2 * exceptions-x86.c: exception support for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
12 #if _WIN32_WINNT < 0x0501
13 /* Required for Vectored Exception Handling. */
15 #define _WIN32_WINNT 0x0501
16 #endif /* _WIN32_WINNT < 0x0501 */
22 #include <mono/arch/x86/x86-codegen.h>
23 #include <mono/metadata/appdomain.h>
24 #include <mono/metadata/tabledefs.h>
25 #include <mono/metadata/threads.h>
26 #include <mono/metadata/debug-helpers.h>
27 #include <mono/metadata/exception.h>
28 #include <mono/metadata/gc-internal.h>
29 #include <mono/metadata/mono-debug.h>
30 #include <mono/utils/mono-mmap.h>
36 static gpointer signal_exception_trampoline;
39 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot) MONO_INTERNAL;
42 static void (*restore_stack) (void *);
44 static MonoW32ExceptionHandler fpe_handler;
45 static MonoW32ExceptionHandler ill_handler;
46 static MonoW32ExceptionHandler segv_handler;
48 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
49 gpointer mono_win_vectored_exception_handle;
50 extern gboolean mono_win_chained_exception_needs_run;
51 extern int (*gUnhandledExceptionHandler)(EXCEPTION_POINTERS*);
53 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
54 # define PROCESS_CALLBACK_FILTER_ENABLED 1
57 #define W32_SEH_HANDLE_EX(_ex) \
58 if (_ex##_handler) _ex##_handler(0, ep, sctx)
60 LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
62 #ifndef MONO_CROSS_COMPILE
63 if (mono_old_win_toplevel_exception_filter) {
64 return (*mono_old_win_toplevel_exception_filter)(ep);
68 mono_handle_native_sigsegv (SIGSEGV, NULL);
70 return EXCEPTION_CONTINUE_SEARCH;
74 * mono_win32_get_handle_stackoverflow (void):
76 * Returns a pointer to a method which restores the current context stack
77 * and calls handle_exceptions, when done restores the original stack.
80 mono_win32_get_handle_stackoverflow (void)
82 static guint8 *start = NULL;
88 /* restore_contect (void *sigctx) */
89 start = code = mono_global_codeman_reserve (128);
91 /* load context into ebx */
92 x86_mov_reg_membase (code, X86_EBX, X86_ESP, 4, 4);
94 /* move current stack into edi for later restore */
95 x86_mov_reg_reg (code, X86_EDI, X86_ESP, 4);
97 /* use the new freed stack from sigcontext */
98 x86_mov_reg_membase (code, X86_ESP, X86_EBX, G_STRUCT_OFFSET (struct sigcontext, esp), 4);
100 /* get the current domain */
101 x86_call_code (code, mono_domain_get);
103 /* get stack overflow exception from domain object */
104 x86_mov_reg_membase (code, X86_EAX, X86_EAX, G_STRUCT_OFFSET (MonoDomain, stack_overflow_ex), 4);
106 /* call mono_arch_handle_exception (sctx, stack_overflow_exception_obj) */
107 x86_push_reg (code, X86_EAX);
108 x86_push_reg (code, X86_EBX);
109 x86_call_code (code, mono_arch_handle_exception);
111 /* restore the SEH handler stack */
112 x86_mov_reg_reg (code, X86_ESP, X86_EDI, 4);
120 /* Special hack to workaround the fact that the
121 * when the SEH handler is called the stack is
122 * to small to recover.
124 * Stack walking part of this method is from mono_handle_exception
126 * The idea is simple;
127 * - walk the stack to free some space (64k)
128 * - set esp to new stack location
129 * - call mono_arch_handle_exception with stack overflow exception
130 * - set esp to SEH handlers stack
134 win32_handle_stack_overflow (EXCEPTION_POINTERS* ep, struct sigcontext *sctx)
138 MonoDomain *domain = mono_domain_get ();
140 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
141 MonoLMF *lmf = jit_tls->lmf;
142 MonoContext initial_ctx;
144 guint32 free_stack = 0;
145 StackFrameInfo frame;
147 /* convert sigcontext to MonoContext (due to reuse of stack walking helpers */
148 mono_arch_sigctx_to_monoctx (sctx, &ctx);
150 /* get our os page size */
152 page_size = si.dwPageSize;
154 /* Let's walk the stack to recover
155 * the needed stack space (if possible)
157 memset (&rji, 0, sizeof (rji));
160 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
162 /* try to free 64kb from our stack */
166 mono_arch_find_jit_info (domain, jit_tls, &rji, &ctx, &new_ctx, &lmf, NULL, &frame);
168 g_warning ("Exception inside function without unwind info");
169 g_assert_not_reached ();
172 if (frame.ji != (gpointer)-1) {
173 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
176 /* todo: we should call abort if ji is -1 */
178 } while (free_stack < 64 * 1024 && frame.ji != (gpointer) -1);
180 /* convert into sigcontext to be used in mono_arch_handle_exception */
181 mono_arch_monoctx_to_sigctx (&ctx, sctx);
183 /* todo: install new stack-guard page */
185 /* use the new stack and call mono_arch_handle_exception () */
186 restore_stack (sctx);
190 * Unhandled Exception Filter
191 * Top-level per-process exception handler.
193 LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
195 EXCEPTION_RECORD* er;
197 struct sigcontext* sctx;
200 mono_win_chained_exception_needs_run = FALSE;
201 res = EXCEPTION_CONTINUE_EXECUTION;
203 er = ep->ExceptionRecord;
204 ctx = ep->ContextRecord;
205 sctx = g_malloc(sizeof(struct sigcontext));
207 /* Copy Win32 context to UNIX style context */
208 sctx->eax = ctx->Eax;
209 sctx->ebx = ctx->Ebx;
210 sctx->ecx = ctx->Ecx;
211 sctx->edx = ctx->Edx;
212 sctx->ebp = ctx->Ebp;
213 sctx->esp = ctx->Esp;
214 sctx->esi = ctx->Esi;
215 sctx->edi = ctx->Edi;
216 sctx->eip = ctx->Eip;
218 switch (er->ExceptionCode) {
219 case EXCEPTION_STACK_OVERFLOW:
220 win32_handle_stack_overflow (ep, sctx);
222 case EXCEPTION_ACCESS_VIOLATION:
223 W32_SEH_HANDLE_EX(segv);
225 case EXCEPTION_ILLEGAL_INSTRUCTION:
226 W32_SEH_HANDLE_EX(ill);
228 case EXCEPTION_INT_DIVIDE_BY_ZERO:
229 case EXCEPTION_INT_OVERFLOW:
230 case EXCEPTION_FLT_DIVIDE_BY_ZERO:
231 case EXCEPTION_FLT_OVERFLOW:
232 case EXCEPTION_FLT_UNDERFLOW:
233 case EXCEPTION_FLT_INEXACT_RESULT:
234 W32_SEH_HANDLE_EX(fpe);
240 if (mono_win_chained_exception_needs_run) {
241 /* Don't copy context back if we chained exception
242 * as the handler may have modfied the EXCEPTION_POINTERS
243 * directly. We don't pass sigcontext to chained handlers.
244 * Return continue search so the UnhandledExceptionFilter
245 * can correctly chain the exception.
247 res = EXCEPTION_CONTINUE_SEARCH;
249 /* Copy context back */
250 ctx->Eax = sctx->eax;
251 ctx->Ebx = sctx->ebx;
252 ctx->Ecx = sctx->ecx;
253 ctx->Edx = sctx->edx;
254 ctx->Ebp = sctx->ebp;
255 ctx->Esp = sctx->esp;
256 ctx->Esi = sctx->esi;
257 ctx->Edi = sctx->edi;
258 ctx->Eip = sctx->eip;
261 /* TODO: Find right place to free this in stack overflow case */
262 if (er->ExceptionCode != EXCEPTION_STACK_OVERFLOW)
268 void win32_seh_init()
270 /* install restore stack helper */
272 restore_stack = mono_win32_get_handle_stackoverflow ();
274 mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
275 mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
278 void win32_seh_cleanup()
280 if (mono_old_win_toplevel_exception_filter) SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
281 RemoveVectoredExceptionHandler (seh_unhandled_exception_filter);
284 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
288 fpe_handler = handler;
291 ill_handler = handler;
294 segv_handler = handler;
301 #endif /* TARGET_WIN32 */
304 * mono_arch_get_restore_context:
306 * Returns a pointer to a method which restores a previously saved sigcontext.
309 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
311 guint8 *start = NULL;
313 MonoJumpInfo *ji = NULL;
314 GSList *unwind_ops = NULL;
316 /* restore_contect (MonoContext *ctx) */
318 start = code = mono_global_codeman_reserve (128);
321 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
324 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebx), 4);
327 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (MonoContext, edi), 4);
330 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (MonoContext, esi), 4);
333 x86_mov_reg_membase (code, X86_EDX, X86_EAX, G_STRUCT_OFFSET (MonoContext, edx), 4);
336 * The context resides on the stack, in the stack frame of the
337 * caller of this function. The stack pointer that we need to
338 * restore is potentially many stack frames higher up, so the
339 * distance between them can easily be more than the red zone
340 * size. Hence the stack pointer can be restored only after
341 * we have finished loading everything from the context.
344 /* load ESP into EBP */
345 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (MonoContext, esp), 4);
346 /* Align it, it can be unaligned if it was captured asynchronously */
347 x86_alu_reg_imm (code, X86_AND, X86_EBP, ~(MONO_ARCH_LOCALLOC_ALIGNMENT - 1));
348 /* load return address into ECX */
349 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eip), 4);
350 /* save the return addr to the restored stack - 4 */
351 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
353 /* load EBP into ECX */
354 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
355 /* save EBP to the restored stack - 8 */
356 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
358 /* load EAX into ECX */
359 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eax), 4);
360 /* save EAX to the restored stack - 12 */
361 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
364 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ecx), 4);
366 /* restore ESP - 12 */
367 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
369 x86_pop_reg (code, X86_EAX);
371 x86_pop_reg (code, X86_EBP);
372 /* jump to the saved IP */
375 nacl_global_codeman_validate(&start, 128, &code);
378 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
382 for (l = unwind_ops; l; l = l->next)
384 g_slist_free (unwind_ops);
391 * mono_arch_get_call_filter:
393 * Returns a pointer to a method which calls an exception filter. We
394 * also use this function to call finally handlers (we pass NULL as
395 * @exc object in this case).
398 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
402 MonoJumpInfo *ji = NULL;
403 GSList *unwind_ops = NULL;
404 guint kMaxCodeSize = NACL_SIZE (64, 128);
406 /* call_filter (MonoContext *ctx, unsigned long eip) */
407 start = code = mono_global_codeman_reserve (kMaxCodeSize);
409 x86_push_reg (code, X86_EBP);
410 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
411 x86_push_reg (code, X86_EBX);
412 x86_push_reg (code, X86_EDI);
413 x86_push_reg (code, X86_ESI);
416 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
418 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
420 x86_push_reg (code, X86_EBP);
423 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
424 /* restore registers used by global register allocation (EBX & ESI) */
425 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebx), 4);
426 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (MonoContext, esi), 4);
427 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (MonoContext, edi), 4);
429 /* align stack and save ESP */
430 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
431 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
432 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
433 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
434 x86_push_reg (code, X86_EDX);
436 /* call the handler */
437 x86_call_reg (code, X86_ECX);
440 x86_pop_reg (code, X86_ESP);
443 x86_pop_reg (code, X86_EBP);
445 /* restore saved regs */
446 x86_pop_reg (code, X86_ESI);
447 x86_pop_reg (code, X86_EDI);
448 x86_pop_reg (code, X86_EBX);
452 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
455 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
459 for (l = unwind_ops; l; l = l->next)
461 g_slist_free (unwind_ops);
464 g_assert ((code - start) < kMaxCodeSize);
469 * mono_x86_throw_exception:
471 * C function called from the throw trampolines.
474 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
475 mgreg_t eip, gboolean rethrow)
479 ctx.esp = regs [X86_ESP];
481 ctx.ebp = regs [X86_EBP];
482 ctx.edi = regs [X86_EDI];
483 ctx.esi = regs [X86_ESI];
484 ctx.ebx = regs [X86_EBX];
485 ctx.edx = regs [X86_EDX];
486 ctx.ecx = regs [X86_ECX];
487 ctx.eax = regs [X86_EAX];
490 /* The OSX ABI specifies 16 byte alignment at call sites */
491 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
494 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
495 MonoException *mono_ex = (MonoException*)exc;
497 mono_ex->stack_trace = NULL;
500 /* adjust eip so that it point into the call instruction */
503 mono_handle_exception (&ctx, exc);
505 mono_restore_context (&ctx);
507 g_assert_not_reached ();
511 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
512 mgreg_t eip, gint32 pc_offset)
514 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
517 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
521 /* Negate the ip adjustment done in mono_x86_throw_exception () */
524 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
528 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
529 mgreg_t eip, gboolean rethrow)
533 ctx.esp = regs [X86_ESP];
535 ctx.ebp = regs [X86_EBP];
536 ctx.edi = regs [X86_EDI];
537 ctx.esi = regs [X86_ESI];
538 ctx.ebx = regs [X86_EBX];
539 ctx.edx = regs [X86_EDX];
540 ctx.ecx = regs [X86_ECX];
541 ctx.eax = regs [X86_EAX];
543 mono_resume_unwind (&ctx);
547 * get_throw_trampoline:
549 * Generate a call to mono_x86_throw_exception/
550 * mono_x86_throw_corlib_exception.
551 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
552 * which doesn't push the arguments.
555 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
557 guint8 *start, *code;
558 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
559 MonoJumpInfo *ji = NULL;
560 GSList *unwind_ops = NULL;
561 guint kMaxCodeSize = NACL_SIZE (128, 256);
563 start = code = mono_global_codeman_reserve (kMaxCodeSize);
568 * On apple, the stack is misaligned by the pushing of the return address.
571 /* On OSX, we don't generate alignment code to save space */
574 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
577 * The stack looks like this:
578 * <pc offset> (only if corlib is TRUE)
579 * <exception object>/<type token>
580 * <return addr> <- esp (unaligned on apple)
583 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
584 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
587 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
588 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
593 arg_offsets [3] = 12;
597 for (i = 0; i < X86_NREG; ++i)
599 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
600 /* Calculate the offset between the current sp and the sp of the caller */
602 /* LLVM doesn't push the arguments */
603 stack_offset = stack_size + 4;
607 stack_offset = stack_size + 4 + 8;
609 /* We don't generate stack alignment code on osx to save space */
612 /* One argument + stack alignment */
613 stack_offset = stack_size + 4 + 4;
615 /* Pop the alignment added by OP_THROW too */
616 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
618 if (mono_do_x86_stack_align)
619 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
624 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
625 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
627 /* Set arg1 == regs */
628 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
629 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
630 /* Set arg2 == exc/ex_token_index */
632 x86_mov_reg_imm (code, X86_EAX, 0);
634 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
635 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
636 /* Set arg3 == eip */
638 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
640 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
641 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
642 /* Set arg4 == rethrow/pc_offset */
644 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
646 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
649 * The caller is LLVM code which passes the absolute address not a pc offset,
650 * so compensate by passing 0 as 'ip' and passing the negated abs address as
653 x86_neg_reg (code, X86_EAX);
655 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
657 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
661 // This can be called from runtime code, which can't guarantee that
662 // ebx contains the got address.
663 // So emit the got address loading code too
664 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
665 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");
666 x86_call_reg (code, X86_EAX);
668 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
670 x86_breakpoint (code);
672 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
674 g_assert ((code - start) < kMaxCodeSize);
677 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
681 for (l = unwind_ops; l; l = l->next)
683 g_slist_free (unwind_ops);
690 * mono_arch_get_throw_exception:
692 * Returns a function pointer which can be used to raise
693 * exceptions. The returned function has the following
694 * signature: void (*func) (MonoException *exc);
695 * For example to raise an arithmetic exception you can use:
697 * x86_push_imm (code, mono_get_exception_arithmetic ());
698 * x86_call_code (code, arch_get_throw_exception ());
702 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
704 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
708 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
710 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
714 * mono_arch_get_throw_corlib_exception:
716 * Returns a function pointer which can be used to raise
717 * corlib exceptions. The returned function has the following
718 * signature: void (*func) (guint32 ex_token, guint32 offset);
719 * Here, offset is the offset which needs to be substracted from the caller IP
720 * to get the IP of the throw. Passing the offset has the advantage that it
721 * needs no relocations in the caller.
724 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
726 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
730 mono_arch_exceptions_init (void)
735 * If we're running WoW64, we need to set the usermode exception policy
736 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
737 * or (eventually) Windows 7 SP1.
743 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
746 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
747 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
748 if (getter && setter) {
750 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
756 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
760 /* LLVM needs different throw trampolines */
761 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
762 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
764 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
765 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
767 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
768 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
770 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
771 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
773 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
774 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
776 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
780 * mono_arch_find_jit_info:
782 * See exceptions-amd64.c for docs.
785 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
786 MonoJitInfo *ji, MonoContext *ctx,
787 MonoContext *new_ctx, MonoLMF **lmf,
788 mgreg_t **save_locations,
789 StackFrameInfo *frame)
791 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
793 memset (frame, 0, sizeof (StackFrameInfo));
799 gssize regs [MONO_MAX_IREGS + 1];
801 guint32 unwind_info_len;
804 frame->type = FRAME_TYPE_MANAGED;
807 unwind_info = mono_aot_get_unwind_info (ji, &unwind_info_len);
809 unwind_info = mono_get_cached_unwind_info (ji->used_regs, &unwind_info_len);
811 regs [X86_EAX] = new_ctx->eax;
812 regs [X86_EBX] = new_ctx->ebx;
813 regs [X86_ECX] = new_ctx->ecx;
814 regs [X86_EDX] = new_ctx->edx;
815 regs [X86_ESP] = new_ctx->esp;
816 regs [X86_EBP] = new_ctx->ebp;
817 regs [X86_ESI] = new_ctx->esi;
818 regs [X86_EDI] = new_ctx->edi;
819 regs [X86_NREG] = new_ctx->eip;
821 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
822 (guint8*)ji->code_start + ji->code_size,
823 ip, regs, MONO_MAX_IREGS + 1,
824 save_locations, MONO_MAX_IREGS, &cfa);
826 new_ctx->eax = regs [X86_EAX];
827 new_ctx->ebx = regs [X86_EBX];
828 new_ctx->ecx = regs [X86_ECX];
829 new_ctx->edx = regs [X86_EDX];
830 new_ctx->esp = regs [X86_ESP];
831 new_ctx->ebp = regs [X86_EBP];
832 new_ctx->esi = regs [X86_ESI];
833 new_ctx->edi = regs [X86_EDI];
834 new_ctx->eip = regs [X86_NREG];
836 /* The CFA becomes the new SP value */
837 new_ctx->esp = (gssize)cfa;
842 if (*lmf && ((*lmf) != jit_tls->first_lmf)) {
843 gboolean is_tramp = ((guint32)((*lmf)->previous_lmf) & 1);
847 /* lmf->esp is only set in trampoline frames */
848 lmf_esp = (gpointer)(*lmf)->esp;
850 /* In non-trampoline frames, ebp is the frame pointer */
851 lmf_esp = (gpointer)(*lmf)->ebp;
852 if (MONO_CONTEXT_GET_SP (ctx) >= lmf_esp)
853 /* remove any unused lmf */
854 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
857 /* Pop arguments off the stack */
859 * FIXME: LLVM doesn't push these, we can't use ji->from_llvm as it describes
863 if (ji->has_arch_eh_info)
864 new_ctx->esp += mono_jit_info_get_arch_eh_info (ji)->stack_size;
870 if (((guint64)(*lmf)->previous_lmf) & 2) {
872 * This LMF entry is created by the soft debug code to mark transitions to
873 * managed code done during invokes.
875 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
877 g_assert (ext->debugger_invoke);
879 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
881 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
883 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
888 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
890 if (!((guint32)((*lmf)->previous_lmf) & 1))
893 g_assert_not_reached ();
894 /* Trampoline lmf frame */
895 frame->method = (*lmf)->method;
898 new_ctx->esi = (*lmf)->esi;
899 new_ctx->edi = (*lmf)->edi;
900 new_ctx->ebx = (*lmf)->ebx;
901 new_ctx->ebp = (*lmf)->ebp;
902 new_ctx->eip = (*lmf)->eip;
908 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
910 /* Check if we are in a trampoline LMF frame */
911 if ((guint32)((*lmf)->previous_lmf) & 1) {
912 /* lmf->esp is set by the trampoline code */
913 new_ctx->esp = (*lmf)->esp;
915 /* Pop arguments off the stack */
916 /* FIXME: Handle the delegate case too ((*lmf)->method == NULL) */
917 /* FIXME: Handle the IMT/vtable case too */
920 if ((*lmf)->method) {
921 MonoMethod *method = (*lmf)->method;
922 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (method)->param_count + 1);
924 guint32 stack_to_pop = mono_arch_get_argument_info (NULL, mono_method_signature (method), mono_method_signature (method)->param_count, arg_info);
925 new_ctx->esp += stack_to_pop;
931 /* the lmf is always stored on the stack, so the following
932 * expression points to a stack location which can be used as ESP */
933 new_ctx->esp = (unsigned long)&((*lmf)->eip);
935 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
944 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
946 mono_sigctx_to_monoctx (sigctx, mctx);
950 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
952 mono_monoctx_to_sigctx (mctx, sigctx);
956 mono_arch_ip_from_context (void *sigctx)
958 #if defined(__native_client__)
959 printf("WARNING: mono_arch_ip_from_context() called!\n");
962 #ifdef MONO_ARCH_USE_SIGACTION
963 ucontext_t *ctx = (ucontext_t*)sigctx;
964 return (gpointer)UCONTEXT_REG_EIP (ctx);
966 struct sigcontext *ctx = sigctx;
967 return (gpointer)ctx->SC_EIP;
969 #endif /* __native_client__ */
975 * Called by resuming from a signal handler.
978 handle_signal_exception (gpointer obj)
980 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
983 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
985 mono_handle_exception (&ctx, obj);
987 mono_restore_context (&ctx);
991 * mono_x86_get_signal_exception_trampoline:
993 * This x86 specific trampoline is used to call handle_signal_exception.
996 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
998 guint8 *start, *code;
999 MonoJumpInfo *ji = NULL;
1000 GSList *unwind_ops = NULL;
1003 start = code = mono_global_codeman_reserve (128);
1006 x86_push_reg (code, X86_ECX);
1008 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
1009 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
1011 /* Fix the alignment to be what apple expects */
1014 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
1015 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
1018 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
1019 /* Branch to target */
1020 x86_call_reg (code, X86_EDX);
1022 g_assert ((code - start) < 128);
1025 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
1029 for (l = unwind_ops; l; l = l->next)
1031 g_slist_free (unwind_ops);
1039 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
1042 * Can't pass the obj on the stack, since we are executing on the
1043 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
1044 * So put it into a register, and branch to a trampoline which
1047 ctx->eax = (mgreg_t)user_data;
1048 ctx->ecx = ctx->eip;
1049 ctx->edx = (mgreg_t)async_cb;
1052 ctx->esp = (ctx->esp - 16) & ~15;
1053 ctx->eip = (mgreg_t)signal_exception_trampoline;
1057 mono_arch_handle_exception (void *sigctx, gpointer obj)
1059 #if defined(MONO_ARCH_USE_SIGACTION)
1061 ucontext_t *ctx = (ucontext_t*)sigctx;
1064 * Handling the exception in the signal handler is problematic, since the original
1065 * signal is disabled, and we could run arbitrary code though the debugger. So
1066 * resume into the normal stack and do most work there if possible.
1068 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1070 /* Pass the ctx parameter in TLS */
1071 mono_arch_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1073 mctx = jit_tls->ex_ctx;
1074 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1075 mono_monoctx_to_sigctx (&mctx, sigctx);
1078 #elif defined (TARGET_WIN32)
1080 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1081 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1083 mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1085 mctx = jit_tls->ex_ctx;
1086 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1087 mono_monoctx_to_sigctx (&mctx, sigctx);
1093 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1095 mono_handle_exception (&mctx, obj);
1097 mono_arch_monoctx_to_sigctx (&mctx, sigctx);
1104 restore_soft_guard_pages (void)
1106 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1107 if (jit_tls->stack_ovf_guard_base)
1108 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1112 * this function modifies mctx so that when it is restored, it
1113 * won't execcute starting at mctx.eip, but in a function that
1114 * will restore the protection on the soft-guard pages and return back to
1115 * continue at mctx.eip.
1118 prepare_for_guard_pages (MonoContext *mctx)
1121 sp = (gpointer)(mctx->esp);
1123 /* the resturn addr */
1124 sp [0] = (gpointer)(mctx->eip);
1125 mctx->eip = (unsigned long)restore_soft_guard_pages;
1126 mctx->esp = (unsigned long)sp;
1130 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1136 mono_handle_exception (&mctx, obj);
1138 prepare_for_guard_pages (&mctx);
1139 mono_restore_context (&mctx);
1143 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
1145 #ifdef MONO_ARCH_USE_SIGACTION
1146 MonoException *exc = NULL;
1147 ucontext_t *ctx = (ucontext_t*)sigctx;
1148 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1152 /* if we didn't find a managed method for the ip address and it matches the fault
1153 * address, we assume we followed a broken pointer during an indirect call, so
1154 * we try the lookup again with the return address pushed on the stack
1156 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1157 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1158 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1160 UCONTEXT_REG_EIP (ctx) = sp [0];
1163 exc = mono_domain_get ()->stack_overflow_ex;
1165 mono_handle_native_sigsegv (SIGSEGV, sigctx);
1166 /* setup a call frame on the real stack so that control is returned there
1167 * and exception handling can continue.
1168 * If this was a stack overflow the caller already ensured the stack pages
1169 * needed have been unprotected.
1170 * The frame looks like:
1177 // FIXME: test_only is no more.
1178 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1181 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1182 sp = (gpointer)((char*)sp - frame_size);
1183 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1186 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1189 sp [2] = (gpointer)stack_ovf;
1190 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1191 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1192 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1193 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1197 #if MONO_SUPPORT_TASKLETS
1198 MonoContinuationRestore
1199 mono_tasklets_arch_restore (void)
1201 static guint8* saved = NULL;
1202 guint8 *code, *start;
1204 #ifdef __native_client_codegen__
1205 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1208 return (MonoContinuationRestore)saved;
1209 code = start = mono_global_codeman_reserve (48);
1210 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1211 /* put cont in edx */
1212 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1213 /* state in eax, so it's setup as the return value */
1214 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1216 /* setup the copy of the stack */
1217 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1218 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1220 x86_mov_reg_membase (code, X86_ESI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1221 x86_mov_reg_membase (code, X86_EDI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1222 x86_prefix (code, X86_REP_PREFIX);
1225 /* now restore the registers from the LMF */
1226 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1227 x86_mov_reg_membase (code, X86_EBX, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebx), 4);
1228 x86_mov_reg_membase (code, X86_EBP, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebp), 4);
1229 x86_mov_reg_membase (code, X86_ESI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, esi), 4);
1230 x86_mov_reg_membase (code, X86_EDI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, edi), 4);
1232 /* restore the lmf chain */
1233 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1234 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1236 x86_jump_membase (code, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_ip));
1237 g_assert ((code - start) <= 48);
1239 return (MonoContinuationRestore)saved;
1244 * mono_arch_setup_resume_sighandler_ctx:
1246 * Setup CTX so execution continues at FUNC.
1249 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1251 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1254 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1256 MONO_CONTEXT_SET_IP (ctx, func);