1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#include <private/bionic_asm.h> 34 35// The internal structure of a jmp_buf is totally private. 36// Current layout (changes from release to release): 37// 38// word name description 39// 0 edx registers 40// 1 ebx 41// 2 esp 42// 3 ebp 43// 4 esi 44// 5 edi 45// 6 sigmask signal mask (not used with _setjmp / _longjmp) 46// 7 sigflag/cookie setjmp cookie in top 31 bits, signal mask flag in low bit 47// 8 checksum checksum of the core registers, to give better error messages. 48// 9 reserved 49 50#define _JB_EDX 0 51#define _JB_EBX 1 52#define _JB_ESP 2 53#define _JB_EBP 3 54#define _JB_ESI 4 55#define _JB_EDI 5 56#define _JB_SIGMASK 6 57#define _JB_SIGFLAG 7 58#define _JB_CHECKSUM 8 59 60.macro m_mangle_registers reg 61 xorl \reg,%edx 62 xorl \reg,%ebx 63 xorl \reg,%esp 64 xorl \reg,%ebp 65 xorl \reg,%esi 66 xorl \reg,%edi 67.endm 68 69.macro m_unmangle_registers reg 70 m_mangle_registers \reg 71.endm 72 73.macro m_calculate_checksum dst, src 74 movl $0, \dst 75 .irp i,0,1,2,3,4,5 76 xorl (\i*4)(\src), \dst 77 .endr 78.endm 79 80ENTRY(setjmp) 81 movl 4(%esp),%ecx 82 mov $1,%eax 83 jmp .L_sigsetjmp 84END(setjmp) 85 86ENTRY(_setjmp) 87 movl 4(%esp),%ecx 88 movl $0,%eax 89 jmp .L_sigsetjmp 90END(_setjmp) 91 92ENTRY(sigsetjmp) 93 movl 4(%esp),%ecx 94 movl 8(%esp),%eax 95 96.L_sigsetjmp: 97 PIC_PROLOGUE 98 pushl %eax 99 call PIC_PLT(__bionic_setjmp_cookie_get) 100 addl $4,%esp 101 PIC_EPILOGUE 102 103 // Record the setjmp cookie and whether or not we're saving the signal mask. 104 movl %eax,(_JB_SIGFLAG * 4)(%ecx) 105 106 // Do we need to save the signal mask? 107 testl $1,%eax 108 jz 1f 109 110 // Get the current signal mask. 111 PIC_PROLOGUE 112 pushl $0 113 call PIC_PLT(sigblock) 114 addl $4,%esp 115 PIC_EPILOGUE 116 117 // Save the signal mask. 118 movl 4(%esp),%ecx 119 movl %eax,(_JB_SIGMASK * 4)(%ecx) 120 1211: 122 // Fetch the setjmp cookie and clear the signal flag bit. 123 movl (_JB_SIGFLAG * 4)(%ecx),%eax 124 andl $-2,%eax 125 126 // Save the callee-save registers. 127 movl 0(%esp),%edx 128 m_mangle_registers %eax 129 movl %edx,(_JB_EDX * 4)(%ecx) 130 movl %ebx,(_JB_EBX * 4)(%ecx) 131 movl %esp,(_JB_ESP * 4)(%ecx) 132 movl %ebp,(_JB_EBP * 4)(%ecx) 133 movl %esi,(_JB_ESI * 4)(%ecx) 134 movl %edi,(_JB_EDI * 4)(%ecx) 135 m_unmangle_registers %eax 136 137 m_calculate_checksum %eax, %ecx 138 movl %eax, (_JB_CHECKSUM * 4)(%ecx) 139 140 xorl %eax,%eax 141 ret 142END(sigsetjmp) 143 144ENTRY(siglongjmp) 145 movl 4(%esp),%edx 146 147 // Check the checksum before doing anything. 148 m_calculate_checksum %eax, %edx 149 xorl (_JB_CHECKSUM * 4)(%edx), %eax 150 jnz 3f 151 152 // Do we have a signal mask to restore? 153 movl (_JB_SIGFLAG * 4)(%edx), %eax 154 testl $1,%eax 155 jz 1f 156 157 // Restore the signal mask. 158 PIC_PROLOGUE 159 pushl (_JB_SIGMASK * 4)(%edx) 160 call PIC_PLT(sigsetmask) 161 addl $4,%esp 162 PIC_EPILOGUE 163 1641: 165 // Restore the callee-save registers. 166 movl 4(%esp),%edx 167 movl 8(%esp),%eax 168 169 movl (_JB_SIGFLAG * 4)(%edx),%ecx 170 andl $-2,%ecx 171 172 movl %ecx,%ebx 173 movl %ecx,%esp 174 movl %ecx,%ebp 175 movl %ecx,%esi 176 movl %ecx,%edi 177 xorl (_JB_EDX * 4)(%edx),%ecx 178 xorl (_JB_EBX * 4)(%edx),%ebx 179 xorl (_JB_ESP * 4)(%edx),%esp 180 xorl (_JB_EBP * 4)(%edx),%ebp 181 xorl (_JB_ESI * 4)(%edx),%esi 182 xorl (_JB_EDI * 4)(%edx),%edi 183 184 PIC_PROLOGUE 185 pushl %eax 186 pushl %ecx 187 pushl (_JB_SIGFLAG * 4)(%edx) 188 call PIC_PLT(__bionic_setjmp_cookie_check) 189 addl $4,%esp 190 popl %ecx 191 popl %eax 192 PIC_EPILOGUE 193 194 testl %eax,%eax 195 jnz 2f 196 incl %eax 1972: 198 movl %ecx,0(%esp) 199 ret 200 2013: 202 PIC_PROLOGUE 203 pushl (_JB_SIGMASK * 4)(%edx) 204 call PIC_PLT(__bionic_setjmp_checksum_mismatch) 205END(siglongjmp) 206 207ALIAS_SYMBOL(longjmp, siglongjmp) 208ALIAS_SYMBOL(_longjmp, siglongjmp) 209