libunwind/src/libunwind.cpp

   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