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