[net-next-2.6.git] / arch / mn10300 / mm / fault.c

/* MN10300 MMU Fault handler
 *
 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Modified by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/vt_kern.h>		/* For unblank_screen() */

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/hardirq.h>
#include <asm/gdb-stub.h>
#include <asm/cpu-regs.h>

/*
 * Unlock any spinlocks which will prevent us from getting the
 * message out
 */
void bust_spinlocks(int yes)
{
	if (yes) {
		oops_in_progress = 1;
#ifdef CONFIG_SMP
		/* Many serial drivers do __global_cli() */
		global_irq_lock = 0;
#endif
	} else {
		int loglevel_save = console_loglevel;
#ifdef CONFIG_VT
		unblank_screen();
#endif
		oops_in_progress = 0;
		/*
		 * OK, the message is on the console.  Now we call printk()
		 * without oops_in_progress set so that printk will give klogd
		 * a poke.  Hold onto your hats...
		 */
		console_loglevel = 15;	/* NMI oopser may have shut the console
					 * up */
		printk(" ");
		console_loglevel = loglevel_save;
	}
}

void do_BUG(const char *file, int line)
{
	bust_spinlocks(1);
	printk(KERN_EMERG "------------[ cut here ]------------\n");
	printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
}

#if 0
static void print_pagetable_entries(pgd_t *pgdir, unsigned long address)
{
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;

	pgd = pgdir + __pgd_offset(address);
	printk(KERN_DEBUG "pgd entry %p: %016Lx\n",
	       pgd, (long long) pgd_val(*pgd));

	if (!pgd_present(*pgd)) {
		printk(KERN_DEBUG "... pgd not present!\n");
		return;
	}
	pmd = pmd_offset(pgd, address);
	printk(KERN_DEBUG "pmd entry %p: %016Lx\n",
	       pmd, (long long)pmd_val(*pmd));

	if (!pmd_present(*pmd)) {
		printk(KERN_DEBUG "... pmd not present!\n");
		return;
	}
	pte = pte_offset(pmd, address);
	printk(KERN_DEBUG "pte entry %p: %016Lx\n",
	       pte, (long long) pte_val(*pte));

	if (!pte_present(*pte))
		printk(KERN_DEBUG "... pte not present!\n");
}
#endif

asmlinkage void monitor_signal(struct pt_regs *);

/*
 * This routine handles page faults.  It determines the address,
 * and the problem, and then passes it off to one of the appropriate
 * routines.
 *
 * fault_code:
 * - LSW: either MMUFCR_IFC or MMUFCR_DFC as appropriate
 * - MSW: 0 if data access, 1 if instruction access
 * - bit 0: TLB miss flag
 * - bit 1: initial write
 * - bit 2: page invalid
 * - bit 3: protection violation
 * - bit 4: accessor (0=user 1=kernel)
 * - bit 5: 0=read 1=write
 * - bit 6-8: page protection spec
 * - bit 9: illegal address
 * - bit 16: 0=data 1=ins
 *
 */
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
			      unsigned long address)
{
	struct vm_area_struct *vma;
	struct task_struct *tsk;
	struct mm_struct *mm;
	unsigned long page;
	siginfo_t info;
	int write, fault;

#ifdef CONFIG_GDBSTUB
	/* handle GDB stub causing a fault */
	if (gdbstub_busy) {
		gdbstub_exception(regs, TBR & TBR_INT_CODE);
		return;
	}
#endif

#if 0
	printk(KERN_DEBUG "--- do_page_fault(%p,%s:%04lx,%08lx)\n",
	       regs,
	       fault_code & 0x10000 ? "ins" : "data",
	       fault_code & 0xffff, address);
#endif

	tsk = current;

	/*
	 * 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
	 * and that the fault was a page not present (invalid) error
	 */
	if (address >= VMALLOC_START && address < VMALLOC_END &&
	    (fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR &&
	    (fault_code & MMUFCR_xFC_PGINVAL) == MMUFCR_xFC_PGINVAL
	    )
		goto vmalloc_fault;

	mm = tsk->mm;
	info.si_code = SEGV_MAPERR;

	/*
	 * If we're in an interrupt or have no user
	 * context, we must not take the fault..
	 */
	if (in_atomic() || !mm)
		goto no_context;

	down_read(&mm->mmap_sem);

	vma = find_vma(mm, address);
	if (!vma)
		goto bad_area;
	if (vma->vm_start <= address)
		goto good_area;
	if (!(vma->vm_flags & VM_GROWSDOWN))
		goto bad_area;

	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
		/* accessing the stack below the stack pointer is always a
		 * bug */
		if ((address & PAGE_MASK) + 2 * PAGE_SIZE < regs->sp) {
#if 0
			printk(KERN_WARNING
			       "[%d] ### Access below stack @%lx (sp=%lx)\n",
			       current->pid, address, regs->sp);
			printk(KERN_WARNING
			       "vma [%08x - %08x]\n",
			       vma->vm_start, vma->vm_end);
			show_registers(regs);
			printk(KERN_WARNING
			       "[%d] ### Code: [%08lx]"
			       " %02x %02x %02x %02x %02x %02x %02x %02x\n",
			       current->pid,
			       regs->pc,
			       ((u8 *) regs->pc)[0],
			       ((u8 *) regs->pc)[1],
			       ((u8 *) regs->pc)[2],
			       ((u8 *) regs->pc)[3],
			       ((u8 *) regs->pc)[4],
			       ((u8 *) regs->pc)[5],
			       ((u8 *) regs->pc)[6],
			       ((u8 *) regs->pc)[7]
			       );
#endif
			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 (fault_code & (MMUFCR_xFC_PGINVAL|MMUFCR_xFC_TYPE)) {
	default:	/* 3: write, present */
	case MMUFCR_xFC_TYPE_WRITE:
#ifdef TEST_VERIFY_AREA
		if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR)
			printk(KERN_DEBUG "WP fault at %08lx\n", regs->pc);
#endif
		/* write to absent page */
	case MMUFCR_xFC_PGINVAL | MMUFCR_xFC_TYPE_WRITE:
		if (!(vma->vm_flags & VM_WRITE))
			goto bad_area;
		write++;
		break;

		/* read from protected page */
	case MMUFCR_xFC_TYPE_READ:
		goto bad_area;

		/* read from absent page present */
	case MMUFCR_xFC_PGINVAL | MMUFCR_xFC_TYPE_READ:
		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
			goto bad_area;
		break;
	}

	/*
	 * If for any reason at all we couldn't handle the fault,
	 * make sure we exit gracefully rather than endlessly redo
	 * the fault.
	 */
	fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
	if (unlikely(fault & VM_FAULT_ERROR)) {
		if (fault & VM_FAULT_OOM)
			goto out_of_memory;
		else if (fault & VM_FAULT_SIGBUS)
			goto do_sigbus;
		BUG();
	}
	if (fault & VM_FAULT_MAJOR)
		current->maj_flt++;
	else
		current->min_flt++;

	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);
	monitor_signal(regs);

	/* User mode accesses just cause a SIGSEGV */
	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
		info.si_signo = SIGSEGV;
		info.si_errno = 0;
		/* info.si_code has been set above */
		info.si_addr = (void *)address;
		force_sig_info(SIGSEGV, &info, tsk);
		return;
	}

no_context:
	monitor_signal(regs);
	/* Are we prepared to handle this kernel fault?  */
	if (fixup_exception(regs))
		return;

/*
 * Oops. The kernel tried to access some bad page. We'll have to
 * terminate things with extreme prejudice.
 */

	bust_spinlocks(1);

	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 virtual address %08lx\n", address);
	printk(" printing pc:\n");
	printk(KERN_ALERT "%08lx\n", regs->pc);

#ifdef CONFIG_GDBSTUB
	gdbstub_intercept(
		regs, fault_code & 0x00010000 ? EXCEP_IAERROR : EXCEP_DAERROR);
#endif

	page = PTBR;
	page = ((unsigned long *) __va(page))[address >> 22];
	printk(KERN_ALERT "*pde = %08lx\n", page);
	if (page & 1) {
		page &= PAGE_MASK;
		address &= 0x003ff000;
		page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
		printk(KERN_ALERT "*pte = %08lx\n", page);
	}

	die("Oops", regs, fault_code);
	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 ((fault_code & MMUFCR_xFC_ACCESS) != MMUFCR_xFC_ACCESS_USR)
		goto no_context;
	pagefault_out_of_memory();
	return;

do_sigbus:
	up_read(&mm->mmap_sem);
	monitor_signal(regs);

	/*
	 * Send a sigbus, regardless of whether we were in kernel
	 * or user mode.
	 */
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRERR;
	info.si_addr = (void *)address;
	force_sig_info(SIGBUS, &info, tsk);

	/* Kernel mode? Handle exceptions or die */
	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR)
		goto no_context;
	return;

vmalloc_fault:
	{
		/*
		 * Synchronize this task's top level page-table
		 * with the 'reference' page table.
		 *
		 * Do _not_ use "tsk" here. We might be inside
		 * an interrupt in the middle of a task switch..
		 */
		int index = pgd_index(address);
		pgd_t *pgd, *pgd_k;
		pud_t *pud, *pud_k;
		pmd_t *pmd, *pmd_k;
		pte_t *pte_k;

		pgd_k = init_mm.pgd + index;

		if (!pgd_present(*pgd_k))
			goto no_context;

		pud_k = pud_offset(pgd_k, address);
		if (!pud_present(*pud_k))
			goto no_context;

		pmd_k = pmd_offset(pud_k, address);
		if (!pmd_present(*pmd_k))
			goto no_context;

		pgd = (pgd_t *) PTBR + index;
		pud = pud_offset(pgd, address);
		pmd = pmd_offset(pud, address);
		set_pmd(pmd, *pmd_k);

		pte_k = pte_offset_kernel(pmd_k, address);
		if (!pte_present(*pte_k))
			goto no_context;
		return;
	}
}
Commit	Line	Data
b920de1b DH	1	/* MN10300 MMU Fault handler
	2	*
	3	* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
	4	* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
	5	* Modified by David Howells (dhowells@redhat.com)
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public Licence
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the Licence, or (at your option) any later version.
	11	*/
	12
	13	#include <linux/signal.h>
	14	#include <linux/sched.h>
	15	#include <linux/kernel.h>
	16	#include <linux/errno.h>
	17	#include <linux/string.h>
	18	#include <linux/types.h>
	19	#include <linux/ptrace.h>
	20	#include <linux/mman.h>
	21	#include <linux/mm.h>
	22	#include <linux/smp.h>
b920de1b DH	23	#include <linux/interrupt.h>
	24	#include <linux/init.h>
	25	#include <linux/vt_kern.h> /* For unblank_screen() */
	26
	27	#include <asm/system.h>
	28	#include <asm/uaccess.h>
	29	#include <asm/pgalloc.h>
	30	#include <asm/hardirq.h>
	31	#include <asm/gdb-stub.h>
	32	#include <asm/cpu-regs.h>
	33
	34	/*
	35	* Unlock any spinlocks which will prevent us from getting the
	36	* message out
	37	*/
	38	void bust_spinlocks(int yes)
	39	{
	40	if (yes) {
	41	oops_in_progress = 1;
	42	#ifdef CONFIG_SMP
	43	/* Many serial drivers do __global_cli() */
	44	global_irq_lock = 0;
	45	#endif
	46	} else {
	47	int loglevel_save = console_loglevel;
	48	#ifdef CONFIG_VT
	49	unblank_screen();
	50	#endif
	51	oops_in_progress = 0;
	52	/*
	53	* OK, the message is on the console. Now we call printk()
	54	* without oops_in_progress set so that printk will give klogd
	55	* a poke. Hold onto your hats...
	56	*/
	57	console_loglevel = 15; /* NMI oopser may have shut the console
	58	* up */
	59	printk(" ");
	60	console_loglevel = loglevel_save;
	61	}
	62	}
	63
	64	void do_BUG(const char *file, int line)
	65	{
	66	bust_spinlocks(1);
	67	printk(KERN_EMERG "------------[ cut here ]------------\n");
	68	printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
	69	}
	70
	71	#if 0
	72	static void print_pagetable_entries(pgd_t *pgdir, unsigned long address)
	73	{
	74	pgd_t *pgd;
	75	pmd_t *pmd;
	76	pte_t *pte;
	77
	78	pgd = pgdir + __pgd_offset(address);
	79	printk(KERN_DEBUG "pgd entry %p: %016Lx\n",
	80	pgd, (long long) pgd_val(*pgd));
	81
	82	if (!pgd_present(*pgd)) {
	83	printk(KERN_DEBUG "... pgd not present!\n");
	84	return;
	85	}
	86	pmd = pmd_offset(pgd, address);
87	printk(KERN_DEBUG "pmd entry %p: %016Lx\n",
88	pmd, (long long)pmd_val(*pmd));
89
90	if (!pmd_present(*pmd)) {
91	printk(KERN_DEBUG "... pmd not present!\n");
92	return;
93	}
94	pte = pte_offset(pmd, address);
95	printk(KERN_DEBUG "pte entry %p: %016Lx\n",
96	pte, (long long) pte_val(*pte));
97
98	if (!pte_present(*pte))
99	printk(KERN_DEBUG "... pte not present!\n");
100	}
101	#endif
102
103	asmlinkage void monitor_signal(struct pt_regs *);
104
105	/*
106	* This routine handles page faults. It determines the address,
107	* and the problem, and then passes it off to one of the appropriate
108	* routines.
109	*
110	* fault_code:
111	* - LSW: either MMUFCR_IFC or MMUFCR_DFC as appropriate
112	* - MSW: 0 if data access, 1 if instruction access
113	* - bit 0: TLB miss flag
114	* - bit 1: initial write
115	* - bit 2: page invalid
116	* - bit 3: protection violation
117	* - bit 4: accessor (0=user 1=kernel)
118	* - bit 5: 0=read 1=write
119	* - bit 6-8: page protection spec
120	* - bit 9: illegal address
121	* - bit 16: 0=data 1=ins
122	*
123	*/
124	asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long fault_code,
125	unsigned long address)
126	{
127	struct vm_area_struct *vma;
128	struct task_struct *tsk;
129	struct mm_struct *mm;
130	unsigned long page;
131	siginfo_t info;
132	int write, fault;
133
134	#ifdef CONFIG_GDBSTUB
135	/* handle GDB stub causing a fault */
136	if (gdbstub_busy) {
137	gdbstub_exception(regs, TBR & TBR_INT_CODE);
138	return;
139	}
140	#endif
141
142	#if 0
143	printk(KERN_DEBUG "--- do_page_fault(%p,%s:%04lx,%08lx)\n",
144	regs,
145	fault_code & 0x10000 ? "ins" : "data",
146	fault_code & 0xffff, address);
147	#endif
148
149	tsk = current;
150
151	/*
152	* We fault-in kernel-space virtual memory on-demand. The
153	* 'reference' page table is init_mm.pgd.
154	*
155	* NOTE! We MUST NOT take any locks for this case. We may
156	* be in an interrupt or a critical region, and should
157	* only copy the information from the master page table,
158	* nothing more.
159	*
160	* This verifies that the fault happens in kernel space
161	* and that the fault was a page not present (invalid) error
162	*/
163	if (address >= VMALLOC_START && address < VMALLOC_END &&
164	(fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR &&
165	(fault_code & MMUFCR_xFC_PGINVAL) == MMUFCR_xFC_PGINVAL
166	)
167	goto vmalloc_fault;
168
169	mm = tsk->mm;
170	info.si_code = SEGV_MAPERR;
171
172	/*
173	* If we're in an interrupt or have no user
174	* context, we must not take the fault..
175	*/
d1c6d2e5	176	if (in_atomic() \|\| !mm)
b920de1b DH	177	goto no_context;
	178
	179	down_read(&mm->mmap_sem);
	180
	181	vma = find_vma(mm, address);
	182	if (!vma)
	183	goto bad_area;
	184	if (vma->vm_start <= address)
	185	goto good_area;
	186	if (!(vma->vm_flags & VM_GROWSDOWN))
	187	goto bad_area;
	188
	189	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
	190	/* accessing the stack below the stack pointer is always a
	191	* bug */
	192	if ((address & PAGE_MASK) + 2 * PAGE_SIZE < regs->sp) {
	193	#if 0
	194	printk(KERN_WARNING
	195	"[%d] ### Access below stack @%lx (sp=%lx)\n",
	196	current->pid, address, regs->sp);
	197	printk(KERN_WARNING
	198	"vma [%08x - %08x]\n",
	199	vma->vm_start, vma->vm_end);
	200	show_registers(regs);
	201	printk(KERN_WARNING
	202	"[%d] ### Code: [%08lx]"
	203	" %02x %02x %02x %02x %02x %02x %02x %02x\n",
	204	current->pid,
	205	regs->pc,
	206	((u8 *) regs->pc)[0],
	207	((u8 *) regs->pc)[1],
	208	((u8 *) regs->pc)[2],
	209	((u8 *) regs->pc)[3],
	210	((u8 *) regs->pc)[4],
	211	((u8 *) regs->pc)[5],
	212	((u8 *) regs->pc)[6],
	213	((u8 *) regs->pc)[7]
	214	);
	215	#endif
	216	goto bad_area;
	217	}
	218	}
	219
	220	if (expand_stack(vma, address))
	221	goto bad_area;
	222
	223	/*
	224	* Ok, we have a good vm_area for this memory access, so
	225	* we can handle it..
	226	*/
	227	good_area:
	228	info.si_code = SEGV_ACCERR;
	229	write = 0;
	230	switch (fault_code & (MMUFCR_xFC_PGINVAL\|MMUFCR_xFC_TYPE)) {
	231	default: /* 3: write, present */
	232	case MMUFCR_xFC_TYPE_WRITE:
	233	#ifdef TEST_VERIFY_AREA
	234	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR)
	235	printk(KERN_DEBUG "WP fault at %08lx\n", regs->pc);
	236	#endif
	237	/* write to absent page */
	238	case MMUFCR_xFC_PGINVAL \| MMUFCR_xFC_TYPE_WRITE:
	239	if (!(vma->vm_flags & VM_WRITE))
	240	goto bad_area;
241	write++;
242	break;
243
244	/* read from protected page */
245	case MMUFCR_xFC_TYPE_READ:
246	goto bad_area;
247
248	/* read from absent page present */
249	case MMUFCR_xFC_PGINVAL \| MMUFCR_xFC_TYPE_READ:
250	if (!(vma->vm_flags & (VM_READ \| VM_EXEC)))
251	goto bad_area;
252	break;
253	}
254
255	/*
256	* If for any reason at all we couldn't handle the fault,
257	* make sure we exit gracefully rather than endlessly redo
258	* the fault.
259	*/
d06063cc	260	fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
b920de1b DH	261	if (unlikely(fault & VM_FAULT_ERROR)) {
	262	if (fault & VM_FAULT_OOM)
	263	goto out_of_memory;
	264	else if (fault & VM_FAULT_SIGBUS)
	265	goto do_sigbus;
	266	BUG();
	267	}
	268	if (fault & VM_FAULT_MAJOR)
	269	current->maj_flt++;
	270	else
	271	current->min_flt++;
	272
	273	up_read(&mm->mmap_sem);
	274	return;
	275
	276	/*
	277	* Something tried to access memory that isn't in our memory map..
	278	* Fix it, but check if it's kernel or user first..
	279	*/
	280	bad_area:
	281	up_read(&mm->mmap_sem);
	282	monitor_signal(regs);
	283
	284	/* User mode accesses just cause a SIGSEGV */
	285	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
	286	info.si_signo = SIGSEGV;
	287	info.si_errno = 0;
	288	/* info.si_code has been set above */
	289	info.si_addr = (void *)address;
	290	force_sig_info(SIGSEGV, &info, tsk);
	291	return;
	292	}
	293
	294	no_context:
	295	monitor_signal(regs);
	296	/* Are we prepared to handle this kernel fault? */
	297	if (fixup_exception(regs))
	298	return;
	299
	300	/*
	301	* Oops. The kernel tried to access some bad page. We'll have to
	302	* terminate things with extreme prejudice.
	303	*/
	304
	305	bust_spinlocks(1);
	306
	307	if (address < PAGE_SIZE)
	308	printk(KERN_ALERT
	309	"Unable to handle kernel NULL pointer dereference");
	310	else
	311	printk(KERN_ALERT
	312	"Unable to handle kernel paging request");
	313	printk(" at virtual address %08lx\n", address);
	314	printk(" printing pc:\n");
	315	printk(KERN_ALERT "%08lx\n", regs->pc);
	316
	317	#ifdef CONFIG_GDBSTUB
	318	gdbstub_intercept(
	319	regs, fault_code & 0x00010000 ? EXCEP_IAERROR : EXCEP_DAERROR);
	320	#endif
	321
	322	page = PTBR;
	323	page = ((unsigned long *) __va(page))[address >> 22];
	324	printk(KERN_ALERT "*pde = %08lx\n", page);
325	if (page & 1) {
326	page &= PAGE_MASK;
327	address &= 0x003ff000;
328	page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
329	printk(KERN_ALERT "*pte = %08lx\n", page);
330	}
331
332	die("Oops", regs, fault_code);
333	do_exit(SIGKILL);
334
335	/*
336	* We ran out of memory, or some other thing happened to us that made
337	* us unable to handle the page fault gracefully.
338	*/
339	out_of_memory:
340	up_read(&mm->mmap_sem);
c421b08e NP	341	if ((fault_code & MMUFCR_xFC_ACCESS) != MMUFCR_xFC_ACCESS_USR)
	342	goto no_context;
	343	pagefault_out_of_memory();
	344	return;
b920de1b DH	345
	346	do_sigbus:
	347	up_read(&mm->mmap_sem);
	348	monitor_signal(regs);
	349
	350	/*
	351	* Send a sigbus, regardless of whether we were in kernel
	352	* or user mode.
	353	*/
	354	info.si_signo = SIGBUS;
	355	info.si_errno = 0;
	356	info.si_code = BUS_ADRERR;
	357	info.si_addr = (void *)address;
	358	force_sig_info(SIGBUS, &info, tsk);
	359
	360	/* Kernel mode? Handle exceptions or die */
	361	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_SR)
	362	goto no_context;
	363	return;
	364
	365	vmalloc_fault:
	366	{
	367	/*
	368	* Synchronize this task's top level page-table
	369	* with the 'reference' page table.
	370	*
	371	* Do _not_ use "tsk" here. We might be inside
	372	* an interrupt in the middle of a task switch..
	373	*/
	374	int index = pgd_index(address);
	375	pgd_t pgd, pgd_k;
	376	pud_t pud, pud_k;
	377	pmd_t pmd, pmd_k;
	378	pte_t *pte_k;
	379
	380	pgd_k = init_mm.pgd + index;
	381
	382	if (!pgd_present(*pgd_k))
	383	goto no_context;
	384
	385	pud_k = pud_offset(pgd_k, address);
	386	if (!pud_present(*pud_k))
	387	goto no_context;
	388
	389	pmd_k = pmd_offset(pud_k, address);
	390	if (!pmd_present(*pmd_k))
	391	goto no_context;
	392
	393	pgd = (pgd_t *) PTBR + index;
	394	pud = pud_offset(pgd, address);
	395	pmd = pmd_offset(pud, address);
	396	set_pmd(pmd, *pmd_k);
	397
	398	pte_k = pte_offset_kernel(pmd_k, address);
	399	if (!pte_present(*pte_k))
	400	goto no_context;
	401	return;
	402	}
	403	}