coregrind/m_trampoline.S

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/*--- Trampoline code page stuff.                   m_trampoline.S ---*/
/*--------------------------------------------------------------------*/

/*
  This file is part of Valgrind, a dynamic binary instrumentation
  framework.

  Copyright (C) 2000-2005 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 "pub_tool_basics_asm.h"
#include "vki_unistd.h"

/* ------------------ SIMULATED CPU HELPERS ------------------ */
/* 
   Replacements for some functions to do with vsyscalls and signals.
   This code runs on the simulated CPU.
*/

/*---------------- x86-linux ----------------*/
#if defined(VGP_x86_linux)

.global VG_(trampoline_stuff_start)
VG_(trampoline_stuff_start):

.global VG_(x86_linux_SUBST_FOR_sigreturn)
VG_(x86_linux_SUBST_FOR_sigreturn):
        /* This is a very specific sequence which GDB uses to
           recognize signal handler frames. */
        popl    %eax
        movl    $__NR_sigreturn, %eax
        int     $0x80
        ud2

.global VG_(x86_linux_SUBST_FOR_rt_sigreturn)
VG_(x86_linux_SUBST_FOR_rt_sigreturn):
        /* Likewise for rt signal frames */
        movl    $__NR_rt_sigreturn, %eax
        int     $0x80
        ud2

.global VG_(x86_linux_REDIR_FOR__dl_sysinfo_int80)
VG_(x86_linux_REDIR_FOR__dl_sysinfo_int80):
	/* We can point our sysinfo stuff here */
	int	$0x80
	ret
	
.global VG_(trampoline_stuff_end)
VG_(trampoline_stuff_end):

	
/*---------------- amd64-linux ----------------*/
#else
#if defined(VGP_amd64_linux)

.global VG_(trampoline_stuff_start)
VG_(trampoline_stuff_start):

.global VG_(amd64_linux_SUBST_FOR_rt_sigreturn)
VG_(amd64_linux_SUBST_FOR_rt_sigreturn):
        /* This is a very specific sequence which GDB uses to
           recognize signal handler frames. */
        movq    $__NR_rt_sigreturn, %rax
        syscall
        ud2

.global VG_(amd64_linux_REDIR_FOR_vgettimeofday)
VG_(amd64_linux_REDIR_FOR_vgettimeofday):
        movq    $__NR_gettimeofday, %rax
        syscall
        ret

.global VG_(amd64_linux_REDIR_FOR_vtime)
VG_(amd64_linux_REDIR_FOR_vtime):
        movq    $__NR_time, %rax
        syscall
        ret

.global VG_(trampoline_stuff_end)
VG_(trampoline_stuff_end):


/*---------------- ppc32-linux ----------------*/
#else
#if defined(VGP_ppc32_linux)

.global VG_(trampoline_stuff_start)
VG_(trampoline_stuff_start):

/* There's no particular reason that this needs to be handwritten
   assembly, but since that's what this file contains, here's a
   simple strlen implementation (written in C and compiled by gcc.)
*/
.global VG_(ppc32_linux_REDIR_FOR_strlen)
VG_(ppc32_linux_REDIR_FOR_strlen):
        lbz 4,0(3)
        li 9,0
        cmpwi 0,4,0
        beq- 0,.L8
.L9:
        lbzu 5,1(3)
        addi 9,9,1
        cmpwi 0,5,0
        bne+ 0,.L9
.L8:
        mr 3,9
        blr

.global VG_(trampoline_stuff_end)
VG_(trampoline_stuff_end):


/*---------------- unknown ----------------*/
#else
#  error Unknown platform

#endif
#endif
#endif


/* Let the linker know we don't need an executable stack */
.section .note.GNU-stack,"",@progbits
		
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/*--- end                                                          ---*/
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