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