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, sctx)
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);
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, MONO_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 /* convert sigcontext to MonoContext (due to reuse of stack walking helpers */
143 mono_arch_sigctx_to_monoctx (sctx, &ctx);
145 /* get our os page size */
147 page_size = si.dwPageSize;
149 /* Let's walk the stack to recover
150 * the needed stack space (if possible)
152 memset (&rji, 0, sizeof (rji));
155 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
157 /* try to free 64kb from our stack */
161 mono_arch_find_jit_info (domain, jit_tls, &rji, &ctx, &new_ctx, &lmf, NULL, &frame);
163 g_warning ("Exception inside function without unwind info");
164 g_assert_not_reached ();
167 if (frame.ji != (gpointer)-1) {
168 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
171 /* todo: we should call abort if ji is -1 */
173 } while (free_stack < 64 * 1024 && frame.ji != (gpointer) -1);
175 /* convert into sigcontext to be used in mono_arch_handle_exception */
176 mono_arch_monoctx_to_sigctx (&ctx, sctx);
178 /* todo: install new stack-guard page */
180 /* use the new stack and call mono_arch_handle_exception () */
181 restore_stack (sctx);
185 * Unhandled Exception Filter
186 * Top-level per-process exception handler.
188 LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
190 EXCEPTION_RECORD* er;
192 struct sigcontext* sctx;
194 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
196 /* If the thread is not managed by the runtime return early */
198 return EXCEPTION_CONTINUE_SEARCH;
200 jit_tls->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);
237 jit_tls->mono_win_chained_exception_needs_run = TRUE;
241 if (jit_tls->mono_win_chained_exception_needs_run) {
242 /* Don't copy context back if we chained exception
243 * as the handler may have modfied the EXCEPTION_POINTERS
244 * directly. We don't pass sigcontext to chained handlers.
245 * Return continue search so the UnhandledExceptionFilter
246 * can correctly chain the exception.
248 res = EXCEPTION_CONTINUE_SEARCH;
250 /* Copy context back */
251 ctx->Eax = sctx->eax;
252 ctx->Ebx = sctx->ebx;
253 ctx->Ecx = sctx->ecx;
254 ctx->Edx = sctx->edx;
255 ctx->Ebp = sctx->ebp;
256 ctx->Esp = sctx->esp;
257 ctx->Esi = sctx->esi;
258 ctx->Edi = sctx->edi;
259 ctx->Eip = sctx->eip;
262 /* TODO: Find right place to free this in stack overflow case */
263 if (er->ExceptionCode != EXCEPTION_STACK_OVERFLOW)
269 void win32_seh_init()
271 /* install restore stack helper */
273 restore_stack = mono_win32_get_handle_stackoverflow ();
275 mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
276 mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
279 void win32_seh_cleanup()
281 if (mono_old_win_toplevel_exception_filter) SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
282 RemoveVectoredExceptionHandler (seh_unhandled_exception_filter);
285 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
289 fpe_handler = handler;
292 ill_handler = handler;
295 segv_handler = handler;
302 #endif /* TARGET_WIN32 */
305 * mono_arch_get_restore_context:
307 * Returns a pointer to a method which restores a previously saved sigcontext.
310 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
312 guint8 *start = NULL;
314 MonoJumpInfo *ji = NULL;
315 GSList *unwind_ops = NULL;
317 /* restore_contect (MonoContext *ctx) */
319 start = code = mono_global_codeman_reserve (128);
322 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
325 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
328 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
331 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
334 x86_mov_reg_membase (code, X86_EDX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edx), 4);
337 * The context resides on the stack, in the stack frame of the
338 * caller of this function. The stack pointer that we need to
339 * restore is potentially many stack frames higher up, so the
340 * distance between them can easily be more than the red zone
341 * size. Hence the stack pointer can be restored only after
342 * we have finished loading everything from the context.
345 /* load ESP into EBP */
346 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esp), 4);
347 /* load return address into ECX */
348 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eip), 4);
349 /* save the return addr to the restored stack - 4 */
350 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
352 /* load EBP into ECX */
353 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
354 /* save EBP to the restored stack - 8 */
355 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
357 /* load EAX into ECX */
358 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eax), 4);
359 /* save EAX to the restored stack - 12 */
360 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
363 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ecx), 4);
365 /* restore ESP - 12 */
366 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
368 x86_pop_reg (code, X86_EAX);
370 x86_pop_reg (code, X86_EBP);
371 /* jump to the saved IP */
374 nacl_global_codeman_validate(&start, 128, &code);
377 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
381 for (l = unwind_ops; l; l = l->next)
383 g_slist_free (unwind_ops);
390 * mono_arch_get_call_filter:
392 * Returns a pointer to a method which calls an exception filter. We
393 * also use this function to call finally handlers (we pass NULL as
394 * @exc object in this case).
397 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
401 MonoJumpInfo *ji = NULL;
402 GSList *unwind_ops = NULL;
403 guint kMaxCodeSize = NACL_SIZE (64, 128);
405 /* call_filter (MonoContext *ctx, unsigned long eip) */
406 start = code = mono_global_codeman_reserve (kMaxCodeSize);
408 x86_push_reg (code, X86_EBP);
409 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
410 x86_push_reg (code, X86_EBX);
411 x86_push_reg (code, X86_EDI);
412 x86_push_reg (code, X86_ESI);
415 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
417 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
419 x86_push_reg (code, X86_EBP);
422 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
423 /* restore registers used by global register allocation (EBX & ESI) */
424 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
425 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
426 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
428 /* align stack and save ESP */
429 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
430 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
431 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
432 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
433 x86_push_reg (code, X86_EDX);
435 /* call the handler */
436 x86_call_reg (code, X86_ECX);
439 x86_pop_reg (code, X86_ESP);
442 x86_pop_reg (code, X86_EBP);
444 /* restore saved regs */
445 x86_pop_reg (code, X86_ESI);
446 x86_pop_reg (code, X86_EDI);
447 x86_pop_reg (code, X86_EBX);
451 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
454 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
458 for (l = unwind_ops; l; l = l->next)
460 g_slist_free (unwind_ops);
463 g_assert ((code - start) < kMaxCodeSize);
468 * mono_x86_throw_exception:
470 * C function called from the throw trampolines.
473 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
474 mgreg_t eip, gboolean rethrow)
478 ctx.esp = regs [X86_ESP];
480 ctx.ebp = regs [X86_EBP];
481 ctx.edi = regs [X86_EDI];
482 ctx.esi = regs [X86_ESI];
483 ctx.ebx = regs [X86_EBX];
484 ctx.edx = regs [X86_EDX];
485 ctx.ecx = regs [X86_ECX];
486 ctx.eax = regs [X86_EAX];
489 /* The OSX ABI specifies 16 byte alignment at call sites */
490 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
493 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
494 MonoException *mono_ex = (MonoException*)exc;
496 mono_ex->stack_trace = NULL;
499 /* adjust eip so that it point into the call instruction */
502 mono_handle_exception (&ctx, exc);
504 mono_restore_context (&ctx);
506 g_assert_not_reached ();
510 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
511 mgreg_t eip, gint32 pc_offset)
513 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
516 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
520 /* Negate the ip adjustment done in mono_x86_throw_exception () */
523 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
527 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
528 mgreg_t eip, gboolean rethrow)
532 ctx.esp = regs [X86_ESP];
534 ctx.ebp = regs [X86_EBP];
535 ctx.edi = regs [X86_EDI];
536 ctx.esi = regs [X86_ESI];
537 ctx.ebx = regs [X86_EBX];
538 ctx.edx = regs [X86_EDX];
539 ctx.ecx = regs [X86_ECX];
540 ctx.eax = regs [X86_EAX];
542 mono_resume_unwind (&ctx);
546 * get_throw_trampoline:
548 * Generate a call to mono_x86_throw_exception/
549 * mono_x86_throw_corlib_exception.
550 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
551 * which doesn't push the arguments.
554 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
556 guint8 *start, *code;
557 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
558 MonoJumpInfo *ji = NULL;
559 GSList *unwind_ops = NULL;
560 guint kMaxCodeSize = NACL_SIZE (128, 256);
562 start = code = mono_global_codeman_reserve (kMaxCodeSize);
567 * On apple, the stack is misaligned by the pushing of the return address.
570 /* On OSX, we don't generate alignment code to save space */
573 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
576 * The stack looks like this:
577 * <pc offset> (only if corlib is TRUE)
578 * <exception object>/<type token>
579 * <return addr> <- esp (unaligned on apple)
582 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
583 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
586 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
587 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
592 arg_offsets [3] = 12;
596 for (i = 0; i < X86_NREG; ++i)
598 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
599 /* Calculate the offset between the current sp and the sp of the caller */
601 /* LLVM doesn't push the arguments */
602 stack_offset = stack_size + 4;
606 stack_offset = stack_size + 4 + 8;
608 /* We don't generate stack alignment code on osx to save space */
611 /* One argument + stack alignment */
612 stack_offset = stack_size + 4 + 4;
614 /* Pop the alignment added by OP_THROW too */
615 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
617 if (mono_do_x86_stack_align)
618 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
623 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
624 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
626 /* Set arg1 == regs */
627 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
628 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
629 /* Set arg2 == exc/ex_token_index */
631 x86_mov_reg_imm (code, X86_EAX, 0);
633 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
634 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
635 /* Set arg3 == eip */
637 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
639 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
640 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
641 /* Set arg4 == rethrow/pc_offset */
643 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
645 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
648 * The caller is LLVM code which passes the absolute address not a pc offset,
649 * so compensate by passing 0 as 'ip' and passing the negated abs address as
652 x86_neg_reg (code, X86_EAX);
654 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
656 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
660 // This can be called from runtime code, which can't guarantee that
661 // ebx contains the got address.
662 // So emit the got address loading code too
663 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
664 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");
665 x86_call_reg (code, X86_EAX);
667 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
669 x86_breakpoint (code);
671 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
673 g_assert ((code - start) < kMaxCodeSize);
676 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
680 for (l = unwind_ops; l; l = l->next)
682 g_slist_free (unwind_ops);
689 * mono_arch_get_throw_exception:
691 * Returns a function pointer which can be used to raise
692 * exceptions. The returned function has the following
693 * signature: void (*func) (MonoException *exc);
694 * For example to raise an arithmetic exception you can use:
696 * x86_push_imm (code, mono_get_exception_arithmetic ());
697 * x86_call_code (code, arch_get_throw_exception ());
701 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
703 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
707 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
709 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
713 * mono_arch_get_throw_corlib_exception:
715 * Returns a function pointer which can be used to raise
716 * corlib exceptions. The returned function has the following
717 * signature: void (*func) (guint32 ex_token, guint32 offset);
718 * Here, offset is the offset which needs to be substracted from the caller IP
719 * to get the IP of the throw. Passing the offset has the advantage that it
720 * needs no relocations in the caller.
723 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
725 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
729 mono_arch_exceptions_init (void)
734 * If we're running WoW64, we need to set the usermode exception policy
735 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
736 * or (eventually) Windows 7 SP1.
742 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
745 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
746 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
747 if (getter && setter) {
749 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
755 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
759 /* LLVM needs different throw trampolines */
760 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
761 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
763 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
764 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
766 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
767 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
769 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
770 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
772 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
773 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
775 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
779 * mono_arch_find_jit_info:
781 * See exceptions-amd64.c for docs.
784 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
785 MonoJitInfo *ji, MonoContext *ctx,
786 MonoContext *new_ctx, MonoLMF **lmf,
787 mgreg_t **save_locations,
788 StackFrameInfo *frame)
790 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
792 memset (frame, 0, sizeof (StackFrameInfo));
798 gssize regs [MONO_MAX_IREGS + 1];
800 guint32 unwind_info_len;
803 frame->type = FRAME_TYPE_MANAGED;
805 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
807 regs [X86_EAX] = new_ctx->eax;
808 regs [X86_EBX] = new_ctx->ebx;
809 regs [X86_ECX] = new_ctx->ecx;
810 regs [X86_EDX] = new_ctx->edx;
811 regs [X86_ESP] = new_ctx->esp;
812 regs [X86_EBP] = new_ctx->ebp;
813 regs [X86_ESI] = new_ctx->esi;
814 regs [X86_EDI] = new_ctx->edi;
815 regs [X86_NREG] = new_ctx->eip;
817 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
818 (guint8*)ji->code_start + ji->code_size,
819 ip, NULL, regs, MONO_MAX_IREGS + 1,
820 save_locations, MONO_MAX_IREGS, &cfa);
822 new_ctx->eax = regs [X86_EAX];
823 new_ctx->ebx = regs [X86_EBX];
824 new_ctx->ecx = regs [X86_ECX];
825 new_ctx->edx = regs [X86_EDX];
826 new_ctx->esp = regs [X86_ESP];
827 new_ctx->ebp = regs [X86_EBP];
828 new_ctx->esi = regs [X86_ESI];
829 new_ctx->edi = regs [X86_EDI];
830 new_ctx->eip = regs [X86_NREG];
832 /* The CFA becomes the new SP value */
833 new_ctx->esp = (gssize)cfa;
839 #ifndef MONO_X86_NO_PUSHES
840 /* Pop arguments off the stack */
841 if (ji->has_arch_eh_info) {
844 stack_size = mono_jit_info_get_arch_eh_info (ji)->stack_size;
848 MonoJitInfo *caller_ji;
850 caller_ji = mini_jit_info_table_find (domain, (char*)new_ctx->eip, NULL);
851 /* LLVM doesn't push the arguments */
852 if (caller_ji && !caller_ji->from_llvm)
853 new_ctx->esp += stack_size;
855 new_ctx->esp += stack_size;
864 if (((guint64)(*lmf)->previous_lmf) & 2) {
866 * This LMF entry is created by the soft debug code to mark transitions to
867 * managed code done during invokes.
869 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
871 g_assert (ext->debugger_invoke);
873 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
875 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
877 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
882 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
884 if (!((guint32)((*lmf)->previous_lmf) & 1))
887 g_assert_not_reached ();
888 /* Trampoline lmf frame */
889 frame->method = (*lmf)->method;
892 new_ctx->esi = (*lmf)->esi;
893 new_ctx->edi = (*lmf)->edi;
894 new_ctx->ebx = (*lmf)->ebx;
895 new_ctx->ebp = (*lmf)->ebp;
896 new_ctx->eip = (*lmf)->eip;
902 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
904 /* Check if we are in a trampoline LMF frame */
905 if ((guint32)((*lmf)->previous_lmf) & 1) {
906 /* lmf->esp is set by the trampoline code */
907 new_ctx->esp = (*lmf)->esp;
909 /* Pop arguments off the stack */
910 /* FIXME: Handle the delegate case too ((*lmf)->method == NULL) */
911 /* FIXME: Handle the IMT/vtable case too */
914 if ((*lmf)->method) {
915 MonoMethod *method = (*lmf)->method;
916 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (method)->param_count + 1);
918 guint32 stack_to_pop = mono_arch_get_argument_info (NULL, mono_method_signature (method), mono_method_signature (method)->param_count, arg_info);
919 new_ctx->esp += stack_to_pop;
925 /* the lmf is always stored on the stack, so the following
926 * expression points to a stack location which can be used as ESP */
927 new_ctx->esp = (unsigned long)&((*lmf)->eip);
929 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
938 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
940 mono_sigctx_to_monoctx (sigctx, mctx);
944 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
946 mono_monoctx_to_sigctx (mctx, sigctx);
950 mono_arch_ip_from_context (void *sigctx)
952 #if defined(__native_client__)
953 printf("WARNING: mono_arch_ip_from_context() called!\n");
956 #ifdef MONO_ARCH_USE_SIGACTION
957 ucontext_t *ctx = (ucontext_t*)sigctx;
958 return (gpointer)UCONTEXT_REG_EIP (ctx);
960 struct sigcontext *ctx = sigctx;
961 return (gpointer)ctx->SC_EIP;
963 #endif /* __native_client__ */
969 * Called by resuming from a signal handler.
972 handle_signal_exception (gpointer obj)
974 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
977 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
979 mono_handle_exception (&ctx, obj);
981 mono_restore_context (&ctx);
985 * mono_x86_get_signal_exception_trampoline:
987 * This x86 specific trampoline is used to call handle_signal_exception.
990 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
992 guint8 *start, *code;
993 MonoJumpInfo *ji = NULL;
994 GSList *unwind_ops = NULL;
997 start = code = mono_global_codeman_reserve (128);
1000 x86_push_reg (code, X86_ECX);
1002 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
1003 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
1005 /* Fix the alignment to be what apple expects */
1008 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
1009 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
1012 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
1013 /* Branch to target */
1014 x86_call_reg (code, X86_EDX);
1016 g_assert ((code - start) < 128);
1019 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
1023 for (l = unwind_ops; l; l = l->next)
1025 g_slist_free (unwind_ops);
1033 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
1036 * Can't pass the obj on the stack, since we are executing on the
1037 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
1038 * So put it into a register, and branch to a trampoline which
1041 ctx->eax = (mgreg_t)user_data;
1042 ctx->ecx = ctx->eip;
1043 ctx->edx = (mgreg_t)async_cb;
1046 ctx->esp = (ctx->esp - 16) & ~15;
1047 ctx->eip = (mgreg_t)signal_exception_trampoline;
1051 mono_arch_handle_exception (void *sigctx, gpointer obj)
1053 #if defined(MONO_ARCH_USE_SIGACTION)
1055 ucontext_t *ctx = (ucontext_t*)sigctx;
1058 * Handling the exception in the signal handler is problematic, since the original
1059 * signal is disabled, and we could run arbitrary code though the debugger. So
1060 * resume into the normal stack and do most work there if possible.
1062 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1064 /* Pass the ctx parameter in TLS */
1065 mono_arch_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1067 mctx = jit_tls->ex_ctx;
1068 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1069 mono_monoctx_to_sigctx (&mctx, sigctx);
1072 #elif defined (TARGET_WIN32)
1074 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1075 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1077 mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1079 mctx = jit_tls->ex_ctx;
1080 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1081 mono_monoctx_to_sigctx (&mctx, sigctx);
1087 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1089 mono_handle_exception (&mctx, obj);
1091 mono_arch_monoctx_to_sigctx (&mctx, sigctx);
1098 restore_soft_guard_pages (void)
1100 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1101 if (jit_tls->stack_ovf_guard_base)
1102 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1106 * this function modifies mctx so that when it is restored, it
1107 * won't execcute starting at mctx.eip, but in a function that
1108 * will restore the protection on the soft-guard pages and return back to
1109 * continue at mctx.eip.
1112 prepare_for_guard_pages (MonoContext *mctx)
1115 sp = (gpointer)(mctx->esp);
1117 /* the resturn addr */
1118 sp [0] = (gpointer)(mctx->eip);
1119 mctx->eip = (unsigned long)restore_soft_guard_pages;
1120 mctx->esp = (unsigned long)sp;
1124 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1130 mono_handle_exception (&mctx, obj);
1132 prepare_for_guard_pages (&mctx);
1133 mono_restore_context (&mctx);
1137 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
1139 #ifdef MONO_ARCH_USE_SIGACTION
1140 MonoException *exc = NULL;
1141 ucontext_t *ctx = (ucontext_t*)sigctx;
1142 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1146 /* if we didn't find a managed method for the ip address and it matches the fault
1147 * address, we assume we followed a broken pointer during an indirect call, so
1148 * we try the lookup again with the return address pushed on the stack
1150 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1151 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1152 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1154 UCONTEXT_REG_EIP (ctx) = sp [0];
1157 exc = mono_domain_get ()->stack_overflow_ex;
1159 mono_handle_native_sigsegv (SIGSEGV, sigctx);
1160 /* setup a call frame on the real stack so that control is returned there
1161 * and exception handling can continue.
1162 * If this was a stack overflow the caller already ensured the stack pages
1163 * needed have been unprotected.
1164 * The frame looks like:
1171 // FIXME: test_only is no more.
1172 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1175 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1176 sp = (gpointer)((char*)sp - frame_size);
1177 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1180 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1183 sp [2] = (gpointer)stack_ovf;
1184 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1185 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1186 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1187 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1191 #if MONO_SUPPORT_TASKLETS
1192 MonoContinuationRestore
1193 mono_tasklets_arch_restore (void)
1195 static guint8* saved = NULL;
1196 guint8 *code, *start;
1198 #ifdef __native_client_codegen__
1199 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1202 return (MonoContinuationRestore)saved;
1203 code = start = mono_global_codeman_reserve (48);
1204 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1205 /* put cont in edx */
1206 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1207 /* state in eax, so it's setup as the return value */
1208 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1210 /* setup the copy of the stack */
1211 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1212 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1214 x86_mov_reg_membase (code, X86_ESI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1215 x86_mov_reg_membase (code, X86_EDI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1216 x86_prefix (code, X86_REP_PREFIX);
1219 /* now restore the registers from the LMF */
1220 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1221 x86_mov_reg_membase (code, X86_EBX, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebx), 4);
1222 x86_mov_reg_membase (code, X86_EBP, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebp), 4);
1223 x86_mov_reg_membase (code, X86_ESI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, esi), 4);
1224 x86_mov_reg_membase (code, X86_EDI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, edi), 4);
1226 /* restore the lmf chain */
1227 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1228 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1230 x86_jump_membase (code, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_ip));
1231 g_assert ((code - start) <= 48);
1233 return (MonoContinuationRestore)saved;
1238 * mono_arch_setup_resume_sighandler_ctx:
1240 * Setup CTX so execution continues at FUNC.
1243 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1245 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1248 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1250 MONO_CONTEXT_SET_IP (ctx, func);