2 * exceptions-x86.c: exception support for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
16 #include <mono/metadata/abi-details.h>
17 #include <mono/arch/x86/x86-codegen.h>
18 #include <mono/metadata/appdomain.h>
19 #include <mono/metadata/tabledefs.h>
20 #include <mono/metadata/threads.h>
21 #include <mono/metadata/debug-helpers.h>
22 #include <mono/metadata/exception.h>
23 #include <mono/metadata/gc-internal.h>
24 #include <mono/metadata/mono-debug.h>
25 #include <mono/utils/mono-mmap.h>
31 static gpointer signal_exception_trampoline;
34 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot) MONO_INTERNAL;
37 static void (*restore_stack) (void *);
39 static MonoW32ExceptionHandler fpe_handler;
40 static MonoW32ExceptionHandler ill_handler;
41 static MonoW32ExceptionHandler segv_handler;
43 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
44 gpointer mono_win_vectored_exception_handle;
45 extern int (*gUnhandledExceptionHandler)(EXCEPTION_POINTERS*);
47 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
48 # define PROCESS_CALLBACK_FILTER_ENABLED 1
51 #define W32_SEH_HANDLE_EX(_ex) \
52 if (_ex##_handler) _ex##_handler(0, ep, ctx)
54 LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
56 #ifndef MONO_CROSS_COMPILE
57 if (mono_old_win_toplevel_exception_filter) {
58 return (*mono_old_win_toplevel_exception_filter)(ep);
62 mono_handle_native_sigsegv (SIGSEGV, NULL, NULL);
64 return EXCEPTION_CONTINUE_SEARCH;
68 * mono_win32_get_handle_stackoverflow (void):
70 * Returns a pointer to a method which restores the current context stack
71 * and calls handle_exceptions, when done restores the original stack.
74 mono_win32_get_handle_stackoverflow (void)
76 static guint8 *start = NULL;
82 /* restore_contect (void *sigctx) */
83 start = code = mono_global_codeman_reserve (128);
85 /* load context into ebx */
86 x86_mov_reg_membase (code, X86_EBX, X86_ESP, 4, 4);
88 /* move current stack into edi for later restore */
89 x86_mov_reg_reg (code, X86_EDI, X86_ESP, 4);
91 /* use the new freed stack from sigcontext */
92 /* XXX replace usage of struct sigcontext with MonoContext so we can use MONO_STRUCT_OFFSET */
93 x86_mov_reg_membase (code, X86_ESP, X86_EBX, G_STRUCT_OFFSET (struct sigcontext, esp), 4);
95 /* get the current domain */
96 x86_call_code (code, mono_domain_get);
98 /* get stack overflow exception from domain object */
99 x86_mov_reg_membase (code, X86_EAX, X86_EAX, G_STRUCT_OFFSET (MonoDomain, stack_overflow_ex), 4);
101 /* call mono_arch_handle_exception (sctx, stack_overflow_exception_obj) */
102 x86_push_reg (code, X86_EAX);
103 x86_push_reg (code, X86_EBX);
104 x86_call_code (code, mono_arch_handle_exception);
106 /* restore the SEH handler stack */
107 x86_mov_reg_reg (code, X86_ESP, X86_EDI, 4);
115 /* Special hack to workaround the fact that the
116 * when the SEH handler is called the stack is
117 * to small to recover.
119 * Stack walking part of this method is from mono_handle_exception
121 * The idea is simple;
122 * - walk the stack to free some space (64k)
123 * - set esp to new stack location
124 * - call mono_arch_handle_exception with stack overflow exception
125 * - set esp to SEH handlers stack
129 win32_handle_stack_overflow (EXCEPTION_POINTERS* ep, struct sigcontext *sctx)
133 MonoDomain *domain = mono_domain_get ();
135 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
136 MonoLMF *lmf = jit_tls->lmf;
137 MonoContext initial_ctx;
139 guint32 free_stack = 0;
140 StackFrameInfo frame;
142 mono_sigctx_to_monoctx (sctx, &ctx);
144 /* get our os page size */
146 page_size = si.dwPageSize;
148 /* Let's walk the stack to recover
149 * the needed stack space (if possible)
151 memset (&rji, 0, sizeof (rji));
154 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
156 /* try to free 64kb from our stack */
160 mono_arch_find_jit_info (domain, jit_tls, &rji, &ctx, &new_ctx, &lmf, NULL, &frame);
162 g_warning ("Exception inside function without unwind info");
163 g_assert_not_reached ();
166 if (frame.ji != (gpointer)-1) {
167 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
170 /* todo: we should call abort if ji is -1 */
172 } while (free_stack < 64 * 1024 && frame.ji != (gpointer) -1);
174 mono_monoctx_to_sigctx (&ctx, sctx);
176 /* todo: install new stack-guard page */
178 /* use the new stack and call mono_arch_handle_exception () */
179 restore_stack (sctx);
183 * Unhandled Exception Filter
184 * Top-level per-process exception handler.
186 LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
188 EXCEPTION_RECORD* er;
191 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
193 /* If the thread is not managed by the runtime return early */
195 return EXCEPTION_CONTINUE_SEARCH;
197 jit_tls->mono_win_chained_exception_needs_run = FALSE;
198 res = EXCEPTION_CONTINUE_EXECUTION;
200 er = ep->ExceptionRecord;
201 ctx = ep->ContextRecord;
203 switch (er->ExceptionCode) {
204 case EXCEPTION_STACK_OVERFLOW:
205 win32_handle_stack_overflow (ep, ctx);
207 case EXCEPTION_ACCESS_VIOLATION:
208 W32_SEH_HANDLE_EX(segv);
210 case EXCEPTION_ILLEGAL_INSTRUCTION:
211 W32_SEH_HANDLE_EX(ill);
213 case EXCEPTION_INT_DIVIDE_BY_ZERO:
214 case EXCEPTION_INT_OVERFLOW:
215 case EXCEPTION_FLT_DIVIDE_BY_ZERO:
216 case EXCEPTION_FLT_OVERFLOW:
217 case EXCEPTION_FLT_UNDERFLOW:
218 case EXCEPTION_FLT_INEXACT_RESULT:
219 W32_SEH_HANDLE_EX(fpe);
222 jit_tls->mono_win_chained_exception_needs_run = TRUE;
226 if (jit_tls->mono_win_chained_exception_needs_run) {
227 /* Don't copy context back if we chained exception
228 * as the handler may have modfied the EXCEPTION_POINTERS
229 * directly. We don't pass sigcontext to chained handlers.
230 * Return continue search so the UnhandledExceptionFilter
231 * can correctly chain the exception.
233 res = EXCEPTION_CONTINUE_SEARCH;
239 void win32_seh_init()
241 /* install restore stack helper */
243 restore_stack = mono_win32_get_handle_stackoverflow ();
245 mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
246 mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
249 void win32_seh_cleanup()
251 if (mono_old_win_toplevel_exception_filter)
252 SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
253 RemoveVectoredExceptionHandler (mono_win_vectored_exception_handle);
256 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
260 fpe_handler = handler;
263 ill_handler = handler;
266 segv_handler = handler;
273 #endif /* TARGET_WIN32 */
276 * mono_arch_get_restore_context:
278 * Returns a pointer to a method which restores a previously saved sigcontext.
281 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
283 guint8 *start = NULL;
285 MonoJumpInfo *ji = NULL;
286 GSList *unwind_ops = NULL;
288 /* restore_contect (MonoContext *ctx) */
290 start = code = mono_global_codeman_reserve (128);
293 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
296 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
299 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
302 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
305 x86_mov_reg_membase (code, X86_EDX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edx), 4);
308 * The context resides on the stack, in the stack frame of the
309 * caller of this function. The stack pointer that we need to
310 * restore is potentially many stack frames higher up, so the
311 * distance between them can easily be more than the red zone
312 * size. Hence the stack pointer can be restored only after
313 * we have finished loading everything from the context.
316 /* load ESP into EBP */
317 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esp), 4);
318 /* load return address into ECX */
319 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eip), 4);
320 /* save the return addr to the restored stack - 4 */
321 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
323 /* load EBP into ECX */
324 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
325 /* save EBP to the restored stack - 8 */
326 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
328 /* load EAX into ECX */
329 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eax), 4);
330 /* save EAX to the restored stack - 12 */
331 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
334 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ecx), 4);
336 /* restore ESP - 12 */
337 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
339 x86_pop_reg (code, X86_EAX);
341 x86_pop_reg (code, X86_EBP);
342 /* jump to the saved IP */
345 nacl_global_codeman_validate(&start, 128, &code);
348 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
352 for (l = unwind_ops; l; l = l->next)
354 g_slist_free (unwind_ops);
361 * mono_arch_get_call_filter:
363 * Returns a pointer to a method which calls an exception filter. We
364 * also use this function to call finally handlers (we pass NULL as
365 * @exc object in this case).
368 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
372 MonoJumpInfo *ji = NULL;
373 GSList *unwind_ops = NULL;
374 guint kMaxCodeSize = NACL_SIZE (64, 128);
376 /* call_filter (MonoContext *ctx, unsigned long eip) */
377 start = code = mono_global_codeman_reserve (kMaxCodeSize);
379 x86_push_reg (code, X86_EBP);
380 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
381 x86_push_reg (code, X86_EBX);
382 x86_push_reg (code, X86_EDI);
383 x86_push_reg (code, X86_ESI);
386 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
388 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
390 x86_push_reg (code, X86_EBP);
393 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
394 /* restore registers used by global register allocation (EBX & ESI) */
395 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
396 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
397 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
399 /* align stack and save ESP */
400 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
401 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
402 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
403 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
404 x86_push_reg (code, X86_EDX);
406 /* call the handler */
407 x86_call_reg (code, X86_ECX);
410 x86_pop_reg (code, X86_ESP);
413 x86_pop_reg (code, X86_EBP);
415 /* restore saved regs */
416 x86_pop_reg (code, X86_ESI);
417 x86_pop_reg (code, X86_EDI);
418 x86_pop_reg (code, X86_EBX);
422 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
425 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
429 for (l = unwind_ops; l; l = l->next)
431 g_slist_free (unwind_ops);
434 g_assert ((code - start) < kMaxCodeSize);
439 * mono_x86_throw_exception:
441 * C function called from the throw trampolines.
444 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
445 mgreg_t eip, gboolean rethrow)
449 ctx.esp = regs [X86_ESP];
451 ctx.ebp = regs [X86_EBP];
452 ctx.edi = regs [X86_EDI];
453 ctx.esi = regs [X86_ESI];
454 ctx.ebx = regs [X86_EBX];
455 ctx.edx = regs [X86_EDX];
456 ctx.ecx = regs [X86_ECX];
457 ctx.eax = regs [X86_EAX];
460 /* The OSX ABI specifies 16 byte alignment at call sites */
461 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
464 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
465 MonoException *mono_ex = (MonoException*)exc;
467 mono_ex->stack_trace = NULL;
470 /* adjust eip so that it point into the call instruction */
473 mono_handle_exception (&ctx, exc);
475 mono_restore_context (&ctx);
477 g_assert_not_reached ();
481 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
482 mgreg_t eip, gint32 pc_offset)
484 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
487 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
491 /* Negate the ip adjustment done in mono_x86_throw_exception () */
494 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
498 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
499 mgreg_t eip, gboolean rethrow)
503 ctx.esp = regs [X86_ESP];
505 ctx.ebp = regs [X86_EBP];
506 ctx.edi = regs [X86_EDI];
507 ctx.esi = regs [X86_ESI];
508 ctx.ebx = regs [X86_EBX];
509 ctx.edx = regs [X86_EDX];
510 ctx.ecx = regs [X86_ECX];
511 ctx.eax = regs [X86_EAX];
513 mono_resume_unwind (&ctx);
517 * get_throw_trampoline:
519 * Generate a call to mono_x86_throw_exception/
520 * mono_x86_throw_corlib_exception.
521 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
522 * which doesn't push the arguments.
525 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
527 guint8 *start, *code;
528 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
529 MonoJumpInfo *ji = NULL;
530 GSList *unwind_ops = NULL;
531 guint kMaxCodeSize = NACL_SIZE (128, 256);
533 start = code = mono_global_codeman_reserve (kMaxCodeSize);
538 * On apple, the stack is misaligned by the pushing of the return address.
541 /* On OSX, we don't generate alignment code to save space */
544 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
547 * The stack looks like this:
548 * <pc offset> (only if corlib is TRUE)
549 * <exception object>/<type token>
550 * <return addr> <- esp (unaligned on apple)
553 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
554 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
557 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
558 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
563 arg_offsets [3] = 12;
567 for (i = 0; i < X86_NREG; ++i)
569 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
570 /* Calculate the offset between the current sp and the sp of the caller */
572 /* LLVM doesn't push the arguments */
573 stack_offset = stack_size + 4;
577 stack_offset = stack_size + 4 + 8;
579 /* We don't generate stack alignment code on osx to save space */
582 /* One argument + stack alignment */
583 stack_offset = stack_size + 4 + 4;
585 /* Pop the alignment added by OP_THROW too */
586 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
588 if (mono_do_x86_stack_align)
589 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
594 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
595 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
597 /* Set arg1 == regs */
598 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
599 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
600 /* Set arg2 == exc/ex_token_index */
602 x86_mov_reg_imm (code, X86_EAX, 0);
604 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
605 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
606 /* Set arg3 == eip */
608 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
610 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
611 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
612 /* Set arg4 == rethrow/pc_offset */
614 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
616 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
619 * The caller is LLVM code which passes the absolute address not a pc offset,
620 * so compensate by passing 0 as 'ip' and passing the negated abs address as
623 x86_neg_reg (code, X86_EAX);
625 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
627 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
631 // This can be called from runtime code, which can't guarantee that
632 // ebx contains the got address.
633 // So emit the got address loading code too
634 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
635 code = mono_arch_emit_load_aotconst (start, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, corlib ? "mono_x86_throw_corlib_exception" : "mono_x86_throw_exception");
636 x86_call_reg (code, X86_EAX);
638 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
640 x86_breakpoint (code);
642 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
644 g_assert ((code - start) < kMaxCodeSize);
647 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
651 for (l = unwind_ops; l; l = l->next)
653 g_slist_free (unwind_ops);
660 * mono_arch_get_throw_exception:
662 * Returns a function pointer which can be used to raise
663 * exceptions. The returned function has the following
664 * signature: void (*func) (MonoException *exc);
665 * For example to raise an arithmetic exception you can use:
667 * x86_push_imm (code, mono_get_exception_arithmetic ());
668 * x86_call_code (code, arch_get_throw_exception ());
672 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
674 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
678 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
680 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
684 * mono_arch_get_throw_corlib_exception:
686 * Returns a function pointer which can be used to raise
687 * corlib exceptions. The returned function has the following
688 * signature: void (*func) (guint32 ex_token, guint32 offset);
689 * Here, offset is the offset which needs to be substracted from the caller IP
690 * to get the IP of the throw. Passing the offset has the advantage that it
691 * needs no relocations in the caller.
694 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
696 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
700 mono_arch_exceptions_init (void)
705 * If we're running WoW64, we need to set the usermode exception policy
706 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
707 * or (eventually) Windows 7 SP1.
713 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
716 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
717 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
718 if (getter && setter) {
720 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
726 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
730 /* LLVM needs different throw trampolines */
731 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
732 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
734 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
735 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
737 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
738 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
740 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
741 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
743 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
744 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
746 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
750 * mono_arch_find_jit_info:
752 * See exceptions-amd64.c for docs.
755 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
756 MonoJitInfo *ji, MonoContext *ctx,
757 MonoContext *new_ctx, MonoLMF **lmf,
758 mgreg_t **save_locations,
759 StackFrameInfo *frame)
761 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
763 memset (frame, 0, sizeof (StackFrameInfo));
769 gssize regs [MONO_MAX_IREGS + 1];
771 guint32 unwind_info_len;
774 frame->type = FRAME_TYPE_MANAGED;
776 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
778 regs [X86_EAX] = new_ctx->eax;
779 regs [X86_EBX] = new_ctx->ebx;
780 regs [X86_ECX] = new_ctx->ecx;
781 regs [X86_EDX] = new_ctx->edx;
782 regs [X86_ESP] = new_ctx->esp;
783 regs [X86_EBP] = new_ctx->ebp;
784 regs [X86_ESI] = new_ctx->esi;
785 regs [X86_EDI] = new_ctx->edi;
786 regs [X86_NREG] = new_ctx->eip;
788 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
789 (guint8*)ji->code_start + ji->code_size,
790 ip, NULL, regs, MONO_MAX_IREGS + 1,
791 save_locations, MONO_MAX_IREGS, &cfa);
793 new_ctx->eax = regs [X86_EAX];
794 new_ctx->ebx = regs [X86_EBX];
795 new_ctx->ecx = regs [X86_ECX];
796 new_ctx->edx = regs [X86_EDX];
797 new_ctx->esp = regs [X86_ESP];
798 new_ctx->ebp = regs [X86_EBP];
799 new_ctx->esi = regs [X86_ESI];
800 new_ctx->edi = regs [X86_EDI];
801 new_ctx->eip = regs [X86_NREG];
803 /* The CFA becomes the new SP value */
804 new_ctx->esp = (gssize)cfa;
812 if (((guint64)(*lmf)->previous_lmf) & 2) {
814 * This LMF entry is created by the soft debug code to mark transitions to
815 * managed code done during invokes.
817 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
819 g_assert (ext->debugger_invoke);
821 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
823 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
825 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
830 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
835 frame->method = (*lmf)->method;
838 new_ctx->esi = (*lmf)->esi;
839 new_ctx->edi = (*lmf)->edi;
840 new_ctx->ebx = (*lmf)->ebx;
841 new_ctx->ebp = (*lmf)->ebp;
842 new_ctx->eip = (*lmf)->eip;
847 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
849 /* Check if we are in a trampoline LMF frame */
850 if ((guint32)((*lmf)->previous_lmf) & 1) {
851 /* lmf->esp is set by the trampoline code */
852 new_ctx->esp = (*lmf)->esp;
855 /* the lmf is always stored on the stack, so the following
856 * expression points to a stack location which can be used as ESP */
857 new_ctx->esp = (unsigned long)&((*lmf)->eip);
859 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
868 mono_arch_ip_from_context (void *sigctx)
870 #if defined(__native_client__)
871 printf("WARNING: mono_arch_ip_from_context() called!\n");
873 #elif defined(MONO_ARCH_USE_SIGACTION)
874 ucontext_t *ctx = (ucontext_t*)sigctx;
875 return (gpointer)UCONTEXT_REG_EIP (ctx);
876 #elif defined(HOST_WIN32)
877 return ((CONTEXT*)sigctx)->Eip;
879 struct sigcontext *ctx = sigctx;
880 return (gpointer)ctx->SC_EIP;
887 * Called by resuming from a signal handler.
890 handle_signal_exception (gpointer obj)
892 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
895 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
897 mono_handle_exception (&ctx, obj);
899 mono_restore_context (&ctx);
903 * mono_x86_get_signal_exception_trampoline:
905 * This x86 specific trampoline is used to call handle_signal_exception.
908 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
910 guint8 *start, *code;
911 MonoJumpInfo *ji = NULL;
912 GSList *unwind_ops = NULL;
915 start = code = mono_global_codeman_reserve (128);
918 x86_push_reg (code, X86_ECX);
920 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
921 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
923 /* Fix the alignment to be what apple expects */
926 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
927 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
930 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
931 /* Branch to target */
932 x86_call_reg (code, X86_EDX);
934 g_assert ((code - start) < 128);
937 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
941 for (l = unwind_ops; l; l = l->next)
943 g_slist_free (unwind_ops);
951 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
954 * Can't pass the obj on the stack, since we are executing on the
955 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
956 * So put it into a register, and branch to a trampoline which
959 ctx->eax = (mgreg_t)user_data;
961 ctx->edx = (mgreg_t)async_cb;
964 ctx->esp = (ctx->esp - 16) & ~15;
965 ctx->eip = (mgreg_t)signal_exception_trampoline;
969 mono_arch_handle_exception (void *sigctx, gpointer obj)
971 #if defined(MONO_ARCH_USE_SIGACTION)
973 ucontext_t *ctx = (ucontext_t*)sigctx;
976 * Handling the exception in the signal handler is problematic, since the original
977 * signal is disabled, and we could run arbitrary code though the debugger. So
978 * resume into the normal stack and do most work there if possible.
980 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
982 /* Pass the ctx parameter in TLS */
983 mono_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
985 mctx = jit_tls->ex_ctx;
986 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
987 mono_monoctx_to_sigctx (&mctx, sigctx);
990 #elif defined (TARGET_WIN32)
992 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
993 struct sigcontext *ctx = (struct sigcontext *)sigctx;
995 mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
997 mctx = jit_tls->ex_ctx;
998 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
999 mono_monoctx_to_sigctx (&mctx, sigctx);
1005 mono_sigctx_to_monoctx (sigctx, &mctx);
1007 mono_handle_exception (&mctx, obj);
1009 mono_monoctx_to_sigctx (&mctx, sigctx);
1016 restore_soft_guard_pages (void)
1018 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1019 if (jit_tls->stack_ovf_guard_base)
1020 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1024 * this function modifies mctx so that when it is restored, it
1025 * won't execcute starting at mctx.eip, but in a function that
1026 * will restore the protection on the soft-guard pages and return back to
1027 * continue at mctx.eip.
1030 prepare_for_guard_pages (MonoContext *mctx)
1033 sp = (gpointer)(mctx->esp);
1035 /* the resturn addr */
1036 sp [0] = (gpointer)(mctx->eip);
1037 mctx->eip = (unsigned long)restore_soft_guard_pages;
1038 mctx->esp = (unsigned long)sp;
1042 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1048 mono_handle_exception (&mctx, obj);
1050 prepare_for_guard_pages (&mctx);
1051 mono_restore_context (&mctx);
1055 mono_arch_handle_altstack_exception (void *sigctx, MONO_SIG_HANDLER_INFO_TYPE *siginfo, gpointer fault_addr, gboolean stack_ovf)
1057 #ifdef MONO_ARCH_USE_SIGACTION
1058 MonoException *exc = NULL;
1059 ucontext_t *ctx = (ucontext_t*)sigctx;
1060 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1064 /* if we didn't find a managed method for the ip address and it matches the fault
1065 * address, we assume we followed a broken pointer during an indirect call, so
1066 * we try the lookup again with the return address pushed on the stack
1068 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1069 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1070 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1072 UCONTEXT_REG_EIP (ctx) = sp [0];
1075 exc = mono_domain_get ()->stack_overflow_ex;
1077 mono_handle_native_sigsegv (SIGSEGV, sigctx, siginfo);
1078 /* setup a call frame on the real stack so that control is returned there
1079 * and exception handling can continue.
1080 * If this was a stack overflow the caller already ensured the stack pages
1081 * needed have been unprotected.
1082 * The frame looks like:
1089 // FIXME: test_only is no more.
1090 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1093 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1094 sp = (gpointer)((char*)sp - frame_size);
1095 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1098 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1101 sp [2] = (gpointer)stack_ovf;
1102 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1103 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1104 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1105 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1109 #if MONO_SUPPORT_TASKLETS
1110 MonoContinuationRestore
1111 mono_tasklets_arch_restore (void)
1113 static guint8* saved = NULL;
1114 guint8 *code, *start;
1116 #ifdef __native_client_codegen__
1117 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1120 return (MonoContinuationRestore)saved;
1121 code = start = mono_global_codeman_reserve (48);
1122 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1123 /* put cont in edx */
1124 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1125 /* state in eax, so it's setup as the return value */
1126 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1128 /* setup the copy of the stack */
1129 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1130 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1132 x86_mov_reg_membase (code, X86_ESI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1133 x86_mov_reg_membase (code, X86_EDI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1134 x86_prefix (code, X86_REP_PREFIX);
1137 /* now restore the registers from the LMF */
1138 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1139 x86_mov_reg_membase (code, X86_EBX, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebx), 4);
1140 x86_mov_reg_membase (code, X86_EBP, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebp), 4);
1141 x86_mov_reg_membase (code, X86_ESI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, esi), 4);
1142 x86_mov_reg_membase (code, X86_EDI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, edi), 4);
1144 /* restore the lmf chain */
1145 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1146 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1148 x86_jump_membase (code, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_ip));
1149 g_assert ((code - start) <= 48);
1151 return (MonoContinuationRestore)saved;
1156 * mono_arch_setup_resume_sighandler_ctx:
1158 * Setup CTX so execution continues at FUNC.
1161 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1163 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1166 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1168 MONO_CONTEXT_SET_IP (ctx, func);