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