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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 #include "unwind_ext.h"
15 
16 
17 // private keymgr stuff
18 #define KEYMGR_GCC3_DW2_OBJ_LIST 302
19 extern "C" {
20  extern void _keymgr_set_and_unlock_processwide_ptr(int key, void *ptr);
21  extern void *_keymgr_get_and_lock_processwide_ptr(int key);
22 }
23 
24 // undocumented libgcc "struct object"
25 struct libgcc_object {
26   void          *start;
27   void          *unused1;
28   void          *unused2;
29   void          *fde;
30   unsigned long  encoding;
31   void          *fde_end;
32   libgcc_object *next;
33 };
34 
35 // undocumented libgcc "struct km_object_info" referenced by
36 // KEYMGR_GCC3_DW2_OBJ_LIST
37 struct libgcc_object_info {
38   libgcc_object   *seen_objects;
39   libgcc_object   *unseen_objects;
40   unsigned         spare[2];
41 };
42 
43 
44 // static linker symbols to prevent wrong two level namespace for _Unwind symbols
45 #if defined(__arm__)
46    #define NOT_HERE_BEFORE_5_0(sym)     \
47        extern const char sym##_tmp30 __asm("$ld$hide$os3.0$_" #sym ); \
48        __attribute__((visibility("default"))) const char sym##_tmp30 = 0; \
49        extern const char sym##_tmp31 __asm("$ld$hide$os3.1$_" #sym ); \
50           __attribute__((visibility("default"))) const char sym##_tmp31 = 0; \
51        extern const char sym##_tmp32 __asm("$ld$hide$os3.2$_" #sym );\
52            __attribute__((visibility("default"))) const char sym##_tmp32 = 0; \
53        extern const char sym##_tmp40 __asm("$ld$hide$os4.0$_" #sym ); \
54           __attribute__((visibility("default"))) const char sym##_tmp40 = 0; \
55        extern const char sym##_tmp41 __asm("$ld$hide$os4.1$_" #sym ); \
56           __attribute__((visibility("default"))) const char sym##_tmp41 = 0; \
57        extern const char sym##_tmp42 __asm("$ld$hide$os4.2$_" #sym ); \
58           __attribute__((visibility("default"))) const char sym##_tmp42 = 0; \
59        extern const char sym##_tmp43 __asm("$ld$hide$os4.3$_" #sym ); \
60           __attribute__((visibility("default"))) const char sym##_tmp43 = 0;
61 #elif defined(__arm64__)
62   #define NOT_HERE_BEFORE_10_6(sym)
63   #define NEVER_HERE(sym)
64 #else
65   #define NOT_HERE_BEFORE_10_6(sym) \
66     extern const char sym##_tmp4 __asm("$ld$hide$os10.4$_" #sym ); \
67           __attribute__((visibility("default"))) const char sym##_tmp4 = 0; \
68     extern const char sym##_tmp5 __asm("$ld$hide$os10.5$_" #sym ); \
69           __attribute__((visibility("default"))) const char sym##_tmp5 = 0;
70   #define NEVER_HERE(sym) \
71     extern const char sym##_tmp4 __asm("$ld$hide$os10.4$_" #sym ); \
72           __attribute__((visibility("default"))) const char sym##_tmp4 = 0; \
73     extern const char sym##_tmp5 __asm("$ld$hide$os10.5$_" #sym ); \
74           __attribute__((visibility("default"))) const char sym##_tmp5 = 0; \
75     extern const char sym##_tmp6 __asm("$ld$hide$os10.6$_" #sym ); \
76           __attribute__((visibility("default"))) const char sym##_tmp6 = 0;
77 #endif
78 
79 
80 #if defined(_LIBUNWIND_BUILD_ZERO_COST_APIS)
81 
82 //
83 // symbols in libSystem.dylib in 10.6 and later, but are in libgcc_s.dylib in
84 // earlier versions
85 //
86 NOT_HERE_BEFORE_10_6(_Unwind_DeleteException)
87 NOT_HERE_BEFORE_10_6(_Unwind_Find_FDE)
88 NOT_HERE_BEFORE_10_6(_Unwind_ForcedUnwind)
89 NOT_HERE_BEFORE_10_6(_Unwind_GetGR)
90 NOT_HERE_BEFORE_10_6(_Unwind_GetIP)
91 NOT_HERE_BEFORE_10_6(_Unwind_GetLanguageSpecificData)
92 NOT_HERE_BEFORE_10_6(_Unwind_GetRegionStart)
93 NOT_HERE_BEFORE_10_6(_Unwind_RaiseException)
94 NOT_HERE_BEFORE_10_6(_Unwind_Resume)
95 NOT_HERE_BEFORE_10_6(_Unwind_SetGR)
96 NOT_HERE_BEFORE_10_6(_Unwind_SetIP)
97 NOT_HERE_BEFORE_10_6(_Unwind_Backtrace)
98 NOT_HERE_BEFORE_10_6(_Unwind_FindEnclosingFunction)
99 NOT_HERE_BEFORE_10_6(_Unwind_GetCFA)
100 NOT_HERE_BEFORE_10_6(_Unwind_GetDataRelBase)
101 NOT_HERE_BEFORE_10_6(_Unwind_GetTextRelBase)
102 NOT_HERE_BEFORE_10_6(_Unwind_Resume_or_Rethrow)
103 NOT_HERE_BEFORE_10_6(_Unwind_GetIPInfo)
104 NOT_HERE_BEFORE_10_6(__register_frame)
105 NOT_HERE_BEFORE_10_6(__deregister_frame)
106 
107 //
108 // symbols in libSystem.dylib for compatibility, but we don't want any new code
109 // using them
110 //
111 NEVER_HERE(__register_frame_info_bases)
112 NEVER_HERE(__register_frame_info)
113 NEVER_HERE(__register_frame_info_table_bases)
114 NEVER_HERE(__register_frame_info_table)
115 NEVER_HERE(__register_frame_table)
116 NEVER_HERE(__deregister_frame_info)
117 NEVER_HERE(__deregister_frame_info_bases)
118 
119 #endif // defined(_LIBUNWIND_BUILD_ZERO_COST_APIS)
120 
121 
122 
123 
124 #if defined(_LIBUNWIND_BUILD_SJLJ_APIS)
125 //
126 // symbols in libSystem.dylib in iOS 5.0 and later, but are in libgcc_s.dylib in
127 // earlier versions
128 //
129 NOT_HERE_BEFORE_5_0(_Unwind_GetLanguageSpecificData)
130 NOT_HERE_BEFORE_5_0(_Unwind_GetRegionStart)
131 NOT_HERE_BEFORE_5_0(_Unwind_GetIP)
132 NOT_HERE_BEFORE_5_0(_Unwind_SetGR)
133 NOT_HERE_BEFORE_5_0(_Unwind_SetIP)
134 NOT_HERE_BEFORE_5_0(_Unwind_DeleteException)
135 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Register)
136 NOT_HERE_BEFORE_5_0(_Unwind_GetGR)
137 NOT_HERE_BEFORE_5_0(_Unwind_GetIPInfo)
138 NOT_HERE_BEFORE_5_0(_Unwind_GetCFA)
139 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Resume)
140 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_RaiseException)
141 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Resume_or_Rethrow)
142 NOT_HERE_BEFORE_5_0(_Unwind_SjLj_Unregister)
143 
144 #endif // defined(_LIBUNWIND_BUILD_SJLJ_APIS)
145 
146 
147 namespace libunwind {
148 
149 _LIBUNWIND_HIDDEN
checkKeyMgrRegisteredFDEs(uintptr_t pc,void * & fde)150 bool checkKeyMgrRegisteredFDEs(uintptr_t pc, void *&fde) {
151 #if __MAC_OS_X_VERSION_MIN_REQUIRED
152   // lastly check for old style keymgr registration of dynamically generated
153   // FDEs acquire exclusive access to libgcc_object_info
154   libgcc_object_info *head = (libgcc_object_info *)
155                 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
156   if (head != NULL) {
157     // look at each FDE in keymgr
158     for (libgcc_object *ob = head->unseen_objects; ob != NULL; ob = ob->next) {
159       CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
160       CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
161       const char *msg = CFI_Parser<LocalAddressSpace>::decodeFDE(
162                                       LocalAddressSpace::sThisAddressSpace,
163                                       (uintptr_t)ob->fde, &fdeInfo, &cieInfo);
164       if (msg == NULL) {
165         // Check if this FDE is for a function that includes the pc
166         if ((fdeInfo.pcStart <= pc) && (pc < fdeInfo.pcEnd)) {
167           fde = (void*)fdeInfo.pcStart;
168           _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
169                                                  head);
170           return true;
171         }
172       }
173     }
174   }
175   // release libgcc_object_info
176   _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, head);
177 #else
178   (void)pc;
179   (void)fde;
180 #endif
181   return false;
182 }
183 
184 }
185 
186 
187 #if !defined(FOR_DYLD) && defined(_LIBUNWIND_BUILD_SJLJ_APIS)
188 
189 #ifndef _LIBUNWIND_HAS_NO_THREADS
190   #include <System/pthread_machdep.h>
191 #else
192   _Unwind_FunctionContext *fc_ = nullptr;
193 #endif
194 
195 // Accessors to get get/set linked list of frames for sjlj based execeptions.
196 _LIBUNWIND_HIDDEN
__Unwind_SjLj_GetTopOfFunctionStack()197 struct _Unwind_FunctionContext *__Unwind_SjLj_GetTopOfFunctionStack() {
198 #ifndef _LIBUNWIND_HAS_NO_THREADS
199   return (struct _Unwind_FunctionContext *)
200     _pthread_getspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key);
201 #else
202   return fc_;
203 #endif
204 }
205 
206 _LIBUNWIND_HIDDEN
__Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext * fc)207 void __Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext *fc) {
208 #ifndef _LIBUNWIND_HAS_NO_THREADS
209   _pthread_setspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key, fc);
210 #else
211   fc_ = fc;
212 #endif
213 }
214 #endif
215