coregrind/amd64/helpers.S

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##--- Support routines for the JITter output.      amd64/helpers.S ---##
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/*
  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 "core_asm.h"
#include "vki_unistd.h"

/* ------------------ SIMULATED CPU HELPERS ------------------ */
/* A stubs for a return which we want to catch: a signal return.
   returns and pthread returns.  In the latter case, the thread's
   return value is in %EAX, so we pass this as the first argument
   to the request.  In both cases we use the user request mechanism.
   You need to to read the definition of VALGRIND_MAGIC_SEQUENCE
   in valgrind.h to make sense of this.

   This isn't used in-place.  It is copied into the client address space
   at an arbitary address.  Therefore, this code must be completely
   position-independent.
*/
.global VG_(trampoline_code_start)
.global VG_(trampoline_code_length)
.global VG_(tramp_rt_sigreturn_offset)
.global VG_(tramp_syscall_offset)
	
VG_(trampoline_code_start):
rt_sigreturn_start:
        /* Likewise for rt signal frames */
        movq    $__NR_rt_sigreturn, %rax
        syscall
        ud2

	# We can point our sysinfo stuff here
	.align 16
syscall_start:
	/* unused on amd64 */
tramp_code_end:
			
.data
VG_(trampoline_code_length):
	.long tramp_code_end - VG_(trampoline_code_start)
VG_(tramp_rt_sigreturn_offset):
	.long rt_sigreturn_start - VG_(trampoline_code_start)
VG_(tramp_syscall_offset):
	.long syscall_start - VG_(trampoline_code_start)
.text


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