1/* DWARF2 EH unwinding support for DragonFly BSD: AMD x86-64 and x86. 2 Copyright (C) 2014-2022 Free Software Foundation, Inc. 3 Contributed by John Marino <gnugcc@marino.st> 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 3, or (at your option) 10any later version. 11 12GCC is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17Under Section 7 of GPL version 3, you are granted additional 18permissions described in the GCC Runtime Library Exception, version 193.1, as published by the Free Software Foundation. 20 21You should have received a copy of the GNU General Public License and 22a copy of the GCC Runtime Library Exception along with this program; 23see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24<http://www.gnu.org/licenses/>. */ 25 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 29#include <sys/types.h> 30#include <sys/sysctl.h> 31#include <sys/param.h> 32#include <signal.h> 33#include <sys/ucontext.h> 34#include <machine/sigframe.h> 35#if __DragonFly_version > 400800 36#include <sys/kinfo.h> 37#endif 38 39 40#define REG_NAME(reg) sf_uc.uc_mcontext.mc_## reg 41 42#ifdef __x86_64__ 43#define MD_FALLBACK_FRAME_STATE_FOR x86_64_dragonfly_fallback_frame_state 44 45 46static int 47x86_64_outside_sigtramp_range (unsigned char *pc) 48{ 49 static int sigtramp_range_determined = 0; 50 static unsigned char *sigtramp_start, *sigtramp_end; 51 52 if (sigtramp_range_determined == 0) 53 { 54#if __DragonFly_version > 400800 55 struct kinfo_sigtramp kst = {0}; 56 size_t len = sizeof (kst); 57 int mib[3] = { CTL_KERN, KERN_PROC, KERN_PROC_SIGTRAMP }; 58 59 sigtramp_range_determined = 1; 60 if (sysctl (mib, 3, &kst, &len, NULL, 0) == 0) 61 { 62 sigtramp_range_determined = 2; 63 sigtramp_start = kst.ksigtramp_start; 64 sigtramp_end = kst.ksigtramp_end; 65 } 66#else 67 unsigned long ps_strings; 68 size_t len = sizeof (ps_strings); 69 int mib[2] = { CTL_KERN, KERN_PS_STRINGS }; 70 71 sigtramp_range_determined = 1; 72 if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0) 73 { 74 sigtramp_range_determined = 2; 75 sigtramp_start = (unsigned char *)ps_strings - 32; 76 sigtramp_end = (unsigned char *)ps_strings; 77 } 78#endif 79 } 80 if (sigtramp_range_determined < 2) /* sysctl failed if < 2 */ 81 return 1; 82 83 return (pc < sigtramp_start || pc >= sigtramp_end ); 84} 85 86 87static _Unwind_Reason_Code 88x86_64_dragonfly_fallback_frame_state 89(struct _Unwind_Context *context, _Unwind_FrameState *fs) 90{ 91 struct sigframe *sf; 92 long new_cfa; 93 94 if (x86_64_outside_sigtramp_range(context->ra)) 95 return _URC_END_OF_STACK; 96 97 sf = (struct sigframe *) context->cfa; 98 new_cfa = sf->REG_NAME(rsp); 99 fs->regs.cfa_how = CFA_REG_OFFSET; 100 /* Register 7 is rsp */ 101 fs->regs.cfa_reg = 7; 102 fs->regs.cfa_offset = new_cfa - (long) context->cfa; 103 104 /* The SVR4 register numbering macros aren't usable in libgcc. */ 105 fs->regs.reg[0].how = REG_SAVED_OFFSET; 106 fs->regs.reg[0].loc.offset = (long)&sf->REG_NAME(rax) - new_cfa; 107 fs->regs.reg[1].how = REG_SAVED_OFFSET; 108 fs->regs.reg[1].loc.offset = (long)&sf->REG_NAME(rdx) - new_cfa; 109 fs->regs.reg[2].how = REG_SAVED_OFFSET; 110 fs->regs.reg[2].loc.offset = (long)&sf->REG_NAME(rcx) - new_cfa; 111 fs->regs.reg[3].how = REG_SAVED_OFFSET; 112 fs->regs.reg[3].loc.offset = (long)&sf->REG_NAME(rbx) - new_cfa; 113 fs->regs.reg[4].how = REG_SAVED_OFFSET; 114 fs->regs.reg[4].loc.offset = (long)&sf->REG_NAME(rsi) - new_cfa; 115 fs->regs.reg[5].how = REG_SAVED_OFFSET; 116 fs->regs.reg[5].loc.offset = (long)&sf->REG_NAME(rdi) - new_cfa; 117 fs->regs.reg[6].how = REG_SAVED_OFFSET; 118 fs->regs.reg[6].loc.offset = (long)&sf->REG_NAME(rbp) - new_cfa; 119 fs->regs.reg[8].how = REG_SAVED_OFFSET; 120 fs->regs.reg[8].loc.offset = (long)&sf->REG_NAME(r8) - new_cfa; 121 fs->regs.reg[9].how = REG_SAVED_OFFSET; 122 fs->regs.reg[9].loc.offset = (long)&sf->REG_NAME(r9) - new_cfa; 123 fs->regs.reg[10].how = REG_SAVED_OFFSET; 124 fs->regs.reg[10].loc.offset = (long)&sf->REG_NAME(r10) - new_cfa; 125 fs->regs.reg[11].how = REG_SAVED_OFFSET; 126 fs->regs.reg[11].loc.offset = (long)&sf->REG_NAME(r11) - new_cfa; 127 fs->regs.reg[12].how = REG_SAVED_OFFSET; 128 fs->regs.reg[12].loc.offset = (long)&sf->REG_NAME(r12) - new_cfa; 129 fs->regs.reg[13].how = REG_SAVED_OFFSET; 130 fs->regs.reg[13].loc.offset = (long)&sf->REG_NAME(r13) - new_cfa; 131 fs->regs.reg[14].how = REG_SAVED_OFFSET; 132 fs->regs.reg[14].loc.offset = (long)&sf->REG_NAME(r14) - new_cfa; 133 fs->regs.reg[15].how = REG_SAVED_OFFSET; 134 fs->regs.reg[15].loc.offset = (long)&sf->REG_NAME(r15) - new_cfa; 135 fs->regs.reg[16].how = REG_SAVED_OFFSET; 136 fs->regs.reg[16].loc.offset = (long)&sf->REG_NAME(rip) - new_cfa; 137 fs->retaddr_column = 16; 138 fs->signal_frame = 1; 139 return _URC_NO_REASON; 140} 141 142#else /* Next section is for i386 */ 143 144#define MD_FALLBACK_FRAME_STATE_FOR x86_dragonfly_fallback_frame_state 145 146 147static void 148x86_sigtramp_range (unsigned char **start, unsigned char **end) 149{ 150 unsigned long ps_strings; 151 int mib[2]; 152 size_t len; 153 154 mib[0] = CTL_KERN; 155 mib[1] = KERN_PS_STRINGS; 156 len = sizeof (ps_strings); 157 sysctl (mib, 2, &ps_strings, &len, NULL, 0); 158 159 *start = (unsigned char *)ps_strings - 128; 160 *end = (unsigned char *)ps_strings; 161} 162 163 164static _Unwind_Reason_Code 165x86_dragonfly_fallback_frame_state 166(struct _Unwind_Context *context, _Unwind_FrameState *fs) 167{ 168 unsigned char *pc = context->ra; 169 unsigned char *sigtramp_start, *sigtramp_end; 170 struct sigframe *sf; 171 long new_cfa; 172 173 x86_sigtramp_range(&sigtramp_start, &sigtramp_end); 174 175 if (pc >= sigtramp_end || pc < sigtramp_start) 176 return _URC_END_OF_STACK; 177 178 sf = (struct sigframe *) context->cfa; 179 new_cfa = sf->REG_NAME(esp); 180 fs->regs.cfa_how = CFA_REG_OFFSET; 181 fs->regs.cfa_reg = 4; 182 fs->regs.cfa_offset = new_cfa - (long) context->cfa; 183 184 /* The SVR4 register numbering macros aren't usable in libgcc. */ 185 fs->regs.reg[0].how = REG_SAVED_OFFSET; 186 fs->regs.reg[0].loc.offset = (long)&sf->REG_NAME(eax) - new_cfa; 187 fs->regs.reg[3].how = REG_SAVED_OFFSET; 188 fs->regs.reg[3].loc.offset = (long)&sf->REG_NAME(ebx) - new_cfa; 189 fs->regs.reg[1].how = REG_SAVED_OFFSET; 190 fs->regs.reg[1].loc.offset = (long)&sf->REG_NAME(ecx) - new_cfa; 191 fs->regs.reg[2].how = REG_SAVED_OFFSET; 192 fs->regs.reg[2].loc.offset = (long)&sf->REG_NAME(edx) - new_cfa; 193 fs->regs.reg[6].how = REG_SAVED_OFFSET; 194 fs->regs.reg[6].loc.offset = (long)&sf->REG_NAME(esi) - new_cfa; 195 fs->regs.reg[7].how = REG_SAVED_OFFSET; 196 fs->regs.reg[7].loc.offset = (long)&sf->REG_NAME(edi) - new_cfa; 197 fs->regs.reg[5].how = REG_SAVED_OFFSET; 198 fs->regs.reg[5].loc.offset = (long)&sf->REG_NAME(ebp) - new_cfa; 199 fs->regs.reg[8].how = REG_SAVED_OFFSET; 200 fs->regs.reg[8].loc.offset = (long)&sf->REG_NAME(eip) - new_cfa; 201 fs->retaddr_column = 8; 202 fs->signal_frame = 1; 203 return _URC_NO_REASON; 204} 205#endif /* ifdef __x86_64__ */ 206