1 /* 2 * Copyright 2012 David Chisnall. All rights reserved. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a copy 5 * of this software and associated documentation files (the "Software"), to 6 * deal in the Software without restriction, including without limitation the 7 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 8 * sell copies of the Software, and to permit persons to whom the Software is 9 * furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be 12 * included in all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 15 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 17 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 18 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 19 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 20 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 21 */ 22 23 /** 24 * ARM-specific unwind definitions. These are taken from the ARM EHABI 25 * specification. 26 */ 27 typedef enum 28 { 29 _URC_OK = 0, /* operation completed successfully */ 30 _URC_FOREIGN_EXCEPTION_CAUGHT = 1, 31 _URC_END_OF_STACK = 5, 32 _URC_HANDLER_FOUND = 6, 33 _URC_INSTALL_CONTEXT = 7, 34 _URC_CONTINUE_UNWIND = 8, 35 _URC_FAILURE = 9, /* unspecified failure of some kind */ 36 _URC_FATAL_PHASE1_ERROR = _URC_FAILURE 37 } _Unwind_Reason_Code; 38 39 typedef uint32_t _Unwind_State; 40 #ifdef __clang__ 41 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0; 42 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1; 43 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2; 44 #else // GCC fails at knowing what a constant expression is 45 # define _US_VIRTUAL_UNWIND_FRAME 0 46 # define _US_UNWIND_FRAME_STARTING 1 47 # define _US_UNWIND_FRAME_RESUME 2 48 #endif 49 50 typedef struct _Unwind_Context _Unwind_Context; 51 52 typedef uint32_t _Unwind_EHT_Header; 53 54 struct _Unwind_Exception 55 { 56 uint64_t exception_class; 57 void (*exception_cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception *); 58 /* Unwinder cache, private fields for the unwinder's use */ 59 struct 60 { 61 uint32_t reserved1; 62 uint32_t reserved2; 63 uint32_t reserved3; 64 uint32_t reserved4; 65 uint32_t reserved5; 66 /* init reserved1 to 0, then don't touch */ 67 } unwinder_cache; 68 /* Propagation barrier cache (valid after phase 1): */ 69 struct 70 { 71 uint32_t sp; 72 uint32_t bitpattern[5]; 73 } barrier_cache; 74 /* Cleanup cache (preserved over cleanup): */ 75 struct 76 { 77 uint32_t bitpattern[4]; 78 } cleanup_cache; 79 /* Pr cache (for pr's benefit): */ 80 struct 81 { 82 /** function start address */ 83 uint32_t fnstart; 84 /** pointer to EHT entry header word */ 85 _Unwind_EHT_Header *ehtp; 86 /** additional data */ 87 uint32_t additional; 88 uint32_t reserved1; 89 } pr_cache; 90 /** Force alignment of next item to 8-byte boundary */ 91 long long int :0; 92 }; 93 94 /* Unwinding functions */ 95 _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *ucbp); 96 void _Unwind_Resume(struct _Unwind_Exception *ucbp); 97 void _Unwind_Complete(struct _Unwind_Exception *ucbp); 98 void _Unwind_DeleteException(struct _Unwind_Exception *ucbp); 99 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context*); 100 101 typedef enum 102 { 103 _UVRSR_OK = 0, 104 _UVRSR_NOT_IMPLEMENTED = 1, 105 _UVRSR_FAILED = 2 106 } _Unwind_VRS_Result; 107 typedef enum 108 { 109 _UVRSC_CORE = 0, 110 _UVRSC_VFP = 1, 111 _UVRSC_WMMXD = 3, 112 _UVRSC_WMMXC = 4 113 } _Unwind_VRS_RegClass; 114 typedef enum 115 { 116 _UVRSD_UINT32 = 0, 117 _UVRSD_VFPX = 1, 118 _UVRSD_UINT64 = 3, 119 _UVRSD_FLOAT = 4, 120 _UVRSD_DOUBLE = 5 121 } _Unwind_VRS_DataRepresentation; 122 123 _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context, 124 _Unwind_VRS_RegClass regclass, 125 uint32_t regno, 126 _Unwind_VRS_DataRepresentation representation, 127 void *valuep); 128 _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context, 129 _Unwind_VRS_RegClass regclass, 130 uint32_t regno, 131 _Unwind_VRS_DataRepresentation representation, 132 void *valuep); 133 134 /* Return the base-address for data references. */ 135 extern unsigned long _Unwind_GetDataRelBase(struct _Unwind_Context *); 136 137 /* Return the base-address for text references. */ 138 extern unsigned long _Unwind_GetTextRelBase(struct _Unwind_Context *); 139 extern unsigned long _Unwind_GetRegionStart(struct _Unwind_Context *); 140 141 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) (struct _Unwind_Context *, 142 void *); 143 extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *); 144 extern _Unwind_Reason_Code 145 _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *); 146 147 /** 148 * The next set of functions are compatibility extensions, implementing Itanium 149 * ABI functions on top of ARM ones. 150 */ 151 152 #define _UA_SEARCH_PHASE 1 153 #define _UA_CLEANUP_PHASE 2 154 #define _UA_HANDLER_FRAME 4 155 #define _UA_FORCE_UNWIND 8 156 157 static inline unsigned long _Unwind_GetGR(struct _Unwind_Context *context, int reg) 158 { 159 unsigned long val; 160 _Unwind_VRS_Get(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val); 161 return val; 162 } 163 static inline void _Unwind_SetGR(struct _Unwind_Context *context, int reg, unsigned long val) 164 { 165 _Unwind_VRS_Set(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val); 166 } 167 static inline unsigned long _Unwind_GetIP(_Unwind_Context *context) 168 { 169 // Low bit store the thumb state - discard it 170 return _Unwind_GetGR(context, 15) & ~1; 171 } 172 static inline void _Unwind_SetIP(_Unwind_Context *context, unsigned long val) 173 { 174 // The lowest bit of the instruction pointer indicates whether we're in 175 // thumb or ARM mode. This is assumed to be fixed throughout a function, 176 // so must be propagated when setting the program counter. 177 unsigned long thumbState = _Unwind_GetGR(context, 15) & 1; 178 _Unwind_SetGR(context, 15, (val | thumbState)); 179 } 180 181 /** GNU API function that unwinds the frame */ 182 _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*, struct _Unwind_Context*); 183 184 185 #define DECLARE_PERSONALITY_FUNCTION(name) \ 186 _Unwind_Reason_Code name(_Unwind_State state,\ 187 struct _Unwind_Exception *exceptionObject,\ 188 struct _Unwind_Context *context); 189 190 #define BEGIN_PERSONALITY_FUNCTION(name) \ 191 _Unwind_Reason_Code name(_Unwind_State state,\ 192 struct _Unwind_Exception *exceptionObject,\ 193 struct _Unwind_Context *context)\ 194 {\ 195 int version = 1;\ 196 uint64_t exceptionClass = exceptionObject->exception_class;\ 197 int actions;\ 198 switch (state)\ 199 {\ 200 default: return _URC_FAILURE;\ 201 case _US_VIRTUAL_UNWIND_FRAME:\ 202 {\ 203 actions = _UA_SEARCH_PHASE;\ 204 break;\ 205 }\ 206 case _US_UNWIND_FRAME_STARTING:\ 207 {\ 208 actions = _UA_CLEANUP_PHASE;\ 209 if (exceptionObject->barrier_cache.sp == _Unwind_GetGR(context, 13))\ 210 {\ 211 actions |= _UA_HANDLER_FRAME;\ 212 }\ 213 break;\ 214 }\ 215 case _US_UNWIND_FRAME_RESUME:\ 216 {\ 217 return continueUnwinding(exceptionObject, context);\ 218 break;\ 219 }\ 220 }\ 221 _Unwind_SetGR (context, 12, (unsigned long)exceptionObject);\ 222 223 #define CALL_PERSONALITY_FUNCTION(name) name(state,exceptionObject,context) 224