diff options
Diffstat (limited to 'libsigsegv/src/handler-win32.c')
| -rw-r--r-- | libsigsegv/src/handler-win32.c | 317 |
1 files changed, 0 insertions, 317 deletions
diff --git a/libsigsegv/src/handler-win32.c b/libsigsegv/src/handler-win32.c deleted file mode 100644 index 479bd030..00000000 --- a/libsigsegv/src/handler-win32.c +++ /dev/null @@ -1,317 +0,0 @@ -/* Fault handler information. Woe32 version. - Copyright (C) 1993-1999, 2002-2003, 2007-2008 Bruno Haible <bruno@clisp.org> - Copyright (C) 2003 Paolo Bonzini <bonzini@gnu.org> - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software Foundation, - Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ - -#include "sigsegv.h" - -#define WIN32_LEAN_AND_MEAN /* avoid including junk */ -#include <windows.h> -#include <winerror.h> -/* - * extern LPTOP_LEVEL_EXCEPTION_FILTER SetUnhandledExceptionFilter (LPTOP_LEVEL_EXCEPTION_FILTER TopLevelExceptionFilter); - * extern DWORD VirtualQuery (LPCVOID Address, PMEMORY_BASIC_INFORMATION Buffer, DWORD Length); - * extern BOOL VirtualProtect (LPVOID Address, DWORD Size, DWORD NewProtect, PDWORD OldProtect); - * extern DWORD GetLastError (void); - */ - -/* User's SIGSEGV handler. */ -static sigsegv_handler_t user_handler = (sigsegv_handler_t) NULL; - -/* Stack overflow handling is tricky: - First, we must catch a STATUS_STACK_OVERFLOW exception. This is signalled - when the guard page at the end of the stack has been touched. The operating - system remaps the page with protection PAGE_READWRITE and only then calls - our exception handler. Actually, it's even more complicated: The stack has - the following layout: - - | |guard|----------stack-----------| - - and when the guard page is touched, the system maps it PAGE_READWRITE and - allocates a new guard page below it: - - | |guard|-------------stack--------------| - - Only when no new guard page can be allocated (because the maximum stack - size has been reached), will we see an exception. - - |guard|-------------------------stack--------------------------| - - Second, we must reinstall the guard page. Otherwise, on the next stack - overflow, the application will simply crash (on WinNT: silently, on Win95: - with an error message box and freezing the system). - But since we don't know where %esp points to during the exception handling, - we must first leave the exception handler, before we can restore the guard - page. And %esp must be made to point to a reasonable value before we do - this. - - Note: On WinNT, the guard page has protection PAGE_READWRITE|PAGE_GUARD. - On Win95, which doesn't know PAGE_GUARD, it has protection PAGE_NOACCESS. - */ - -static stackoverflow_handler_t stk_user_handler = - (stackoverflow_handler_t) NULL; -static unsigned long stk_extra_stack; -static unsigned long stk_extra_stack_size; - -static void -stack_overflow_handler (unsigned long faulting_page_address, stackoverflow_context_t context) -{ - MEMORY_BASIC_INFORMATION info; - DWORD oldprot; - unsigned long base; - unsigned long address; - - /* First get stack's base address. */ - if (VirtualQuery ((void*) faulting_page_address, &info, sizeof (info)) - != sizeof (info)) - goto failed; - base = (unsigned long) info.AllocationBase; - - /* Now search for the first existing page. */ - address = base; - for (;;) - { - if (VirtualQuery ((void*) address, &info, sizeof (info)) != sizeof (info)) - goto failed; - if (address != (unsigned long) info.BaseAddress) - goto failed; - if (info.State != MEM_FREE) - { - if ((unsigned long) info.AllocationBase != base) - goto failed; - if (info.State == MEM_COMMIT) - break; - } - address = (unsigned long) info.BaseAddress + info.RegionSize; - } - - /* Now add the PAGE_GUARD bit to the first existing page. */ - /* On WinNT this works... */ - if (VirtualProtect (info.BaseAddress, 0x1000, info.Protect | PAGE_GUARD, - &oldprot)) - goto ok; - if (GetLastError () == ERROR_INVALID_PARAMETER) - /* ... but on Win95 we need this: */ - if (VirtualProtect (info.BaseAddress, 0x1000, PAGE_NOACCESS, &oldprot)) - goto ok; - failed: - for (;;) - (*stk_user_handler) (1, context); - ok: - for (;;) - (*stk_user_handler) (0, context); -} - -/* This is the stack overflow and page fault handler. */ -static LONG WINAPI -main_exception_filter (EXCEPTION_POINTERS *ExceptionInfo) -{ - if ((stk_user_handler - && ExceptionInfo->ExceptionRecord->ExceptionCode == STATUS_STACK_OVERFLOW - ) - || - (user_handler != (sigsegv_handler_t)NULL - && ExceptionInfo->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION - )) - { -#if 0 /* for debugging only */ - printf ("Exception!\n"); - printf ("Code = 0x%x\n", - ExceptionInfo->ExceptionRecord->ExceptionCode); - printf ("Flags = 0x%x\n", - ExceptionInfo->ExceptionRecord->ExceptionFlags); - printf ("Address = 0x%x\n", - ExceptionInfo->ExceptionRecord->ExceptionAddress); - printf ("Params:"); - { - DWORD i; - for (i = 0; i < ExceptionInfo->ExceptionRecord->NumberParameters; i++) - printf (" 0x%x,", - ExceptionInfo->ExceptionRecord->ExceptionInformation[i]); - } - printf ("\n"); - printf ("Registers:\n"); - printf ("eip = 0x%x\n", ExceptionInfo->ContextRecord->Eip); - printf ("eax = 0x%x, ", ExceptionInfo->ContextRecord->Eax); - printf ("ebx = 0x%x, ", ExceptionInfo->ContextRecord->Ebx); - printf ("ecx = 0x%x, ", ExceptionInfo->ContextRecord->Ecx); - printf ("edx = 0x%x\n", ExceptionInfo->ContextRecord->Edx); - printf ("esi = 0x%x, ", ExceptionInfo->ContextRecord->Esi); - printf ("edi = 0x%x, ", ExceptionInfo->ContextRecord->Edi); - printf ("ebp = 0x%x, ", ExceptionInfo->ContextRecord->Ebp); - printf ("esp = 0x%x\n", ExceptionInfo->ContextRecord->Esp); -#endif - if (ExceptionInfo->ExceptionRecord->NumberParameters == 2) - { - if (stk_user_handler - && ExceptionInfo->ExceptionRecord->ExceptionCode == STATUS_STACK_OVERFLOW) - { - char *address = (char *) ExceptionInfo->ExceptionRecord->ExceptionInformation[1]; - /* Restart the program, giving it a sane value for %esp. - At the same time, copy the contents of - ExceptionInfo->ContextRecord (which, on Windows XP, happens - to be allocated in the guard page, where it will be - inaccessible as soon as we restore the PAGE_GUARD bit!) to - this new stack. */ - unsigned long faulting_page_address = (unsigned long)address & -0x1000; - unsigned long new_safe_esp = ((stk_extra_stack + stk_extra_stack_size) & -16); - CONTEXT *orig_context = ExceptionInfo->ContextRecord; - CONTEXT *safe_context = (CONTEXT *) (new_safe_esp -= sizeof (CONTEXT)); /* make room */ - memcpy (safe_context, orig_context, sizeof (CONTEXT)); - new_safe_esp -= 8; /* make room for arguments */ - new_safe_esp &= -16; /* align */ - new_safe_esp -= 4; /* make room for (unused) return address slot */ - ExceptionInfo->ContextRecord->Esp = new_safe_esp; - /* Call stack_overflow_handler(faulting_page_address,safe_context). */ - ExceptionInfo->ContextRecord->Eip = (unsigned long)&stack_overflow_handler; - *(unsigned long *)(new_safe_esp + 4) = faulting_page_address; - *(unsigned long *)(new_safe_esp + 8) = (unsigned long) safe_context; - return EXCEPTION_CONTINUE_EXECUTION; - } - if (user_handler != (sigsegv_handler_t) NULL - && ExceptionInfo->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION) - { - /* ExceptionInfo->ExceptionRecord->ExceptionInformation[0] is 1 - if it's a write access, 0 if it's a read access. But we don't - need this info because we don't have it on Unix either. */ - void *address = (void *) ExceptionInfo->ExceptionRecord->ExceptionInformation[1]; - if ((*user_handler) (address, 1)) - return EXCEPTION_CONTINUE_EXECUTION; - } - } - } - return EXCEPTION_CONTINUE_SEARCH; -} - -#if defined __CYGWIN__ && defined __i386__ - -/* In Cygwin programs, SetUnhandledExceptionFilter has no effect because Cygwin - installs a global exception handler. We have to dig deep in order to install - our main_exception_filter. */ - -/* Data structures for the current thread's exception handler chain. - On the x86 Windows uses register fs, offset 0 to point to the current - exception handler; Cygwin mucks with it, so we must do the same... :-/ */ - -/* Magic taken from winsup/cygwin/include/exceptions.h. */ - -struct exception_list - { - struct exception_list *prev; - int (*handler) (EXCEPTION_RECORD *, void *, CONTEXT *, void *); - }; -typedef struct exception_list exception_list; - -/* Magic taken from winsup/cygwin/exceptions.cc. */ - -__asm__ (".equ __except_list,0"); - -extern exception_list *_except_list __asm__ ("%fs:__except_list"); - -/* For debugging. _except_list is not otherwise accessible from gdb. */ -static exception_list * -debug_get_except_list () -{ - return _except_list; -} - -/* Cygwin's original exception handler. */ -static int (*cygwin_exception_handler) (EXCEPTION_RECORD *, void *, CONTEXT *, void *); - -/* Our exception handler. */ -static int -libsigsegv_exception_handler (EXCEPTION_RECORD *exception, void *frame, CONTEXT *context, void *dispatch) -{ - EXCEPTION_POINTERS ExceptionInfo; - ExceptionInfo.ExceptionRecord = exception; - ExceptionInfo.ContextRecord = context; - if (main_exception_filter (&ExceptionInfo) == EXCEPTION_CONTINUE_SEARCH) - return cygwin_exception_handler (exception, frame, context, dispatch); - else - return 0; -} - -static void -do_install_main_exception_filter () -{ - /* We cannot insert any handler into the chain, because such handlers - must lie on the stack (?). Instead, we have to replace(!) Cygwin's - global exception handler. */ - cygwin_exception_handler = _except_list->handler; - _except_list->handler = libsigsegv_exception_handler; -} - -#else - -static void -do_install_main_exception_filter () -{ - SetUnhandledExceptionFilter ((LPTOP_LEVEL_EXCEPTION_FILTER) &main_exception_filter); -} - -#endif - -static void -install_main_exception_filter () -{ - static int main_exception_filter_installed = 0; - - if (!main_exception_filter_installed) - { - do_install_main_exception_filter (); - main_exception_filter_installed = 1; - } -} - -int -sigsegv_install_handler (sigsegv_handler_t handler) -{ - user_handler = handler; - install_main_exception_filter (); - return 0; -} - -void -sigsegv_deinstall_handler (void) -{ - user_handler = (sigsegv_handler_t) NULL; -} - -int -sigsegv_leave_handler (void (*continuation) (void*, void*, void*), - void* cont_arg1, void* cont_arg2, void* cont_arg3) -{ - (*continuation) (cont_arg1, cont_arg2, cont_arg3); - return 1; -} - -int -stackoverflow_install_handler (stackoverflow_handler_t handler, - void *extra_stack, unsigned long extra_stack_size) -{ - stk_user_handler = handler; - stk_extra_stack = (unsigned long) extra_stack; - stk_extra_stack_size = extra_stack_size; - install_main_exception_filter (); - return 0; -} - -void -stackoverflow_deinstall_handler (void) -{ - stk_user_handler = (stackoverflow_handler_t) NULL; -} |