2 * exceptions-x86.c: exception support for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
16 #include <mono/metadata/abi-details.h>
17 #include <mono/arch/x86/x86-codegen.h>
18 #include <mono/metadata/appdomain.h>
19 #include <mono/metadata/tabledefs.h>
20 #include <mono/metadata/threads.h>
21 #include <mono/metadata/debug-helpers.h>
22 #include <mono/metadata/exception.h>
23 #include <mono/metadata/gc-internal.h>
24 #include <mono/metadata/mono-debug.h>
25 #include <mono/utils/mono-mmap.h>
31 static gpointer signal_exception_trampoline;
34 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot) MONO_INTERNAL;
37 static void (*restore_stack) (void *);
39 static MonoW32ExceptionHandler fpe_handler;
40 static MonoW32ExceptionHandler ill_handler;
41 static MonoW32ExceptionHandler segv_handler;
43 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
44 gpointer mono_win_vectored_exception_handle;
45 extern int (*gUnhandledExceptionHandler)(EXCEPTION_POINTERS*);
47 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
48 # define PROCESS_CALLBACK_FILTER_ENABLED 1
51 #define W32_SEH_HANDLE_EX(_ex) \
52 if (_ex##_handler) _ex##_handler(0, ep, ctx)
54 LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
56 #ifndef MONO_CROSS_COMPILE
57 if (mono_old_win_toplevel_exception_filter) {
58 return (*mono_old_win_toplevel_exception_filter)(ep);
62 mono_handle_native_sigsegv (SIGSEGV, NULL);
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;
193 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
195 /* If the thread is not managed by the runtime return early */
197 return EXCEPTION_CONTINUE_SEARCH;
199 jit_tls->mono_win_chained_exception_needs_run = FALSE;
200 res = EXCEPTION_CONTINUE_EXECUTION;
202 er = ep->ExceptionRecord;
203 ctx = ep->ContextRecord;
205 switch (er->ExceptionCode) {
206 case EXCEPTION_STACK_OVERFLOW:
207 win32_handle_stack_overflow (ep, ctx);
209 case EXCEPTION_ACCESS_VIOLATION:
210 W32_SEH_HANDLE_EX(segv);
212 case EXCEPTION_ILLEGAL_INSTRUCTION:
213 W32_SEH_HANDLE_EX(ill);
215 case EXCEPTION_INT_DIVIDE_BY_ZERO:
216 case EXCEPTION_INT_OVERFLOW:
217 case EXCEPTION_FLT_DIVIDE_BY_ZERO:
218 case EXCEPTION_FLT_OVERFLOW:
219 case EXCEPTION_FLT_UNDERFLOW:
220 case EXCEPTION_FLT_INEXACT_RESULT:
221 W32_SEH_HANDLE_EX(fpe);
224 jit_tls->mono_win_chained_exception_needs_run = TRUE;
228 if (jit_tls->mono_win_chained_exception_needs_run) {
229 /* Don't copy context back if we chained exception
230 * as the handler may have modfied the EXCEPTION_POINTERS
231 * directly. We don't pass sigcontext to chained handlers.
232 * Return continue search so the UnhandledExceptionFilter
233 * can correctly chain the exception.
235 res = EXCEPTION_CONTINUE_SEARCH;
241 void win32_seh_init()
243 /* install restore stack helper */
245 restore_stack = mono_win32_get_handle_stackoverflow ();
247 mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
248 mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
251 void win32_seh_cleanup()
253 if (mono_old_win_toplevel_exception_filter)
254 SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
255 RemoveVectoredExceptionHandler (mono_win_vectored_exception_handle);
258 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
262 fpe_handler = handler;
265 ill_handler = handler;
268 segv_handler = handler;
275 #endif /* TARGET_WIN32 */
278 * mono_arch_get_restore_context:
280 * Returns a pointer to a method which restores a previously saved sigcontext.
283 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
285 guint8 *start = NULL;
287 MonoJumpInfo *ji = NULL;
288 GSList *unwind_ops = NULL;
290 /* restore_contect (MonoContext *ctx) */
292 start = code = mono_global_codeman_reserve (128);
295 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
298 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
301 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
304 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
307 x86_mov_reg_membase (code, X86_EDX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edx), 4);
310 * The context resides on the stack, in the stack frame of the
311 * caller of this function. The stack pointer that we need to
312 * restore is potentially many stack frames higher up, so the
313 * distance between them can easily be more than the red zone
314 * size. Hence the stack pointer can be restored only after
315 * we have finished loading everything from the context.
318 /* load ESP into EBP */
319 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esp), 4);
320 /* load return address into ECX */
321 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eip), 4);
322 /* save the return addr to the restored stack - 4 */
323 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
325 /* load EBP into ECX */
326 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
327 /* save EBP to the restored stack - 8 */
328 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
330 /* load EAX into ECX */
331 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eax), 4);
332 /* save EAX to the restored stack - 12 */
333 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
336 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ecx), 4);
338 /* restore ESP - 12 */
339 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
341 x86_pop_reg (code, X86_EAX);
343 x86_pop_reg (code, X86_EBP);
344 /* jump to the saved IP */
347 nacl_global_codeman_validate(&start, 128, &code);
350 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
354 for (l = unwind_ops; l; l = l->next)
356 g_slist_free (unwind_ops);
363 * mono_arch_get_call_filter:
365 * Returns a pointer to a method which calls an exception filter. We
366 * also use this function to call finally handlers (we pass NULL as
367 * @exc object in this case).
370 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
374 MonoJumpInfo *ji = NULL;
375 GSList *unwind_ops = NULL;
376 guint kMaxCodeSize = NACL_SIZE (64, 128);
378 /* call_filter (MonoContext *ctx, unsigned long eip) */
379 start = code = mono_global_codeman_reserve (kMaxCodeSize);
381 x86_push_reg (code, X86_EBP);
382 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
383 x86_push_reg (code, X86_EBX);
384 x86_push_reg (code, X86_EDI);
385 x86_push_reg (code, X86_ESI);
388 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
390 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
392 x86_push_reg (code, X86_EBP);
395 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
396 /* restore registers used by global register allocation (EBX & ESI) */
397 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
398 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
399 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
401 /* align stack and save ESP */
402 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
403 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
404 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
405 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
406 x86_push_reg (code, X86_EDX);
408 /* call the handler */
409 x86_call_reg (code, X86_ECX);
412 x86_pop_reg (code, X86_ESP);
415 x86_pop_reg (code, X86_EBP);
417 /* restore saved regs */
418 x86_pop_reg (code, X86_ESI);
419 x86_pop_reg (code, X86_EDI);
420 x86_pop_reg (code, X86_EBX);
424 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
427 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
431 for (l = unwind_ops; l; l = l->next)
433 g_slist_free (unwind_ops);
436 g_assert ((code - start) < kMaxCodeSize);
441 * mono_x86_throw_exception:
443 * C function called from the throw trampolines.
446 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
447 mgreg_t eip, gboolean rethrow)
451 ctx.esp = regs [X86_ESP];
453 ctx.ebp = regs [X86_EBP];
454 ctx.edi = regs [X86_EDI];
455 ctx.esi = regs [X86_ESI];
456 ctx.ebx = regs [X86_EBX];
457 ctx.edx = regs [X86_EDX];
458 ctx.ecx = regs [X86_ECX];
459 ctx.eax = regs [X86_EAX];
462 /* The OSX ABI specifies 16 byte alignment at call sites */
463 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
466 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
467 MonoException *mono_ex = (MonoException*)exc;
469 mono_ex->stack_trace = NULL;
472 /* adjust eip so that it point into the call instruction */
475 mono_handle_exception (&ctx, exc);
477 mono_restore_context (&ctx);
479 g_assert_not_reached ();
483 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
484 mgreg_t eip, gint32 pc_offset)
486 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
489 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
493 /* Negate the ip adjustment done in mono_x86_throw_exception () */
496 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
500 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
501 mgreg_t eip, gboolean rethrow)
505 ctx.esp = regs [X86_ESP];
507 ctx.ebp = regs [X86_EBP];
508 ctx.edi = regs [X86_EDI];
509 ctx.esi = regs [X86_ESI];
510 ctx.ebx = regs [X86_EBX];
511 ctx.edx = regs [X86_EDX];
512 ctx.ecx = regs [X86_ECX];
513 ctx.eax = regs [X86_EAX];
515 mono_resume_unwind (&ctx);
519 * get_throw_trampoline:
521 * Generate a call to mono_x86_throw_exception/
522 * mono_x86_throw_corlib_exception.
523 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
524 * which doesn't push the arguments.
527 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
529 guint8 *start, *code;
530 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
531 MonoJumpInfo *ji = NULL;
532 GSList *unwind_ops = NULL;
533 guint kMaxCodeSize = NACL_SIZE (128, 256);
535 start = code = mono_global_codeman_reserve (kMaxCodeSize);
540 * On apple, the stack is misaligned by the pushing of the return address.
543 /* On OSX, we don't generate alignment code to save space */
546 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
549 * The stack looks like this:
550 * <pc offset> (only if corlib is TRUE)
551 * <exception object>/<type token>
552 * <return addr> <- esp (unaligned on apple)
555 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
556 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
559 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
560 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
565 arg_offsets [3] = 12;
569 for (i = 0; i < X86_NREG; ++i)
571 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
572 /* Calculate the offset between the current sp and the sp of the caller */
574 /* LLVM doesn't push the arguments */
575 stack_offset = stack_size + 4;
579 stack_offset = stack_size + 4 + 8;
581 /* We don't generate stack alignment code on osx to save space */
584 /* One argument + stack alignment */
585 stack_offset = stack_size + 4 + 4;
587 /* Pop the alignment added by OP_THROW too */
588 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
590 if (mono_do_x86_stack_align)
591 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
596 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
597 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
599 /* Set arg1 == regs */
600 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
601 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
602 /* Set arg2 == exc/ex_token_index */
604 x86_mov_reg_imm (code, X86_EAX, 0);
606 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
607 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
608 /* Set arg3 == eip */
610 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
612 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
613 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
614 /* Set arg4 == rethrow/pc_offset */
616 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
618 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
621 * The caller is LLVM code which passes the absolute address not a pc offset,
622 * so compensate by passing 0 as 'ip' and passing the negated abs address as
625 x86_neg_reg (code, X86_EAX);
627 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
629 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
633 // This can be called from runtime code, which can't guarantee that
634 // ebx contains the got address.
635 // So emit the got address loading code too
636 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
637 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");
638 x86_call_reg (code, X86_EAX);
640 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
642 x86_breakpoint (code);
644 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
646 g_assert ((code - start) < kMaxCodeSize);
649 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
653 for (l = unwind_ops; l; l = l->next)
655 g_slist_free (unwind_ops);
662 * mono_arch_get_throw_exception:
664 * Returns a function pointer which can be used to raise
665 * exceptions. The returned function has the following
666 * signature: void (*func) (MonoException *exc);
667 * For example to raise an arithmetic exception you can use:
669 * x86_push_imm (code, mono_get_exception_arithmetic ());
670 * x86_call_code (code, arch_get_throw_exception ());
674 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
676 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
680 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
682 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
686 * mono_arch_get_throw_corlib_exception:
688 * Returns a function pointer which can be used to raise
689 * corlib exceptions. The returned function has the following
690 * signature: void (*func) (guint32 ex_token, guint32 offset);
691 * Here, offset is the offset which needs to be substracted from the caller IP
692 * to get the IP of the throw. Passing the offset has the advantage that it
693 * needs no relocations in the caller.
696 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
698 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
702 mono_arch_exceptions_init (void)
707 * If we're running WoW64, we need to set the usermode exception policy
708 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
709 * or (eventually) Windows 7 SP1.
715 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
718 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
719 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
720 if (getter && setter) {
722 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
728 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
732 /* LLVM needs different throw trampolines */
733 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
734 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
736 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
737 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
739 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
740 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
742 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
743 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
745 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
746 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
748 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
752 * mono_arch_find_jit_info:
754 * See exceptions-amd64.c for docs.
757 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
758 MonoJitInfo *ji, MonoContext *ctx,
759 MonoContext *new_ctx, MonoLMF **lmf,
760 mgreg_t **save_locations,
761 StackFrameInfo *frame)
763 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
765 memset (frame, 0, sizeof (StackFrameInfo));
771 gssize regs [MONO_MAX_IREGS + 1];
773 guint32 unwind_info_len;
776 frame->type = FRAME_TYPE_MANAGED;
778 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
780 regs [X86_EAX] = new_ctx->eax;
781 regs [X86_EBX] = new_ctx->ebx;
782 regs [X86_ECX] = new_ctx->ecx;
783 regs [X86_EDX] = new_ctx->edx;
784 regs [X86_ESP] = new_ctx->esp;
785 regs [X86_EBP] = new_ctx->ebp;
786 regs [X86_ESI] = new_ctx->esi;
787 regs [X86_EDI] = new_ctx->edi;
788 regs [X86_NREG] = new_ctx->eip;
790 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
791 (guint8*)ji->code_start + ji->code_size,
792 ip, NULL, regs, MONO_MAX_IREGS + 1,
793 save_locations, MONO_MAX_IREGS, &cfa);
795 new_ctx->eax = regs [X86_EAX];
796 new_ctx->ebx = regs [X86_EBX];
797 new_ctx->ecx = regs [X86_ECX];
798 new_ctx->edx = regs [X86_EDX];
799 new_ctx->esp = regs [X86_ESP];
800 new_ctx->ebp = regs [X86_EBP];
801 new_ctx->esi = regs [X86_ESI];
802 new_ctx->edi = regs [X86_EDI];
803 new_ctx->eip = regs [X86_NREG];
805 /* The CFA becomes the new SP value */
806 new_ctx->esp = (gssize)cfa;
814 if (((guint64)(*lmf)->previous_lmf) & 2) {
816 * This LMF entry is created by the soft debug code to mark transitions to
817 * managed code done during invokes.
819 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
821 g_assert (ext->debugger_invoke);
823 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
825 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
827 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
832 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
834 if (!((guint32)((*lmf)->previous_lmf) & 1))
837 g_assert_not_reached ();
838 /* Trampoline lmf frame */
839 frame->method = (*lmf)->method;
842 new_ctx->esi = (*lmf)->esi;
843 new_ctx->edi = (*lmf)->edi;
844 new_ctx->ebx = (*lmf)->ebx;
845 new_ctx->ebp = (*lmf)->ebp;
846 new_ctx->eip = (*lmf)->eip;
852 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
854 /* Check if we are in a trampoline LMF frame */
855 if ((guint32)((*lmf)->previous_lmf) & 1) {
856 /* lmf->esp is set by the trampoline code */
857 new_ctx->esp = (*lmf)->esp;
859 /* Pop arguments off the stack */
860 /* FIXME: Handle the delegate case too ((*lmf)->method == NULL) */
861 /* FIXME: Handle the IMT/vtable case too */
864 if ((*lmf)->method) {
865 MonoMethod *method = (*lmf)->method;
866 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (method)->param_count + 1);
868 guint32 stack_to_pop = mono_arch_get_argument_info (NULL, mono_method_signature (method), mono_method_signature (method)->param_count, arg_info);
869 new_ctx->esp += stack_to_pop;
875 /* the lmf is always stored on the stack, so the following
876 * expression points to a stack location which can be used as ESP */
877 new_ctx->esp = (unsigned long)&((*lmf)->eip);
879 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
888 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
890 mono_sigctx_to_monoctx (sigctx, mctx);
894 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
896 mono_monoctx_to_sigctx (mctx, sigctx);
900 mono_arch_ip_from_context (void *sigctx)
902 #if defined(__native_client__)
903 printf("WARNING: mono_arch_ip_from_context() called!\n");
905 #elif defined(MONO_ARCH_USE_SIGACTION)
906 ucontext_t *ctx = (ucontext_t*)sigctx;
907 return (gpointer)UCONTEXT_REG_EIP (ctx);
908 #elif defined(HOST_WIN32)
909 return ((CONTEXT*)sigctx)->Eip;
911 struct sigcontext *ctx = sigctx;
912 return (gpointer)ctx->SC_EIP;
919 * Called by resuming from a signal handler.
922 handle_signal_exception (gpointer obj)
924 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
927 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
929 mono_handle_exception (&ctx, obj);
931 mono_restore_context (&ctx);
935 * mono_x86_get_signal_exception_trampoline:
937 * This x86 specific trampoline is used to call handle_signal_exception.
940 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
942 guint8 *start, *code;
943 MonoJumpInfo *ji = NULL;
944 GSList *unwind_ops = NULL;
947 start = code = mono_global_codeman_reserve (128);
950 x86_push_reg (code, X86_ECX);
952 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
953 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
955 /* Fix the alignment to be what apple expects */
958 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
959 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
962 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
963 /* Branch to target */
964 x86_call_reg (code, X86_EDX);
966 g_assert ((code - start) < 128);
969 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
973 for (l = unwind_ops; l; l = l->next)
975 g_slist_free (unwind_ops);
983 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
986 * Can't pass the obj on the stack, since we are executing on the
987 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
988 * So put it into a register, and branch to a trampoline which
991 ctx->eax = (mgreg_t)user_data;
993 ctx->edx = (mgreg_t)async_cb;
996 ctx->esp = (ctx->esp - 16) & ~15;
997 ctx->eip = (mgreg_t)signal_exception_trampoline;
1001 mono_arch_handle_exception (void *sigctx, gpointer obj)
1003 #if defined(MONO_ARCH_USE_SIGACTION)
1005 ucontext_t *ctx = (ucontext_t*)sigctx;
1008 * Handling the exception in the signal handler is problematic, since the original
1009 * signal is disabled, and we could run arbitrary code though the debugger. So
1010 * resume into the normal stack and do most work there if possible.
1012 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1014 /* Pass the ctx parameter in TLS */
1015 mono_arch_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1017 mctx = jit_tls->ex_ctx;
1018 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1019 mono_monoctx_to_sigctx (&mctx, sigctx);
1022 #elif defined (TARGET_WIN32)
1024 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1025 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1027 mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1029 mctx = jit_tls->ex_ctx;
1030 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1031 mono_monoctx_to_sigctx (&mctx, sigctx);
1037 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1039 mono_handle_exception (&mctx, obj);
1041 mono_arch_monoctx_to_sigctx (&mctx, sigctx);
1048 restore_soft_guard_pages (void)
1050 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1051 if (jit_tls->stack_ovf_guard_base)
1052 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1056 * this function modifies mctx so that when it is restored, it
1057 * won't execcute starting at mctx.eip, but in a function that
1058 * will restore the protection on the soft-guard pages and return back to
1059 * continue at mctx.eip.
1062 prepare_for_guard_pages (MonoContext *mctx)
1065 sp = (gpointer)(mctx->esp);
1067 /* the resturn addr */
1068 sp [0] = (gpointer)(mctx->eip);
1069 mctx->eip = (unsigned long)restore_soft_guard_pages;
1070 mctx->esp = (unsigned long)sp;
1074 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1080 mono_handle_exception (&mctx, obj);
1082 prepare_for_guard_pages (&mctx);
1083 mono_restore_context (&mctx);
1087 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
1089 #ifdef MONO_ARCH_USE_SIGACTION
1090 MonoException *exc = NULL;
1091 ucontext_t *ctx = (ucontext_t*)sigctx;
1092 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1096 /* if we didn't find a managed method for the ip address and it matches the fault
1097 * address, we assume we followed a broken pointer during an indirect call, so
1098 * we try the lookup again with the return address pushed on the stack
1100 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1101 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1102 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1104 UCONTEXT_REG_EIP (ctx) = sp [0];
1107 exc = mono_domain_get ()->stack_overflow_ex;
1109 mono_handle_native_sigsegv (SIGSEGV, sigctx);
1110 /* setup a call frame on the real stack so that control is returned there
1111 * and exception handling can continue.
1112 * If this was a stack overflow the caller already ensured the stack pages
1113 * needed have been unprotected.
1114 * The frame looks like:
1121 // FIXME: test_only is no more.
1122 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1125 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1126 sp = (gpointer)((char*)sp - frame_size);
1127 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1130 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1133 sp [2] = (gpointer)stack_ovf;
1134 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1135 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1136 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1137 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1141 #if MONO_SUPPORT_TASKLETS
1142 MonoContinuationRestore
1143 mono_tasklets_arch_restore (void)
1145 static guint8* saved = NULL;
1146 guint8 *code, *start;
1148 #ifdef __native_client_codegen__
1149 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1152 return (MonoContinuationRestore)saved;
1153 code = start = mono_global_codeman_reserve (48);
1154 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1155 /* put cont in edx */
1156 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1157 /* state in eax, so it's setup as the return value */
1158 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1160 /* setup the copy of the stack */
1161 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1162 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1164 x86_mov_reg_membase (code, X86_ESI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1165 x86_mov_reg_membase (code, X86_EDI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1166 x86_prefix (code, X86_REP_PREFIX);
1169 /* now restore the registers from the LMF */
1170 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1171 x86_mov_reg_membase (code, X86_EBX, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebx), 4);
1172 x86_mov_reg_membase (code, X86_EBP, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebp), 4);
1173 x86_mov_reg_membase (code, X86_ESI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, esi), 4);
1174 x86_mov_reg_membase (code, X86_EDI, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, edi), 4);
1176 /* restore the lmf chain */
1177 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1178 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1180 x86_jump_membase (code, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_ip));
1181 g_assert ((code - start) <= 48);
1183 return (MonoContinuationRestore)saved;
1188 * mono_arch_setup_resume_sighandler_ctx:
1190 * Setup CTX so execution continues at FUNC.
1193 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1195 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1198 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1200 MONO_CONTEXT_SET_IP (ctx, func);