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 "DwarfParser.hpp"
13 #include "unwind_ext.h"
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 _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 // _LIBUNWIND_BUILD_ZERO_COST_APIS
119 
120 
121 
122 
123 #if _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 // _LIBUNWIND_BUILD_SJLJ_APIS
144 
145 
146 namespace libunwind {
147 
148 _LIBUNWIND_HIDDEN
checkKeyMgrRegisteredFDEs(uintptr_t pc,void * & fde)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 
185 
186 #if !defined(FOR_DYLD) && _LIBUNWIND_BUILD_SJLJ_APIS
187 
188 #include <System/pthread_machdep.h>
189 
190 // Accessors to get get/set linked list of frames for sjlj based execeptions.
191 _LIBUNWIND_HIDDEN
__Unwind_SjLj_GetTopOfFunctionStack()192 struct _Unwind_FunctionContext *__Unwind_SjLj_GetTopOfFunctionStack() {
193   return (struct _Unwind_FunctionContext *)
194     _pthread_getspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key);
195 }
196 
197 _LIBUNWIND_HIDDEN
__Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext * fc)198 void __Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext *fc) {
199   _pthread_setspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key, fc);
200 }
201 #endif
202 
203 
204 
205 
206