1 /* DWARF2 EH unwinding support for AMD x86-64 and x86. 2 Copyright (C) 2009-2022 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 GCC is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 Under Section 7 of GPL version 3, you are granted additional 17 permissions described in the GCC Runtime Library Exception, version 18 3.1, as published by the Free Software Foundation. 19 20 You should have received a copy of the GNU General Public License and 21 a copy of the GCC Runtime Library Exception along with this program; 22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 <http://www.gnu.org/licenses/>. */ 24 25 /* Do code reading to identify a signal frame, and set the frame 26 state data appropriately. See unwind-dw2.c for the structs. */ 27 28 #include <ucontext.h> 29 #include <sys/frame.h> 30 31 #ifdef __x86_64__ 32 33 #define MD_FALLBACK_FRAME_STATE_FOR x86_64_fallback_frame_state 34 35 static _Unwind_Reason_Code 36 x86_64_fallback_frame_state (struct _Unwind_Context *context, 37 _Unwind_FrameState *fs) 38 { 39 unsigned char *pc = context->ra; 40 mcontext_t *mctx; 41 long new_cfa; 42 43 if (/* Solaris 10+ 44 ------------ 45 <__sighndlr+0>: push %rbp 46 <__sighndlr+1>: mov %rsp,%rbp 47 <__sighndlr+4>: callq *%rcx 48 <__sighndlr+6>: leaveq <--- PC 49 <__sighndlr+7>: retq */ 50 *(unsigned long *)(pc - 6) == 0xc3c9d1ffe5894855) 51 52 /* We need to move up three frames: 53 54 <signal handler> <-- context->cfa 55 __sighndlr 56 call_user_handler 57 sigacthandler 58 <kernel> 59 60 context->cfa points into the frame after the saved frame pointer and 61 saved pc (struct frame). 62 63 The ucontext_t structure is in the kernel frame after the signal 64 number and a siginfo_t *. Since the frame sizes vary even within 65 Solaris 10 updates, we need to walk the stack to get there. */ 66 { 67 struct frame *fp = (struct frame *) context->cfa - 1; 68 struct handler_args { 69 int signo; 70 siginfo_t *sip; 71 ucontext_t ucontext; 72 } *handler_args; 73 ucontext_t *ucp; 74 75 /* Next frame: __sighndlr frame pointer. */ 76 fp = (struct frame *) fp->fr_savfp; 77 /* call_user_handler frame pointer. */ 78 fp = (struct frame *) fp->fr_savfp; 79 /* sigacthandler frame pointer. */ 80 fp = (struct frame *) fp->fr_savfp; 81 82 /* The argument area precedes the struct frame. */ 83 handler_args = (struct handler_args *) (fp + 1); 84 ucp = &handler_args->ucontext; 85 mctx = &ucp->uc_mcontext; 86 } 87 else 88 return _URC_END_OF_STACK; 89 90 new_cfa = mctx->gregs[REG_RSP]; 91 92 fs->regs.cfa_how = CFA_REG_OFFSET; 93 fs->regs.cfa_reg = 7; 94 fs->regs.cfa_offset = new_cfa - (long) context->cfa; 95 96 /* The SVR4 register numbering macros aren't usable in libgcc. */ 97 fs->regs.reg[0].how = REG_SAVED_OFFSET; 98 fs->regs.reg[0].loc.offset = (long)&mctx->gregs[REG_RAX] - new_cfa; 99 fs->regs.reg[1].how = REG_SAVED_OFFSET; 100 fs->regs.reg[1].loc.offset = (long)&mctx->gregs[REG_RDX] - new_cfa; 101 fs->regs.reg[2].how = REG_SAVED_OFFSET; 102 fs->regs.reg[2].loc.offset = (long)&mctx->gregs[REG_RCX] - new_cfa; 103 fs->regs.reg[3].how = REG_SAVED_OFFSET; 104 fs->regs.reg[3].loc.offset = (long)&mctx->gregs[REG_RBX] - new_cfa; 105 fs->regs.reg[4].how = REG_SAVED_OFFSET; 106 fs->regs.reg[4].loc.offset = (long)&mctx->gregs[REG_RSI] - new_cfa; 107 fs->regs.reg[5].how = REG_SAVED_OFFSET; 108 fs->regs.reg[5].loc.offset = (long)&mctx->gregs[REG_RDI] - new_cfa; 109 fs->regs.reg[6].how = REG_SAVED_OFFSET; 110 fs->regs.reg[6].loc.offset = (long)&mctx->gregs[REG_RBP] - new_cfa; 111 fs->regs.reg[8].how = REG_SAVED_OFFSET; 112 fs->regs.reg[8].loc.offset = (long)&mctx->gregs[REG_R8] - new_cfa; 113 fs->regs.reg[9].how = REG_SAVED_OFFSET; 114 fs->regs.reg[9].loc.offset = (long)&mctx->gregs[REG_R9] - new_cfa; 115 fs->regs.reg[10].how = REG_SAVED_OFFSET; 116 fs->regs.reg[10].loc.offset = (long)&mctx->gregs[REG_R10] - new_cfa; 117 fs->regs.reg[11].how = REG_SAVED_OFFSET; 118 fs->regs.reg[11].loc.offset = (long)&mctx->gregs[REG_R11] - new_cfa; 119 fs->regs.reg[12].how = REG_SAVED_OFFSET; 120 fs->regs.reg[12].loc.offset = (long)&mctx->gregs[REG_R12] - new_cfa; 121 fs->regs.reg[13].how = REG_SAVED_OFFSET; 122 fs->regs.reg[13].loc.offset = (long)&mctx->gregs[REG_R13] - new_cfa; 123 fs->regs.reg[14].how = REG_SAVED_OFFSET; 124 fs->regs.reg[14].loc.offset = (long)&mctx->gregs[REG_R14] - new_cfa; 125 fs->regs.reg[15].how = REG_SAVED_OFFSET; 126 fs->regs.reg[15].loc.offset = (long)&mctx->gregs[REG_R15] - new_cfa; 127 fs->regs.reg[16].how = REG_SAVED_OFFSET; 128 fs->regs.reg[16].loc.offset = (long)&mctx->gregs[REG_RIP] - new_cfa; 129 fs->retaddr_column = 16; 130 fs->signal_frame = 1; 131 132 return _URC_NO_REASON; 133 } 134 135 #else 136 137 #define MD_FALLBACK_FRAME_STATE_FOR x86_fallback_frame_state 138 139 static _Unwind_Reason_Code 140 x86_fallback_frame_state (struct _Unwind_Context *context, 141 _Unwind_FrameState *fs) 142 { 143 unsigned char *pc = context->ra; 144 mcontext_t *mctx; 145 long new_cfa; 146 147 if (/* Solaris 11 since snv_125 148 ------------------------- 149 <__sighndlr+0> push %ebp 150 <__sighndlr+1> mov %esp,%ebp 151 <__sighndlr+3> and $0xfffffff0,%esp 152 <__sighndlr+6> sub $0x4,%esp 153 <__sighndlr+9> pushl 0x10(%ebp) 154 <__sighndlr+12> pushl 0xc(%ebp) 155 <__sighndlr+15> pushl 0x8(%ebp) 156 <__sighndlr+18> call *0x14(%ebp) 157 <__sighndlr+21> leave <--- PC 158 <__sighndlr+22> ret */ 159 (*(unsigned long *)(pc - 21) == 0x83ec8b55 160 && *(unsigned long *)(pc - 17) == 0xec83f0e4 161 && *(unsigned long *)(pc - 13) == 0x1075ff04 162 && *(unsigned long *)(pc - 9) == 0xff0c75ff 163 && *(unsigned long *)(pc - 5) == 0x55ff0875 164 && (*(unsigned long *)(pc - 1) & 0x00ffffff) == 0x00c3c914)) 165 { 166 struct handler_args { 167 int signo; 168 siginfo_t *sip; 169 ucontext_t *ucontext; 170 } *handler_args = context->cfa; 171 mctx = &handler_args->ucontext->uc_mcontext; 172 } 173 else 174 return _URC_END_OF_STACK; 175 176 new_cfa = mctx->gregs[UESP]; 177 178 fs->regs.cfa_how = CFA_REG_OFFSET; 179 fs->regs.cfa_reg = 4; 180 fs->regs.cfa_offset = new_cfa - (long) context->cfa; 181 182 /* The SVR4 register numbering macros aren't usable in libgcc. */ 183 fs->regs.reg[0].how = REG_SAVED_OFFSET; 184 fs->regs.reg[0].loc.offset = (long)&mctx->gregs[EAX] - new_cfa; 185 fs->regs.reg[3].how = REG_SAVED_OFFSET; 186 fs->regs.reg[3].loc.offset = (long)&mctx->gregs[EBX] - new_cfa; 187 fs->regs.reg[1].how = REG_SAVED_OFFSET; 188 fs->regs.reg[1].loc.offset = (long)&mctx->gregs[ECX] - new_cfa; 189 fs->regs.reg[2].how = REG_SAVED_OFFSET; 190 fs->regs.reg[2].loc.offset = (long)&mctx->gregs[EDX] - new_cfa; 191 fs->regs.reg[6].how = REG_SAVED_OFFSET; 192 fs->regs.reg[6].loc.offset = (long)&mctx->gregs[ESI] - new_cfa; 193 fs->regs.reg[7].how = REG_SAVED_OFFSET; 194 fs->regs.reg[7].loc.offset = (long)&mctx->gregs[EDI] - new_cfa; 195 fs->regs.reg[5].how = REG_SAVED_OFFSET; 196 fs->regs.reg[5].loc.offset = (long)&mctx->gregs[EBP] - new_cfa; 197 fs->regs.reg[8].how = REG_SAVED_OFFSET; 198 fs->regs.reg[8].loc.offset = (long)&mctx->gregs[EIP] - new_cfa; 199 fs->retaddr_column = 8; 200 201 /* SIGFPE for IEEE-754 exceptions is delivered after the faulting insn 202 rather than before it, so don't set fs->signal_frame in that case. 203 We test whether the ES field of the Status Register is zero. */ 204 if ((mctx->fpregs.fp_reg_set.fpchip_state.status & 0x80) == 0) 205 fs->signal_frame = 1; 206 207 return _URC_NO_REASON; 208 } 209 210 #endif 211