1 /* DWARF2 EH unwinding support for AMD x86-64 and x86.
2 Copyright (C) 2004, 2005, 2006, 2009, 2010, 2011
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
26 /* Do code reading to identify a signal frame, and set the frame
27 state data appropriately. See unwind-dw2.c for the structs.
28 Don't use this at all if inhibit_libc is used. */
35 #include <sys/ucontext.h>
37 #define MD_FALLBACK_FRAME_STATE_FOR x86_64_fallback_frame_state
39 static _Unwind_Reason_Code
40 x86_64_fallback_frame_state (struct _Unwind_Context *context,
41 _Unwind_FrameState *fs)
43 unsigned char *pc = context->ra;
44 struct sigcontext *sc;
47 /* movq $__NR_rt_sigreturn, %rax ; syscall. */
49 #define RT_SIGRETURN_SYSCALL 0x050f0000000fc0c7ULL
51 #define RT_SIGRETURN_SYSCALL 0x050f40002006c0c7ULL
53 if (*(unsigned char *)(pc+0) == 0x48
54 && *(unsigned long long *)(pc+1) == RT_SIGRETURN_SYSCALL)
56 struct ucontext *uc_ = context->cfa;
57 /* The void * cast is necessary to avoid an aliasing warning.
58 The aliasing warning is correct, but should not be a problem
59 because it does not alias anything. */
60 sc = (struct sigcontext *) (void *) &uc_->uc_mcontext;
63 return _URC_END_OF_STACK;
66 fs->regs.cfa_how = CFA_REG_OFFSET;
67 /* Register 7 is rsp */
69 fs->regs.cfa_offset = new_cfa - (long) context->cfa;
71 /* The SVR4 register numbering macros aren't usable in libgcc. */
72 fs->regs.reg[0].how = REG_SAVED_OFFSET;
73 fs->regs.reg[0].loc.offset = (long)&sc->rax - new_cfa;
74 fs->regs.reg[1].how = REG_SAVED_OFFSET;
75 fs->regs.reg[1].loc.offset = (long)&sc->rdx - new_cfa;
76 fs->regs.reg[2].how = REG_SAVED_OFFSET;
77 fs->regs.reg[2].loc.offset = (long)&sc->rcx - new_cfa;
78 fs->regs.reg[3].how = REG_SAVED_OFFSET;
79 fs->regs.reg[3].loc.offset = (long)&sc->rbx - new_cfa;
80 fs->regs.reg[4].how = REG_SAVED_OFFSET;
81 fs->regs.reg[4].loc.offset = (long)&sc->rsi - new_cfa;
82 fs->regs.reg[5].how = REG_SAVED_OFFSET;
83 fs->regs.reg[5].loc.offset = (long)&sc->rdi - new_cfa;
84 fs->regs.reg[6].how = REG_SAVED_OFFSET;
85 fs->regs.reg[6].loc.offset = (long)&sc->rbp - new_cfa;
86 fs->regs.reg[8].how = REG_SAVED_OFFSET;
87 fs->regs.reg[8].loc.offset = (long)&sc->r8 - new_cfa;
88 fs->regs.reg[9].how = REG_SAVED_OFFSET;
89 fs->regs.reg[9].loc.offset = (long)&sc->r9 - new_cfa;
90 fs->regs.reg[10].how = REG_SAVED_OFFSET;
91 fs->regs.reg[10].loc.offset = (long)&sc->r10 - new_cfa;
92 fs->regs.reg[11].how = REG_SAVED_OFFSET;
93 fs->regs.reg[11].loc.offset = (long)&sc->r11 - new_cfa;
94 fs->regs.reg[12].how = REG_SAVED_OFFSET;
95 fs->regs.reg[12].loc.offset = (long)&sc->r12 - new_cfa;
96 fs->regs.reg[13].how = REG_SAVED_OFFSET;
97 fs->regs.reg[13].loc.offset = (long)&sc->r13 - new_cfa;
98 fs->regs.reg[14].how = REG_SAVED_OFFSET;
99 fs->regs.reg[14].loc.offset = (long)&sc->r14 - new_cfa;
100 fs->regs.reg[15].how = REG_SAVED_OFFSET;
101 fs->regs.reg[15].loc.offset = (long)&sc->r15 - new_cfa;
102 fs->regs.reg[16].how = REG_SAVED_OFFSET;
103 fs->regs.reg[16].loc.offset = (long)&sc->rip - new_cfa;
104 fs->retaddr_column = 16;
105 fs->signal_frame = 1;
106 return _URC_NO_REASON;
109 #else /* ifdef __x86_64__ */
111 /* There's no sys/ucontext.h for glibc 2.0, so no
112 signal-turned-exceptions for them. There's also no configure-run for
113 the target, so we can't check on (e.g.) HAVE_SYS_UCONTEXT_H. Using the
114 target libc version macro should be enough. */
115 #if defined __GLIBC__ && !(__GLIBC__ == 2 && __GLIBC_MINOR__ == 0)
118 #include <sys/ucontext.h>
120 #define MD_FALLBACK_FRAME_STATE_FOR x86_fallback_frame_state
122 static _Unwind_Reason_Code
123 x86_fallback_frame_state (struct _Unwind_Context *context,
124 _Unwind_FrameState *fs)
126 unsigned char *pc = context->ra;
127 struct sigcontext *sc;
130 /* popl %eax ; movl $__NR_sigreturn,%eax ; int $0x80 */
131 if (*(unsigned short *)(pc+0) == 0xb858
132 && *(unsigned int *)(pc+2) == 119
133 && *(unsigned short *)(pc+6) == 0x80cd)
134 sc = context->cfa + 4;
135 /* movl $__NR_rt_sigreturn,%eax ; int $0x80 */
136 else if (*(unsigned char *)(pc+0) == 0xb8
137 && *(unsigned int *)(pc+1) == 173
138 && *(unsigned short *)(pc+5) == 0x80cd)
142 struct siginfo *pinfo;
146 } *rt_ = context->cfa;
147 /* The void * cast is necessary to avoid an aliasing warning.
148 The aliasing warning is correct, but should not be a problem
149 because it does not alias anything. */
150 sc = (struct sigcontext *) (void *) &rt_->uc.uc_mcontext;
153 return _URC_END_OF_STACK;
156 fs->regs.cfa_how = CFA_REG_OFFSET;
157 fs->regs.cfa_reg = 4;
158 fs->regs.cfa_offset = new_cfa - (long) context->cfa;
160 /* The SVR4 register numbering macros aren't usable in libgcc. */
161 fs->regs.reg[0].how = REG_SAVED_OFFSET;
162 fs->regs.reg[0].loc.offset = (long)&sc->eax - new_cfa;
163 fs->regs.reg[3].how = REG_SAVED_OFFSET;
164 fs->regs.reg[3].loc.offset = (long)&sc->ebx - new_cfa;
165 fs->regs.reg[1].how = REG_SAVED_OFFSET;
166 fs->regs.reg[1].loc.offset = (long)&sc->ecx - new_cfa;
167 fs->regs.reg[2].how = REG_SAVED_OFFSET;
168 fs->regs.reg[2].loc.offset = (long)&sc->edx - new_cfa;
169 fs->regs.reg[6].how = REG_SAVED_OFFSET;
170 fs->regs.reg[6].loc.offset = (long)&sc->esi - new_cfa;
171 fs->regs.reg[7].how = REG_SAVED_OFFSET;
172 fs->regs.reg[7].loc.offset = (long)&sc->edi - new_cfa;
173 fs->regs.reg[5].how = REG_SAVED_OFFSET;
174 fs->regs.reg[5].loc.offset = (long)&sc->ebp - new_cfa;
175 fs->regs.reg[8].how = REG_SAVED_OFFSET;
176 fs->regs.reg[8].loc.offset = (long)&sc->eip - new_cfa;
177 fs->retaddr_column = 8;
178 fs->signal_frame = 1;
179 return _URC_NO_REASON;
182 #define MD_FROB_UPDATE_CONTEXT x86_frob_update_context
184 /* Fix up for kernels that have vDSO, but don't have S flag in it. */
187 x86_frob_update_context (struct _Unwind_Context *context,
188 _Unwind_FrameState *fs ATTRIBUTE_UNUSED)
190 unsigned char *pc = context->ra;
192 /* movl $__NR_rt_sigreturn,%eax ; {int $0x80 | syscall} */
193 if (*(unsigned char *)(pc+0) == 0xb8
194 && *(unsigned int *)(pc+1) == 173
195 && (*(unsigned short *)(pc+5) == 0x80cd
196 || *(unsigned short *)(pc+5) == 0x050f))
197 _Unwind_SetSignalFrame (context, 1);
200 #endif /* not glibc 2.0 */
201 #endif /* ifdef __x86_64__ */
202 #endif /* ifdef inhibit_libc */