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