1/* libunwind - a platform-independent unwind library 2 Copyright (C) 2002-2004 Hewlett-Packard Co 3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com> 4 5This file is part of libunwind. 6 7Permission is hereby granted, free of charge, to any person obtaining 8a copy of this software and associated documentation files (the 9"Software"), to deal in the Software without restriction, including 10without limitation the rights to use, copy, modify, merge, publish, 11distribute, sublicense, and/or sell copies of the Software, and to 12permit persons to whom the Software is furnished to do so, subject to 13the following conditions: 14 15The above copyright notice and this permission notice shall be 16included in all copies or substantial portions of the Software. 17 18THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 22LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 23OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 24WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 25 26#include "unwind_i.h" 27#include "offsets.h" 28 29PROTECTED int 30unw_is_signal_frame (unw_cursor_t *cursor) 31{ 32 struct cursor *c = (struct cursor *) cursor; 33 unw_word_t w0, w1, ip; 34 unw_addr_space_t as; 35 unw_accessors_t *a; 36 void *arg; 37 int ret; 38 39 as = c->dwarf.as; 40 a = unw_get_accessors (as); 41 arg = c->dwarf.as_arg; 42 43 /* Check if EIP points at sigreturn() sequence. On Linux, this is: 44 45 __restore: 46 0x58 pop %eax 47 0xb8 0x77 0x00 0x00 0x00 movl 0x77,%eax 48 0xcd 0x80 int 0x80 49 50 without SA_SIGINFO, and 51 52 __restore_rt: 53 0xb8 0xad 0x00 0x00 0x00 movl 0xad,%eax 54 0xcd 0x80 int 0x80 55 0x00 56 57 if SA_SIGINFO is specified. 58 */ 59 ip = c->dwarf.ip; 60 if ((*a->access_mem) (as, ip, &w0, 0, arg) < 0 61 || (*a->access_mem) (as, ip + 4, &w1, 0, arg) < 0) 62 ret = 0; 63 else 64 ret = ((w0 == 0x0077b858 && w1 == 0x80cd0000) 65 || (w0 == 0x0000adb8 && (w1 & 0xffffff) == 0x80cd00)); 66 Debug (16, "returning %d\n", ret); 67 return ret; 68} 69 70PROTECTED int 71unw_handle_signal_frame (unw_cursor_t *cursor) 72{ 73 struct cursor *c = (struct cursor *) cursor; 74 int ret; 75 76 /* c->esp points at the arguments to the handler. Without 77 SA_SIGINFO, the arguments consist of a signal number 78 followed by a struct sigcontext. With SA_SIGINFO, the 79 arguments consist a signal number, a siginfo *, and a 80 ucontext *. */ 81 unw_word_t sc_addr; 82 unw_word_t siginfo_ptr_addr = c->dwarf.cfa + 4; 83 unw_word_t sigcontext_ptr_addr = c->dwarf.cfa + 8; 84 unw_word_t siginfo_ptr, sigcontext_ptr; 85 struct dwarf_loc esp_loc, siginfo_ptr_loc, sigcontext_ptr_loc; 86 87 siginfo_ptr_loc = DWARF_LOC (siginfo_ptr_addr, 0); 88 sigcontext_ptr_loc = DWARF_LOC (sigcontext_ptr_addr, 0); 89 ret = (dwarf_get (&c->dwarf, siginfo_ptr_loc, &siginfo_ptr) 90 | dwarf_get (&c->dwarf, sigcontext_ptr_loc, &sigcontext_ptr)); 91 if (ret < 0) 92 { 93 Debug (2, "returning 0\n"); 94 return 0; 95 } 96 if (siginfo_ptr < c->dwarf.cfa 97 || siginfo_ptr > c->dwarf.cfa + 256 98 || sigcontext_ptr < c->dwarf.cfa 99 || sigcontext_ptr > c->dwarf.cfa + 256) 100 { 101 /* Not plausible for SA_SIGINFO signal */ 102 c->sigcontext_format = X86_SCF_LINUX_SIGFRAME; 103 c->sigcontext_addr = sc_addr = c->dwarf.cfa + 4; 104 } 105 else 106 { 107 /* If SA_SIGINFO were not specified, we actually read 108 various segment pointers instead. We believe that at 109 least fs and _fsh are always zero for linux, so it is 110 not just unlikely, but impossible that we would end 111 up here. */ 112 c->sigcontext_format = X86_SCF_LINUX_RT_SIGFRAME; 113 c->sigcontext_addr = sigcontext_ptr; 114 sc_addr = sigcontext_ptr + LINUX_UC_MCONTEXT_OFF; 115 } 116 esp_loc = DWARF_LOC (sc_addr + LINUX_SC_ESP_OFF, 0); 117 ret = dwarf_get (&c->dwarf, esp_loc, &c->dwarf.cfa); 118 if (ret < 0) 119 { 120 Debug (2, "returning 0\n"); 121 return 0; 122 } 123 124 c->dwarf.loc[EAX] = DWARF_LOC (sc_addr + LINUX_SC_EAX_OFF, 0); 125 c->dwarf.loc[ECX] = DWARF_LOC (sc_addr + LINUX_SC_ECX_OFF, 0); 126 c->dwarf.loc[EDX] = DWARF_LOC (sc_addr + LINUX_SC_EDX_OFF, 0); 127 c->dwarf.loc[EBX] = DWARF_LOC (sc_addr + LINUX_SC_EBX_OFF, 0); 128 c->dwarf.loc[EBP] = DWARF_LOC (sc_addr + LINUX_SC_EBP_OFF, 0); 129 c->dwarf.loc[ESI] = DWARF_LOC (sc_addr + LINUX_SC_ESI_OFF, 0); 130 c->dwarf.loc[EDI] = DWARF_LOC (sc_addr + LINUX_SC_EDI_OFF, 0); 131 c->dwarf.loc[EFLAGS] = DWARF_NULL_LOC; 132 c->dwarf.loc[TRAPNO] = DWARF_NULL_LOC; 133 c->dwarf.loc[ST0] = DWARF_NULL_LOC; 134 c->dwarf.loc[EIP] = DWARF_LOC (sc_addr + LINUX_SC_EIP_OFF, 0); 135 c->dwarf.loc[ESP] = DWARF_LOC (sc_addr + LINUX_SC_ESP_OFF, 0); 136 137 return 0; 138} 139 140HIDDEN dwarf_loc_t 141x86_get_scratch_loc (struct cursor *c, unw_regnum_t reg) 142{ 143 unw_word_t addr = c->sigcontext_addr, fpstate_addr, off; 144 int ret, is_fpstate = 0; 145 146 switch (c->sigcontext_format) 147 { 148 case X86_SCF_NONE: 149 return DWARF_REG_LOC (&c->dwarf, reg); 150 151 case X86_SCF_LINUX_SIGFRAME: 152 break; 153 154 case X86_SCF_LINUX_RT_SIGFRAME: 155 addr += LINUX_UC_MCONTEXT_OFF; 156 break; 157 158 default: 159 return DWARF_NULL_LOC; 160 } 161 162 switch (reg) 163 { 164 case UNW_X86_GS: off = LINUX_SC_GS_OFF; break; 165 case UNW_X86_FS: off = LINUX_SC_FS_OFF; break; 166 case UNW_X86_ES: off = LINUX_SC_ES_OFF; break; 167 case UNW_X86_DS: off = LINUX_SC_DS_OFF; break; 168 case UNW_X86_EDI: off = LINUX_SC_EDI_OFF; break; 169 case UNW_X86_ESI: off = LINUX_SC_ESI_OFF; break; 170 case UNW_X86_EBP: off = LINUX_SC_EBP_OFF; break; 171 case UNW_X86_ESP: off = LINUX_SC_ESP_OFF; break; 172 case UNW_X86_EBX: off = LINUX_SC_EBX_OFF; break; 173 case UNW_X86_EDX: off = LINUX_SC_EDX_OFF; break; 174 case UNW_X86_ECX: off = LINUX_SC_ECX_OFF; break; 175 case UNW_X86_EAX: off = LINUX_SC_EAX_OFF; break; 176 case UNW_X86_TRAPNO: off = LINUX_SC_TRAPNO_OFF; break; 177 case UNW_X86_EIP: off = LINUX_SC_EIP_OFF; break; 178 case UNW_X86_CS: off = LINUX_SC_CS_OFF; break; 179 case UNW_X86_EFLAGS: off = LINUX_SC_EFLAGS_OFF; break; 180 case UNW_X86_SS: off = LINUX_SC_SS_OFF; break; 181 182 /* The following is probably not correct for all possible cases. 183 Somebody who understands this better should review this for 184 correctness. */ 185 186 case UNW_X86_FCW: is_fpstate = 1; off = LINUX_FPSTATE_CW_OFF; break; 187 case UNW_X86_FSW: is_fpstate = 1; off = LINUX_FPSTATE_SW_OFF; break; 188 case UNW_X86_FTW: is_fpstate = 1; off = LINUX_FPSTATE_TAG_OFF; break; 189 case UNW_X86_FCS: is_fpstate = 1; off = LINUX_FPSTATE_CSSEL_OFF; break; 190 case UNW_X86_FIP: is_fpstate = 1; off = LINUX_FPSTATE_IPOFF_OFF; break; 191 case UNW_X86_FEA: is_fpstate = 1; off = LINUX_FPSTATE_DATAOFF_OFF; break; 192 case UNW_X86_FDS: is_fpstate = 1; off = LINUX_FPSTATE_DATASEL_OFF; break; 193 case UNW_X86_MXCSR: is_fpstate = 1; off = LINUX_FPSTATE_MXCSR_OFF; break; 194 195 /* stacked fp registers */ 196 case UNW_X86_ST0: case UNW_X86_ST1: case UNW_X86_ST2: case UNW_X86_ST3: 197 case UNW_X86_ST4: case UNW_X86_ST5: case UNW_X86_ST6: case UNW_X86_ST7: 198 is_fpstate = 1; 199 off = LINUX_FPSTATE_ST0_OFF + 10*(reg - UNW_X86_ST0); 200 break; 201 202 /* SSE fp registers */ 203 case UNW_X86_XMM0_lo: case UNW_X86_XMM0_hi: 204 case UNW_X86_XMM1_lo: case UNW_X86_XMM1_hi: 205 case UNW_X86_XMM2_lo: case UNW_X86_XMM2_hi: 206 case UNW_X86_XMM3_lo: case UNW_X86_XMM3_hi: 207 case UNW_X86_XMM4_lo: case UNW_X86_XMM4_hi: 208 case UNW_X86_XMM5_lo: case UNW_X86_XMM5_hi: 209 case UNW_X86_XMM6_lo: case UNW_X86_XMM6_hi: 210 case UNW_X86_XMM7_lo: case UNW_X86_XMM7_hi: 211 is_fpstate = 1; 212 off = LINUX_FPSTATE_XMM0_OFF + 8*(reg - UNW_X86_XMM0_lo); 213 break; 214 case UNW_X86_XMM0: 215 case UNW_X86_XMM1: 216 case UNW_X86_XMM2: 217 case UNW_X86_XMM3: 218 case UNW_X86_XMM4: 219 case UNW_X86_XMM5: 220 case UNW_X86_XMM6: 221 case UNW_X86_XMM7: 222 is_fpstate = 1; 223 off = LINUX_FPSTATE_XMM0_OFF + 16*(reg - UNW_X86_XMM0); 224 break; 225 226 case UNW_X86_FOP: 227 case UNW_X86_TSS: 228 case UNW_X86_LDT: 229 default: 230 return DWARF_REG_LOC (&c->dwarf, reg); 231 } 232 233 if (is_fpstate) 234 { 235 if ((ret = dwarf_get (&c->dwarf, 236 DWARF_MEM_LOC (&c->dwarf, 237 addr + LINUX_SC_FPSTATE_OFF), 238 &fpstate_addr)) < 0) 239 return DWARF_NULL_LOC; 240 241 if (!fpstate_addr) 242 return DWARF_NULL_LOC; 243 244 return DWARF_MEM_LOC (c, fpstate_addr + off); 245 } 246 else 247 return DWARF_MEM_LOC (c, addr + off); 248} 249 250#ifndef UNW_REMOTE_ONLY 251HIDDEN void * 252x86_r_uc_addr (ucontext_t *uc, int reg) 253{ 254 void *addr; 255 256 switch (reg) 257 { 258 case UNW_X86_GS: addr = &uc->uc_mcontext.gregs[REG_GS]; break; 259 case UNW_X86_FS: addr = &uc->uc_mcontext.gregs[REG_FS]; break; 260 case UNW_X86_ES: addr = &uc->uc_mcontext.gregs[REG_ES]; break; 261 case UNW_X86_DS: addr = &uc->uc_mcontext.gregs[REG_DS]; break; 262 case UNW_X86_EAX: addr = &uc->uc_mcontext.gregs[REG_EAX]; break; 263 case UNW_X86_EBX: addr = &uc->uc_mcontext.gregs[REG_EBX]; break; 264 case UNW_X86_ECX: addr = &uc->uc_mcontext.gregs[REG_ECX]; break; 265 case UNW_X86_EDX: addr = &uc->uc_mcontext.gregs[REG_EDX]; break; 266 case UNW_X86_ESI: addr = &uc->uc_mcontext.gregs[REG_ESI]; break; 267 case UNW_X86_EDI: addr = &uc->uc_mcontext.gregs[REG_EDI]; break; 268 case UNW_X86_EBP: addr = &uc->uc_mcontext.gregs[REG_EBP]; break; 269 case UNW_X86_EIP: addr = &uc->uc_mcontext.gregs[REG_EIP]; break; 270 case UNW_X86_ESP: addr = &uc->uc_mcontext.gregs[REG_ESP]; break; 271 case UNW_X86_TRAPNO: addr = &uc->uc_mcontext.gregs[REG_TRAPNO]; break; 272 case UNW_X86_CS: addr = &uc->uc_mcontext.gregs[REG_CS]; break; 273 case UNW_X86_EFLAGS: addr = &uc->uc_mcontext.gregs[REG_EFL]; break; 274 case UNW_X86_SS: addr = &uc->uc_mcontext.gregs[REG_SS]; break; 275 276 default: 277 addr = NULL; 278 } 279 return addr; 280} 281 282HIDDEN int 283x86_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg) 284{ 285 struct cursor *c = (struct cursor *) cursor; 286 ucontext_t *uc = c->uc; 287 288 /* Ensure c->pi is up-to-date. On x86, it's relatively common to be 289 missing DWARF unwind info. We don't want to fail in that case, 290 because the frame-chain still would let us do a backtrace at 291 least. */ 292 dwarf_make_proc_info (&c->dwarf); 293 294 if (unlikely (c->sigcontext_format != X86_SCF_NONE)) 295 { 296 struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr; 297 298 Debug (8, "resuming at ip=%x via sigreturn(%p)\n", c->dwarf.ip, sc); 299 300#if !defined(__ANDROID__) 301 sigreturn (sc); 302#endif 303 } 304 else 305 { 306 Debug (8, "resuming at ip=%x via setcontext()\n", c->dwarf.ip); 307#if !defined(__ANDROID__) 308 setcontext (uc); 309#endif 310 } 311 return -UNW_EINVAL; 312} 313#endif 314