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 /* For uint32_t and uint64_t */ 24 #include <stdint.h> 25 26 /** 27 * ARM-specific unwind definitions. These are taken from the ARM EHABI 28 * specification. 29 */ 30 typedef enum 31 { 32 _URC_NO_REASON = 0, 33 _URC_OK = 0, /* operation completed successfully */ 34 _URC_FOREIGN_EXCEPTION_CAUGHT = 1, 35 _URC_END_OF_STACK = 5, 36 _URC_HANDLER_FOUND = 6, 37 _URC_INSTALL_CONTEXT = 7, 38 _URC_CONTINUE_UNWIND = 8, 39 _URC_FAILURE = 9, /* unspecified failure of some kind */ 40 _URC_FATAL_PHASE1_ERROR = _URC_FAILURE 41 } _Unwind_Reason_Code; 42 43 typedef uint32_t _Unwind_State; 44 #ifdef __clang__ 45 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0; 46 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1; 47 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2; 48 static const _Unwind_State _US_ACTION_MASK = 3; 49 #else // GCC fails at knowing what a constant expression is 50 # define _US_VIRTUAL_UNWIND_FRAME 0 51 # define _US_UNWIND_FRAME_STARTING 1 52 # define _US_UNWIND_FRAME_RESUME 2 53 # define _US_ACTION_MASK 3 54 #endif 55 56 typedef struct _Unwind_Context _Unwind_Context; 57 58 typedef uint32_t _Unwind_EHT_Header; 59 60 struct _Unwind_Exception 61 { 62 uint64_t exception_class; 63 void (*exception_cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception *); 64 /* Unwinder cache, private fields for the unwinder's use */ 65 struct 66 { 67 uint32_t reserved1; 68 uint32_t reserved2; 69 uint32_t reserved3; 70 uint32_t reserved4; 71 uint32_t reserved5; 72 /* init reserved1 to 0, then don't touch */ 73 } unwinder_cache; 74 /* Propagation barrier cache (valid after phase 1): */ 75 struct 76 { 77 uint32_t sp; 78 uint32_t bitpattern[5]; 79 } barrier_cache; 80 /* Cleanup cache (preserved over cleanup): */ 81 struct 82 { 83 uint32_t bitpattern[4]; 84 } cleanup_cache; 85 /* Pr cache (for pr's benefit): */ 86 struct 87 { 88 /** function start address */ 89 uint32_t fnstart; 90 /** pointer to EHT entry header word */ 91 _Unwind_EHT_Header *ehtp; 92 /** additional data */ 93 uint32_t additional; 94 uint32_t reserved1; 95 } pr_cache; 96 /** Force alignment of next item to 8-byte boundary */ 97 long long int :0; 98 } __attribute__((__aligned__(8))); 99 100 /* Unwinding functions */ 101 _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *ucbp); 102 void _Unwind_Resume(struct _Unwind_Exception *ucbp); 103 void _Unwind_Complete(struct _Unwind_Exception *ucbp); 104 void _Unwind_DeleteException(struct _Unwind_Exception *ucbp); 105 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context*); 106 107 typedef enum 108 { 109 _UVRSR_OK = 0, 110 _UVRSR_NOT_IMPLEMENTED = 1, 111 _UVRSR_FAILED = 2 112 } _Unwind_VRS_Result; 113 typedef enum 114 { 115 _UVRSC_CORE = 0, 116 _UVRSC_VFP = 1, 117 _UVRSC_WMMXD = 3, 118 _UVRSC_WMMXC = 4 119 } _Unwind_VRS_RegClass; 120 typedef enum 121 { 122 _UVRSD_UINT32 = 0, 123 _UVRSD_VFPX = 1, 124 _UVRSD_UINT64 = 3, 125 _UVRSD_FLOAT = 4, 126 _UVRSD_DOUBLE = 5 127 } _Unwind_VRS_DataRepresentation; 128 129 _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context, 130 _Unwind_VRS_RegClass regclass, 131 uint32_t regno, 132 _Unwind_VRS_DataRepresentation representation, 133 void *valuep); 134 _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context, 135 _Unwind_VRS_RegClass regclass, 136 uint32_t regno, 137 _Unwind_VRS_DataRepresentation representation, 138 void *valuep); 139 140 /* Return the base-address for data references. */ 141 extern unsigned long _Unwind_GetDataRelBase(struct _Unwind_Context *); 142 143 /* Return the base-address for text references. */ 144 extern unsigned long _Unwind_GetTextRelBase(struct _Unwind_Context *); 145 extern unsigned long _Unwind_GetRegionStart(struct _Unwind_Context *); 146 147 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) (struct _Unwind_Context *, 148 void *); 149 extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *); 150 extern _Unwind_Reason_Code 151 _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *); 152 153 /** 154 * The next set of functions are compatibility extensions, implementing Itanium 155 * ABI functions on top of ARM ones. 156 */ 157 158 #define _UA_SEARCH_PHASE 1 159 #define _UA_CLEANUP_PHASE 2 160 #define _UA_HANDLER_FRAME 4 161 #define _UA_FORCE_UNWIND 8 162 163 static inline unsigned long _Unwind_GetGR(struct _Unwind_Context *context, int reg) 164 { 165 unsigned long val; 166 _Unwind_VRS_Get(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val); 167 return val; 168 } 169 static inline void _Unwind_SetGR(struct _Unwind_Context *context, int reg, unsigned long val) 170 { 171 _Unwind_VRS_Set(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val); 172 } 173 static inline unsigned long _Unwind_GetIP(_Unwind_Context *context) 174 { 175 // Low bit store the thumb state - discard it 176 return _Unwind_GetGR(context, 15) & ~1; 177 } 178 static inline void _Unwind_SetIP(_Unwind_Context *context, unsigned long val) 179 { 180 // The lowest bit of the instruction pointer indicates whether we're in 181 // thumb or ARM mode. This is assumed to be fixed throughout a function, 182 // so must be propagated when setting the program counter. 183 unsigned long thumbState = _Unwind_GetGR(context, 15) & 1; 184 _Unwind_SetGR(context, 15, (val | thumbState)); 185 } 186 187 /** GNU API function that unwinds the frame */ 188 _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*, struct _Unwind_Context*); 189 190 191 #define DECLARE_PERSONALITY_FUNCTION(name) \ 192 _Unwind_Reason_Code name(_Unwind_State state,\ 193 struct _Unwind_Exception *exceptionObject,\ 194 struct _Unwind_Context *context); 195 196 #define BEGIN_PERSONALITY_FUNCTION(name) \ 197 _Unwind_Reason_Code name(_Unwind_State state,\ 198 struct _Unwind_Exception *exceptionObject,\ 199 struct _Unwind_Context *context)\ 200 {\ 201 int version = 1;\ 202 uint64_t exceptionClass = exceptionObject->exception_class;\ 203 int actions;\ 204 switch (state)\ 205 {\ 206 default: return _URC_FAILURE;\ 207 case _US_VIRTUAL_UNWIND_FRAME:\ 208 {\ 209 actions = _UA_SEARCH_PHASE;\ 210 break;\ 211 }\ 212 case _US_UNWIND_FRAME_STARTING:\ 213 {\ 214 actions = _UA_CLEANUP_PHASE;\ 215 if (exceptionObject->barrier_cache.sp == _Unwind_GetGR(context, 13))\ 216 {\ 217 actions |= _UA_HANDLER_FRAME;\ 218 }\ 219 break;\ 220 }\ 221 case _US_UNWIND_FRAME_RESUME:\ 222 {\ 223 return continueUnwinding(exceptionObject, context);\ 224 break;\ 225 }\ 226 }\ 227 _Unwind_SetGR (context, 12, reinterpret_cast<unsigned long>(exceptionObject));\ 228 229 #define CALL_PERSONALITY_FUNCTION(name) name(state,exceptionObject,context) 230