/* * signal.c * Exception handling - NullPointer, divison by zero *  * Copyright (c) 2004, 2005 *	TU Dresden, Operating System Group.  All rights reserved. * * See the file "license.terms" for information on usage and redistribution * of this file. * * written by Alexander Boettcher <ab764283@os.inf.tu-dresden.de> */#include "config.h"#include "debug.h"#include "config-std.h"#include "config-signal.h"#include "config-mem.h"#include "config-setjmp.h"#include "jthread.h"#include "md.h"#if defined(INTERPRETER)#define	DEFINEFRAME()		/* Does nothing */#define	EXCEPTIONPROTO		int sig#define	EXCEPTIONFRAME(f, c)	/* Does nothing */#define	EXCEPTIONFRAMEPTR	0#elif defined(TRANSLATOR)#define	DEFINEFRAME()		exceptionFrame frame#define	EXCEPTIONFRAMEPTR	&frame#endif /* TRANSLATOR */#define SIG_T   void*#include <l4/util/idt.h>#include <l4/log/l4log.h>#include <l4/l4rm/l4rm.h>static struct { exchandler_t floatingHandler; exchandler_t nullHandler; exchandler_t stackOverflowHandler;} leafleterr;static struct {      l4util_idt_header_t header;      l4util_idt_desc_t   desc[0x20];      char                padding[L4_PAGESIZE-sizeof(l4util_idt_header_t)                                             -sizeof(l4util_idt_desc_t)*0x20];} __attribute__((packed,aligned(L4_PAGESIZE))) idt;static void nullException(void);static void floatingException(void);/* * Each Java thread calls this function to register itself for the exceptions. */void drops_registerForExceptions(void){ l4util_idt_load (&idt.header);}/* * Setup the internal exceptions. */voidjthread_initexceptions(exchandler_t _nullHandler,		       exchandler_t _floatingHandler,		       exchandler_t _stackOverflowHandler){  leafleterr.floatingHandler      = _floatingHandler;  leafleterr.nullHandler          = _nullHandler;  leafleterr.stackOverflowHandler = _stackOverflowHandler;  l4util_idt_init (&idt.header, 0x20);  l4util_idt_entry(&idt.header,  0, floatingException);  // divide error  l4util_idt_entry(&idt.header, 14, nullException);      // page fault  l4util_idt_entry(&idt.header, 16, floatingException);  // floating point error  // register IDT in LIDT for this thread  drops_registerForExceptions();  // enable unresolvable page fault handling in l4rm  l4rm_enable_pagefault_exceptions();                     }/* * Null exception handler * kernel sets the thread to this function */static voidnullException(){	DEFINEFRAME();	EXCEPTIONFRAME(frame, ctx);	leafleterr.nullHandler(EXCEPTIONFRAMEPTR);}/* * Division by zero,  *  kernel sets the thread to this function */static voidfloatingException(void){	DEFINEFRAME();	EXCEPTIONFRAME(frame, ctx);	leafleterr.floatingHandler(EXCEPTIONFRAMEPTR);}