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__) && !defined(__USING_WASM_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 #elif defined(__s390x__) 79 # define REGISTER_KIND Registers_s390x 80 #elif defined(__loongarch__) && __loongarch_grlen == 64 81 #define REGISTER_KIND Registers_loongarch 82 #else 83 # error Architecture not supported 84 #endif 85 // Use "placement new" to allocate UnwindCursor in the cursor buffer. 86 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, REGISTER_KIND> *>(cursor)) 87 UnwindCursor<LocalAddressSpace, REGISTER_KIND>( 88 context, LocalAddressSpace::sThisAddressSpace); 89 #undef REGISTER_KIND 90 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 91 co->setInfoBasedOnIPRegister(); 92 93 return UNW_ESUCCESS; 94 } 95 _LIBUNWIND_WEAK_ALIAS(__unw_init_local, unw_init_local) 96 97 /// Get value of specified register at cursor position in stack frame. 98 _LIBUNWIND_HIDDEN int __unw_get_reg(unw_cursor_t *cursor, unw_regnum_t regNum, 99 unw_word_t *value) { 100 _LIBUNWIND_TRACE_API("__unw_get_reg(cursor=%p, regNum=%d, &value=%p)", 101 static_cast<void *>(cursor), regNum, 102 static_cast<void *>(value)); 103 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 104 if (co->validReg(regNum)) { 105 *value = co->getReg(regNum); 106 return UNW_ESUCCESS; 107 } 108 return UNW_EBADREG; 109 } 110 _LIBUNWIND_WEAK_ALIAS(__unw_get_reg, unw_get_reg) 111 112 /// Set value of specified register at cursor position in stack frame. 113 _LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum, 114 unw_word_t value) { 115 _LIBUNWIND_TRACE_API("__unw_set_reg(cursor=%p, regNum=%d, value=0x%" PRIxPTR 116 ")", 117 static_cast<void *>(cursor), regNum, value); 118 typedef LocalAddressSpace::pint_t pint_t; 119 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 120 if (co->validReg(regNum)) { 121 co->setReg(regNum, (pint_t)value); 122 // special case altering IP to re-find info (being called by personality 123 // function) 124 if (regNum == UNW_REG_IP) { 125 unw_proc_info_t info; 126 // First, get the FDE for the old location and then update it. 127 co->getInfo(&info); 128 co->setInfoBasedOnIPRegister(false); 129 // If the original call expects stack adjustment, perform this now. 130 // Normal frame unwinding would have included the offset already in the 131 // CFA computation. 132 // Note: for PA-RISC and other platforms where the stack grows up, 133 // this should actually be - info.gp. LLVM doesn't currently support 134 // any such platforms and Clang doesn't export a macro for them. 135 if (info.gp) 136 co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + info.gp); 137 } 138 return UNW_ESUCCESS; 139 } 140 return UNW_EBADREG; 141 } 142 _LIBUNWIND_WEAK_ALIAS(__unw_set_reg, unw_set_reg) 143 144 /// Get value of specified float register at cursor position in stack frame. 145 _LIBUNWIND_HIDDEN int __unw_get_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum, 146 unw_fpreg_t *value) { 147 _LIBUNWIND_TRACE_API("__unw_get_fpreg(cursor=%p, regNum=%d, &value=%p)", 148 static_cast<void *>(cursor), regNum, 149 static_cast<void *>(value)); 150 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 151 if (co->validFloatReg(regNum)) { 152 *value = co->getFloatReg(regNum); 153 return UNW_ESUCCESS; 154 } 155 return UNW_EBADREG; 156 } 157 _LIBUNWIND_WEAK_ALIAS(__unw_get_fpreg, unw_get_fpreg) 158 159 /// Set value of specified float register at cursor position in stack frame. 160 _LIBUNWIND_HIDDEN int __unw_set_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum, 161 unw_fpreg_t value) { 162 #if defined(_LIBUNWIND_ARM_EHABI) 163 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%llX)", 164 static_cast<void *>(cursor), regNum, value); 165 #else 166 _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%g)", 167 static_cast<void *>(cursor), regNum, value); 168 #endif 169 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 170 if (co->validFloatReg(regNum)) { 171 co->setFloatReg(regNum, value); 172 return UNW_ESUCCESS; 173 } 174 return UNW_EBADREG; 175 } 176 _LIBUNWIND_WEAK_ALIAS(__unw_set_fpreg, unw_set_fpreg) 177 178 /// Move cursor to next frame. 179 _LIBUNWIND_HIDDEN int __unw_step(unw_cursor_t *cursor) { 180 _LIBUNWIND_TRACE_API("__unw_step(cursor=%p)", static_cast<void *>(cursor)); 181 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 182 return co->step(); 183 } 184 _LIBUNWIND_WEAK_ALIAS(__unw_step, unw_step) 185 186 // Move cursor to next frame and for stage2 of unwinding. 187 // This resets MTE tags of tagged frames to zero. 188 extern "C" _LIBUNWIND_HIDDEN int __unw_step_stage2(unw_cursor_t *cursor) { 189 _LIBUNWIND_TRACE_API("__unw_step_stage2(cursor=%p)", 190 static_cast<void *>(cursor)); 191 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 192 return co->step(true); 193 } 194 195 /// Get unwind info at cursor position in stack frame. 196 _LIBUNWIND_HIDDEN int __unw_get_proc_info(unw_cursor_t *cursor, 197 unw_proc_info_t *info) { 198 _LIBUNWIND_TRACE_API("__unw_get_proc_info(cursor=%p, &info=%p)", 199 static_cast<void *>(cursor), static_cast<void *>(info)); 200 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 201 co->getInfo(info); 202 if (info->end_ip == 0) 203 return UNW_ENOINFO; 204 return UNW_ESUCCESS; 205 } 206 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_info, unw_get_proc_info) 207 208 /// Resume execution at cursor position (aka longjump). 209 _LIBUNWIND_HIDDEN int __unw_resume(unw_cursor_t *cursor) { 210 _LIBUNWIND_TRACE_API("__unw_resume(cursor=%p)", static_cast<void *>(cursor)); 211 #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__) 212 // Inform the ASan runtime that now might be a good time to clean stuff up. 213 __asan_handle_no_return(); 214 #endif 215 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 216 co->jumpto(); 217 return UNW_EUNSPEC; 218 } 219 _LIBUNWIND_WEAK_ALIAS(__unw_resume, unw_resume) 220 221 /// Get name of function at cursor position in stack frame. 222 _LIBUNWIND_HIDDEN int __unw_get_proc_name(unw_cursor_t *cursor, char *buf, 223 size_t bufLen, unw_word_t *offset) { 224 _LIBUNWIND_TRACE_API("__unw_get_proc_name(cursor=%p, &buf=%p, bufLen=%lu)", 225 static_cast<void *>(cursor), static_cast<void *>(buf), 226 static_cast<unsigned long>(bufLen)); 227 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 228 if (co->getFunctionName(buf, bufLen, offset)) 229 return UNW_ESUCCESS; 230 return UNW_EUNSPEC; 231 } 232 _LIBUNWIND_WEAK_ALIAS(__unw_get_proc_name, unw_get_proc_name) 233 234 /// Checks if a register is a floating-point register. 235 _LIBUNWIND_HIDDEN int __unw_is_fpreg(unw_cursor_t *cursor, 236 unw_regnum_t regNum) { 237 _LIBUNWIND_TRACE_API("__unw_is_fpreg(cursor=%p, regNum=%d)", 238 static_cast<void *>(cursor), regNum); 239 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 240 return co->validFloatReg(regNum); 241 } 242 _LIBUNWIND_WEAK_ALIAS(__unw_is_fpreg, unw_is_fpreg) 243 244 /// Checks if a register is a floating-point register. 245 _LIBUNWIND_HIDDEN const char *__unw_regname(unw_cursor_t *cursor, 246 unw_regnum_t regNum) { 247 _LIBUNWIND_TRACE_API("__unw_regname(cursor=%p, regNum=%d)", 248 static_cast<void *>(cursor), regNum); 249 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 250 return co->getRegisterName(regNum); 251 } 252 _LIBUNWIND_WEAK_ALIAS(__unw_regname, unw_regname) 253 254 /// Checks if current frame is signal trampoline. 255 _LIBUNWIND_HIDDEN int __unw_is_signal_frame(unw_cursor_t *cursor) { 256 _LIBUNWIND_TRACE_API("__unw_is_signal_frame(cursor=%p)", 257 static_cast<void *>(cursor)); 258 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 259 return co->isSignalFrame(); 260 } 261 _LIBUNWIND_WEAK_ALIAS(__unw_is_signal_frame, unw_is_signal_frame) 262 263 #ifdef _AIX 264 _LIBUNWIND_EXPORT uintptr_t __unw_get_data_rel_base(unw_cursor_t *cursor) { 265 _LIBUNWIND_TRACE_API("unw_get_data_rel_base(cursor=%p)", 266 static_cast<void *>(cursor)); 267 AbstractUnwindCursor *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); 268 return co->getDataRelBase(); 269 } 270 _LIBUNWIND_WEAK_ALIAS(__unw_get_data_rel_base, unw_get_data_rel_base) 271 #endif 272 273 #ifdef __arm__ 274 // Save VFP registers d0-d15 using FSTMIADX instead of FSTMIADD 275 _LIBUNWIND_HIDDEN void __unw_save_vfp_as_X(unw_cursor_t *cursor) { 276 _LIBUNWIND_TRACE_API("__unw_get_fpreg_save_vfp_as_X(cursor=%p)", 277 static_cast<void *>(cursor)); 278 AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor; 279 return co->saveVFPAsX(); 280 } 281 _LIBUNWIND_WEAK_ALIAS(__unw_save_vfp_as_X, unw_save_vfp_as_X) 282 #endif 283 284 285 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 286 /// SPI: walks cached DWARF entries 287 _LIBUNWIND_HIDDEN void __unw_iterate_dwarf_unwind_cache(void (*func)( 288 unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) { 289 _LIBUNWIND_TRACE_API("__unw_iterate_dwarf_unwind_cache(func=%p)", 290 reinterpret_cast<void *>(func)); 291 DwarfFDECache<LocalAddressSpace>::iterateCacheEntries(func); 292 } 293 _LIBUNWIND_WEAK_ALIAS(__unw_iterate_dwarf_unwind_cache, 294 unw_iterate_dwarf_unwind_cache) 295 296 /// IPI: for __register_frame() 297 void __unw_add_dynamic_fde(unw_word_t fde) { 298 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 299 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 300 const char *message = CFI_Parser<LocalAddressSpace>::decodeFDE( 301 LocalAddressSpace::sThisAddressSpace, 302 (LocalAddressSpace::pint_t) fde, &fdeInfo, &cieInfo); 303 if (message == NULL) { 304 // dynamically registered FDEs don't have a mach_header group they are in. 305 // Use fde as mh_group 306 unw_word_t mh_group = fdeInfo.fdeStart; 307 DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group, 308 fdeInfo.pcStart, fdeInfo.pcEnd, 309 fdeInfo.fdeStart); 310 } else { 311 _LIBUNWIND_DEBUG_LOG("__unw_add_dynamic_fde: bad fde: %s", message); 312 } 313 } 314 315 /// IPI: for __deregister_frame() 316 void __unw_remove_dynamic_fde(unw_word_t fde) { 317 // fde is own mh_group 318 DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde); 319 } 320 321 void __unw_add_dynamic_eh_frame_section(unw_word_t eh_frame_start) { 322 // The eh_frame section start serves as the mh_group 323 unw_word_t mh_group = eh_frame_start; 324 CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo; 325 CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo; 326 auto p = (LocalAddressSpace::pint_t)eh_frame_start; 327 while (LocalAddressSpace::sThisAddressSpace.get32(p)) { 328 if (CFI_Parser<LocalAddressSpace>::decodeFDE( 329 LocalAddressSpace::sThisAddressSpace, p, &fdeInfo, &cieInfo, 330 true) == NULL) { 331 DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group, 332 fdeInfo.pcStart, fdeInfo.pcEnd, 333 fdeInfo.fdeStart); 334 p += fdeInfo.fdeLength; 335 } else if (CFI_Parser<LocalAddressSpace>::parseCIE( 336 LocalAddressSpace::sThisAddressSpace, p, &cieInfo) == NULL) { 337 p += cieInfo.cieLength; 338 } else 339 return; 340 } 341 } 342 343 void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start) { 344 // The eh_frame section start serves as the mh_group 345 DwarfFDECache<LocalAddressSpace>::removeAllIn( 346 (LocalAddressSpace::pint_t)eh_frame_start); 347 } 348 349 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND) 350 #endif // !defined(__USING_SJLJ_EXCEPTIONS__) && 351 // !defined(__USING_WASM_EXCEPTIONS__) 352 353 #ifdef __APPLE__ 354 355 namespace libunwind { 356 357 static constexpr size_t MAX_DYNAMIC_UNWIND_SECTIONS_FINDERS = 8; 358 359 static RWMutex findDynamicUnwindSectionsLock; 360 static size_t numDynamicUnwindSectionsFinders = 0; 361 static unw_find_dynamic_unwind_sections 362 dynamicUnwindSectionsFinders[MAX_DYNAMIC_UNWIND_SECTIONS_FINDERS] = {0}; 363 364 bool findDynamicUnwindSections(void *addr, unw_dynamic_unwind_sections *info) { 365 bool found = false; 366 findDynamicUnwindSectionsLock.lock_shared(); 367 for (size_t i = 0; i != numDynamicUnwindSectionsFinders; ++i) { 368 if (dynamicUnwindSectionsFinders[i]((unw_word_t)addr, info)) { 369 found = true; 370 break; 371 } 372 } 373 findDynamicUnwindSectionsLock.unlock_shared(); 374 return found; 375 } 376 377 } // namespace libunwind 378 379 int __unw_add_find_dynamic_unwind_sections( 380 unw_find_dynamic_unwind_sections find_dynamic_unwind_sections) { 381 findDynamicUnwindSectionsLock.lock(); 382 383 // Check that we have enough space... 384 if (numDynamicUnwindSectionsFinders == MAX_DYNAMIC_UNWIND_SECTIONS_FINDERS) { 385 findDynamicUnwindSectionsLock.unlock(); 386 return UNW_ENOMEM; 387 } 388 389 // Check for value already present... 390 for (size_t i = 0; i != numDynamicUnwindSectionsFinders; ++i) { 391 if (dynamicUnwindSectionsFinders[i] == find_dynamic_unwind_sections) { 392 findDynamicUnwindSectionsLock.unlock(); 393 return UNW_EINVAL; 394 } 395 } 396 397 // Success -- add callback entry. 398 dynamicUnwindSectionsFinders[numDynamicUnwindSectionsFinders++] = 399 find_dynamic_unwind_sections; 400 findDynamicUnwindSectionsLock.unlock(); 401 402 return UNW_ESUCCESS; 403 } 404 405 int __unw_remove_find_dynamic_unwind_sections( 406 unw_find_dynamic_unwind_sections find_dynamic_unwind_sections) { 407 findDynamicUnwindSectionsLock.lock(); 408 409 // Find index to remove. 410 size_t finderIdx = numDynamicUnwindSectionsFinders; 411 for (size_t i = 0; i != numDynamicUnwindSectionsFinders; ++i) { 412 if (dynamicUnwindSectionsFinders[i] == find_dynamic_unwind_sections) { 413 finderIdx = i; 414 break; 415 } 416 } 417 418 // If no such registration is present then error out. 419 if (finderIdx == numDynamicUnwindSectionsFinders) { 420 findDynamicUnwindSectionsLock.unlock(); 421 return UNW_EINVAL; 422 } 423 424 // Remove entry. 425 for (size_t i = finderIdx; i != numDynamicUnwindSectionsFinders - 1; ++i) 426 dynamicUnwindSectionsFinders[i] = dynamicUnwindSectionsFinders[i + 1]; 427 dynamicUnwindSectionsFinders[--numDynamicUnwindSectionsFinders] = nullptr; 428 429 findDynamicUnwindSectionsLock.unlock(); 430 return UNW_ESUCCESS; 431 } 432 433 #endif // __APPLE__ 434 435 // Add logging hooks in Debug builds only 436 #ifndef NDEBUG 437 #include <stdlib.h> 438 439 _LIBUNWIND_HIDDEN 440 bool logAPIs() { 441 // do manual lock to avoid use of _cxa_guard_acquire or initializers 442 static bool checked = false; 443 static bool log = false; 444 if (!checked) { 445 log = (getenv("LIBUNWIND_PRINT_APIS") != NULL); 446 checked = true; 447 } 448 return log; 449 } 450 451 _LIBUNWIND_HIDDEN 452 bool logUnwinding() { 453 // do manual lock to avoid use of _cxa_guard_acquire or initializers 454 static bool checked = false; 455 static bool log = false; 456 if (!checked) { 457 log = (getenv("LIBUNWIND_PRINT_UNWINDING") != NULL); 458 checked = true; 459 } 460 return log; 461 } 462 463 _LIBUNWIND_HIDDEN 464 bool logDWARF() { 465 // do manual lock to avoid use of _cxa_guard_acquire or initializers 466 static bool checked = false; 467 static bool log = false; 468 if (!checked) { 469 log = (getenv("LIBUNWIND_PRINT_DWARF") != NULL); 470 checked = true; 471 } 472 return log; 473 } 474 475 #endif // NDEBUG 476 477