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         64-bit signal mask (not used with _setjmp / _longjmp)
46// 7      "               "
47// 8      sigflag/cookie  setjmp cookie in top 31 bits, signal mask flag in low bit
48// 9      checksum        checksum of the core registers, to give better error messages.
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 8
58#define _JB_CHECKSUM 9
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__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(setjmp)
82  movl 4(%esp),%ecx
83  mov $1,%eax
84  jmp .L_sigsetjmp
85END(setjmp)
86
87ENTRY(_setjmp)
88__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_setjmp)
89  movl 4(%esp),%ecx
90  movl $0,%eax
91  jmp .L_sigsetjmp
92END(_setjmp)
93
94ENTRY(sigsetjmp)
95__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(sigsetjmp)
96  movl 4(%esp),%ecx
97  movl 8(%esp),%eax
98
99.L_sigsetjmp:
100  PIC_PROLOGUE
101  pushl %eax
102  call PIC_PLT(__bionic_setjmp_cookie_get)
103  addl $4,%esp
104  PIC_EPILOGUE
105
106  // Record the setjmp cookie and whether or not we're saving the signal mask.
107  movl %eax,(_JB_SIGFLAG * 4)(%ecx)
108
109  // Do we need to save the signal mask?
110  testl $1,%eax
111  jz 1f
112
113  // Save the current signal mask.
114  pushl %ecx
115  PIC_PROLOGUE
116  leal (_JB_SIGMASK * 4)(%ecx),%eax
117  pushl %eax
118  pushl $0 // NULL
119  pushl $2 // SIG_SETMASK
120  call PIC_PLT(sigprocmask64)
121  addl $12,%esp
122  PIC_EPILOGUE
123  popl %ecx
124
1251:
126  // Fetch the setjmp cookie and clear the signal flag bit.
127  movl (_JB_SIGFLAG * 4)(%ecx),%eax
128  andl $-2,%eax
129
130  // Save the callee-save registers.
131  movl 0(%esp),%edx
132  m_mangle_registers %eax
133  movl %edx,(_JB_EDX * 4)(%ecx)
134  movl %ebx,(_JB_EBX * 4)(%ecx)
135  movl %esp,(_JB_ESP * 4)(%ecx)
136  movl %ebp,(_JB_EBP * 4)(%ecx)
137  movl %esi,(_JB_ESI * 4)(%ecx)
138  movl %edi,(_JB_EDI * 4)(%ecx)
139  m_unmangle_registers %eax
140
141  m_calculate_checksum %eax, %ecx
142  movl %eax, (_JB_CHECKSUM * 4)(%ecx)
143
144  xorl %eax,%eax
145  ret
146END(sigsetjmp)
147
148ENTRY(siglongjmp)
149__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(siglongjmp)
150  movl 4(%esp),%edx
151
152  // Check the checksum before doing anything.
153  m_calculate_checksum %eax, %edx
154  xorl (_JB_CHECKSUM * 4)(%edx), %eax
155  jnz 3f
156
157  // Do we have a signal mask to restore?
158  movl (_JB_SIGFLAG * 4)(%edx), %eax
159  testl $1,%eax
160  jz 1f
161
162  // Restore the signal mask.
163  leal (_JB_SIGMASK * 4)(%edx),%eax
164  PIC_PROLOGUE
165  pushl $0 // NULL
166  pushl %eax
167  pushl $2 // SIG_SETMASK
168  call PIC_PLT(sigprocmask64)
169  addl $12,%esp
170  PIC_EPILOGUE
171
1721:
173  // Restore the callee-save registers.
174  movl 4(%esp),%edx
175  movl 8(%esp),%eax
176
177  movl (_JB_SIGFLAG * 4)(%edx),%ecx
178  andl $-2,%ecx
179
180  movl %ecx,%ebx
181  movl %ecx,%esp
182  movl %ecx,%ebp
183  movl %ecx,%esi
184  movl %ecx,%edi
185  xorl (_JB_EDX * 4)(%edx),%ecx
186  xorl (_JB_EBX * 4)(%edx),%ebx
187  xorl (_JB_ESP * 4)(%edx),%esp
188  xorl (_JB_EBP * 4)(%edx),%ebp
189  xorl (_JB_ESI * 4)(%edx),%esi
190  xorl (_JB_EDI * 4)(%edx),%edi
191
192  PIC_PROLOGUE
193  pushl %eax
194  pushl %ecx
195  pushl (_JB_SIGFLAG * 4)(%edx)
196  call PIC_PLT(__bionic_setjmp_cookie_check)
197  addl $4,%esp
198  popl %ecx
199  popl %eax
200  PIC_EPILOGUE
201
202  testl %eax,%eax
203  jnz 2f
204  incl %eax
2052:
206  movl %ecx,0(%esp)
207  ret
208
2093:
210  PIC_PROLOGUE
211  pushl (_JB_SIGMASK * 4)(%edx)
212  call PIC_PLT(__bionic_setjmp_checksum_mismatch)
213END(siglongjmp)
214
215ALIAS_SYMBOL(longjmp, siglongjmp)
216__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(longjmp)
217ALIAS_SYMBOL(_longjmp, siglongjmp)
218__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_longjmp)
219