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 /* load return address into ECX */
347 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eip), 4);
348 /* save the return addr to the restored stack - 4 */
349 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
351 /* load EBP into ECX */
352 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
353 /* save EBP to the restored stack - 8 */
354 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
356 /* load EAX into ECX */
357 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eax), 4);
358 /* save EAX to the restored stack - 12 */
359 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
362 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ecx), 4);
364 /* restore ESP - 12 */
365 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
367 x86_pop_reg (code, X86_EAX);
369 x86_pop_reg (code, X86_EBP);
370 /* jump to the saved IP */
373 nacl_global_codeman_validate(&start, 128, &code);
376 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
380 for (l = unwind_ops; l; l = l->next)
382 g_slist_free (unwind_ops);
389 * mono_arch_get_call_filter:
391 * Returns a pointer to a method which calls an exception filter. We
392 * also use this function to call finally handlers (we pass NULL as
393 * @exc object in this case).
396 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
400 MonoJumpInfo *ji = NULL;
401 GSList *unwind_ops = NULL;
402 guint kMaxCodeSize = NACL_SIZE (64, 128);
404 /* call_filter (MonoContext *ctx, unsigned long eip) */
405 start = code = mono_global_codeman_reserve (kMaxCodeSize);
407 x86_push_reg (code, X86_EBP);
408 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
409 x86_push_reg (code, X86_EBX);
410 x86_push_reg (code, X86_EDI);
411 x86_push_reg (code, X86_ESI);
414 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
416 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
418 x86_push_reg (code, X86_EBP);
421 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
422 /* restore registers used by global register allocation (EBX & ESI) */
423 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebx), 4);
424 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (MonoContext, esi), 4);
425 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (MonoContext, edi), 4);
427 /* align stack and save ESP */
428 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
429 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
430 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
431 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
432 x86_push_reg (code, X86_EDX);
434 /* call the handler */
435 x86_call_reg (code, X86_ECX);
438 x86_pop_reg (code, X86_ESP);
441 x86_pop_reg (code, X86_EBP);
443 /* restore saved regs */
444 x86_pop_reg (code, X86_ESI);
445 x86_pop_reg (code, X86_EDI);
446 x86_pop_reg (code, X86_EBX);
450 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
453 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
457 for (l = unwind_ops; l; l = l->next)
459 g_slist_free (unwind_ops);
462 g_assert ((code - start) < kMaxCodeSize);
467 * mono_x86_throw_exception:
469 * C function called from the throw trampolines.
472 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
473 mgreg_t eip, gboolean rethrow)
477 ctx.esp = regs [X86_ESP];
479 ctx.ebp = regs [X86_EBP];
480 ctx.edi = regs [X86_EDI];
481 ctx.esi = regs [X86_ESI];
482 ctx.ebx = regs [X86_EBX];
483 ctx.edx = regs [X86_EDX];
484 ctx.ecx = regs [X86_ECX];
485 ctx.eax = regs [X86_EAX];
488 /* The OSX ABI specifies 16 byte alignment at call sites */
489 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
492 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
493 MonoException *mono_ex = (MonoException*)exc;
495 mono_ex->stack_trace = NULL;
498 /* adjust eip so that it point into the call instruction */
501 mono_handle_exception (&ctx, exc);
503 mono_restore_context (&ctx);
505 g_assert_not_reached ();
509 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
510 mgreg_t eip, gint32 pc_offset)
512 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
515 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
519 /* Negate the ip adjustment done in mono_x86_throw_exception () */
522 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
526 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
527 mgreg_t eip, gboolean rethrow)
531 ctx.esp = regs [X86_ESP];
533 ctx.ebp = regs [X86_EBP];
534 ctx.edi = regs [X86_EDI];
535 ctx.esi = regs [X86_ESI];
536 ctx.ebx = regs [X86_EBX];
537 ctx.edx = regs [X86_EDX];
538 ctx.ecx = regs [X86_ECX];
539 ctx.eax = regs [X86_EAX];
541 mono_resume_unwind (&ctx);
545 * get_throw_trampoline:
547 * Generate a call to mono_x86_throw_exception/
548 * mono_x86_throw_corlib_exception.
549 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
550 * which doesn't push the arguments.
553 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
555 guint8 *start, *code;
556 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
557 MonoJumpInfo *ji = NULL;
558 GSList *unwind_ops = NULL;
559 guint kMaxCodeSize = NACL_SIZE (128, 256);
561 start = code = mono_global_codeman_reserve (kMaxCodeSize);
566 * On apple, the stack is misaligned by the pushing of the return address.
569 /* On OSX, we don't generate alignment code to save space */
572 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
575 * The stack looks like this:
576 * <pc offset> (only if corlib is TRUE)
577 * <exception object>/<type token>
578 * <return addr> <- esp (unaligned on apple)
581 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
582 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
585 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
586 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
591 arg_offsets [3] = 12;
595 for (i = 0; i < X86_NREG; ++i)
597 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
598 /* Calculate the offset between the current sp and the sp of the caller */
600 /* LLVM doesn't push the arguments */
601 stack_offset = stack_size + 4;
605 stack_offset = stack_size + 4 + 8;
607 /* We don't generate stack alignment code on osx to save space */
610 /* One argument + stack alignment */
611 stack_offset = stack_size + 4 + 4;
613 /* Pop the alignment added by OP_THROW too */
614 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
616 if (mono_do_x86_stack_align)
617 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
622 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
623 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
625 /* Set arg1 == regs */
626 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
627 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
628 /* Set arg2 == exc/ex_token_index */
630 x86_mov_reg_imm (code, X86_EAX, 0);
632 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
633 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
634 /* Set arg3 == eip */
636 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
638 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
639 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
640 /* Set arg4 == rethrow/pc_offset */
642 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
644 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
647 * The caller is LLVM code which passes the absolute address not a pc offset,
648 * so compensate by passing 0 as 'ip' and passing the negated abs address as
651 x86_neg_reg (code, X86_EAX);
653 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
655 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
659 // This can be called from runtime code, which can't guarantee that
660 // ebx contains the got address.
661 // So emit the got address loading code too
662 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
663 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");
664 x86_call_reg (code, X86_EAX);
666 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
668 x86_breakpoint (code);
670 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
672 g_assert ((code - start) < kMaxCodeSize);
675 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
679 for (l = unwind_ops; l; l = l->next)
681 g_slist_free (unwind_ops);
688 * mono_arch_get_throw_exception:
690 * Returns a function pointer which can be used to raise
691 * exceptions. The returned function has the following
692 * signature: void (*func) (MonoException *exc);
693 * For example to raise an arithmetic exception you can use:
695 * x86_push_imm (code, mono_get_exception_arithmetic ());
696 * x86_call_code (code, arch_get_throw_exception ());
700 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
702 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
706 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
708 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
712 * mono_arch_get_throw_corlib_exception:
714 * Returns a function pointer which can be used to raise
715 * corlib exceptions. The returned function has the following
716 * signature: void (*func) (guint32 ex_token, guint32 offset);
717 * Here, offset is the offset which needs to be substracted from the caller IP
718 * to get the IP of the throw. Passing the offset has the advantage that it
719 * needs no relocations in the caller.
722 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
724 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
728 mono_arch_exceptions_init (void)
733 * If we're running WoW64, we need to set the usermode exception policy
734 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
735 * or (eventually) Windows 7 SP1.
741 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
744 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
745 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
746 if (getter && setter) {
748 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
754 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
758 /* LLVM needs different throw trampolines */
759 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
760 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
762 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
763 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
765 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
766 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
768 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
769 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
771 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
772 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
774 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
778 * mono_arch_find_jit_info:
780 * See exceptions-amd64.c for docs.
783 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
784 MonoJitInfo *ji, MonoContext *ctx,
785 MonoContext *new_ctx, MonoLMF **lmf,
786 mgreg_t **save_locations,
787 StackFrameInfo *frame)
789 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
791 memset (frame, 0, sizeof (StackFrameInfo));
797 gssize regs [MONO_MAX_IREGS + 1];
799 guint32 unwind_info_len;
802 frame->type = FRAME_TYPE_MANAGED;
804 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
806 regs [X86_EAX] = new_ctx->eax;
807 regs [X86_EBX] = new_ctx->ebx;
808 regs [X86_ECX] = new_ctx->ecx;
809 regs [X86_EDX] = new_ctx->edx;
810 regs [X86_ESP] = new_ctx->esp;
811 regs [X86_EBP] = new_ctx->ebp;
812 regs [X86_ESI] = new_ctx->esi;
813 regs [X86_EDI] = new_ctx->edi;
814 regs [X86_NREG] = new_ctx->eip;
816 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
817 (guint8*)ji->code_start + ji->code_size,
818 ip, regs, MONO_MAX_IREGS + 1,
819 save_locations, MONO_MAX_IREGS, &cfa);
821 new_ctx->eax = regs [X86_EAX];
822 new_ctx->ebx = regs [X86_EBX];
823 new_ctx->ecx = regs [X86_ECX];
824 new_ctx->edx = regs [X86_EDX];
825 new_ctx->esp = regs [X86_ESP];
826 new_ctx->ebp = regs [X86_EBP];
827 new_ctx->esi = regs [X86_ESI];
828 new_ctx->edi = regs [X86_EDI];
829 new_ctx->eip = regs [X86_NREG];
831 /* The CFA becomes the new SP value */
832 new_ctx->esp = (gssize)cfa;
837 if (*lmf && ((*lmf) != jit_tls->first_lmf)) {
838 gboolean is_tramp = ((guint32)((*lmf)->previous_lmf) & 1);
842 /* lmf->esp is only set in trampoline frames */
843 lmf_esp = (gpointer)(*lmf)->esp;
845 /* In non-trampoline frames, ebp is the frame pointer */
846 lmf_esp = (gpointer)(*lmf)->ebp;
847 if (MONO_CONTEXT_GET_SP (ctx) >= lmf_esp)
848 /* remove any unused lmf */
849 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
852 /* Pop arguments off the stack */
854 * FIXME: LLVM doesn't push these, we can't use ji->from_llvm as it describes
858 if (ji->has_arch_eh_info)
859 new_ctx->esp += mono_jit_info_get_arch_eh_info (ji)->stack_size;
865 if (((guint64)(*lmf)->previous_lmf) & 2) {
867 * This LMF entry is created by the soft debug code to mark transitions to
868 * managed code done during invokes.
870 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
872 g_assert (ext->debugger_invoke);
874 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
876 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
878 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
883 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
885 if (!((guint32)((*lmf)->previous_lmf) & 1))
888 g_assert_not_reached ();
889 /* Trampoline lmf frame */
890 frame->method = (*lmf)->method;
893 new_ctx->esi = (*lmf)->esi;
894 new_ctx->edi = (*lmf)->edi;
895 new_ctx->ebx = (*lmf)->ebx;
896 new_ctx->ebp = (*lmf)->ebp;
897 new_ctx->eip = (*lmf)->eip;
903 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
905 /* Check if we are in a trampoline LMF frame */
906 if ((guint32)((*lmf)->previous_lmf) & 1) {
907 /* lmf->esp is set by the trampoline code */
908 new_ctx->esp = (*lmf)->esp;
910 /* Pop arguments off the stack */
911 /* FIXME: Handle the delegate case too ((*lmf)->method == NULL) */
912 /* FIXME: Handle the IMT/vtable case too */
915 if ((*lmf)->method) {
916 MonoMethod *method = (*lmf)->method;
917 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (method)->param_count + 1);
919 guint32 stack_to_pop = mono_arch_get_argument_info (NULL, mono_method_signature (method), mono_method_signature (method)->param_count, arg_info);
920 new_ctx->esp += stack_to_pop;
926 /* the lmf is always stored on the stack, so the following
927 * expression points to a stack location which can be used as ESP */
928 new_ctx->esp = (unsigned long)&((*lmf)->eip);
930 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
939 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
941 mono_sigctx_to_monoctx (sigctx, mctx);
945 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
947 mono_monoctx_to_sigctx (mctx, sigctx);
951 mono_arch_ip_from_context (void *sigctx)
953 #if defined(__native_client__)
954 printf("WARNING: mono_arch_ip_from_context() called!\n");
957 #ifdef MONO_ARCH_USE_SIGACTION
958 ucontext_t *ctx = (ucontext_t*)sigctx;
959 return (gpointer)UCONTEXT_REG_EIP (ctx);
961 struct sigcontext *ctx = sigctx;
962 return (gpointer)ctx->SC_EIP;
964 #endif /* __native_client__ */
970 * Called by resuming from a signal handler.
973 handle_signal_exception (gpointer obj)
975 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
978 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
980 mono_handle_exception (&ctx, obj);
982 mono_restore_context (&ctx);
986 * mono_x86_get_signal_exception_trampoline:
988 * This x86 specific trampoline is used to call handle_signal_exception.
991 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
993 guint8 *start, *code;
994 MonoJumpInfo *ji = NULL;
995 GSList *unwind_ops = NULL;
998 start = code = mono_global_codeman_reserve (128);
1001 x86_push_reg (code, X86_ECX);
1003 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
1004 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
1006 /* Fix the alignment to be what apple expects */
1009 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
1010 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
1013 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
1014 /* Branch to target */
1015 x86_call_reg (code, X86_EDX);
1017 g_assert ((code - start) < 128);
1020 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
1024 for (l = unwind_ops; l; l = l->next)
1026 g_slist_free (unwind_ops);
1034 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
1037 * Can't pass the obj on the stack, since we are executing on the
1038 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
1039 * So put it into a register, and branch to a trampoline which
1042 ctx->eax = (mgreg_t)user_data;
1043 ctx->ecx = ctx->eip;
1044 ctx->edx = (mgreg_t)async_cb;
1047 ctx->esp = (ctx->esp - 16) & ~15;
1048 ctx->eip = (mgreg_t)signal_exception_trampoline;
1052 mono_arch_handle_exception (void *sigctx, gpointer obj)
1054 #if defined(MONO_ARCH_USE_SIGACTION)
1056 ucontext_t *ctx = (ucontext_t*)sigctx;
1059 * Handling the exception in the signal handler is problematic, since the original
1060 * signal is disabled, and we could run arbitrary code though the debugger. So
1061 * resume into the normal stack and do most work there if possible.
1063 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1065 /* Pass the ctx parameter in TLS */
1066 mono_arch_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1068 mctx = jit_tls->ex_ctx;
1069 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1070 mono_monoctx_to_sigctx (&mctx, sigctx);
1073 #elif defined (TARGET_WIN32)
1075 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1076 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1078 mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1080 mctx = jit_tls->ex_ctx;
1081 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1082 mono_monoctx_to_sigctx (&mctx, sigctx);
1088 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1090 mono_handle_exception (&mctx, obj);
1092 mono_arch_monoctx_to_sigctx (&mctx, sigctx);
1099 restore_soft_guard_pages (void)
1101 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1102 if (jit_tls->stack_ovf_guard_base)
1103 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1107 * this function modifies mctx so that when it is restored, it
1108 * won't execcute starting at mctx.eip, but in a function that
1109 * will restore the protection on the soft-guard pages and return back to
1110 * continue at mctx.eip.
1113 prepare_for_guard_pages (MonoContext *mctx)
1116 sp = (gpointer)(mctx->esp);
1118 /* the resturn addr */
1119 sp [0] = (gpointer)(mctx->eip);
1120 mctx->eip = (unsigned long)restore_soft_guard_pages;
1121 mctx->esp = (unsigned long)sp;
1125 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1131 mono_handle_exception (&mctx, obj);
1133 prepare_for_guard_pages (&mctx);
1134 mono_restore_context (&mctx);
1138 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
1140 #ifdef MONO_ARCH_USE_SIGACTION
1141 MonoException *exc = NULL;
1142 ucontext_t *ctx = (ucontext_t*)sigctx;
1143 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1147 /* if we didn't find a managed method for the ip address and it matches the fault
1148 * address, we assume we followed a broken pointer during an indirect call, so
1149 * we try the lookup again with the return address pushed on the stack
1151 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1152 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1153 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1155 UCONTEXT_REG_EIP (ctx) = sp [0];
1158 exc = mono_domain_get ()->stack_overflow_ex;
1160 mono_handle_native_sigsegv (SIGSEGV, sigctx);
1161 /* setup a call frame on the real stack so that control is returned there
1162 * and exception handling can continue.
1163 * If this was a stack overflow the caller already ensured the stack pages
1164 * needed have been unprotected.
1165 * The frame looks like:
1172 // FIXME: test_only is no more.
1173 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1176 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1177 sp = (gpointer)((char*)sp - frame_size);
1178 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1181 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1184 sp [2] = (gpointer)stack_ovf;
1185 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1186 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1187 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1188 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1192 #if MONO_SUPPORT_TASKLETS
1193 MonoContinuationRestore
1194 mono_tasklets_arch_restore (void)
1196 static guint8* saved = NULL;
1197 guint8 *code, *start;
1199 #ifdef __native_client_codegen__
1200 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1203 return (MonoContinuationRestore)saved;
1204 code = start = mono_global_codeman_reserve (48);
1205 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1206 /* put cont in edx */
1207 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1208 /* state in eax, so it's setup as the return value */
1209 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1211 /* setup the copy of the stack */
1212 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1213 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1215 x86_mov_reg_membase (code, X86_ESI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1216 x86_mov_reg_membase (code, X86_EDI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1217 x86_prefix (code, X86_REP_PREFIX);
1220 /* now restore the registers from the LMF */
1221 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1222 x86_mov_reg_membase (code, X86_EBX, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebx), 4);
1223 x86_mov_reg_membase (code, X86_EBP, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebp), 4);
1224 x86_mov_reg_membase (code, X86_ESI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, esi), 4);
1225 x86_mov_reg_membase (code, X86_EDI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, edi), 4);
1227 /* restore the lmf chain */
1228 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1229 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1231 x86_jump_membase (code, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_ip));
1232 g_assert ((code - start) <= 48);
1234 return (MonoContinuationRestore)saved;
1239 * mono_arch_setup_resume_sighandler_ctx:
1241 * Setup CTX so execution continues at FUNC.
1244 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1246 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1249 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1251 MONO_CONTEXT_SET_IP (ctx, func);