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 int _Unwind_Action;
44
45 typedef uint32_t _Unwind_State;
46 #ifdef __clang__
47 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0;
48 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1;
49 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2;
50 static const _Unwind_State _US_ACTION_MASK = 3;
51 #else // GCC fails at knowing what a constant expression is
52 # define _US_VIRTUAL_UNWIND_FRAME 0
53 # define _US_UNWIND_FRAME_STARTING 1
54 # define _US_UNWIND_FRAME_RESUME 2
55 # define _US_ACTION_MASK 3
56 #endif
57
58 typedef struct _Unwind_Context _Unwind_Context;
59
60 typedef uint32_t _Unwind_EHT_Header;
61
62 struct _Unwind_Exception
63 {
64 uint64_t exception_class;
65 void (*exception_cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception *);
66 /* Unwinder cache, private fields for the unwinder's use */
67 struct
68 {
69 uint32_t reserved1;
70 uint32_t reserved2;
71 uint32_t reserved3;
72 uint32_t reserved4;
73 uint32_t reserved5;
74 /* init reserved1 to 0, then don't touch */
75 } unwinder_cache;
76 /* Propagation barrier cache (valid after phase 1): */
77 struct
78 {
79 uint32_t sp;
80 uint32_t bitpattern[5];
81 } barrier_cache;
82 /* Cleanup cache (preserved over cleanup): */
83 struct
84 {
85 uint32_t bitpattern[4];
86 } cleanup_cache;
87 /* Pr cache (for pr's benefit): */
88 struct
89 {
90 /** function start address */
91 uint32_t fnstart;
92 /** pointer to EHT entry header word */
93 _Unwind_EHT_Header *ehtp;
94 /** additional data */
95 uint32_t additional;
96 uint32_t reserved1;
97 } pr_cache;
98 /** Force alignment of next item to 8-byte boundary */
99 long long int :0;
100 } __attribute__((__aligned__(8)));
101
102 /* Unwinding functions */
103 _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception *ucbp);
104 void _Unwind_Resume(struct _Unwind_Exception *ucbp);
105 void _Unwind_Complete(struct _Unwind_Exception *ucbp);
106 void _Unwind_DeleteException(struct _Unwind_Exception *ucbp);
107 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context*);
108
109 typedef enum
110 {
111 _UVRSR_OK = 0,
112 _UVRSR_NOT_IMPLEMENTED = 1,
113 _UVRSR_FAILED = 2
114 } _Unwind_VRS_Result;
115 typedef enum
116 {
117 _UVRSC_CORE = 0,
118 _UVRSC_VFP = 1,
119 _UVRSC_WMMXD = 3,
120 _UVRSC_WMMXC = 4
121 } _Unwind_VRS_RegClass;
122 typedef enum
123 {
124 _UVRSD_UINT32 = 0,
125 _UVRSD_VFPX = 1,
126 _UVRSD_UINT64 = 3,
127 _UVRSD_FLOAT = 4,
128 _UVRSD_DOUBLE = 5
129 } _Unwind_VRS_DataRepresentation;
130
131 _Unwind_VRS_Result _Unwind_VRS_Get(_Unwind_Context *context,
132 _Unwind_VRS_RegClass regclass,
133 uint32_t regno,
134 _Unwind_VRS_DataRepresentation representation,
135 void *valuep);
136 _Unwind_VRS_Result _Unwind_VRS_Set(_Unwind_Context *context,
137 _Unwind_VRS_RegClass regclass,
138 uint32_t regno,
139 _Unwind_VRS_DataRepresentation representation,
140 void *valuep);
141
142 /* Return the base-address for data references. */
143 extern unsigned long _Unwind_GetDataRelBase(struct _Unwind_Context *);
144
145 /* Return the base-address for text references. */
146 extern unsigned long _Unwind_GetTextRelBase(struct _Unwind_Context *);
147 extern unsigned long _Unwind_GetRegionStart(struct _Unwind_Context *);
148
149 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn) (struct _Unwind_Context *,
150 void *);
151 extern _Unwind_Reason_Code _Unwind_Backtrace (_Unwind_Trace_Fn, void *);
152 extern _Unwind_Reason_Code
153 _Unwind_Resume_or_Rethrow (struct _Unwind_Exception *);
154
155 /**
156 * The next set of functions are compatibility extensions, implementing Itanium
157 * ABI functions on top of ARM ones.
158 */
159
160 #define _UA_SEARCH_PHASE 1
161 #define _UA_CLEANUP_PHASE 2
162 #define _UA_HANDLER_FRAME 4
163 #define _UA_FORCE_UNWIND 8
164
_Unwind_GetGR(struct _Unwind_Context * context,int reg)165 static inline unsigned long _Unwind_GetGR(struct _Unwind_Context *context, int reg)
166 {
167 unsigned long val;
168 _Unwind_VRS_Get(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
169 return val;
170 }
_Unwind_SetGR(struct _Unwind_Context * context,int reg,unsigned long val)171 static inline void _Unwind_SetGR(struct _Unwind_Context *context, int reg, unsigned long val)
172 {
173 _Unwind_VRS_Set(context, _UVRSC_CORE, reg, _UVRSD_UINT32, &val);
174 }
_Unwind_GetIP(_Unwind_Context * context)175 static inline unsigned long _Unwind_GetIP(_Unwind_Context *context)
176 {
177 // Low bit store the thumb state - discard it
178 return _Unwind_GetGR(context, 15) & ~1;
179 }
_Unwind_SetIP(_Unwind_Context * context,unsigned long val)180 static inline void _Unwind_SetIP(_Unwind_Context *context, unsigned long val)
181 {
182 // The lowest bit of the instruction pointer indicates whether we're in
183 // thumb or ARM mode. This is assumed to be fixed throughout a function,
184 // so must be propagated when setting the program counter.
185 unsigned long thumbState = _Unwind_GetGR(context, 15) & 1;
186 _Unwind_SetGR(context, 15, (val | thumbState));
187 }
188
189 /** GNU API function that unwinds the frame */
190 _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*, struct _Unwind_Context*);
191
192
193 #define DECLARE_PERSONALITY_FUNCTION(name) \
194 _Unwind_Reason_Code name(_Unwind_State state,\
195 struct _Unwind_Exception *exceptionObject,\
196 struct _Unwind_Context *context);
197
198 #define BEGIN_PERSONALITY_FUNCTION(name) \
199 _Unwind_Reason_Code name(_Unwind_State state,\
200 struct _Unwind_Exception *exceptionObject,\
201 struct _Unwind_Context *context)\
202 {\
203 int version = 1;\
204 uint64_t exceptionClass = exceptionObject->exception_class;\
205 int actions;\
206 switch (state)\
207 {\
208 default: return _URC_FAILURE;\
209 case _US_VIRTUAL_UNWIND_FRAME:\
210 {\
211 actions = _UA_SEARCH_PHASE;\
212 break;\
213 }\
214 case _US_UNWIND_FRAME_STARTING:\
215 {\
216 actions = _UA_CLEANUP_PHASE;\
217 if (exceptionObject->barrier_cache.sp == _Unwind_GetGR(context, 13))\
218 {\
219 actions |= _UA_HANDLER_FRAME;\
220 }\
221 break;\
222 }\
223 case _US_UNWIND_FRAME_RESUME:\
224 {\
225 return continueUnwinding(exceptionObject, context);\
226 break;\
227 }\
228 }\
229 _Unwind_SetGR (context, 12, reinterpret_cast<unsigned long>(exceptionObject));\
230
231 #define CALL_PERSONALITY_FUNCTION(name) name(state,exceptionObject,context)
232