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/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#include <private/bionic_asm.h>
// The internal structure of a jmp_buf is totally private.
// Current layout (changes from release to release):
//
// word name description
// 0 edx registers
// 1 ebx
// 2 esp
// 3 ebp
// 4 esi
// 5 edi
// 6 sigmask 64-bit signal mask (not used with _setjmp / _longjmp)
// 7 " "
// 8 sigflag/cookie setjmp cookie in top 31 bits, signal mask flag in low bit
// 9 checksum checksum of the core registers, to give better error messages.
#define _JB_EDX 0
#define _JB_EBX 1
#define _JB_ESP 2
#define _JB_EBP 3
#define _JB_ESI 4
#define _JB_EDI 5
#define _JB_SIGMASK 6
#define _JB_SIGFLAG 8
#define _JB_CHECKSUM 9
.macro m_calculate_checksum dst, src
movl $0, \dst
.irp i,0,1,2,3,4,5
xorl (\i*4)(\src), \dst
.endr
.endm
ENTRY(setjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(setjmp)
movl 4(%esp),%ecx
mov $1,%eax
jmp .L_sigsetjmp
END(setjmp)
ENTRY(_setjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_setjmp)
movl 4(%esp),%ecx
movl $0,%eax
jmp .L_sigsetjmp
END(_setjmp)
ENTRY(sigsetjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(sigsetjmp)
movl 4(%esp),%ecx
movl 8(%esp),%eax
.L_sigsetjmp:
PIC_PROLOGUE
pushl %eax
call PIC_PLT(__bionic_setjmp_cookie_get)
addl $4,%esp
PIC_EPILOGUE
// Record the setjmp cookie and whether or not we're saving the signal mask.
movl %eax,(_JB_SIGFLAG * 4)(%ecx)
// Do we need to save the signal mask?
testl $1,%eax
jz 1f
// Save the current signal mask.
pushl %ecx
PIC_PROLOGUE
leal (_JB_SIGMASK * 4)(%ecx),%eax
pushl %eax
pushl $0 // NULL
pushl $2 // SIG_SETMASK
call PIC_PLT(sigprocmask64)
addl $12,%esp
PIC_EPILOGUE
popl %ecx
1:
// Fetch the setjmp cookie and clear the signal flag bit.
movl (_JB_SIGFLAG * 4)(%ecx),%eax
andl $-2,%eax
// Save the callee-save registers.
movl 0(%esp),%edx
.macro m_mangle_register reg, offset
movl \reg,(\offset * 4)(%ecx)
xorl %eax,(\offset * 4)(%ecx)
.endm
m_mangle_register %edx, _JB_EDX
m_mangle_register %ebx, _JB_EBX
m_mangle_register %esp, _JB_ESP
m_mangle_register %ebp, _JB_EBP
m_mangle_register %esi, _JB_ESI
m_mangle_register %edi, _JB_EDI
m_calculate_checksum %eax, %ecx
movl %eax, (_JB_CHECKSUM * 4)(%ecx)
xorl %eax,%eax
ret
END(sigsetjmp)
ENTRY(siglongjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(siglongjmp)
movl 4(%esp),%edx
// Check the checksum before doing anything.
m_calculate_checksum %eax, %edx
xorl (_JB_CHECKSUM * 4)(%edx), %eax
jnz 3f
// Do we have a signal mask to restore?
movl (_JB_SIGFLAG * 4)(%edx), %eax
testl $1,%eax
jz 1f
// Restore the signal mask.
leal (_JB_SIGMASK * 4)(%edx),%eax
PIC_PROLOGUE
pushl $0 // NULL
pushl %eax
pushl $2 // SIG_SETMASK
call PIC_PLT(sigprocmask64)
addl $12,%esp
PIC_EPILOGUE
1:
// Restore the callee-save registers.
movl 4(%esp),%edx
movl 8(%esp),%eax
// Fetch the setjmp cookie and clear the signal flag bit.
movl (_JB_SIGFLAG * 4)(%edx),%ecx
andl $-2,%ecx
// Carefully unmangle esp/ebp without ever having an invalid value in the
// register (http://b/152210274).
movl (_JB_ESP * 4)(%edx),%edi
xorl %ecx,%edi
movl %edi,%esp
movl (_JB_EBP * 4)(%edx),%edi
xorl %ecx,%edi
movl %edi,%ebp
// The others don't matter as much, but we do need to finish using the cookie
// from %ecx before we clobber it, so we seed each register with the cookie.
movl %ecx,%ebx
movl %ecx,%esi
movl %ecx,%edi
xorl (_JB_EDX * 4)(%edx),%ecx
xorl (_JB_EBX * 4)(%edx),%ebx
xorl (_JB_ESI * 4)(%edx),%esi
xorl (_JB_EDI * 4)(%edx),%edi
PIC_PROLOGUE
pushl %eax
pushl %ecx
pushl (_JB_SIGFLAG * 4)(%edx)
call PIC_PLT(__bionic_setjmp_cookie_check)
addl $4,%esp
popl %ecx
popl %eax
PIC_EPILOGUE
testl %eax,%eax
jnz 2f
incl %eax
2:
movl %ecx,0(%esp)
ret
3:
PIC_PROLOGUE
pushl (_JB_SIGMASK * 4)(%edx)
call PIC_PLT(__bionic_setjmp_checksum_mismatch)
END(siglongjmp)
ALIAS_SYMBOL(longjmp, siglongjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(longjmp)
ALIAS_SYMBOL(_longjmp, siglongjmp)
__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_longjmp)
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