1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 // 8 // Implements unw_* functions from <libunwind.h> 9 // 10 //===----------------------------------------------------------------------===// 11 12 #include <libunwind.h> 13 14 #include "config.h" 15 #include "libunwind_ext.h" 16 17 #include <stdlib.h> 18 19 // Define the __has_feature extension for compilers that do not support it so 20 // that we can later check for the presence of ASan in a compiler-neutral way. 21 #if !defined(__has_feature) 22 #define __has_feature(feature) 0 23 #endif 24 25 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) 26 #include <sanitizer/asan_interface.h> 27 #endif 28 29 #if !defined(__USING_SJLJ_EXCEPTIONS__) 30 #include "AddressSpace.hpp" 31 #include "UnwindCursor.hpp" 32 33 using namespace libunwind; 34 35 /// internal object to represent this processes address space 36 LocalAddressSpace LocalAddressSpace::sThisAddressSpace; 37 38 _LIBUNWIND_EXPORT unw_addr_space_t unw_local_addr_space = 39 (unw_addr_space_t)&LocalAddressSpace::sThisAddressSpace; 40 41 /// Create a cursor of a thread in this process given 'context' recorded by 42 /// __unw_getcontext(). 43 _LIBUNWIND_HIDDEN int __unw_init_local(unw_cursor_t *cursor, 44 unw_context_t *context) { 45 _LIBUNWIND_TRACE_API("__unw_init_local(cursor=%p, context=%p)", 46 static_cast<void *>(cursor), 47 static_cast<void *>(context)); 48 #if defined(__i386__) 49 # define REGISTER_KIND Registers_x86 50 #elif defined(__x86_64__) 51 # define REGISTER_KIND Registers_x86_64 52 #elif defined(__powerpc64__) 53 # define REGISTER_KIND Registers_ppc64 54 #elif defined(__powerpc__) 55 # define REGISTER_KIND Registers_ppc 56 #elif defined(__aarch64__) 57 # define REGISTER_KIND Registers_arm64 58 #elif defined(__arm__) 59 # define REGISTER_KIND Registers_arm 60 #elif defined(__or1k__) 61 # define REGISTER_KIND Registers_or1k 62 #elif defined(__hexagon__) 63 # define REGISTER_KIND Registers_hexagon 64 #elif defined(__mips__) && defined(_ABIO32) && _MIPS_SIM == _ABIO32 65 # define REGISTER_KIND Registers_mips_o32 66 #elif defined(__mips64) 67 # define REGISTER_KIND Registers_mips_newabi 68 #elif defined(__mips__) 69 # warning The MIPS architecture is not supported with this ABI and environment! 70 #elif defined(__sparc__) && defined(__arch64__) 71 #define REGISTER_KIND Registers_sparc64 72 #elif defined(__sparc__) 73 # define REGISTER_KIND Registers_sparc 74 #elif defined(__riscv) 75 # define REGISTER_KIND Registers_riscv 76 #elif defined(__ve__) 77 # define REGISTER_KIND Registers_ve 78 #else 79 # error Architecture not supported 80 #endif 81 // Use "placement new" to allocate UnwindCursor in the cursor buffer. 82 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, REGISTER_KIND> *>(cursor)) 83 UnwindCursor<LocalAddressSpace, REGISTER_KIND>( 84 context, LocalAddressSpace::sThisAddressSpace); 85 #undef REGISTER_KIND 86 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 87 co->setInfoBasedOnIPRegister(); 88 89 return UNW_ESUCCESS; 90 } 91 _LIBUNWIND_WEAK_ALIAS(__unw_init_local, unw_init_local) 92 93 /// Get value of specified register at cursor position in stack frame. 94 _LIBUNWIND_HIDDEN int __unw_get_reg(unw_cursor_t *cursor, unw_regnum_t regNum, 95 unw_word_t *value) { 96 _LIBUNWIND_TRACE_API("__unw_get_reg(cursor=%p, regNum=%d, &value=%p)", 97 static_cast<void *>(cursor), regNum, 98 static_cast<void *>(value)); 99 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 100 if (co->validReg(regNum)) { 101 *value = co->getReg(regNum); 102 return UNW_ESUCCESS; 103 } 104 return UNW_EBADREG; 105 } 106 _LIBUNWIND_WEAK_ALIAS(__unw_get_reg, unw_get_reg) 107 108 /// Set value of specified register at cursor position in stack frame. 109 _LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum, 110 unw_word_t value) { 111 _LIBUNWIND_TRACE_API("__unw_set_reg(cursor=%p, regNum=%d, value=0x%" PRIxPTR 112 ")", 113 static_cast<void *>(cursor), regNum, value); 114 typedef LocalAddressSpace::pint_t pint_t; 115 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 116 if (co->validReg(regNum)) { 117 co->setReg(regNum, (pint_t)value); 118 // specical case altering IP to re-find info (being called by personality 119 // function) 120 if (regNum == UNW_REG_IP) { 121 unw_proc_info_t info; 122 // First, get the FDE for the old location and then update it. 123 co->getInfo(&info); 124 co->setInfoBasedOnIPRegister(false); 125 // If the original call expects stack adjustment, perform this now. 126 // Normal frame unwinding would have included the offset already in the 127 // CFA computation. 128 // Note: for PA-RISC and other platforms where the stack grows up, 129 // this should actually be - info.gp. LLVM doesn't currently support 130 // any such platforms and Clang doesn't export a macro for them. 131 if (info.gp) 132 co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + info.gp); 133 } 134 return UNW_ESUCCESS; 135 } 136 return UNW_EBADREG; 137 } 138 _LIBUNWIND_WEAK_ALIAS(__unw_set_reg, unw_set_reg) 139 140 /// Get value of specified float register at cursor position in stack frame. 141 _LIBUNWIND_HIDDEN int __unw_get_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum, 142 unw_fpreg_t *value) { 143 _LIBUNWIND_TRACE_API("__unw_get_fpreg(cursor=%p, regNum=%d, &value=%p)", 144 static_cast<void *>(cursor), regNum, 145 static_cast<void *>(value)); 146 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 147 if (co->validFloatReg(regNum)) { 148 *value = co->getFloatReg(regNum); 149 return UNW_ESUCCESS; 150 } 151 return UNW_EBADREG; 152 } 153 _LIBUNWIND_WEAK_ALIAS(__unw_get_fpreg, unw_get_fpreg) 154 155 /// Set value of specified float register at cursor position in stack frame. 156 _LIBUNWIND_HIDDEN int __unw_set_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum, 157 unw_fpreg_t value) { 158 #if defined(_LIBUNWIND_ARM_EHABI) 159 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%llX)", 160 static_cast<void *>(cursor), regNum, value); 161 #else 162 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%g)", 163 static_cast<void *>(cursor), regNum, value); 164 #endif 165 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 166 if (co->validFloatReg(regNum)) { 167 co->setFloatReg(regNum, value); 168 return UNW_ESUCCESS; 169 } 170 return UNW_EBADREG; 171 } 172 _LIBUNWIND_WEAK_ALIAS(__unw_set_fpreg, unw_set_fpreg) 173 174 /// Move cursor to next frame. 175 _LIBUNWIND_HIDDEN int __unw_step(unw_cursor_t *cursor) { 176 _LIBUNWIND_TRACE_API("__unw_step(cursor=%p)", static_cast<void *>(cursor)); 177 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 178 return co->step(); 179 } 180 _LIBUNWIND_WEAK_ALIAS(__unw_step, unw_step) 181 182 /// Get unwind info at cursor position in stack frame. 183 _LIBUNWIND_HIDDEN int __unw_get_proc_info(unw_cursor_t *cursor, 184 unw_proc_info_t *info) { 185 _LIBUNWIND_TRACE_API("__unw_get_proc_info(cursor=%p, &info=%p)", 186 static_cast<void *>(cursor), static_cast<void *>(info)); 187 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 188 co->getInfo(info); 189 if (info->end_ip == 0) 190 return UNW_ENOINFO; 191 return UNW_ESUCCESS; 192 } 193 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_info, unw_get_proc_info) 194 195 /// Resume execution at cursor position (aka longjump). 196 _LIBUNWIND_HIDDEN int __unw_resume(unw_cursor_t *cursor) { 197 _LIBUNWIND_TRACE_API("__unw_resume(cursor=%p)", static_cast<void *>(cursor)); 198 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) 199 // Inform the ASan runtime that now might be a good time to clean stuff up. 200 __asan_handle_no_return(); 201 #endif 202 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 203 co->jumpto(); 204 return UNW_EUNSPEC; 205 } 206 _LIBUNWIND_WEAK_ALIAS(__unw_resume, unw_resume) 207 208 /// Get name of function at cursor position in stack frame. 209 _LIBUNWIND_HIDDEN int __unw_get_proc_name(unw_cursor_t *cursor, char *buf, 210 size_t bufLen, unw_word_t *offset) { 211 _LIBUNWIND_TRACE_API("__unw_get_proc_name(cursor=%p, &buf=%p, bufLen=%lu)", 212 static_cast<void *>(cursor), static_cast<void *>(buf), 213 static_cast<unsigned long>(bufLen)); 214 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 215 if (co->getFunctionName(buf, bufLen, offset)) 216 return UNW_ESUCCESS; 217 return UNW_EUNSPEC; 218 } 219 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_name, unw_get_proc_name) 220 221 /// Checks if a register is a floating-point register. 222 _LIBUNWIND_HIDDEN int __unw_is_fpreg(unw_cursor_t *cursor, 223 unw_regnum_t regNum) { 224 _LIBUNWIND_TRACE_API("__unw_is_fpreg(cursor=%p, regNum=%d)", 225 static_cast<void *>(cursor), regNum); 226 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 227 return co->validFloatReg(regNum); 228 } 229 _LIBUNWIND_WEAK_ALIAS(__unw_is_fpreg, unw_is_fpreg) 230 231 /// Checks if a register is a floating-point register. 232 _LIBUNWIND_HIDDEN const char *__unw_regname(unw_cursor_t *cursor, 233 unw_regnum_t regNum) { 234 _LIBUNWIND_TRACE_API("__unw_regname(cursor=%p, regNum=%d)", 235 static_cast<void *>(cursor), regNum); 236 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 237 return co->getRegisterName(regNum); 238 } 239 _LIBUNWIND_WEAK_ALIAS(__unw_regname, unw_regname) 240 241 /// Checks if current frame is signal trampoline. 242 _LIBUNWIND_HIDDEN int __unw_is_signal_frame(unw_cursor_t *cursor) { 243 _LIBUNWIND_TRACE_API("__unw_is_signal_frame(cursor=%p)", 244 static_cast<void *>(cursor)); 245 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 246 return co->isSignalFrame(); 247 } 248 _LIBUNWIND_WEAK_ALIAS(__unw_is_signal_frame, unw_is_signal_frame) 249 250 #ifdef __arm__ 251 // Save VFP registers d0-d15 using FSTMIADX instead of FSTMIADD 252 _LIBUNWIND_HIDDEN void __unw_save_vfp_as_X(unw_cursor_t *cursor) { 253 _LIBUNWIND_TRACE_API("__unw_get_fpreg_save_vfp_as_X(cursor=%p)", 254 static_cast<void *>(cursor)); 255 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 256 return co->saveVFPAsX(); 257 } 258 _LIBUNWIND_WEAK_ALIAS(__unw_save_vfp_as_X, unw_save_vfp_as_X) 259 #endif 260 261 262 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 263 /// SPI: walks cached DWARF entries 264 _LIBUNWIND_HIDDEN void __unw_iterate_dwarf_unwind_cache(void (*func)( 265 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 266 _LIBUNWIND_TRACE_API("__unw_iterate_dwarf_unwind_cache(func=%p)", 267 reinterpret_cast<void *>(func)); 268 DwarfFDECache<LocalAddressSpace>::iterateCacheEntries(func); 269 } 270 _LIBUNWIND_WEAK_ALIAS(__unw_iterate_dwarf_unwind_cache, 271 unw_iterate_dwarf_unwind_cache) 272 273 /// IPI: for __register_frame() 274 void __unw_add_dynamic_fde(unw_word_t fde) { 275 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 276 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 277 const char *message = CFI_Parser<LocalAddressSpace>::decodeFDE( 278 LocalAddressSpace::sThisAddressSpace, 279 (LocalAddressSpace::pint_t) fde, &fdeInfo, &cieInfo); 280 if (message == NULL) { 281 // dynamically registered FDEs don't have a mach_header group they are in. 282 // Use fde as mh_group 283 unw_word_t mh_group = fdeInfo.fdeStart; 284 DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group, 285 fdeInfo.pcStart, fdeInfo.pcEnd, 286 fdeInfo.fdeStart); 287 } else { 288 _LIBUNWIND_DEBUG_LOG("__unw_add_dynamic_fde: bad fde: %s", message); 289 } 290 } 291 292 /// IPI: for __deregister_frame() 293 void __unw_remove_dynamic_fde(unw_word_t fde) { 294 // fde is own mh_group 295 DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde); 296 } 297 298 void __unw_add_dynamic_eh_frame_section(unw_word_t eh_frame_start) { 299 // The eh_frame section start serves as the mh_group 300 unw_word_t mh_group = eh_frame_start; 301 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 302 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 303 auto p = (LocalAddressSpace::pint_t)eh_frame_start; 304 while (true) { 305 if (CFI_Parser<LocalAddressSpace>::decodeFDE( 306 LocalAddressSpace::sThisAddressSpace, p, &fdeInfo, &cieInfo, 307 true) == NULL) { 308 DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group, 309 fdeInfo.pcStart, fdeInfo.pcEnd, 310 fdeInfo.fdeStart); 311 p += fdeInfo.fdeLength; 312 } else if (CFI_Parser<LocalAddressSpace>::parseCIE( 313 LocalAddressSpace::sThisAddressSpace, p, &cieInfo) == NULL) { 314 p += cieInfo.cieLength; 315 } else 316 return; 317 } 318 } 319 320 void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start) { 321 // The eh_frame section start serves as the mh_group 322 DwarfFDECache<LocalAddressSpace>::removeAllIn( 323 (LocalAddressSpace::pint_t)eh_frame_start); 324 } 325 326 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 327 #endif // !defined(__USING_SJLJ_EXCEPTIONS__) 328 329 330 331 // Add logging hooks in Debug builds only 332 #ifndef NDEBUG 333 #include <stdlib.h> 334 335 _LIBUNWIND_HIDDEN 336 bool logAPIs() { 337 // do manual lock to avoid use of _cxa_guard_acquire or initializers 338 static bool checked = false; 339 static bool log = false; 340 if (!checked) { 341 log = (getenv("LIBUNWIND_PRINT_APIS") != NULL); 342 checked = true; 343 } 344 return log; 345 } 346 347 _LIBUNWIND_HIDDEN 348 bool logUnwinding() { 349 // do manual lock to avoid use of _cxa_guard_acquire or initializers 350 static bool checked = false; 351 static bool log = false; 352 if (!checked) { 353 log = (getenv("LIBUNWIND_PRINT_UNWINDING") != NULL); 354 checked = true; 355 } 356 return log; 357 } 358 359 _LIBUNWIND_HIDDEN 360 bool logDWARF() { 361 // do manual lock to avoid use of _cxa_guard_acquire or initializers 362 static bool checked = false; 363 static bool log = false; 364 if (!checked) { 365 log = (getenv("LIBUNWIND_PRINT_DWARF") != NULL); 366 checked = true; 367 } 368 return log; 369 } 370 371 #endif // NDEBUG 372 373