2 * exceptions-x86.c: exception support for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
15 #ifdef HAVE_UCONTEXT_H
19 #include <mono/metadata/abi-details.h>
20 #include <mono/arch/x86/x86-codegen.h>
21 #include <mono/metadata/appdomain.h>
22 #include <mono/metadata/tabledefs.h>
23 #include <mono/metadata/threads.h>
24 #include <mono/metadata/debug-helpers.h>
25 #include <mono/metadata/exception.h>
26 #include <mono/metadata/gc-internals.h>
27 #include <mono/metadata/mono-debug.h>
28 #include <mono/utils/mono-mmap.h>
34 static gpointer signal_exception_trampoline;
37 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot);
40 static void (*restore_stack) (void *);
42 static MonoW32ExceptionHandler fpe_handler;
43 static MonoW32ExceptionHandler ill_handler;
44 static MonoW32ExceptionHandler segv_handler;
46 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
47 gpointer mono_win_vectored_exception_handle;
48 extern int (*gUnhandledExceptionHandler)(EXCEPTION_POINTERS*);
50 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
51 # define PROCESS_CALLBACK_FILTER_ENABLED 1
54 #define W32_SEH_HANDLE_EX(_ex) \
55 if (_ex##_handler) _ex##_handler(0, ep, ctx)
57 LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
59 #ifndef MONO_CROSS_COMPILE
60 if (mono_old_win_toplevel_exception_filter) {
61 return (*mono_old_win_toplevel_exception_filter)(ep);
65 mono_handle_native_sigsegv (SIGSEGV, NULL, NULL);
67 return EXCEPTION_CONTINUE_SEARCH;
71 * mono_win32_get_handle_stackoverflow (void):
73 * Returns a pointer to a method which restores the current context stack
74 * and calls handle_exceptions, when done restores the original stack.
77 mono_win32_get_handle_stackoverflow (void)
79 static guint8 *start = NULL;
85 /* restore_contect (void *sigctx) */
86 start = code = mono_global_codeman_reserve (128);
88 /* load context into ebx */
89 x86_mov_reg_membase (code, X86_EBX, X86_ESP, 4, 4);
91 /* move current stack into edi for later restore */
92 x86_mov_reg_reg (code, X86_EDI, X86_ESP, 4);
94 /* use the new freed stack from sigcontext */
95 /* XXX replace usage of struct sigcontext with MonoContext so we can use MONO_STRUCT_OFFSET */
96 x86_mov_reg_membase (code, X86_ESP, X86_EBX, G_STRUCT_OFFSET (struct sigcontext, esp), 4);
98 /* get the current domain */
99 x86_call_code (code, mono_domain_get);
101 /* get stack overflow exception from domain object */
102 x86_mov_reg_membase (code, X86_EAX, X86_EAX, G_STRUCT_OFFSET (MonoDomain, stack_overflow_ex), 4);
104 /* call mono_arch_handle_exception (sctx, stack_overflow_exception_obj) */
105 x86_push_reg (code, X86_EAX);
106 x86_push_reg (code, X86_EBX);
107 x86_call_code (code, mono_arch_handle_exception);
109 /* restore the SEH handler stack */
110 x86_mov_reg_reg (code, X86_ESP, X86_EDI, 4);
115 mono_arch_flush_icache (start, code - start);
116 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
121 /* Special hack to workaround the fact that the
122 * when the SEH handler is called the stack is
123 * to small to recover.
125 * Stack walking part of this method is from mono_handle_exception
127 * The idea is simple;
128 * - walk the stack to free some space (64k)
129 * - set esp to new stack location
130 * - call mono_arch_handle_exception with stack overflow exception
131 * - set esp to SEH handlers stack
135 win32_handle_stack_overflow (EXCEPTION_POINTERS* ep, struct sigcontext *sctx)
139 MonoDomain *domain = mono_domain_get ();
141 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
142 MonoLMF *lmf = jit_tls->lmf;
143 MonoContext initial_ctx;
145 guint32 free_stack = 0;
146 StackFrameInfo frame;
148 mono_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_unwind_frame (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 mono_monoctx_to_sigctx (&ctx, sctx);
182 /* todo: install new stack-guard page */
184 /* use the new stack and call mono_arch_handle_exception () */
185 restore_stack (sctx);
189 * Unhandled Exception Filter
190 * Top-level per-process exception handler.
192 LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
194 EXCEPTION_RECORD* er;
197 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
199 /* If the thread is not managed by the runtime return early */
201 return EXCEPTION_CONTINUE_SEARCH;
203 jit_tls->mono_win_chained_exception_needs_run = FALSE;
204 res = EXCEPTION_CONTINUE_EXECUTION;
206 er = ep->ExceptionRecord;
207 ctx = ep->ContextRecord;
209 switch (er->ExceptionCode) {
210 case EXCEPTION_STACK_OVERFLOW:
211 win32_handle_stack_overflow (ep, ctx);
213 case EXCEPTION_ACCESS_VIOLATION:
214 W32_SEH_HANDLE_EX(segv);
216 case EXCEPTION_ILLEGAL_INSTRUCTION:
217 W32_SEH_HANDLE_EX(ill);
219 case EXCEPTION_INT_DIVIDE_BY_ZERO:
220 case EXCEPTION_INT_OVERFLOW:
221 case EXCEPTION_FLT_DIVIDE_BY_ZERO:
222 case EXCEPTION_FLT_OVERFLOW:
223 case EXCEPTION_FLT_UNDERFLOW:
224 case EXCEPTION_FLT_INEXACT_RESULT:
225 W32_SEH_HANDLE_EX(fpe);
228 jit_tls->mono_win_chained_exception_needs_run = TRUE;
232 if (jit_tls->mono_win_chained_exception_needs_run) {
233 /* Don't copy context back if we chained exception
234 * as the handler may have modfied the EXCEPTION_POINTERS
235 * directly. We don't pass sigcontext to chained handlers.
236 * Return continue search so the UnhandledExceptionFilter
237 * can correctly chain the exception.
239 res = EXCEPTION_CONTINUE_SEARCH;
245 void win32_seh_init()
247 /* install restore stack helper */
249 restore_stack = mono_win32_get_handle_stackoverflow ();
251 mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
252 mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
255 void win32_seh_cleanup()
257 if (mono_old_win_toplevel_exception_filter)
258 SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
259 RemoveVectoredExceptionHandler (mono_win_vectored_exception_handle);
262 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
266 fpe_handler = handler;
269 ill_handler = handler;
272 segv_handler = handler;
279 #endif /* TARGET_WIN32 */
282 * mono_arch_get_restore_context:
284 * Returns a pointer to a method which restores a previously saved sigcontext.
287 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
289 guint8 *start = NULL;
291 MonoJumpInfo *ji = NULL;
292 GSList *unwind_ops = NULL;
294 /* restore_contect (MonoContext *ctx) */
296 start = code = mono_global_codeman_reserve (128);
299 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
302 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
305 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
308 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
311 x86_mov_reg_membase (code, X86_EDX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edx), 4);
314 * The context resides on the stack, in the stack frame of the
315 * caller of this function. The stack pointer that we need to
316 * restore is potentially many stack frames higher up, so the
317 * distance between them can easily be more than the red zone
318 * size. Hence the stack pointer can be restored only after
319 * we have finished loading everything from the context.
322 /* load ESP into EBP */
323 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esp), 4);
324 /* load return address into ECX */
325 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eip), 4);
326 /* save the return addr to the restored stack - 4 */
327 x86_mov_membase_reg (code, X86_EBP, -4, X86_ECX, 4);
329 /* load EBP into ECX */
330 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
331 /* save EBP to the restored stack - 8 */
332 x86_mov_membase_reg (code, X86_EBP, -8, X86_ECX, 4);
334 /* load EAX into ECX */
335 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, eax), 4);
336 /* save EAX to the restored stack - 12 */
337 x86_mov_membase_reg (code, X86_EBP, -12, X86_ECX, 4);
340 x86_mov_reg_membase (code, X86_ECX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ecx), 4);
342 /* restore ESP - 12 */
343 x86_lea_membase (code, X86_ESP, X86_EBP, -12);
345 x86_pop_reg (code, X86_EAX);
347 x86_pop_reg (code, X86_EBP);
348 /* jump to the saved IP */
352 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
356 for (l = unwind_ops; l; l = l->next)
358 g_slist_free (unwind_ops);
361 mono_arch_flush_icache (start, code - start);
362 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
368 * mono_arch_get_call_filter:
370 * Returns a pointer to a method which calls an exception filter. We
371 * also use this function to call finally handlers (we pass NULL as
372 * @exc object in this case).
375 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
379 MonoJumpInfo *ji = NULL;
380 GSList *unwind_ops = NULL;
381 guint kMaxCodeSize = 64;
383 /* call_filter (MonoContext *ctx, unsigned long eip) */
384 start = code = mono_global_codeman_reserve (kMaxCodeSize);
386 x86_push_reg (code, X86_EBP);
387 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
388 x86_push_reg (code, X86_EBX);
389 x86_push_reg (code, X86_EDI);
390 x86_push_reg (code, X86_ESI);
393 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
395 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
397 x86_push_reg (code, X86_EBP);
400 x86_mov_reg_membase (code, X86_EBP, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebp), 4);
401 /* restore registers used by global register allocation (EBX & ESI) */
402 x86_mov_reg_membase (code, X86_EBX, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, ebx), 4);
403 x86_mov_reg_membase (code, X86_ESI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, esi), 4);
404 x86_mov_reg_membase (code, X86_EDI, X86_EAX, MONO_STRUCT_OFFSET (MonoContext, edi), 4);
406 /* align stack and save ESP */
407 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
408 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
409 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
410 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
411 x86_push_reg (code, X86_EDX);
413 /* call the handler */
414 x86_call_reg (code, X86_ECX);
417 x86_pop_reg (code, X86_ESP);
420 x86_pop_reg (code, X86_EBP);
422 /* restore saved regs */
423 x86_pop_reg (code, X86_ESI);
424 x86_pop_reg (code, X86_EDI);
425 x86_pop_reg (code, X86_EBX);
430 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
434 for (l = unwind_ops; l; l = l->next)
436 g_slist_free (unwind_ops);
439 mono_arch_flush_icache (start, code - start);
440 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
442 g_assert ((code - start) < kMaxCodeSize);
447 * mono_x86_throw_exception:
449 * C function called from the throw trampolines.
452 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
453 mgreg_t eip, gboolean rethrow)
458 ctx.esp = regs [X86_ESP];
460 ctx.ebp = regs [X86_EBP];
461 ctx.edi = regs [X86_EDI];
462 ctx.esi = regs [X86_ESI];
463 ctx.ebx = regs [X86_EBX];
464 ctx.edx = regs [X86_EDX];
465 ctx.ecx = regs [X86_ECX];
466 ctx.eax = regs [X86_EAX];
469 /* The OSX ABI specifies 16 byte alignment at call sites */
470 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
473 if (mono_object_isinst_checked (exc, mono_defaults.exception_class, &error)) {
474 MonoException *mono_ex = (MonoException*)exc;
476 mono_ex->stack_trace = NULL;
477 mono_ex->trace_ips = NULL;
480 mono_error_assert_ok (&error);
482 /* adjust eip so that it point into the call instruction */
485 mono_handle_exception (&ctx, exc);
487 mono_restore_context (&ctx);
489 g_assert_not_reached ();
493 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
494 mgreg_t eip, gint32 pc_offset)
496 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
499 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
503 /* Negate the ip adjustment done in mono_x86_throw_exception () */
506 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
510 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
511 mgreg_t eip, gboolean rethrow)
515 ctx.esp = regs [X86_ESP];
517 ctx.ebp = regs [X86_EBP];
518 ctx.edi = regs [X86_EDI];
519 ctx.esi = regs [X86_ESI];
520 ctx.ebx = regs [X86_EBX];
521 ctx.edx = regs [X86_EDX];
522 ctx.ecx = regs [X86_ECX];
523 ctx.eax = regs [X86_EAX];
525 mono_resume_unwind (&ctx);
529 * get_throw_trampoline:
531 * Generate a call to mono_x86_throw_exception/
532 * mono_x86_throw_corlib_exception.
533 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
534 * which doesn't push the arguments.
537 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
539 guint8 *start, *code, *labels [16];
540 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
541 MonoJumpInfo *ji = NULL;
542 GSList *unwind_ops = NULL;
543 guint kMaxCodeSize = 128;
545 start = code = mono_global_codeman_reserve (kMaxCodeSize);
550 * On apple, the stack is misaligned by the pushing of the return address.
553 /* On OSX, we don't generate alignment code to save space */
556 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
559 * The stack looks like this:
560 * <pc offset> (only if corlib is TRUE)
561 * <exception object>/<type token>
562 * <return addr> <- esp (unaligned on apple)
565 unwind_ops = mono_arch_get_cie_program ();
568 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
569 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
574 arg_offsets [3] = 12;
578 for (i = 0; i < X86_NREG; ++i)
580 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
581 /* Calculate the offset between the current sp and the sp of the caller */
583 /* LLVM doesn't push the arguments */
584 stack_offset = stack_size + 4;
588 stack_offset = stack_size + 4 + 8;
590 /* We don't generate stack alignment code on osx to save space */
593 /* One argument + stack alignment */
594 stack_offset = stack_size + 4 + 4;
596 /* Pop the alignment added by OP_THROW too */
597 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
599 if (mono_do_x86_stack_align)
600 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
605 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
606 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
611 x86_shift_reg_imm (code, X86_SHR, X86_EAX, 11);
612 x86_alu_reg_imm (code, X86_AND, X86_EAX, 7);
613 x86_alu_reg_imm (code, X86_CMP, X86_EAX, 0);
615 x86_branch8 (code, X86_CC_EQ, 0, FALSE);
617 x86_jump_code (code, labels [0]);
618 mono_x86_patch (labels [1], code);
620 /* Set arg1 == regs */
621 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
622 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
623 /* Set arg2 == exc/ex_token_index */
625 x86_mov_reg_imm (code, X86_EAX, 0);
627 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
628 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
629 /* Set arg3 == eip */
631 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
633 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
634 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
635 /* Set arg4 == rethrow/pc_offset */
637 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
639 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
642 * The caller is LLVM code which passes the absolute address not a pc offset,
643 * so compensate by passing 0 as 'ip' and passing the negated abs address as
646 x86_neg_reg (code, X86_EAX);
648 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
650 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
654 // This can be called from runtime code, which can't guarantee that
655 // ebx contains the got address.
656 // So emit the got address loading code too
657 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
658 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");
659 x86_call_reg (code, X86_EAX);
661 x86_call_code (code, resume_unwind ? (gpointer)(mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
663 x86_breakpoint (code);
665 g_assert ((code - start) < kMaxCodeSize);
668 *info = mono_tramp_info_create (name, start, code - start, ji, unwind_ops);
672 for (l = unwind_ops; l; l = l->next)
674 g_slist_free (unwind_ops);
677 mono_arch_flush_icache (start, code - start);
678 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
684 * mono_arch_get_throw_exception:
686 * Returns a function pointer which can be used to raise
687 * exceptions. The returned function has the following
688 * signature: void (*func) (MonoException *exc);
689 * For example to raise an arithmetic exception you can use:
691 * x86_push_imm (code, mono_get_exception_arithmetic ());
692 * x86_call_code (code, arch_get_throw_exception ());
696 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
698 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
702 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
704 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
708 * mono_arch_get_throw_corlib_exception:
710 * Returns a function pointer which can be used to raise
711 * corlib exceptions. The returned function has the following
712 * signature: void (*func) (guint32 ex_token, guint32 offset);
713 * Here, offset is the offset which needs to be substracted from the caller IP
714 * to get the IP of the throw. Passing the offset has the advantage that it
715 * needs no relocations in the caller.
718 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
720 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
724 mono_arch_exceptions_init (void)
727 MonoTrampInfo *tinfo;
730 * If we're running WoW64, we need to set the usermode exception policy
731 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
732 * or (eventually) Windows 7 SP1.
738 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
741 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
742 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
743 if (getter && setter) {
745 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
751 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
755 /* LLVM needs different throw trampolines */
756 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, &tinfo, FALSE);
757 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
758 mono_tramp_info_register (tinfo, NULL);
760 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", TRUE, TRUE, FALSE, FALSE, FALSE, &tinfo, FALSE);
761 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
762 mono_tramp_info_register (tinfo, NULL);
764 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, &tinfo, FALSE);
765 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
766 mono_tramp_info_register (tinfo, NULL);
768 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, &tinfo, FALSE);
769 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
770 mono_tramp_info_register (tinfo, NULL);
772 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, &tinfo, FALSE);
773 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
774 mono_tramp_info_register (tinfo, NULL);
776 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (&tinfo, FALSE);
777 mono_tramp_info_register (tinfo, NULL);
781 * mono_arch_unwind_frame:
783 * See exceptions-amd64.c for docs.
786 mono_arch_unwind_frame (MonoDomain *domain, MonoJitTlsData *jit_tls,
787 MonoJitInfo *ji, MonoContext *ctx,
788 MonoContext *new_ctx, MonoLMF **lmf,
789 mgreg_t **save_locations,
790 StackFrameInfo *frame)
792 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
794 memset (frame, 0, sizeof (StackFrameInfo));
800 gssize regs [MONO_MAX_IREGS + 1];
802 guint32 unwind_info_len;
805 if (ji->is_trampoline)
806 frame->type = FRAME_TYPE_TRAMPOLINE;
808 frame->type = FRAME_TYPE_MANAGED;
810 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
812 regs [X86_EAX] = new_ctx->eax;
813 regs [X86_EBX] = new_ctx->ebx;
814 regs [X86_ECX] = new_ctx->ecx;
815 regs [X86_EDX] = new_ctx->edx;
816 regs [X86_ESP] = new_ctx->esp;
817 regs [X86_EBP] = new_ctx->ebp;
818 regs [X86_ESI] = new_ctx->esi;
819 regs [X86_EDI] = new_ctx->edi;
820 regs [X86_NREG] = new_ctx->eip;
822 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
823 (guint8*)ji->code_start + ji->code_size,
824 ip, NULL, regs, MONO_MAX_IREGS + 1,
825 save_locations, MONO_MAX_IREGS, &cfa);
827 new_ctx->eax = regs [X86_EAX];
828 new_ctx->ebx = regs [X86_EBX];
829 new_ctx->ecx = regs [X86_ECX];
830 new_ctx->edx = regs [X86_EDX];
831 new_ctx->esp = regs [X86_ESP];
832 new_ctx->ebp = regs [X86_EBP];
833 new_ctx->esi = regs [X86_ESI];
834 new_ctx->edi = regs [X86_EDI];
835 new_ctx->eip = regs [X86_NREG];
837 /* The CFA becomes the new SP value */
838 new_ctx->esp = (gssize)cfa;
846 if (((guint64)(*lmf)->previous_lmf) & 2) {
848 * This LMF entry is created by the soft debug code to mark transitions to
849 * managed code done during invokes.
851 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
853 g_assert (ext->debugger_invoke);
855 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
857 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
859 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
864 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
869 frame->method = (*lmf)->method;
872 new_ctx->esi = (*lmf)->esi;
873 new_ctx->edi = (*lmf)->edi;
874 new_ctx->ebx = (*lmf)->ebx;
875 new_ctx->ebp = (*lmf)->ebp;
876 new_ctx->eip = (*lmf)->eip;
881 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
883 /* Check if we are in a trampoline LMF frame */
884 if ((guint32)((*lmf)->previous_lmf) & 1) {
885 /* lmf->esp is set by the trampoline code */
886 new_ctx->esp = (*lmf)->esp;
889 /* the lmf is always stored on the stack, so the following
890 * expression points to a stack location which can be used as ESP */
891 new_ctx->esp = (unsigned long)&((*lmf)->eip);
893 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
902 mono_arch_ip_from_context (void *sigctx)
904 #if defined(HOST_WATCHOS)
905 printf("WARNING: mono_arch_ip_from_context() called!\n");
907 #elif defined(MONO_ARCH_USE_SIGACTION)
908 ucontext_t *ctx = (ucontext_t*)sigctx;
909 return (gpointer)UCONTEXT_REG_EIP (ctx);
910 #elif defined(HOST_WIN32)
911 return ((CONTEXT*)sigctx)->Eip;
913 struct sigcontext *ctx = sigctx;
914 return (gpointer)ctx->SC_EIP;
921 * Called by resuming from a signal handler.
924 handle_signal_exception (gpointer obj)
926 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
929 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
931 mono_handle_exception (&ctx, obj);
933 mono_restore_context (&ctx);
937 * mono_x86_get_signal_exception_trampoline:
939 * This x86 specific trampoline is used to call handle_signal_exception.
942 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
944 guint8 *start, *code;
945 MonoJumpInfo *ji = NULL;
946 GSList *unwind_ops = NULL;
949 start = code = mono_global_codeman_reserve (128);
951 /* FIXME no unwind before we push ip */
953 x86_push_reg (code, X86_ECX);
955 mono_add_unwind_op_def_cfa (unwind_ops, code, start, X86_ESP, 4);
956 mono_add_unwind_op_offset (unwind_ops, code, start, X86_NREG, -4);
958 /* Fix the alignment to be what apple expects */
961 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
962 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
965 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
966 /* Branch to target */
967 x86_call_reg (code, X86_EDX);
969 g_assert ((code - start) < 128);
972 *info = mono_tramp_info_create ("x86_signal_exception_trampoline", start, code - start, ji, unwind_ops);
976 for (l = unwind_ops; l; l = l->next)
978 g_slist_free (unwind_ops);
981 mono_arch_flush_icache (start, code - start);
982 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
989 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
992 * Can't pass the obj on the stack, since we are executing on the
993 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
994 * So put it into a register, and branch to a trampoline which
997 ctx->eax = (mgreg_t)user_data;
999 ctx->edx = (mgreg_t)async_cb;
1002 ctx->esp = (ctx->esp - 16) & ~15;
1003 ctx->eip = (mgreg_t)signal_exception_trampoline;
1007 mono_arch_handle_exception (void *sigctx, gpointer obj)
1009 #if defined(MONO_ARCH_USE_SIGACTION)
1011 ucontext_t *ctx = (ucontext_t*)sigctx;
1014 * Handling the exception in the signal handler is problematic, since the original
1015 * signal is disabled, and we could run arbitrary code though the debugger. So
1016 * resume into the normal stack and do most work there if possible.
1018 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1020 /* Pass the ctx parameter in TLS */
1021 mono_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1023 mctx = jit_tls->ex_ctx;
1024 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1025 mono_monoctx_to_sigctx (&mctx, sigctx);
1028 #elif defined (TARGET_WIN32)
1030 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1031 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1033 mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1035 mctx = jit_tls->ex_ctx;
1036 mono_setup_async_callback (&mctx, handle_signal_exception, obj);
1037 mono_monoctx_to_sigctx (&mctx, sigctx);
1043 mono_sigctx_to_monoctx (sigctx, &mctx);
1045 mono_handle_exception (&mctx, obj);
1047 mono_monoctx_to_sigctx (&mctx, sigctx);
1054 restore_soft_guard_pages (void)
1056 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
1057 if (jit_tls->stack_ovf_guard_base)
1058 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1062 * this function modifies mctx so that when it is restored, it
1063 * won't execcute starting at mctx.eip, but in a function that
1064 * will restore the protection on the soft-guard pages and return back to
1065 * continue at mctx.eip.
1068 prepare_for_guard_pages (MonoContext *mctx)
1071 sp = (gpointer)(mctx->esp);
1073 /* the resturn addr */
1074 sp [0] = (gpointer)(mctx->eip);
1075 mctx->eip = (unsigned long)restore_soft_guard_pages;
1076 mctx->esp = (unsigned long)sp;
1080 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
1086 mono_handle_exception (&mctx, obj);
1088 prepare_for_guard_pages (&mctx);
1089 mono_restore_context (&mctx);
1093 mono_arch_handle_altstack_exception (void *sigctx, MONO_SIG_HANDLER_INFO_TYPE *siginfo, gpointer fault_addr, gboolean stack_ovf)
1095 #ifdef MONO_ARCH_USE_SIGACTION
1096 MonoException *exc = NULL;
1097 ucontext_t *ctx = (ucontext_t*)sigctx;
1098 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1102 /* if we didn't find a managed method for the ip address and it matches the fault
1103 * address, we assume we followed a broken pointer during an indirect call, so
1104 * we try the lookup again with the return address pushed on the stack
1106 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1107 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1108 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1110 UCONTEXT_REG_EIP (ctx) = sp [0];
1113 exc = mono_domain_get ()->stack_overflow_ex;
1115 mono_handle_native_sigsegv (SIGSEGV, sigctx, siginfo);
1116 /* setup a call frame on the real stack so that control is returned there
1117 * and exception handling can continue.
1118 * If this was a stack overflow the caller already ensured the stack pages
1119 * needed have been unprotected.
1120 * The frame looks like:
1127 // FIXME: test_only is no more.
1128 frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4;
1131 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1132 sp = (gpointer)((char*)sp - frame_size);
1133 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1136 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1139 sp [2] = (gpointer)stack_ovf;
1140 mono_sigctx_to_monoctx (sigctx, (MonoContext*)(sp + 4));
1141 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1142 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1143 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1147 #if MONO_SUPPORT_TASKLETS
1148 MonoContinuationRestore
1149 mono_tasklets_arch_restore (void)
1151 static guint8* saved = NULL;
1152 guint8 *code, *start;
1155 return (MonoContinuationRestore)saved;
1156 code = start = mono_global_codeman_reserve (48);
1157 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1158 /* put cont in edx */
1159 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1160 /* state in eax, so it's setup as the return value */
1161 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1162 /* lmf_addr in ebx */
1163 x86_mov_reg_membase(code, X86_EBX, X86_ESP, 0x0C, 4);
1165 /* setup the copy of the stack */
1166 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1167 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1169 x86_mov_reg_membase (code, X86_ESI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1170 x86_mov_reg_membase (code, X86_EDI, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1171 x86_prefix (code, X86_REP_PREFIX);
1174 /* now restore the registers from the LMF */
1175 x86_mov_reg_membase (code, X86_ECX, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1176 x86_mov_reg_membase (code, X86_EBP, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, ebp), 4);
1177 x86_mov_reg_membase (code, X86_ESP, X86_ECX, MONO_STRUCT_OFFSET (MonoLMF, esp), 4);
1179 /* restore the lmf chain */
1180 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1181 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1183 x86_jump_membase (code, X86_EDX, MONO_STRUCT_OFFSET (MonoContinuation, return_ip));
1184 g_assert ((code - start) <= 48);
1186 return (MonoContinuationRestore)saved;
1191 * mono_arch_setup_resume_sighandler_ctx:
1193 * Setup CTX so execution continues at FUNC.
1196 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1198 int align = (((gint32)MONO_CONTEXT_GET_SP (ctx)) % MONO_ARCH_FRAME_ALIGNMENT + 4);
1201 MONO_CONTEXT_SET_SP (ctx, (gsize)MONO_CONTEXT_GET_SP (ctx) - align);
1203 MONO_CONTEXT_SET_IP (ctx, func);