2 * exceptions-x86.c: exception support for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
15 #include <mono/arch/x86/x86-codegen.h>
16 #include <mono/metadata/appdomain.h>
17 #include <mono/metadata/tabledefs.h>
18 #include <mono/metadata/threads.h>
19 #include <mono/metadata/debug-helpers.h>
20 #include <mono/metadata/exception.h>
21 #include <mono/metadata/gc-internal.h>
22 #include <mono/metadata/mono-debug.h>
23 #include <mono/utils/mono-mmap.h>
28 #include "debug-mini.h"
30 static gpointer signal_exception_trampoline;
33 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot) MONO_INTERNAL;
36 static void (*restore_stack) (void *);
38 static MonoW32ExceptionHandler fpe_handler;
39 static MonoW32ExceptionHandler ill_handler;
40 static MonoW32ExceptionHandler segv_handler;
42 static LPTOP_LEVEL_EXCEPTION_FILTER old_handler;
44 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
45 # define PROCESS_CALLBACK_FILTER_ENABLED 1
48 #define W32_SEH_HANDLE_EX(_ex) \
49 if (_ex##_handler) _ex##_handler(0, er, sctx)
52 * mono_win32_get_handle_stackoverflow (void):
54 * Returns a pointer to a method which restores the current context stack
55 * and calls handle_exceptions, when done restores the original stack.
58 mono_win32_get_handle_stackoverflow (void)
60 static guint8 *start = NULL;
66 /* restore_contect (void *sigctx) */
67 start = code = mono_global_codeman_reserve (128);
69 /* load context into ebx */
70 x86_mov_reg_membase (code, X86_EBX, X86_ESP, 4, 4);
72 /* move current stack into edi for later restore */
73 x86_mov_reg_reg (code, X86_EDI, X86_ESP, 4);
75 /* use the new freed stack from sigcontext */
76 x86_mov_reg_membase (code, X86_ESP, X86_EBX, G_STRUCT_OFFSET (struct sigcontext, esp), 4);
78 /* get the current domain */
79 x86_call_code (code, mono_domain_get);
81 /* get stack overflow exception from domain object */
82 x86_mov_reg_membase (code, X86_EAX, X86_EAX, G_STRUCT_OFFSET (MonoDomain, stack_overflow_ex), 4);
84 /* call mono_arch_handle_exception (sctx, stack_overflow_exception_obj, FALSE) */
85 x86_push_imm (code, 0);
86 x86_push_reg (code, X86_EAX);
87 x86_push_reg (code, X86_EBX);
88 x86_call_code (code, mono_arch_handle_exception);
90 /* restore the SEH handler stack */
91 x86_mov_reg_reg (code, X86_ESP, X86_EDI, 4);
99 /* Special hack to workaround the fact that the
100 * when the SEH handler is called the stack is
101 * to small to recover.
103 * Stack walking part of this method is from mono_handle_exception
105 * The idea is simple;
106 * - walk the stack to free some space (64k)
107 * - set esp to new stack location
108 * - call mono_arch_handle_exception with stack overflow exception
109 * - set esp to SEH handlers stack
113 win32_handle_stack_overflow (EXCEPTION_POINTERS* ep, struct sigcontext *sctx)
117 MonoDomain *domain = mono_domain_get ();
119 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
120 MonoLMF *lmf = jit_tls->lmf;
121 MonoContext initial_ctx;
123 guint32 free_stack = 0;
124 StackFrameInfo frame;
126 /* convert sigcontext to MonoContext (due to reuse of stack walking helpers */
127 mono_arch_sigctx_to_monoctx (sctx, &ctx);
129 /* get our os page size */
131 page_size = si.dwPageSize;
133 /* Let's walk the stack to recover
134 * the needed stack space (if possible)
136 memset (&rji, 0, sizeof (rji));
139 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
141 /* try to free 64kb from our stack */
145 mono_arch_find_jit_info (domain, jit_tls, &rji, &ctx, &new_ctx, &lmf, &frame);
147 g_warning ("Exception inside function without unwind info");
148 g_assert_not_reached ();
151 if (frame.ji != (gpointer)-1) {
152 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (&ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
155 /* todo: we should call abort if ji is -1 */
157 } while (free_stack < 64 * 1024 && frame.ji != (gpointer) -1);
159 /* convert into sigcontext to be used in mono_arch_handle_exception */
160 mono_arch_monoctx_to_sigctx (&ctx, sctx);
162 /* todo: install new stack-guard page */
164 /* use the new stack and call mono_arch_handle_exception () */
165 restore_stack (sctx);
169 * Unhandled Exception Filter
170 * Top-level per-process exception handler.
172 LONG CALLBACK seh_handler(EXCEPTION_POINTERS* ep)
174 EXCEPTION_RECORD* er;
176 struct sigcontext* sctx;
179 res = EXCEPTION_CONTINUE_EXECUTION;
181 er = ep->ExceptionRecord;
182 ctx = ep->ContextRecord;
183 sctx = g_malloc(sizeof(struct sigcontext));
185 /* Copy Win32 context to UNIX style context */
186 sctx->eax = ctx->Eax;
187 sctx->ebx = ctx->Ebx;
188 sctx->ecx = ctx->Ecx;
189 sctx->edx = ctx->Edx;
190 sctx->ebp = ctx->Ebp;
191 sctx->esp = ctx->Esp;
192 sctx->esi = ctx->Esi;
193 sctx->edi = ctx->Edi;
194 sctx->eip = ctx->Eip;
196 switch (er->ExceptionCode) {
197 case EXCEPTION_STACK_OVERFLOW:
198 win32_handle_stack_overflow (ep, sctx);
200 case EXCEPTION_ACCESS_VIOLATION:
201 W32_SEH_HANDLE_EX(segv);
203 case EXCEPTION_ILLEGAL_INSTRUCTION:
204 W32_SEH_HANDLE_EX(ill);
206 case EXCEPTION_INT_DIVIDE_BY_ZERO:
207 case EXCEPTION_INT_OVERFLOW:
208 case EXCEPTION_FLT_DIVIDE_BY_ZERO:
209 case EXCEPTION_FLT_OVERFLOW:
210 case EXCEPTION_FLT_UNDERFLOW:
211 case EXCEPTION_FLT_INEXACT_RESULT:
212 W32_SEH_HANDLE_EX(fpe);
218 /* Copy context back */
219 ctx->Eax = sctx->eax;
220 ctx->Ebx = sctx->ebx;
221 ctx->Ecx = sctx->ecx;
222 ctx->Edx = sctx->edx;
223 ctx->Ebp = sctx->ebp;
224 ctx->Esp = sctx->esp;
225 ctx->Esi = sctx->esi;
226 ctx->Edi = sctx->edi;
227 ctx->Eip = sctx->eip;
234 void win32_seh_init()
236 /* install restore stack helper */
238 restore_stack = mono_win32_get_handle_stackoverflow ();
240 old_handler = SetUnhandledExceptionFilter(seh_handler);
243 void win32_seh_cleanup()
245 if (old_handler) SetUnhandledExceptionFilter(old_handler);
248 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
252 fpe_handler = handler;
255 ill_handler = handler;
258 segv_handler = handler;
265 #endif /* TARGET_WIN32 */
268 * mono_arch_get_restore_context:
270 * Returns a pointer to a method which restores a previously saved sigcontext.
273 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
275 guint8 *start = NULL;
277 MonoJumpInfo *ji = NULL;
278 GSList *unwind_ops = NULL;
280 /* restore_contect (MonoContext *ctx) */
282 start = code = mono_global_codeman_reserve (128);
285 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 4, 4);
287 /* get return address, stored in ECX */
288 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eip), 4);
290 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebx), 4);
292 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (MonoContext, edi), 4);
294 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (MonoContext, esi), 4);
296 x86_mov_reg_membase (code, X86_ESP, X86_EAX, G_STRUCT_OFFSET (MonoContext, esp), 4);
297 /* save the return addr to the restored stack */
298 x86_push_reg (code, X86_ECX);
300 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
302 x86_mov_reg_membase (code, X86_ECX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ecx), 4);
304 x86_mov_reg_membase (code, X86_EDX, X86_EAX, G_STRUCT_OFFSET (MonoContext, edx), 4);
306 x86_mov_reg_membase (code, X86_EAX, X86_EAX, G_STRUCT_OFFSET (MonoContext, eax), 4);
308 /* jump to the saved IP */
311 #if defined(__native_client_codegen__) && defined(__native_client__)
312 nacl_global_codeman_validate(&start, 128, &code);
316 *info = mono_tramp_info_create (g_strdup_printf ("restore_context"), start, code - start, ji, unwind_ops);
320 for (l = unwind_ops; l; l = l->next)
322 g_slist_free (unwind_ops);
329 * mono_arch_get_call_filter:
331 * Returns a pointer to a method which calls an exception filter. We
332 * also use this function to call finally handlers (we pass NULL as
333 * @exc object in this case).
336 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
340 MonoJumpInfo *ji = NULL;
341 GSList *unwind_ops = NULL;
342 guint kMaxCodeSize = NACL_SIZE (64, 128);
344 /* call_filter (MonoContext *ctx, unsigned long eip) */
345 start = code = mono_global_codeman_reserve (kMaxCodeSize);
347 x86_push_reg (code, X86_EBP);
348 x86_mov_reg_reg (code, X86_EBP, X86_ESP, 4);
349 x86_push_reg (code, X86_EBX);
350 x86_push_reg (code, X86_EDI);
351 x86_push_reg (code, X86_ESI);
354 x86_mov_reg_membase (code, X86_EAX, X86_EBP, 8, 4);
356 x86_mov_reg_membase (code, X86_ECX, X86_EBP, 12, 4);
358 x86_push_reg (code, X86_EBP);
361 x86_mov_reg_membase (code, X86_EBP, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebp), 4);
362 /* restore registers used by global register allocation (EBX & ESI) */
363 x86_mov_reg_membase (code, X86_EBX, X86_EAX, G_STRUCT_OFFSET (MonoContext, ebx), 4);
364 x86_mov_reg_membase (code, X86_ESI, X86_EAX, G_STRUCT_OFFSET (MonoContext, esi), 4);
365 x86_mov_reg_membase (code, X86_EDI, X86_EAX, G_STRUCT_OFFSET (MonoContext, edi), 4);
367 /* align stack and save ESP */
368 x86_mov_reg_reg (code, X86_EDX, X86_ESP, 4);
369 x86_alu_reg_imm (code, X86_AND, X86_ESP, -MONO_ARCH_FRAME_ALIGNMENT);
370 g_assert (MONO_ARCH_FRAME_ALIGNMENT >= 8);
371 x86_alu_reg_imm (code, X86_SUB, X86_ESP, MONO_ARCH_FRAME_ALIGNMENT - 8);
372 x86_push_reg (code, X86_EDX);
374 /* call the handler */
375 x86_call_reg (code, X86_ECX);
378 x86_pop_reg (code, X86_ESP);
381 x86_pop_reg (code, X86_EBP);
383 /* restore saved regs */
384 x86_pop_reg (code, X86_ESI);
385 x86_pop_reg (code, X86_EDI);
386 x86_pop_reg (code, X86_EBX);
390 #if defined(__native_client_codegen__) && defined(__native_client__)
391 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
395 *info = mono_tramp_info_create (g_strdup_printf ("call_filter"), start, code - start, ji, unwind_ops);
399 for (l = unwind_ops; l; l = l->next)
401 g_slist_free (unwind_ops);
404 g_assert ((code - start) < kMaxCodeSize);
409 * mono_x86_throw_exception:
411 * C function called from the throw trampolines.
414 mono_x86_throw_exception (mgreg_t *regs, MonoObject *exc,
415 mgreg_t eip, gboolean rethrow)
417 static void (*restore_context) (MonoContext *);
420 if (!restore_context)
421 restore_context = mono_get_restore_context ();
423 ctx.esp = regs [X86_ESP];
425 ctx.ebp = regs [X86_EBP];
426 ctx.edi = regs [X86_EDI];
427 ctx.esi = regs [X86_ESI];
428 ctx.ebx = regs [X86_EBX];
429 ctx.edx = regs [X86_EDX];
430 ctx.ecx = regs [X86_ECX];
431 ctx.eax = regs [X86_EAX];
434 /* The OSX ABI specifies 16 byte alignment at call sites */
435 g_assert ((ctx.esp % MONO_ARCH_FRAME_ALIGNMENT) == 0);
438 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
439 MonoException *mono_ex = (MonoException*)exc;
441 mono_ex->stack_trace = NULL;
444 if (mono_debug_using_mono_debugger ()) {
445 guint8 buf [16], *code;
447 mono_breakpoint_clean_code (NULL, (gpointer)eip, 8, buf, sizeof (buf));
450 if (buf [3] == 0xe8) {
451 MonoContext ctx_cp = ctx;
452 ctx_cp.eip = eip - 5;
454 if (mono_debugger_handle_exception (&ctx_cp, exc)) {
455 restore_context (&ctx_cp);
456 g_assert_not_reached ();
461 /* adjust eip so that it point into the call instruction */
464 mono_handle_exception (&ctx, exc, (gpointer)eip, FALSE);
466 restore_context (&ctx);
468 g_assert_not_reached ();
472 mono_x86_throw_corlib_exception (mgreg_t *regs, guint32 ex_token_index,
473 mgreg_t eip, gint32 pc_offset)
475 guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
478 ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
482 /* Negate the ip adjustment done in mono_x86_throw_exception () */
485 mono_x86_throw_exception (regs, (MonoObject*)ex, eip, FALSE);
489 mono_x86_resume_unwind (mgreg_t *regs, MonoObject *exc,
490 mgreg_t eip, gboolean rethrow)
494 ctx.esp = regs [X86_ESP];
496 ctx.ebp = regs [X86_EBP];
497 ctx.edi = regs [X86_EDI];
498 ctx.esi = regs [X86_ESI];
499 ctx.ebx = regs [X86_EBX];
500 ctx.edx = regs [X86_EDX];
501 ctx.ecx = regs [X86_ECX];
502 ctx.eax = regs [X86_EAX];
504 mono_resume_unwind (&ctx);
508 * get_throw_trampoline:
510 * Generate a call to mono_x86_throw_exception/
511 * mono_x86_throw_corlib_exception.
512 * If LLVM is true, generate code which assumes the caller is LLVM generated code,
513 * which doesn't push the arguments.
516 get_throw_trampoline (const char *name, gboolean rethrow, gboolean llvm, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, MonoTrampInfo **info, gboolean aot)
518 guint8 *start, *code;
519 int i, stack_size, stack_offset, arg_offsets [5], regs_offset;
520 MonoJumpInfo *ji = NULL;
521 GSList *unwind_ops = NULL;
522 guint kMaxCodeSize = NACL_SIZE (128, 256);
524 start = code = mono_global_codeman_reserve (kMaxCodeSize);
529 * On apple, the stack is misaligned by the pushing of the return address.
532 /* On OSX, we don't generate alignment code to save space */
535 stack_size += MONO_ARCH_FRAME_ALIGNMENT - 4;
538 * The stack looks like this:
539 * <pc offset> (only if corlib is TRUE)
540 * <exception object>/<type token>
541 * <return addr> <- esp (unaligned on apple)
544 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
545 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
548 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
549 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
554 arg_offsets [3] = 12;
558 for (i = 0; i < X86_NREG; ++i)
560 x86_mov_membase_reg (code, X86_ESP, regs_offset + (i * 4), i, 4);
561 /* Calculate the offset between the current sp and the sp of the caller */
563 /* LLVM doesn't push the arguments */
564 stack_offset = stack_size + 4;
568 stack_offset = stack_size + 4 + 8;
570 /* We don't generate stack alignment code on osx to save space */
573 /* One argument + stack alignment */
574 stack_offset = stack_size + 4 + 4;
576 /* Pop the alignment added by OP_THROW too */
577 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
579 if (mono_do_x86_stack_align)
580 stack_offset += MONO_ARCH_FRAME_ALIGNMENT - 4;
585 x86_lea_membase (code, X86_EAX, X86_ESP, stack_offset);
586 x86_mov_membase_reg (code, X86_ESP, regs_offset + (X86_ESP * 4), X86_EAX, 4);
588 /* Set arg1 == regs */
589 x86_lea_membase (code, X86_EAX, X86_ESP, regs_offset);
590 x86_mov_membase_reg (code, X86_ESP, arg_offsets [0], X86_EAX, 4);
591 /* Set arg2 == exc/ex_token_index */
593 x86_mov_reg_imm (code, X86_EAX, 0);
595 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 4, 4);
596 x86_mov_membase_reg (code, X86_ESP, arg_offsets [1], X86_EAX, 4);
597 /* Set arg3 == eip */
599 x86_alu_reg_reg (code, X86_XOR, X86_EAX, X86_EAX);
601 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size, 4);
602 x86_mov_membase_reg (code, X86_ESP, arg_offsets [2], X86_EAX, 4);
603 /* Set arg4 == rethrow/pc_offset */
605 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], 0, 4);
607 x86_mov_reg_membase (code, X86_EAX, X86_ESP, stack_size + 8, 4);
610 * The caller is LLVM code which passes the absolute address not a pc offset,
611 * so compensate by passing 0 as 'ip' and passing the negated abs address as
614 x86_neg_reg (code, X86_EAX);
616 x86_mov_membase_reg (code, X86_ESP, arg_offsets [3], X86_EAX, 4);
618 x86_mov_membase_imm (code, X86_ESP, arg_offsets [3], rethrow, 4);
622 // This can be called from runtime code, which can't guarantee that
623 // ebx contains the got address.
624 // So emit the got address loading code too
625 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
626 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");
627 x86_call_reg (code, X86_EAX);
629 x86_call_code (code, resume_unwind ? (mono_x86_resume_unwind) : (corlib ? (gpointer)mono_x86_throw_corlib_exception : (gpointer)mono_x86_throw_exception));
631 x86_breakpoint (code);
633 #if defined(__native_client_codegen__) && defined(__native_client__)
634 nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
637 g_assert ((code - start) < kMaxCodeSize);
640 *info = mono_tramp_info_create (g_strdup (name), start, code - start, ji, unwind_ops);
644 for (l = unwind_ops; l; l = l->next)
646 g_slist_free (unwind_ops);
653 * mono_arch_get_throw_exception:
655 * Returns a function pointer which can be used to raise
656 * exceptions. The returned function has the following
657 * signature: void (*func) (MonoException *exc);
658 * For example to raise an arithmetic exception you can use:
660 * x86_push_imm (code, mono_get_exception_arithmetic ());
661 * x86_call_code (code, arch_get_throw_exception ());
665 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
667 return get_throw_trampoline ("throw_exception", FALSE, FALSE, FALSE, FALSE, FALSE, info, aot);
671 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
673 return get_throw_trampoline ("rethrow_exception", TRUE, FALSE, FALSE, FALSE, FALSE, info, aot);
677 * mono_arch_get_throw_corlib_exception:
679 * Returns a function pointer which can be used to raise
680 * corlib exceptions. The returned function has the following
681 * signature: void (*func) (guint32 ex_token, guint32 offset);
682 * Here, offset is the offset which needs to be substracted from the caller IP
683 * to get the IP of the throw. Passing the offset has the advantage that it
684 * needs no relocations in the caller.
687 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
689 return get_throw_trampoline ("throw_corlib_exception", FALSE, FALSE, TRUE, FALSE, FALSE, info, aot);
693 mono_arch_exceptions_init (void)
698 * If we're running WoW64, we need to set the usermode exception policy
699 * for SEHs to behave. This requires hotfix http://support.microsoft.com/kb/976038
700 * or (eventually) Windows 7 SP1.
706 HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
709 getter = GetProcAddress (kernel32, "GetProcessUserModeExceptionPolicy");
710 setter = GetProcAddress (kernel32, "SetProcessUserModeExceptionPolicy");
711 if (getter && setter) {
713 setter (flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
719 signal_exception_trampoline = mono_aot_get_trampoline ("x86_signal_exception_trampoline");
723 /* LLVM needs different throw trampolines */
724 tramp = get_throw_trampoline ("llvm_throw_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
725 mono_register_jit_icall (tramp, "llvm_throw_exception_trampoline", NULL, TRUE);
727 tramp = get_throw_trampoline ("llvm_rethrow_exception_trampoline", FALSE, TRUE, FALSE, FALSE, FALSE, NULL, FALSE);
728 mono_register_jit_icall (tramp, "llvm_rethrow_exception_trampoline", NULL, TRUE);
730 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_trampoline", FALSE, TRUE, TRUE, FALSE, FALSE, NULL, FALSE);
731 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
733 tramp = get_throw_trampoline ("llvm_throw_corlib_exception_abs_trampoline", FALSE, TRUE, TRUE, TRUE, FALSE, NULL, FALSE);
734 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
736 tramp = get_throw_trampoline ("llvm_resume_unwind_trampoline", FALSE, FALSE, FALSE, FALSE, TRUE, NULL, FALSE);
737 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
739 signal_exception_trampoline = mono_x86_get_signal_exception_trampoline (NULL, FALSE);
743 * mono_arch_find_jit_info:
745 * See exceptions-amd64.c for docs.
748 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
749 MonoJitInfo *ji, MonoContext *ctx,
750 MonoContext *new_ctx, MonoLMF **lmf,
751 StackFrameInfo *frame)
753 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
755 memset (frame, 0, sizeof (StackFrameInfo));
757 frame->managed = FALSE;
762 gssize regs [MONO_MAX_IREGS + 1];
764 guint32 unwind_info_len;
767 frame->type = FRAME_TYPE_MANAGED;
769 if (!ji->method->wrapper_type || ji->method->wrapper_type == MONO_WRAPPER_DYNAMIC_METHOD)
770 frame->managed = TRUE;
773 unwind_info = mono_aot_get_unwind_info (ji, &unwind_info_len);
775 unwind_info = mono_get_cached_unwind_info (ji->used_regs, &unwind_info_len);
777 regs [X86_EAX] = new_ctx->eax;
778 regs [X86_EBX] = new_ctx->ebx;
779 regs [X86_ECX] = new_ctx->ecx;
780 regs [X86_EDX] = new_ctx->edx;
781 regs [X86_ESP] = new_ctx->esp;
782 regs [X86_EBP] = new_ctx->ebp;
783 regs [X86_ESI] = new_ctx->esi;
784 regs [X86_EDI] = new_ctx->edi;
785 regs [X86_NREG] = new_ctx->eip;
787 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
788 (guint8*)ji->code_start + ji->code_size,
789 ip, regs, MONO_MAX_IREGS + 1, &cfa);
791 new_ctx->eax = regs [X86_EAX];
792 new_ctx->ebx = regs [X86_EBX];
793 new_ctx->ecx = regs [X86_ECX];
794 new_ctx->edx = regs [X86_EDX];
795 new_ctx->esp = regs [X86_ESP];
796 new_ctx->ebp = regs [X86_EBP];
797 new_ctx->esi = regs [X86_ESI];
798 new_ctx->edi = regs [X86_EDI];
799 new_ctx->eip = regs [X86_NREG];
801 /* The CFA becomes the new SP value */
802 new_ctx->esp = (gssize)cfa;
807 if (*lmf && (MONO_CONTEXT_GET_BP (ctx) >= (gpointer)(*lmf)->ebp)) {
808 /* remove any unused lmf */
809 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
812 /* Pop arguments off the stack */
814 * FIXME: LLVM doesn't push these, we can't use ji->from_llvm as it describes
819 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (ji->method)->param_count + 1);
821 guint32 stack_to_pop = mono_arch_get_argument_info (mono_method_signature (ji->method), mono_method_signature (ji->method)->param_count, arg_info);
822 new_ctx->esp += stack_to_pop;
829 if (((guint64)(*lmf)->previous_lmf) & 2) {
831 * This LMF entry is created by the soft debug code to mark transitions to
832 * managed code done during invokes.
834 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
836 g_assert (ext->debugger_invoke);
838 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
840 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
842 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
847 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
849 if (!((guint32)((*lmf)->previous_lmf) & 1))
852 g_assert_not_reached ();
853 /* Trampoline lmf frame */
854 frame->method = (*lmf)->method;
857 new_ctx->esi = (*lmf)->esi;
858 new_ctx->edi = (*lmf)->edi;
859 new_ctx->ebx = (*lmf)->ebx;
860 new_ctx->ebp = (*lmf)->ebp;
861 new_ctx->eip = (*lmf)->eip;
867 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
869 /* Check if we are in a trampoline LMF frame */
870 if ((guint32)((*lmf)->previous_lmf) & 1) {
871 /* lmf->esp is set by the trampoline code */
872 new_ctx->esp = (*lmf)->esp;
874 /* Pop arguments off the stack */
875 /* FIXME: Handle the delegate case too ((*lmf)->method == NULL) */
876 /* FIXME: Handle the IMT/vtable case too */
878 if ((*lmf)->method) {
879 MonoMethod *method = (*lmf)->method;
880 MonoJitArgumentInfo *arg_info = g_newa (MonoJitArgumentInfo, mono_method_signature (method)->param_count + 1);
882 guint32 stack_to_pop = mono_arch_get_argument_info (mono_method_signature (method), mono_method_signature (method)->param_count, arg_info);
883 new_ctx->esp += stack_to_pop;
888 /* the lmf is always stored on the stack, so the following
889 * expression points to a stack location which can be used as ESP */
890 new_ctx->esp = (unsigned long)&((*lmf)->eip);
892 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
913 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
915 #if defined (__native_client__)
916 printf("WARNING: mono_arch_sigctx_to_monoctx() called!\n");
917 mctx->eax = 0xDEADBEEF;
918 mctx->ebx = 0xDEADBEEF;
919 mctx->ecx = 0xDEADBEEF;
920 mctx->edx = 0xDEADBEEF;
921 mctx->ebp = 0xDEADBEEF;
922 mctx->esp = 0xDEADBEEF;
923 mctx->esi = 0xDEADBEEF;
924 mctx->edi = 0xDEADBEEF;
925 mctx->eip = 0xDEADBEEF;
927 #ifdef MONO_ARCH_USE_SIGACTION
928 ucontext_t *ctx = (ucontext_t*)sigctx;
930 mctx->eax = UCONTEXT_REG_EAX (ctx);
931 mctx->ebx = UCONTEXT_REG_EBX (ctx);
932 mctx->ecx = UCONTEXT_REG_ECX (ctx);
933 mctx->edx = UCONTEXT_REG_EDX (ctx);
934 mctx->ebp = UCONTEXT_REG_EBP (ctx);
935 mctx->esp = UCONTEXT_REG_ESP (ctx);
936 mctx->esi = UCONTEXT_REG_ESI (ctx);
937 mctx->edi = UCONTEXT_REG_EDI (ctx);
938 mctx->eip = UCONTEXT_REG_EIP (ctx);
940 struct sigcontext *ctx = (struct sigcontext *)sigctx;
942 mctx->eax = ctx->SC_EAX;
943 mctx->ebx = ctx->SC_EBX;
944 mctx->ecx = ctx->SC_ECX;
945 mctx->edx = ctx->SC_EDX;
946 mctx->ebp = ctx->SC_EBP;
947 mctx->esp = ctx->SC_ESP;
948 mctx->esi = ctx->SC_ESI;
949 mctx->edi = ctx->SC_EDI;
950 mctx->eip = ctx->SC_EIP;
952 #endif /* if defined(__native_client__) */
956 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
958 #if defined(__native_client__)
959 printf("WARNING: mono_arch_monoctx_to_sigctx() called!\n");
961 #ifdef MONO_ARCH_USE_SIGACTION
962 ucontext_t *ctx = (ucontext_t*)sigctx;
964 UCONTEXT_REG_EAX (ctx) = mctx->eax;
965 UCONTEXT_REG_EBX (ctx) = mctx->ebx;
966 UCONTEXT_REG_ECX (ctx) = mctx->ecx;
967 UCONTEXT_REG_EDX (ctx) = mctx->edx;
968 UCONTEXT_REG_EBP (ctx) = mctx->ebp;
969 UCONTEXT_REG_ESP (ctx) = mctx->esp;
970 UCONTEXT_REG_ESI (ctx) = mctx->esi;
971 UCONTEXT_REG_EDI (ctx) = mctx->edi;
972 UCONTEXT_REG_EIP (ctx) = mctx->eip;
974 struct sigcontext *ctx = (struct sigcontext *)sigctx;
976 ctx->SC_EAX = mctx->eax;
977 ctx->SC_EBX = mctx->ebx;
978 ctx->SC_ECX = mctx->ecx;
979 ctx->SC_EDX = mctx->edx;
980 ctx->SC_EBP = mctx->ebp;
981 ctx->SC_ESP = mctx->esp;
982 ctx->SC_ESI = mctx->esi;
983 ctx->SC_EDI = mctx->edi;
984 ctx->SC_EIP = mctx->eip;
986 #endif /* __native_client__ */
990 mono_arch_ip_from_context (void *sigctx)
992 #if defined(__native_client__)
993 printf("WARNING: mono_arch_ip_from_context() called!\n");
996 #ifdef MONO_ARCH_USE_SIGACTION
997 ucontext_t *ctx = (ucontext_t*)sigctx;
998 return (gpointer)UCONTEXT_REG_EIP (ctx);
1000 struct sigcontext *ctx = sigctx;
1001 return (gpointer)ctx->SC_EIP;
1003 #endif /* __native_client__ */
1009 * Called by resuming from a signal handler.
1012 handle_signal_exception (gpointer obj)
1014 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
1016 static void (*restore_context) (MonoContext *);
1018 if (!restore_context)
1019 restore_context = mono_get_restore_context ();
1021 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
1023 if (mono_debugger_handle_exception (&ctx, (MonoObject *)obj))
1026 mono_handle_exception (&ctx, obj, MONO_CONTEXT_GET_IP (&ctx), FALSE);
1028 restore_context (&ctx);
1032 * mono_x86_get_signal_exception_trampoline:
1034 * This x86 specific trampoline is used to call handle_signal_exception.
1037 mono_x86_get_signal_exception_trampoline (MonoTrampInfo **info, gboolean aot)
1039 guint8 *start, *code;
1040 MonoJumpInfo *ji = NULL;
1041 GSList *unwind_ops = NULL;
1044 start = code = mono_global_codeman_reserve (128);
1047 x86_push_reg (code, X86_ECX);
1049 mono_add_unwind_op_def_cfa (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_ESP, 4);
1050 mono_add_unwind_op_offset (unwind_ops, (guint8*)NULL, (guint8*)NULL, X86_NREG, -4);
1052 /* Fix the alignment to be what apple expects */
1055 x86_alu_reg_imm (code, X86_SUB, X86_ESP, stack_size);
1056 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 4);
1059 x86_mov_membase_reg (code, X86_ESP, 0, X86_EAX, 4);
1060 /* Branch to target */
1061 x86_call_reg (code, X86_EDX);
1063 g_assert ((code - start) < 128);
1066 *info = mono_tramp_info_create (g_strdup ("x86_signal_exception_trampoline"), start, code - start, ji, unwind_ops);
1070 for (l = unwind_ops; l; l = l->next)
1072 g_slist_free (unwind_ops);
1079 mono_arch_handle_exception (void *sigctx, gpointer obj, gboolean test_only)
1081 #if defined(MONO_ARCH_USE_SIGACTION)
1082 ucontext_t *ctx = (ucontext_t*)sigctx;
1085 * Handling the exception in the signal handler is problematic, since the original
1086 * signal is disabled, and we could run arbitrary code though the debugger. So
1087 * resume into the normal stack and do most work there if possible.
1089 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
1090 guint64 sp = UCONTEXT_REG_ESP (ctx);
1092 /* Pass the ctx parameter in TLS */
1093 mono_arch_sigctx_to_monoctx (ctx, &jit_tls->ex_ctx);
1095 * Can't pass the obj on the stack, since we are executing on the
1096 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
1097 * So put it into a register, and branch to a trampoline which
1100 g_assert (!test_only);
1101 UCONTEXT_REG_EAX (ctx) = (gsize)obj;
1102 UCONTEXT_REG_ECX (ctx) = UCONTEXT_REG_EIP (ctx);
1103 UCONTEXT_REG_EDX (ctx) = (gsize)handle_signal_exception;
1105 /* Allocate a stack frame, align it to 16 bytes which is needed on apple */
1108 UCONTEXT_REG_ESP (ctx) = sp;
1110 UCONTEXT_REG_EIP (ctx) = (gsize)signal_exception_trampoline;
1113 #elif defined (TARGET_WIN32)
1114 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
1115 struct sigcontext *ctx = (struct sigcontext *)sigctx;
1116 guint64 sp = ctx->SC_ESP;
1118 mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
1121 * Can't pass the obj on the stack, since we are executing on the
1122 * same stack. Can't save it into MonoJitTlsData, since it needs GC tracking.
1123 * So put it into a register, and branch to a trampoline which
1126 g_assert (!test_only);
1127 ctx->SC_EAX = (gsize)obj;
1128 ctx->SC_ECX = ctx->SC_EIP;
1129 ctx->SC_EDX = (gsize)handle_signal_exception;
1131 /* Allocate a stack frame, align it to 16 bytes which is needed on apple */
1136 ctx->SC_EIP = (gsize)signal_exception_trampoline;
1142 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1144 if (mono_debugger_handle_exception (&mctx, (MonoObject *)obj))
1147 mono_handle_exception (&mctx, obj, (gpointer)mctx.eip, test_only);
1149 mono_arch_monoctx_to_sigctx (&mctx, sigctx);
1156 restore_soft_guard_pages (void)
1158 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
1159 if (jit_tls->stack_ovf_guard_base)
1160 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
1164 * this function modifies mctx so that when it is restored, it
1165 * won't execcute starting at mctx.eip, but in a function that
1166 * will restore the protection on the soft-guard pages and return back to
1167 * continue at mctx.eip.
1170 prepare_for_guard_pages (MonoContext *mctx)
1173 sp = (gpointer)(mctx->esp);
1175 /* the resturn addr */
1176 sp [0] = (gpointer)(mctx->eip);
1177 mctx->eip = (unsigned long)restore_soft_guard_pages;
1178 mctx->esp = (unsigned long)sp;
1182 altstack_handle_and_restore (void *sigctx, gpointer obj, gboolean stack_ovf)
1184 void (*restore_context) (MonoContext *);
1187 restore_context = mono_get_restore_context ();
1188 mono_arch_sigctx_to_monoctx (sigctx, &mctx);
1190 if (mono_debugger_handle_exception (&mctx, (MonoObject *)obj)) {
1192 prepare_for_guard_pages (&mctx);
1193 restore_context (&mctx);
1196 mono_handle_exception (&mctx, obj, (gpointer)mctx.eip, FALSE);
1198 prepare_for_guard_pages (&mctx);
1199 restore_context (&mctx);
1203 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
1205 #ifdef MONO_ARCH_USE_SIGACTION
1206 MonoException *exc = NULL;
1207 ucontext_t *ctx = (ucontext_t*)sigctx;
1208 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_EIP (ctx), NULL);
1212 /* if we didn't find a managed method for the ip address and it matches the fault
1213 * address, we assume we followed a broken pointer during an indirect call, so
1214 * we try the lookup again with the return address pushed on the stack
1216 if (!ji && fault_addr == (gpointer)UCONTEXT_REG_EIP (ctx)) {
1217 glong *sp = (gpointer)UCONTEXT_REG_ESP (ctx);
1218 ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)sp [0], NULL);
1220 UCONTEXT_REG_EIP (ctx) = sp [0];
1223 exc = mono_domain_get ()->stack_overflow_ex;
1225 mono_handle_native_sigsegv (SIGSEGV, sigctx);
1226 /* setup a call frame on the real stack so that control is returned there
1227 * and exception handling can continue.
1228 * If this was a stack overflow the caller already ensured the stack pages
1229 * needed have been unprotected.
1230 * The frame looks like:
1237 frame_size = sizeof (ucontext_t) + sizeof (gpointer) * 4;
1240 sp = (gpointer)(UCONTEXT_REG_ESP (ctx) & ~15);
1241 sp = (gpointer)((char*)sp - frame_size);
1242 /* the incoming arguments are aligned to 16 bytes boundaries, so the return address IP
1245 sp [-1] = (gpointer)UCONTEXT_REG_EIP (ctx);
1248 sp [2] = (gpointer)stack_ovf;
1249 /* may need to adjust pointers in the new struct copy, depending on the OS */
1250 memcpy (sp + 4, ctx, sizeof (ucontext_t));
1251 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
1252 UCONTEXT_REG_EIP (ctx) = (unsigned long)altstack_handle_and_restore;
1253 UCONTEXT_REG_ESP (ctx) = (unsigned long)(sp - 1);
1257 #if MONO_SUPPORT_TASKLETS
1258 MonoContinuationRestore
1259 mono_tasklets_arch_restore (void)
1261 static guint8* saved = NULL;
1262 guint8 *code, *start;
1264 #ifdef __native_client_codegen__
1265 g_print("mono_tasklets_arch_restore needs to be aligned for Native Client\n");
1268 return (MonoContinuationRestore)saved;
1269 code = start = mono_global_codeman_reserve (48);
1270 /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1271 /* put cont in edx */
1272 x86_mov_reg_membase (code, X86_EDX, X86_ESP, 4, 4);
1273 /* setup the copy of the stack */
1274 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, stack_used_size), 4);
1275 x86_shift_reg_imm (code, X86_SHR, X86_ECX, 2);
1277 x86_mov_reg_membase (code, X86_ESI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, saved_stack), 4);
1278 x86_mov_reg_membase (code, X86_EDI, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_sp), 4);
1279 x86_prefix (code, X86_REP_PREFIX);
1282 /* now restore the registers from the LMF */
1283 x86_mov_reg_membase (code, X86_ECX, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, lmf), 4);
1284 x86_mov_reg_membase (code, X86_EBX, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebx), 4);
1285 x86_mov_reg_membase (code, X86_EBP, X86_ECX, G_STRUCT_OFFSET (MonoLMF, ebp), 4);
1286 x86_mov_reg_membase (code, X86_ESI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, esi), 4);
1287 x86_mov_reg_membase (code, X86_EDI, X86_ECX, G_STRUCT_OFFSET (MonoLMF, edi), 4);
1289 /* restore the lmf chain */
1290 /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1291 x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1293 /* state in eax, so it's setup as the return value */
1294 x86_mov_reg_membase (code, X86_EAX, X86_ESP, 8, 4);
1295 x86_jump_membase (code, X86_EDX, G_STRUCT_OFFSET (MonoContinuation, return_ip));
1296 g_assert ((code - start) <= 48);
1298 return (MonoContinuationRestore)saved;