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kernel: Added work-around in UnhandledExceptionFilter for no exec protections.

This commit is contained in:
Alexandre Julliard 2006-05-09 12:58:46 +02:00
parent 08c2555dd8
commit feb7276c73
1 changed files with 46 additions and 8 deletions
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54
dlls/kernel/except.c
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@ -392,16 +392,12 @@ static int start_debugger_atomic(PEXCEPTION_POINTERS epointers)
* If yes, we unprotect the resources to let broken apps continue
* (Windows does this too).
*/
inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
inline static BOOL check_resource_write( void *addr )
{
void *addr, *rsrc;
void *rsrc;
DWORD size;
MEMORY_BASIC_INFORMATION info;
if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
if (rec->NumberParameters < 2) return FALSE;
if (!rec->ExceptionInformation[0]) return FALSE; /* not a write access */
addr = (void *)rec->ExceptionInformation[1];
if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
if (info.State == MEM_FREE || !(info.Type & MEM_IMAGE)) return FALSE;
if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
@ -414,16 +410,58 @@ inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
}
/*******************************************************************
* check_no_exec
*
* Check for executing a protected area.
*/
inline static BOOL check_no_exec( void *addr )
{
MEMORY_BASIC_INFORMATION info;
if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
if (info.State == MEM_FREE) return FALSE;
/* prot |= PAGE_EXECUTE would be a lot easier, but MS developers
* apparently don't grasp the notion of protection bits */
switch(info.Protect)
{
case PAGE_READONLY: info.Protect = PAGE_EXECUTE_READ; break;
case PAGE_READWRITE: info.Protect = PAGE_EXECUTE_READWRITE; break;
case PAGE_WRITECOPY: info.Protect = PAGE_EXECUTE_WRITECOPY; break;
default: return FALSE;
}
/* FIXME: we should probably have a per-app option, and maybe a message box */
FIXME( "No-exec fault triggered at %p, enabling work-around\n", addr );
return VirtualProtect( addr, 1, info.Protect, NULL );
}
/*******************************************************************
* UnhandledExceptionFilter (KERNEL32.@)
*/
DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
{
if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
const EXCEPTION_RECORD *rec = epointers->ExceptionRecord;
if (rec->ExceptionCode == EXCEPTION_ACCESS_VIOLATION && rec->NumberParameters >= 2)
{
switch(rec->ExceptionInformation[0])
{
case 1: /* write access */
if (check_resource_write( (void *)rec->ExceptionInformation[1] ))
return EXCEPTION_CONTINUE_EXECUTION;
break;
case 8: /* execute access */
if (check_no_exec( (void *)rec->ExceptionInformation[1] ))
return EXCEPTION_CONTINUE_EXECUTION;
break;
}
}
if (!NtCurrentTeb()->Peb->BeingDebugged)
{
if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
if (rec->ExceptionCode == CONTROL_C_EXIT)
{
/* do not launch the debugger on ^C, simply terminate the process */
TerminateProcess( GetCurrentProcess(), 1 );