asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code) 
asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code){	struct task_struct *tsk;	struct mm_struct *mm;	struct vm_area_struct * vma;	unsigned long address;	const struct exception_table_entry *fixup;	int write;	siginfo_t info;#ifdef CONFIG_CHECKING	{ 		unsigned long gs; 		struct x8664_pda *pda = cpu_pda + stack_smp_processor_id(); 		rdmsrl(MSR_GS_BASE, gs); 		if (gs != (unsigned long)pda) { 			wrmsrl(MSR_GS_BASE, pda); 			printk("page_fault: wrong gs %lx expected %p\n", gs, pda);		}	}#endif	/* get the address */	__asm__("movq %%cr2,%0":"=r" (address));	if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,					SIGSEGV) == NOTIFY_STOP)		return;	if (likely(regs->eflags & X86_EFLAGS_IF))		local_irq_enable();	if (unlikely(page_fault_trace))		printk("pagefault rip:%lx rsp:%lx cs:%lu ss:%lu address %lx error %lx\n",		       regs->rip,regs->rsp,regs->cs,regs->ss,address,error_code); 	tsk = current;	mm = tsk->mm;	info.si_code = SEGV_MAPERR;	/*	 * We fault-in kernel-space virtual memory on-demand. The	 * 'reference' page table is init_mm.pgd.	 *	 * NOTE! We MUST NOT take any locks for this case. We may	 * be in an interrupt or a critical region, and should	 * only copy the information from the master page table,	 * nothing more.	 *	 * This verifies that the fault happens in kernel space	 * (error_code & 4) == 0, and that the fault was not a	 * protection error (error_code & 1) == 0.	 */	if (unlikely(address >= TASK_SIZE64)) {		if (!(error_code & 5) &&		      ((address >= VMALLOC_START && address < VMALLOC_END) ||		       (address >= MODULES_VADDR && address < MODULES_END))) {			if (vmalloc_fault(address) < 0)				goto bad_area_nosemaphore;			return;		}		/*		 * Don't take the mm semaphore here. If we fixup a prefetch		 * fault we could otherwise deadlock.		 */		goto bad_area_nosemaphore;	}	if (unlikely(error_code & (1 << 3)))		pgtable_bad(address, regs, error_code);	/*	 * If we're in an interrupt or have no user	 * context, we must not take the fault..	 */	if (unlikely(in_atomic() || !mm))		goto bad_area_nosemaphore; again:	/* When running in the kernel we expect faults to occur only to	 * addresses in user space.  All other faults represent errors in the	 * kernel and should generate an OOPS.  Unfortunatly, in the case of an	 * erroneous fault occuring in a code path which already holds mmap_sem	 * we will deadlock attempting to validate the fault against the	 * address space.  Luckily the kernel only validly references user	 * space from well defined areas of code, which are listed in the	 * exceptions table.	 *	 * As the vast majority of faults will be valid we will only perform	 * the source reference check when there is a possibilty of a deadlock.	 * Attempt to lock the address space, if we cannot we then validate the	 * source.  If this is invalid we can skip the address space check,	 * thus avoiding the deadlock.	 */	if (!down_read_trylock(&mm->mmap_sem)) {		if ((error_code & 4) == 0 &&		    !search_exception_tables(regs->rip))			goto bad_area_nosemaphore;		down_read(&mm->mmap_sem);	}	vma = find_vma(mm, address);	if (!vma)		goto bad_area;	if (likely(vma->vm_start <= address))		goto good_area;	if (!(vma->vm_flags & VM_GROWSDOWN))		goto bad_area;	if (error_code & 4) {		// XXX: align red zone size with ABI 		if (address + 128 < regs->rsp)			goto bad_area;	}	if (expand_stack(vma, address))		goto bad_area;/* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */good_area:	info.si_code = SEGV_ACCERR;	write = 0;	switch (error_code & 3) {		default:	/* 3: write, present */			/* fall through */		case 2:		/* write, not present */			if (!(vma->vm_flags & VM_WRITE))				goto bad_area;			write++;			break;		case 1:		/* read, present */			goto bad_area;		case 0:		/* read, not present */			if (!(vma->vm_flags & (VM_READ | VM_EXEC)))				goto bad_area;	}	/*	 * If for any reason at all we couldn't handle the fault,	 * make sure we exit gracefully rather than endlessly redo	 * the fault.	 */	switch (handle_mm_fault(mm, vma, address, write)) {	case VM_FAULT_MINOR:		tsk->min_flt++;		break;	case VM_FAULT_MAJOR:		tsk->maj_flt++;		break;	case VM_FAULT_SIGBUS:		goto do_sigbus;	default:		goto out_of_memory;	}	up_read(&mm->mmap_sem);	return;/* * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */bad_area:	up_read(&mm->mmap_sem);bad_area_nosemaphore:	/* User mode accesses just cause a SIGSEGV */	if (error_code & 4) {		if (is_prefetch(regs, address, error_code))			return;		/* Work around K8 erratum #100 K8 in compat mode		   occasionally jumps to illegal addresses >4GB.  We		   catch this here in the page fault handler because		   these addresses are not reachable. Just detect this		   case and return.  Any code segment in LDT is		   compatibility mode. */		if ((regs->cs == __USER32_CS || (regs->cs & (1<<2))) &&		    (address >> 32))			return;		if (exception_trace && unhandled_signal(tsk, SIGSEGV)) {			printk(		       "%s%s[%d]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",					tsk->pid > 1 ? KERN_INFO : KERN_EMERG,					tsk->comm, tsk->pid, address, regs->rip,					regs->rsp, error_code);		}       		tsk->thread.cr2 = address;		/* Kernel addresses are always protection faults */		tsk->thread.error_code = error_code | (address >= TASK_SIZE);		tsk->thread.trap_no = 14;		info.si_signo = SIGSEGV;		info.si_errno = 0;		/* info.si_code has been set above */		info.si_addr = (void __user *)address;		force_sig_info(SIGSEGV, &info, tsk);		return;	}no_context:		/* Are we prepared to handle this kernel fault?  */	fixup = search_exception_tables(regs->rip);	if (fixup) {		regs->rip = fixup->fixup;		return;	}	/* 	 * Hall of shame of CPU/BIOS bugs.	 */ 	if (is_prefetch(regs, address, error_code)) 		return;	if (is_errata93(regs, address))		return; /* * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */	oops_begin(); 	if (address < PAGE_SIZE)		printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");	else		printk(KERN_ALERT "Unable to handle kernel paging request");	printk(" at %016lx RIP: \n" KERN_ALERT,address);	printk_address(regs->rip);	printk("\n");	dump_pagetable(address);	__die("Oops", regs, error_code);	/* Executive summary in case the body of the oops scrolled away */	printk(KERN_EMERG "CR2: %016lx\n", address);	oops_end(); 	do_exit(SIGKILL);/* * We ran out of memory, or some other thing happened to us that made * us unable to handle the page fault gracefully. */out_of_memory:	up_read(&mm->mmap_sem);	if (current->pid == 1) { 		yield();		goto again;	}	printk("VM: killing process %s\n", tsk->comm);	if (error_code & 4)		do_exit(SIGKILL);	goto no_context;do_sigbus:	up_read(&mm->mmap_sem);	/* Kernel mode? Handle exceptions or die */	if (!(error_code & 4))		goto no_context;	tsk->thread.cr2 = address;	tsk->thread.error_code = error_code;	tsk->thread.trap_no = 14;	info.si_signo = SIGBUS;	info.si_errno = 0;	info.si_code = BUS_ADRERR;	info.si_addr = (void __user *)address;	force_sig_info(SIGBUS, &info, tsk);	return;}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/0f2fbdcbb041f9087da42f8ac2e81f2817098d2a/fault.c/buggy/arch/x86_64/mm/fault.c