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