
ArmAsm

##--------------------------------------------------------------------##
##--- Support for doing system calls. amd64-linux/syscall.S ---##
##--------------------------------------------------------------------##
/*
This file is part of Valgrind, an extensible x86 protected-mode
emulator for monitoring program execution on x86-Unixes.
Copyright (C) 2000-2004 Julian Seward
jseward@acm.org
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "core_asm.h"
#include "vki_unistd.h"
/*
Perform a Linux syscall with the "syscall" instruction.
Incoming args (syscall number + up to 6 args) come in
%rdi, %rsi, %rdx, %rcx, %r8, %r9, and the last one on the stack
(ie. the C calling convention).
They are passed to the syscall in the regs
%rdi, %rsi, %rdx, %r10, %r8, %r9 (yes, really %r10, not %rcx), ie. the
kernel's syscall calling convention.
%rax holds the syscall number and gets the return value.
%rcx and %r11 are clobbered by the syscall; no matter, they
are caller-save (the syscall clobbers no callee-save regs, so
we don't have to do any register saving/restoring).
This has no effect on the virtual machine; the expectation is
that the syscall mechanism makes no useful changes to any
register except %rax, which is returned.
*/
.globl VG_(do_syscall)
VG_(do_syscall):
# Convert function calling convention --> syscall calling convention
movq %rdi, %rax
movq %rsi, %rdi
movq %rdx, %rsi
movq %rcx, %rdx
movq %r8, %r10
movq %r9, %r8
movq 8(%rsp), %r9 # last arg from stack
syscall
ret
# XXX: must reinstate comments also -- see x86-linux/syscall.S
.globl VG_(clone)
VG_(clone):
ud2
.globl VG_(sigreturn)
VG_(sigreturn):
ud2
/* Let the linker know we don't need an executable stack */
.section .note.GNU-stack,"",@progbits
##--------------------------------------------------------------------##
##--- end ---##
##--------------------------------------------------------------------##