src/Unwind_AppleExtras.cpp

   1 //===--------------------- Unwind_AppleExtras.cpp -------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //
   9 //===----------------------------------------------------------------------===//
  10
  11 #include "config.h"
  12 #include "AddressSpace.hpp"
  13 #include "DwarfParser.hpp"
  14
  15
  16 // private keymgr stuff
  17 #define KEYMGR_GCC3_DW2_OBJ_LIST 302
  18 extern "C" {
  19  extern void _keymgr_set_and_unlock_processwide_ptr(int key, void *ptr);
  20  extern void *_keymgr_get_and_lock_processwide_ptr(int key);
  21 }
  22
  23 // undocumented libgcc "struct object"
  24 struct libgcc_object {
  25   void          *start;
  26   void          *unused1;
  27   void          *unused2;
  28   void          *fde;
  29   unsigned long  encoding;
  30   void          *fde_end;
  31   libgcc_object *next;
  32 };
  33
  34 // undocumented libgcc "struct km_object_info" referenced by
  35 // KEYMGR_GCC3_DW2_OBJ_LIST
  36 struct libgcc_object_info {
  37   libgcc_object   *seen_objects;
  38   libgcc_object   *unseen_objects;
  39   unsigned         spare[2];
  40 };
  41
  42
  43 // static linker symbols to prevent wrong two level namespace for _Unwind symbols
  44 #if defined(__arm__)
  45    #define NOT_HERE_BEFORE_5_0(sym)     \
  46        extern const char sym##_tmp30 __asm("$ld$hide$os3.0$_" #sym ); \
  47        __attribute__((visibility("default"))) const char sym##_tmp30 = 0; \
  48        extern const char sym##_tmp31 __asm("$ld$hide$os3.1$_" #sym ); \
  49           __attribute__((visibility("default"))) const char sym##_tmp31 = 0; \
  50        extern const char sym##_tmp32 __asm("$ld$hide$os3.2$_" #sym );\
  51            __attribute__((visibility("default"))) const char sym##_tmp32 = 0; \
  52        extern const char sym##_tmp40 __asm("$ld$hide$os4.0$_" #sym ); \
  53           __attribute__((visibility("default"))) const char sym##_tmp40 = 0; \
  54        extern const char sym##_tmp41 __asm("$ld$hide$os4.1$_" #sym ); \
  55           __attribute__((visibility("default"))) const char sym##_tmp41 = 0; \
  56        extern const char sym##_tmp42 __asm("$ld$hide$os4.2$_" #sym ); \
  57           __attribute__((visibility("default"))) const char sym##_tmp42 = 0; \
  58        extern const char sym##_tmp43 __asm("$ld$hide$os4.3$_" #sym ); \
  59           __attribute__((visibility("default"))) const char sym##_tmp43 = 0;
  60 #elif defined(__arm64__)
  61   #define NOT_HERE_BEFORE_10_6(sym)
  62   #define NEVER_HERE(sym)
  63 #else
  64   #define NOT_HERE_BEFORE_10_6(sym) \
  65     extern const char sym##_tmp4 __asm("$ld$hide$os10.4$_" #sym ); \
  66           __attribute__((visibility("default"))) const char sym##_tmp4 = 0; \
  67     extern const char sym##_tmp5 __asm("$ld$hide$os10.5$_" #sym ); \
  68           __attribute__((visibility("default"))) const char sym##_tmp5 = 0;
  69   #define NEVER_HERE(sym) \
  70     extern const char sym##_tmp4 __asm("$ld$hide$os10.4$_" #sym ); \
  71           __attribute__((visibility("default"))) const char sym##_tmp4 = 0; \
  72     extern const char sym##_tmp5 __asm("$ld$hide$os10.5$_" #sym ); \
  73           __attribute__((visibility("default"))) const char sym##_tmp5 = 0; \
  74     extern const char sym##_tmp6 __asm("$ld$hide$os10.6$_" #sym ); \
  75           __attribute__((visibility("default"))) const char sym##_tmp6 = 0;
  76 #endif
  77
  78
  79 #if defined(_LIBUNWIND_BUILD_ZERO_COST_APIS)
  80
  81 //
  82 // symbols in libSystem.dylib in 10.6 and later, but are in libgcc_s.dylib in
  83 // earlier versions
  84 //
  85 NOT_HERE_BEFORE_10_6(_Unwind_DeleteException)
  86 NOT_HERE_BEFORE_10_6(_Unwind_Find_FDE)
  87 NOT_HERE_BEFORE_10_6(_Unwind_ForcedUnwind)
  88 NOT_HERE_BEFORE_10_6(_Unwind_GetGR)
  89 NOT_HERE_BEFORE_10_6(_Unwind_GetIP)
  90 NOT_HERE_BEFORE_10_6(_Unwind_GetLanguageSpecificData)
  91 NOT_HERE_BEFORE_10_6(_Unwind_GetRegionStart)
  92 NOT_HERE_BEFORE_10_6(_Unwind_RaiseException)
  93 NOT_HERE_BEFORE_10_6(_Unwind_Resume)
  94 NOT_HERE_BEFORE_10_6(_Unwind_SetGR)
  95 NOT_HERE_BEFORE_10_6(_Unwind_SetIP)
  96 NOT_HERE_BEFORE_10_6(_Unwind_Backtrace)
  97 NOT_HERE_BEFORE_10_6(_Unwind_FindEnclosingFunction)
  98 NOT_HERE_BEFORE_10_6(_Unwind_GetCFA)
  99 NOT_HERE_BEFORE_10_6(_Unwind_GetDataRelBase)
 100 NOT_HERE_BEFORE_10_6(_Unwind_GetTextRelBase)
 101 NOT_HERE_BEFORE_10_6(_Unwind_Resume_or_Rethrow)
 102 NOT_HERE_BEFORE_10_6(_Unwind_GetIPInfo)
 103 NOT_HERE_BEFORE_10_6(__register_frame)
 104 NOT_HERE_BEFORE_10_6(__deregister_frame)
 105
 106 //
 107 // symbols in libSystem.dylib for compatibility, but we don't want any new code
 108 // using them
 109 //
 110 NEVER_HERE(__register_frame_info_bases)
 111 NEVER_HERE(__register_frame_info)
 112 NEVER_HERE(__register_frame_info_table_bases)
 113 NEVER_HERE(__register_frame_info_table)
 114 NEVER_HERE(__register_frame_table)
 115 NEVER_HERE(__deregister_frame_info)
 116 NEVER_HERE(__deregister_frame_info_bases)
 117
 118 #endif // defined(_LIBUNWIND_BUILD_ZERO_COST_APIS)
 119
 120
 121
 122
 123 #if defined(_LIBUNWIND_BUILD_SJLJ_APIS)
 124 //
 125 // symbols in libSystem.dylib in iOS 5.0 and later, but are in libgcc_s.dylib in
 126 // earlier versions
 127 //
 128 NOT_HERE_BEFORE_5_0(_Unwind_GetLanguageSpecificData)
 129 NOT_HERE_BEFORE_5_0(_Unwind_GetRegionStart)
 130 NOT_HERE_BEFORE_5_0(_Unwind_GetIP)
 131 NOT_HERE_BEFORE_5_0(_Unwind_SetGR)
 132 NOT_HERE_BEFORE_5_0(_Unwind_SetIP)
 133 NOT_HERE_BEFORE_5_0(_Unwind_DeleteException)
 134 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Register)
 135 NOT_HERE_BEFORE_5_0(_Unwind_GetGR)
 136 NOT_HERE_BEFORE_5_0(_Unwind_GetIPInfo)
 137 NOT_HERE_BEFORE_5_0(_Unwind_GetCFA)
 138 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Resume)
 139 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_RaiseException)
 140 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Resume_or_Rethrow)
 141 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Unregister)
 142
 143 #endif // defined(_LIBUNWIND_BUILD_SJLJ_APIS)
 144
 145
 146 namespace libunwind {
 147
 148 _LIBUNWIND_HIDDEN
 149 bool checkKeyMgrRegisteredFDEs(uintptr_t pc, void *&fde) {
 150 #if __MAC_OS_X_VERSION_MIN_REQUIRED
 151   // lastly check for old style keymgr registration of dynamically generated
 152   // FDEs acquire exclusive access to libgcc_object_info
 153   libgcc_object_info *head = (libgcc_object_info *)
 154                 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
 155   if (head != NULL) {
 156     // look at each FDE in keymgr
 157     for (libgcc_object *ob = head->unseen_objects; ob != NULL; ob = ob->next) {
 158       CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
 159       CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
 160       const char *msg = CFI_Parser<LocalAddressSpace>::decodeFDE(
 161                                       LocalAddressSpace::sThisAddressSpace,
 162                                       (uintptr_t)ob->fde, &fdeInfo, &cieInfo);
 163       if (msg == NULL) {
 164         // Check if this FDE is for a function that includes the pc
 165         if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) {
 166           fde = (void*)fdeInfo.pcStart;
 167           _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
 168                                                  head);
 169           return true;
 170         }
 171       }
 172     }
 173   }
 174   // release libgcc_object_info
 175   _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, head);
 176 #else
 177   (void)pc;
 178   (void)fde;
 179 #endif
 180   return false;
 181 }
 182
 183 }
 184