From: David Lichteblau Date: Mon, 3 Sep 2012 11:31:46 +0000 (+0200) Subject: win32-os.c: Split up handle_exception X-Git-Url: http://repo.macrolet.net/gitweb/?a=commitdiff_plain;h=0285aa5ff8416027932daa001b84429be2ca559b;p=sbcl.git win32-os.c: Split up handle_exception In preparation for various changes to exception handling, split up handle_exception into separate functions for each kind of exception. This change is entirely cosmetic in nature. --- diff --git a/src/runtime/win32-os.c b/src/runtime/win32-os.c index 3d27f78..b3e22ca 100644 --- a/src/runtime/win32-os.c +++ b/src/runtime/win32-os.c @@ -313,108 +313,110 @@ is_valid_lisp_addr(os_vm_address_t addr) /* A tiny bit of interrupt.c state we want our paws on. */ extern boolean internal_errors_enabled; +#if defined(LISP_FEATURE_X86) +static int +handle_single_step(os_context_t *ctx) +{ + if (!single_stepping) + return -1; + + /* We are doing a displaced instruction. At least function + * end breakpoints use this. */ + restore_breakpoint_from_single_step(ctx); + + return 0; +} +#endif + #ifdef LISP_FEATURE_UD2_BREAKPOINTS -#define IS_TRAP_EXCEPTION(exception_record, context) \ - (((exception_record)->ExceptionCode == EXCEPTION_ILLEGAL_INSTRUCTION) && \ - (((unsigned short *)((context)->Eip))[0] == 0x0b0f)) +#define SBCL_EXCEPTION_BREAKPOINT EXCEPTION_ILLEGAL_INSTRUCTION #define TRAP_CODE_WIDTH 2 #else -#define IS_TRAP_EXCEPTION(exception_record, context) \ - ((exception_record)->ExceptionCode == EXCEPTION_BREAKPOINT) +#define SBCL_EXCEPTION_BREAKPOINT EXCEPTION_BREAKPOINT #define TRAP_CODE_WIDTH 1 #endif -/* - * A good explanation of the exception handling semantics is - * http://win32assembly.online.fr/Exceptionhandling.html . - */ - -EXCEPTION_DISPOSITION -handle_exception(EXCEPTION_RECORD *exception_record, - struct lisp_exception_frame *exception_frame, - CONTEXT *context, - void *dispatcher_context) +static int +handle_breakpoint_trap(os_context_t *ctx) { - if (exception_record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)) { - /* If we're being unwound, be graceful about it. */ +#ifdef LISP_FEATURE_UD2_BREAKPOINTS + if (((unsigned short *)((ctx->win32_context)->Eip))[0] != 0x0b0f) + return -1; +#endif - /* Undo any dynamic bindings. */ - unbind_to_here(exception_frame->bindstack_pointer, - arch_os_get_current_thread()); + /* Unlike some other operating systems, Win32 leaves EIP + * pointing to the breakpoint instruction. */ + ctx->Eip += TRAP_CODE_WIDTH; - return ExceptionContinueSearch; - } + /* Now EIP points just after the INT3 byte and aims at the + * 'kind' value (eg trap_Cerror). */ + unsigned char trap = *(unsigned char *)(*os_context_pc_addr(ctx)); - /* For EXCEPTION_ACCESS_VIOLATION only. */ - void *fault_address = (void *)exception_record->ExceptionInformation[1]; + /* This is just for info in case the monitor wants to print an + * approximation. */ + current_control_stack_pointer = + (lispobj *)*os_context_sp_addr(ctx); - if (single_stepping && - exception_record->ExceptionCode == EXCEPTION_SINGLE_STEP) { - /* We are doing a displaced instruction. At least function - * end breakpoints uses this. */ - restore_breakpoint_from_single_step(context); - return ExceptionContinueExecution; - } + handle_trap(ctx, trap); - if (IS_TRAP_EXCEPTION(exception_record, context)) { - unsigned char trap; - /* This is just for info in case the monitor wants to print an - * approximation. */ - current_control_stack_pointer = - (lispobj *)*os_context_sp_addr(context); - /* Unlike some other operating systems, Win32 leaves EIP - * pointing to the breakpoint instruction. */ - context->Eip += TRAP_CODE_WIDTH; - /* Now EIP points just after the INT3 byte and aims at the - * 'kind' value (eg trap_Cerror). */ - trap = *(unsigned char *)(*os_context_pc_addr(context)); - handle_trap(context, trap); - /* Done, we're good to go! */ - return ExceptionContinueExecution; - } - else if (exception_record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION && - (is_valid_lisp_addr(fault_address) || - is_linkage_table_addr(fault_address))) { - /* Pick off GC-related memory fault next. */ - MEMORY_BASIC_INFORMATION mem_info; + /* Done, we're good to go! */ + return 0; +} - if (!VirtualQuery(fault_address, &mem_info, sizeof mem_info)) { - fprintf(stderr, "VirtualQuery: 0x%lx.\n", GetLastError()); - lose("handle_exception: VirtualQuery failure"); - } +static int +handle_access_violation(os_context_t *ctx, + EXCEPTION_RECORD *exception_record, + void *fault_address) +{ + if (!(is_valid_lisp_addr(fault_address) + || is_linkage_table_addr(fault_address))) + return -1; + + /* Pick off GC-related memory fault next. */ + MEMORY_BASIC_INFORMATION mem_info; - if (mem_info.State == MEM_RESERVE) { - /* First use new page, lets get some memory for it. */ - if (!VirtualAlloc(mem_info.BaseAddress, os_vm_page_size, - MEM_COMMIT, PAGE_EXECUTE_READWRITE)) { - fprintf(stderr, "VirtualAlloc: 0x%lx.\n", GetLastError()); - lose("handle_exception: VirtualAlloc failure"); - - } else { - /* - * Now, if the page is supposedly write-protected and this - * is a write, tell the gc that it's been hit. - * - * FIXME: Are we supposed to fall-through to the Lisp - * exception handler if the gc doesn't take the wp violation? - */ - if (exception_record->ExceptionInformation[0]) { - page_index_t index = find_page_index(fault_address); - if ((index != -1) && (page_table[index].write_protected)) { - gencgc_handle_wp_violation(fault_address); - } + if (!VirtualQuery(fault_address, &mem_info, sizeof mem_info)) { + fprintf(stderr, "VirtualQuery: 0x%lx.\n", GetLastError()); + lose("handle_exception: VirtualQuery failure"); + } + + if (mem_info.State == MEM_RESERVE) { + /* First use new page, lets get some memory for it. */ + if (!VirtualAlloc(mem_info.BaseAddress, os_vm_page_size, + MEM_COMMIT, PAGE_EXECUTE_READWRITE)) { + fprintf(stderr, "VirtualAlloc: 0x%lx.\n", GetLastError()); + lose("handle_exception: VirtualAlloc failure"); + + } else { + /* + * Now, if the page is supposedly write-protected and this + * is a write, tell the gc that it's been hit. + * + * FIXME: Are we supposed to fall-through to the Lisp + * exception handler if the gc doesn't take the wp violation? + */ + if (exception_record->ExceptionInformation[0]) { + page_index_t index = find_page_index(fault_address); + if ((index != -1) && (page_table[index].write_protected)) { + gencgc_handle_wp_violation(fault_address); } - return ExceptionContinueExecution; } - - } else if (gencgc_handle_wp_violation(fault_address)) { - /* gc accepts the wp violation, so resume where we left off. */ - return ExceptionContinueExecution; + return 0; } - /* All else failed, drop through to the lisp-side exception handler. */ + } else if (gencgc_handle_wp_violation(fault_address)) { + /* gc accepts the wp violation, so resume where we left off. */ + return 0; } + return -1; +} + +static void +signal_internal_error_or_lose(os_context_t *ctx, + EXCEPTION_RECORD *exception_record, + void *fault_address) +{ /* * If we fall through to here then we need to either forward * the exception to the lisp-side exception handler if it's @@ -431,11 +433,11 @@ handle_exception(EXCEPTION_RECORD *exception_record, * aren't supposed to happen during cold init or reinit * anyway. */ - fake_foreign_function_call(context); + fake_foreign_function_call(ctx); /* Allocate the SAP objects while the "interrupts" are still * disabled. */ - context_sap = alloc_sap(context); + context_sap = alloc_sap(ctx); exception_record_sap = alloc_sap(exception_record); /* The exception system doesn't automatically clear pending @@ -448,10 +450,10 @@ handle_exception(EXCEPTION_RECORD *exception_record, exception_record_sap); /* If Lisp doesn't nlx, we need to put things back. */ - undo_fake_foreign_function_call(context); + undo_fake_foreign_function_call(ctx); /* FIXME: HANDLE-WIN32-EXCEPTION should be allowed to decline */ - return ExceptionContinueExecution; + return; } fprintf(stderr, "Exception Code: 0x%lx.\n", exception_record->ExceptionCode); @@ -470,11 +472,67 @@ handle_exception(EXCEPTION_RECORD *exception_record, fflush(stderr); - fake_foreign_function_call(context); + fake_foreign_function_call(ctx); lose("Exception too early in cold init, cannot continue."); +} + +/* + * A good explanation of the exception handling semantics is + * http://win32assembly.online.fr/Exceptionhandling.html . + */ + +EXCEPTION_DISPOSITION +handle_exception(EXCEPTION_RECORD *exception_record, + struct lisp_exception_frame *exception_frame, + CONTEXT *ctx, + void *dispatcher_context) +{ + if (exception_record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)) { + /* If we're being unwound, be graceful about it. */ + + /* Undo any dynamic bindings. */ + unbind_to_here(exception_frame->bindstack_pointer, + arch_os_get_current_thread()); + + return ExceptionContinueSearch; + } + + DWORD code = exception_record->ExceptionCode; + + /* For EXCEPTION_ACCESS_VIOLATION only. */ + void *fault_address = (void *)exception_record->ExceptionInformation[1]; + + /* This function will become unwieldy. Let's cut it down into + * pieces based on the different exception codes. Each exception + * code handler gets the chance to decline by returning non-zero if it + * isn't happy: */ + + int rc; + switch (code) { + case EXCEPTION_ACCESS_VIOLATION: + rc = handle_access_violation( + ctx, exception_record, fault_address); + break; + + case SBCL_EXCEPTION_BREAKPOINT: + rc = handle_breakpoint_trap(ctx); + break; + +#if defined(LISP_FEATURE_X86) + case EXCEPTION_SINGLE_STEP: + rc = handle_single_step(ctx); + break; +#endif + + default: + rc = -1; + } + + if (rc) + /* All else failed, drop through to the lisp-side exception handler. */ + signal_internal_error_or_lose(ctx, exception_record, fault_address); - /* FIXME: WTF? How are we supposed to end up here? */ - return ExceptionContinueSearch; + return ExceptionContinueExecution; } void