1 | //===----------------------------------------------------------------------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // Implements SEH-based Itanium C++ exceptions. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "config.h" |
14 | |
15 | #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) |
16 | |
17 | #include <unwind.h> |
18 | |
19 | #include <stdint.h> |
20 | #include <stdbool.h> |
21 | #include <stdlib.h> |
22 | |
23 | #include <windef.h> |
24 | #include <excpt.h> |
25 | #include <winnt.h> |
26 | #include <ntstatus.h> |
27 | |
28 | #include "libunwind_ext.h" |
29 | #include "UnwindCursor.hpp" |
30 | |
31 | using namespace libunwind; |
32 | |
33 | #define STATUS_USER_DEFINED (1u << 29) |
34 | |
35 | #define STATUS_GCC_MAGIC (('G' << 16) | ('C' << 8) | 'C') |
36 | |
37 | #define MAKE_CUSTOM_STATUS(s, c) \ |
38 | ((NTSTATUS)(((s) << 30) | STATUS_USER_DEFINED | (c))) |
39 | #define MAKE_GCC_EXCEPTION(c) \ |
40 | MAKE_CUSTOM_STATUS(STATUS_SEVERITY_SUCCESS, STATUS_GCC_MAGIC | ((c) << 24)) |
41 | |
42 | /// SEH exception raised by libunwind when the program calls |
43 | /// \c _Unwind_RaiseException. |
44 | #define STATUS_GCC_THROW MAKE_GCC_EXCEPTION(0) // 0x20474343 |
45 | /// SEH exception raised by libunwind to initiate phase 2 of exception |
46 | /// handling. |
47 | #define STATUS_GCC_UNWIND MAKE_GCC_EXCEPTION(1) // 0x21474343 |
48 | |
49 | static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *ctx); |
50 | static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor); |
51 | static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor, |
52 | DISPATCHER_CONTEXT *disp); |
53 | |
54 | /// Common implementation of SEH-style handler functions used by Itanium- |
55 | /// style frames. Depending on how and why it was called, it may do one of: |
56 | /// a) Delegate to the given Itanium-style personality function; or |
57 | /// b) Initiate a collided unwind to halt unwinding. |
58 | _LIBUNWIND_EXPORT EXCEPTION_DISPOSITION |
59 | _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx, |
60 | DISPATCHER_CONTEXT *disp, _Unwind_Personality_Fn pers) { |
61 | unw_cursor_t cursor; |
62 | _Unwind_Exception *exc; |
63 | _Unwind_Action action; |
64 | struct _Unwind_Context *ctx = nullptr; |
65 | _Unwind_Reason_Code urc; |
66 | uintptr_t retval, target; |
67 | bool ours = false; |
68 | |
69 | _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler(%#010lx(%lx), %p)" , |
70 | ms_exc->ExceptionCode, ms_exc->ExceptionFlags, |
71 | (void *)frame); |
72 | if (ms_exc->ExceptionCode == STATUS_GCC_UNWIND) { |
73 | if (IS_TARGET_UNWIND(ms_exc->ExceptionFlags)) { |
74 | // Set up the upper return value (the lower one and the target PC |
75 | // were set in the call to RtlUnwindEx()) for the landing pad. |
76 | #ifdef __x86_64__ |
77 | disp->ContextRecord->Rdx = ms_exc->ExceptionInformation[3]; |
78 | #elif defined(__arm__) |
79 | disp->ContextRecord->R1 = ms_exc->ExceptionInformation[3]; |
80 | #elif defined(__aarch64__) |
81 | disp->ContextRecord->X1 = ms_exc->ExceptionInformation[3]; |
82 | #endif |
83 | } |
84 | // This is the collided unwind to the landing pad. Nothing to do. |
85 | return ExceptionContinueSearch; |
86 | } |
87 | |
88 | if (ms_exc->ExceptionCode == STATUS_GCC_THROW) { |
89 | // This is (probably) a libunwind-controlled exception/unwind. Recover the |
90 | // parameters which we set below, and pass them to the personality function. |
91 | ours = true; |
92 | exc = (_Unwind_Exception *)ms_exc->ExceptionInformation[0]; |
93 | if (!IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1) { |
94 | ctx = (struct _Unwind_Context *)ms_exc->ExceptionInformation[1]; |
95 | action = (_Unwind_Action)ms_exc->ExceptionInformation[2]; |
96 | } |
97 | } else { |
98 | // Foreign exception. |
99 | // We can't interact with them (we don't know the original target frame |
100 | // that we should pass on to RtlUnwindEx in _Unwind_Resume), so just |
101 | // pass without calling our destructors here. |
102 | return ExceptionContinueSearch; |
103 | } |
104 | if (!ctx) { |
105 | __unw_init_seh(&cursor, disp->ContextRecord); |
106 | __unw_seh_set_disp_ctx(&cursor, disp); |
107 | __unw_set_reg(&cursor, UNW_REG_IP, disp->ControlPc); |
108 | ctx = (struct _Unwind_Context *)&cursor; |
109 | |
110 | if (!IS_UNWINDING(ms_exc->ExceptionFlags)) { |
111 | if (ours && ms_exc->NumberParameters > 1) |
112 | action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_FORCE_UNWIND); |
113 | else |
114 | action = _UA_SEARCH_PHASE; |
115 | } else { |
116 | if (ours && ms_exc->ExceptionInformation[1] == (ULONG_PTR)frame) |
117 | action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME); |
118 | else |
119 | action = _UA_CLEANUP_PHASE; |
120 | } |
121 | } |
122 | |
123 | _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() calling personality " |
124 | "function %p(1, %d, %llx, %p, %p)" , |
125 | (void *)pers, action, exc->exception_class, |
126 | (void *)exc, (void *)ctx); |
127 | urc = pers(1, action, exc->exception_class, exc, ctx); |
128 | _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() personality returned %d" , urc); |
129 | switch (urc) { |
130 | case _URC_CONTINUE_UNWIND: |
131 | // If we're in phase 2, and the personality routine said to continue |
132 | // at the target frame, we're in real trouble. |
133 | if (action & _UA_HANDLER_FRAME) |
134 | _LIBUNWIND_ABORT("Personality continued unwind at the target frame!" ); |
135 | return ExceptionContinueSearch; |
136 | case _URC_HANDLER_FOUND: |
137 | // If we were called by __libunwind_seh_personality(), indicate that |
138 | // a handler was found; otherwise, initiate phase 2 by unwinding. |
139 | if (ours && ms_exc->NumberParameters > 1) |
140 | return 4 /* ExceptionExecuteHandler in mingw */; |
141 | // This should never happen in phase 2. |
142 | if (IS_UNWINDING(ms_exc->ExceptionFlags)) |
143 | _LIBUNWIND_ABORT("Personality indicated exception handler in phase 2!" ); |
144 | exc->private_[1] = (ULONG_PTR)frame; |
145 | if (ours) { |
146 | ms_exc->NumberParameters = 4; |
147 | ms_exc->ExceptionInformation[1] = (ULONG_PTR)frame; |
148 | } |
149 | // FIXME: Indicate target frame in foreign case! |
150 | // phase 2: the clean up phase |
151 | RtlUnwindEx(frame, (PVOID)disp->ControlPc, ms_exc, exc, ms_ctx, disp->HistoryTable); |
152 | _LIBUNWIND_ABORT("RtlUnwindEx() failed" ); |
153 | case _URC_INSTALL_CONTEXT: { |
154 | // If we were called by __libunwind_seh_personality(), indicate that |
155 | // a handler was found; otherwise, it's time to initiate a collided |
156 | // unwind to the target. |
157 | if (ours && !IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1) |
158 | return 4 /* ExceptionExecuteHandler in mingw */; |
159 | // This should never happen in phase 1. |
160 | if (!IS_UNWINDING(ms_exc->ExceptionFlags)) |
161 | _LIBUNWIND_ABORT("Personality installed context during phase 1!" ); |
162 | #ifdef __x86_64__ |
163 | exc->private_[2] = disp->TargetIp; |
164 | __unw_get_reg(&cursor, UNW_X86_64_RAX, &retval); |
165 | __unw_get_reg(&cursor, UNW_X86_64_RDX, &exc->private_[3]); |
166 | #elif defined(__arm__) |
167 | exc->private_[2] = disp->TargetPc; |
168 | __unw_get_reg(&cursor, UNW_ARM_R0, &retval); |
169 | __unw_get_reg(&cursor, UNW_ARM_R1, &exc->private_[3]); |
170 | #elif defined(__aarch64__) |
171 | exc->private_[2] = disp->TargetPc; |
172 | __unw_get_reg(&cursor, UNW_AARCH64_X0, &retval); |
173 | __unw_get_reg(&cursor, UNW_AARCH64_X1, &exc->private_[3]); |
174 | #endif |
175 | __unw_get_reg(&cursor, UNW_REG_IP, &target); |
176 | ms_exc->ExceptionCode = STATUS_GCC_UNWIND; |
177 | #ifdef __x86_64__ |
178 | ms_exc->ExceptionInformation[2] = disp->TargetIp; |
179 | #elif defined(__arm__) || defined(__aarch64__) |
180 | ms_exc->ExceptionInformation[2] = disp->TargetPc; |
181 | #endif |
182 | ms_exc->ExceptionInformation[3] = exc->private_[3]; |
183 | // Give NTRTL some scratch space to keep track of the collided unwind. |
184 | // Don't use the one that was passed in; we don't want to overwrite the |
185 | // context in the DISPATCHER_CONTEXT. |
186 | CONTEXT new_ctx; |
187 | RtlUnwindEx(frame, (PVOID)target, ms_exc, (PVOID)retval, &new_ctx, disp->HistoryTable); |
188 | _LIBUNWIND_ABORT("RtlUnwindEx() failed" ); |
189 | } |
190 | // Anything else indicates a serious problem. |
191 | default: return ExceptionContinueExecution; |
192 | } |
193 | } |
194 | |
195 | /// Personality function returned by \c __unw_get_proc_info() in SEH contexts. |
196 | /// This is a wrapper that calls the real SEH handler function, which in |
197 | /// turn (at least, for Itanium-style frames) calls the real Itanium |
198 | /// personality function (see \c _GCC_specific_handler()). |
199 | extern "C" _Unwind_Reason_Code |
200 | __libunwind_seh_personality(int version, _Unwind_Action state, |
201 | uint64_t klass, _Unwind_Exception *exc, |
202 | struct _Unwind_Context *context) { |
203 | (void)version; |
204 | (void)klass; |
205 | EXCEPTION_RECORD ms_exc; |
206 | bool phase2 = (state & (_UA_SEARCH_PHASE|_UA_CLEANUP_PHASE)) == _UA_CLEANUP_PHASE; |
207 | ms_exc.ExceptionCode = STATUS_GCC_THROW; |
208 | ms_exc.ExceptionFlags = 0; |
209 | ms_exc.NumberParameters = 3; |
210 | ms_exc.ExceptionInformation[0] = (ULONG_PTR)exc; |
211 | ms_exc.ExceptionInformation[1] = (ULONG_PTR)context; |
212 | ms_exc.ExceptionInformation[2] = state; |
213 | DISPATCHER_CONTEXT *disp_ctx = |
214 | __unw_seh_get_disp_ctx((unw_cursor_t *)context); |
215 | _LIBUNWIND_TRACE_UNWINDING("__libunwind_seh_personality() calling " |
216 | "LanguageHandler %p(%p, %p, %p, %p)" , |
217 | (void *)disp_ctx->LanguageHandler, (void *)&ms_exc, |
218 | (void *)disp_ctx->EstablisherFrame, |
219 | (void *)disp_ctx->ContextRecord, (void *)disp_ctx); |
220 | EXCEPTION_DISPOSITION ms_act = disp_ctx->LanguageHandler(&ms_exc, |
221 | (PVOID)disp_ctx->EstablisherFrame, |
222 | disp_ctx->ContextRecord, |
223 | disp_ctx); |
224 | _LIBUNWIND_TRACE_UNWINDING("__libunwind_seh_personality() LanguageHandler " |
225 | "returned %d" , |
226 | (int)ms_act); |
227 | switch (ms_act) { |
228 | case ExceptionContinueExecution: return _URC_END_OF_STACK; |
229 | case ExceptionContinueSearch: return _URC_CONTINUE_UNWIND; |
230 | case 4 /*ExceptionExecuteHandler*/: |
231 | return phase2 ? _URC_INSTALL_CONTEXT : _URC_HANDLER_FOUND; |
232 | default: |
233 | return phase2 ? _URC_FATAL_PHASE2_ERROR : _URC_FATAL_PHASE1_ERROR; |
234 | } |
235 | } |
236 | |
237 | static _Unwind_Reason_Code |
238 | unwind_phase2_forced(unw_context_t *uc, |
239 | _Unwind_Exception *exception_object, |
240 | _Unwind_Stop_Fn stop, void *stop_parameter) { |
241 | unw_cursor_t cursor2; |
242 | __unw_init_local(&cursor2, uc); |
243 | |
244 | // Walk each frame until we reach where search phase said to stop |
245 | while (__unw_step(&cursor2) > 0) { |
246 | |
247 | // Update info about this frame. |
248 | unw_proc_info_t frameInfo; |
249 | if (__unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) { |
250 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): __unw_get_proc_info " |
251 | "failed => _URC_END_OF_STACK" , |
252 | (void *)exception_object); |
253 | return _URC_FATAL_PHASE2_ERROR; |
254 | } |
255 | |
256 | #ifndef NDEBUG |
257 | // When tracing, print state information. |
258 | if (_LIBUNWIND_TRACING_UNWINDING) { |
259 | char functionBuf[512]; |
260 | const char *functionName = functionBuf; |
261 | unw_word_t offset; |
262 | if ((__unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf), |
263 | &offset) != UNW_ESUCCESS) || |
264 | (frameInfo.start_ip + offset > frameInfo.end_ip)) |
265 | functionName = ".anonymous." ; |
266 | _LIBUNWIND_TRACE_UNWINDING( |
267 | "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR |
268 | ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR, |
269 | (void *)exception_object, frameInfo.start_ip, functionName, |
270 | frameInfo.lsda, frameInfo.handler); |
271 | } |
272 | #endif |
273 | |
274 | // Call stop function at each frame. |
275 | _Unwind_Action action = |
276 | (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE); |
277 | _Unwind_Reason_Code stopResult = |
278 | (*stop)(1, action, exception_object->exception_class, exception_object, |
279 | (struct _Unwind_Context *)(&cursor2), stop_parameter); |
280 | _LIBUNWIND_TRACE_UNWINDING( |
281 | "unwind_phase2_forced(ex_ojb=%p): stop function returned %d" , |
282 | (void *)exception_object, stopResult); |
283 | if (stopResult != _URC_NO_REASON) { |
284 | _LIBUNWIND_TRACE_UNWINDING( |
285 | "unwind_phase2_forced(ex_ojb=%p): stopped by stop function" , |
286 | (void *)exception_object); |
287 | return _URC_FATAL_PHASE2_ERROR; |
288 | } |
289 | |
290 | // If there is a personality routine, tell it we are unwinding. |
291 | if (frameInfo.handler != 0) { |
292 | _Unwind_Personality_Fn p = |
293 | (_Unwind_Personality_Fn)(intptr_t)(frameInfo.handler); |
294 | _LIBUNWIND_TRACE_UNWINDING( |
295 | "unwind_phase2_forced(ex_ojb=%p): calling personality function %p" , |
296 | (void *)exception_object, (void *)(uintptr_t)p); |
297 | _Unwind_Reason_Code personalityResult = |
298 | (*p)(1, action, exception_object->exception_class, exception_object, |
299 | (struct _Unwind_Context *)(&cursor2)); |
300 | switch (personalityResult) { |
301 | case _URC_CONTINUE_UNWIND: |
302 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
303 | "personality returned " |
304 | "_URC_CONTINUE_UNWIND" , |
305 | (void *)exception_object); |
306 | // Destructors called, continue unwinding |
307 | break; |
308 | case _URC_INSTALL_CONTEXT: |
309 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
310 | "personality returned " |
311 | "_URC_INSTALL_CONTEXT" , |
312 | (void *)exception_object); |
313 | // We may get control back if landing pad calls _Unwind_Resume(). |
314 | __unw_resume(&cursor2); |
315 | break; |
316 | case _URC_END_OF_STACK: |
317 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
318 | "personality returned " |
319 | "_URC_END_OF_STACK" , |
320 | (void *)exception_object); |
321 | break; |
322 | default: |
323 | // Personality routine returned an unknown result code. |
324 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " |
325 | "personality returned %d, " |
326 | "_URC_FATAL_PHASE2_ERROR" , |
327 | (void *)exception_object, personalityResult); |
328 | return _URC_FATAL_PHASE2_ERROR; |
329 | } |
330 | if (personalityResult == _URC_END_OF_STACK) |
331 | break; |
332 | } |
333 | } |
334 | |
335 | // Call stop function one last time and tell it we've reached the end |
336 | // of the stack. |
337 | _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop " |
338 | "function with _UA_END_OF_STACK" , |
339 | (void *)exception_object); |
340 | _Unwind_Action lastAction = |
341 | (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK); |
342 | (*stop)(1, lastAction, exception_object->exception_class, exception_object, |
343 | (struct _Unwind_Context *)(&cursor2), stop_parameter); |
344 | |
345 | // Clean up phase did not resume at the frame that the search phase said it |
346 | // would. |
347 | return _URC_FATAL_PHASE2_ERROR; |
348 | } |
349 | |
350 | /// Called by \c __cxa_throw(). Only returns if there is a fatal error. |
351 | _LIBUNWIND_EXPORT _Unwind_Reason_Code |
352 | _Unwind_RaiseException(_Unwind_Exception *exception_object) { |
353 | _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)" , |
354 | (void *)exception_object); |
355 | |
356 | // Mark that this is a non-forced unwind, so _Unwind_Resume() |
357 | // can do the right thing. |
358 | memset(exception_object->private_, 0, sizeof(exception_object->private_)); |
359 | |
360 | // phase 1: the search phase |
361 | // We'll let the system do that for us. |
362 | RaiseException(STATUS_GCC_THROW, 0, 1, (ULONG_PTR *)&exception_object); |
363 | |
364 | // If we get here, either something went horribly wrong or we reached the |
365 | // top of the stack. Either way, let libc++abi call std::terminate(). |
366 | return _URC_END_OF_STACK; |
367 | } |
368 | |
369 | /// When \c _Unwind_RaiseException() is in phase2, it hands control |
370 | /// to the personality function at each frame. The personality |
371 | /// may force a jump to a landing pad in that function; the landing |
372 | /// pad code may then call \c _Unwind_Resume() to continue with the |
373 | /// unwinding. Note: the call to \c _Unwind_Resume() is from compiler |
374 | /// generated user code. All other \c _Unwind_* routines are called |
375 | /// by the C++ runtime \c __cxa_* routines. |
376 | /// |
377 | /// Note: re-throwing an exception (as opposed to continuing the unwind) |
378 | /// is implemented by having the code call \c __cxa_rethrow() which |
379 | /// in turn calls \c _Unwind_Resume_or_Rethrow(). |
380 | _LIBUNWIND_EXPORT void |
381 | _Unwind_Resume(_Unwind_Exception *exception_object) { |
382 | _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)" , (void *)exception_object); |
383 | |
384 | if (exception_object->private_[0] != 0) { |
385 | unw_context_t uc; |
386 | |
387 | __unw_getcontext(&uc); |
388 | unwind_phase2_forced(&uc, exception_object, |
389 | (_Unwind_Stop_Fn) exception_object->private_[0], |
390 | (void *)exception_object->private_[4]); |
391 | } else { |
392 | // Recover the parameters for the unwind from the exception object |
393 | // so we can start unwinding again. |
394 | EXCEPTION_RECORD ms_exc; |
395 | CONTEXT ms_ctx; |
396 | UNWIND_HISTORY_TABLE hist; |
397 | |
398 | memset(&ms_exc, 0, sizeof(ms_exc)); |
399 | memset(&hist, 0, sizeof(hist)); |
400 | ms_exc.ExceptionCode = STATUS_GCC_THROW; |
401 | ms_exc.ExceptionFlags = EXCEPTION_NONCONTINUABLE; |
402 | ms_exc.NumberParameters = 4; |
403 | ms_exc.ExceptionInformation[0] = (ULONG_PTR)exception_object; |
404 | ms_exc.ExceptionInformation[1] = exception_object->private_[1]; |
405 | ms_exc.ExceptionInformation[2] = exception_object->private_[2]; |
406 | ms_exc.ExceptionInformation[3] = exception_object->private_[3]; |
407 | RtlUnwindEx((PVOID)exception_object->private_[1], |
408 | (PVOID)exception_object->private_[2], &ms_exc, |
409 | exception_object, &ms_ctx, &hist); |
410 | } |
411 | |
412 | // Clients assume _Unwind_Resume() does not return, so all we can do is abort. |
413 | _LIBUNWIND_ABORT("_Unwind_Resume() can't return" ); |
414 | } |
415 | |
416 | /// Not used by C++. |
417 | /// Unwinds stack, calling "stop" function at each frame. |
418 | /// Could be used to implement \c longjmp(). |
419 | _LIBUNWIND_EXPORT _Unwind_Reason_Code |
420 | _Unwind_ForcedUnwind(_Unwind_Exception *exception_object, |
421 | _Unwind_Stop_Fn stop, void *stop_parameter) { |
422 | _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)" , |
423 | (void *)exception_object, (void *)(uintptr_t)stop); |
424 | unw_context_t uc; |
425 | __unw_getcontext(&uc); |
426 | |
427 | // Mark that this is a forced unwind, so _Unwind_Resume() can do |
428 | // the right thing. |
429 | exception_object->private_[0] = (uintptr_t) stop; |
430 | exception_object->private_[4] = (uintptr_t) stop_parameter; |
431 | |
432 | // do it |
433 | return unwind_phase2_forced(&uc, exception_object, stop, stop_parameter); |
434 | } |
435 | |
436 | /// Called by personality handler during phase 2 to get LSDA for current frame. |
437 | _LIBUNWIND_EXPORT uintptr_t |
438 | _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) { |
439 | uintptr_t result = |
440 | (uintptr_t)__unw_seh_get_disp_ctx((unw_cursor_t *)context)->HandlerData; |
441 | _LIBUNWIND_TRACE_API( |
442 | "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR, |
443 | (void *)context, result); |
444 | return result; |
445 | } |
446 | |
447 | /// Called by personality handler during phase 2 to find the start of the |
448 | /// function. |
449 | _LIBUNWIND_EXPORT uintptr_t |
450 | _Unwind_GetRegionStart(struct _Unwind_Context *context) { |
451 | DISPATCHER_CONTEXT *disp = __unw_seh_get_disp_ctx((unw_cursor_t *)context); |
452 | uintptr_t result = (uintptr_t)disp->FunctionEntry->BeginAddress + disp->ImageBase; |
453 | _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR, |
454 | (void *)context, result); |
455 | return result; |
456 | } |
457 | |
458 | static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *context) { |
459 | #ifdef _LIBUNWIND_TARGET_X86_64 |
460 | new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)) |
461 | UnwindCursor<LocalAddressSpace, Registers_x86_64>( |
462 | context, LocalAddressSpace::sThisAddressSpace); |
463 | auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); |
464 | co->setInfoBasedOnIPRegister(); |
465 | return UNW_ESUCCESS; |
466 | #elif defined(_LIBUNWIND_TARGET_ARM) |
467 | new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)) |
468 | UnwindCursor<LocalAddressSpace, Registers_arm>( |
469 | context, LocalAddressSpace::sThisAddressSpace); |
470 | auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); |
471 | co->setInfoBasedOnIPRegister(); |
472 | return UNW_ESUCCESS; |
473 | #elif defined(_LIBUNWIND_TARGET_AARCH64) |
474 | new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)) |
475 | UnwindCursor<LocalAddressSpace, Registers_arm64>( |
476 | context, LocalAddressSpace::sThisAddressSpace); |
477 | auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); |
478 | co->setInfoBasedOnIPRegister(); |
479 | return UNW_ESUCCESS; |
480 | #else |
481 | return UNW_EINVAL; |
482 | #endif |
483 | } |
484 | |
485 | static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor) { |
486 | #ifdef _LIBUNWIND_TARGET_X86_64 |
487 | return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->getDispatcherContext(); |
488 | #elif defined(_LIBUNWIND_TARGET_ARM) |
489 | return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->getDispatcherContext(); |
490 | #elif defined(_LIBUNWIND_TARGET_AARCH64) |
491 | return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->getDispatcherContext(); |
492 | #else |
493 | return nullptr; |
494 | #endif |
495 | } |
496 | |
497 | static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor, |
498 | DISPATCHER_CONTEXT *disp) { |
499 | #ifdef _LIBUNWIND_TARGET_X86_64 |
500 | reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->setDispatcherContext(disp); |
501 | #elif defined(_LIBUNWIND_TARGET_ARM) |
502 | reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->setDispatcherContext(disp); |
503 | #elif defined(_LIBUNWIND_TARGET_AARCH64) |
504 | reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->setDispatcherContext(disp); |
505 | #endif |
506 | } |
507 | |
508 | #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) |
509 | |