[linux-2.6-block.git] / arch / s390 / lib / uaccess_pt.c

/*
 *  User access functions based on page table walks for enhanced
 *  system layout without hardware support.
 *
 *    Copyright IBM Corp. 2006
 *    Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com)
 */

#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/mm.h>
#include <asm/uaccess.h>
#include <asm/futex.h>
#include "uaccess.h"

static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	pgd = pgd_offset(mm, addr);
	if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
		return (pte_t *) 0x3a;

	pud = pud_offset(pgd, addr);
	if (pud_none(*pud) || unlikely(pud_bad(*pud)))
		return (pte_t *) 0x3b;

	pmd = pmd_offset(pud, addr);
	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
		return (pte_t *) 0x10;

	return pte_offset_map(pmd, addr);
}

static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
					     size_t n, int write_user)
{
	struct mm_struct *mm = current->mm;
	unsigned long offset, pfn, done, size;
	pte_t *pte;
	void *from, *to;

	done = 0;
retry:
	spin_lock(&mm->page_table_lock);
	do {
		pte = follow_table(mm, uaddr);
		if ((unsigned long) pte < 0x1000)
			goto fault;
		if (!pte_present(*pte)) {
			pte = (pte_t *) 0x11;
			goto fault;
		} else if (write_user && !pte_write(*pte)) {
			pte = (pte_t *) 0x04;
			goto fault;
		}

		pfn = pte_pfn(*pte);
		offset = uaddr & (PAGE_SIZE - 1);
		size = min(n - done, PAGE_SIZE - offset);
		if (write_user) {
			to = (void *)((pfn << PAGE_SHIFT) + offset);
			from = kptr + done;
		} else {
			from = (void *)((pfn << PAGE_SHIFT) + offset);
			to = kptr + done;
		}
		memcpy(to, from, size);
		done += size;
		uaddr += size;
	} while (done < n);
	spin_unlock(&mm->page_table_lock);
	return n - done;
fault:
	spin_unlock(&mm->page_table_lock);
	if (__handle_fault(uaddr, (unsigned long) pte, write_user))
		return n - done;
	goto retry;
}

/*
 * Do DAT for user address by page table walk, return kernel address.
 * This function needs to be called with current->mm->page_table_lock held.
 */
static __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
{
	struct mm_struct *mm = current->mm;
	unsigned long pfn;
	pte_t *pte;
	int rc;

retry:
	pte = follow_table(mm, uaddr);
	if ((unsigned long) pte < 0x1000)
		goto fault;
	if (!pte_present(*pte)) {
		pte = (pte_t *) 0x11;
		goto fault;
	}

	pfn = pte_pfn(*pte);
	return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
fault:
	spin_unlock(&mm->page_table_lock);
	rc = __handle_fault(uaddr, (unsigned long) pte, 0);
	spin_lock(&mm->page_table_lock);
	if (!rc)
		goto retry;
	return 0;
}

size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
{
	size_t rc;

	if (segment_eq(get_fs(), KERNEL_DS)) {
		memcpy(to, (void __kernel __force *) from, n);
		return 0;
	}
	rc = __user_copy_pt((unsigned long) from, to, n, 0);
	if (unlikely(rc))
		memset(to + n - rc, 0, rc);
	return rc;
}

size_t copy_to_user_pt(size_t n, void __user *to, const void *from)
{
	if (segment_eq(get_fs(), KERNEL_DS)) {
		memcpy((void __kernel __force *) to, from, n);
		return 0;
	}
	return __user_copy_pt((unsigned long) to, (void *) from, n, 1);
}

static size_t clear_user_pt(size_t n, void __user *to)
{
	long done, size, ret;

	if (segment_eq(get_fs(), KERNEL_DS)) {
		memset((void __kernel __force *) to, 0, n);
		return 0;
	}
	done = 0;
	do {
		if (n - done > PAGE_SIZE)
			size = PAGE_SIZE;
		else
			size = n - done;
		ret = __user_copy_pt((unsigned long) to + done,
				      &empty_zero_page, size, 1);
		done += size;
		if (ret)
			return ret + n - done;
	} while (done < n);
	return 0;
}

static size_t strnlen_user_pt(size_t count, const char __user *src)
{
	char *addr;
	unsigned long uaddr = (unsigned long) src;
	struct mm_struct *mm = current->mm;
	unsigned long offset, pfn, done, len;
	pte_t *pte;
	size_t len_str;

	if (segment_eq(get_fs(), KERNEL_DS))
		return strnlen((const char __kernel __force *) src, count) + 1;
	done = 0;
retry:
	spin_lock(&mm->page_table_lock);
	do {
		pte = follow_table(mm, uaddr);
		if ((unsigned long) pte < 0x1000)
			goto fault;
		if (!pte_present(*pte)) {
			pte = (pte_t *) 0x11;
			goto fault;
		}

		pfn = pte_pfn(*pte);
		offset = uaddr & (PAGE_SIZE-1);
		addr = (char *)(pfn << PAGE_SHIFT) + offset;
		len = min(count - done, PAGE_SIZE - offset);
		len_str = strnlen(addr, len);
		done += len_str;
		uaddr += len_str;
	} while ((len_str == len) && (done < count));
	spin_unlock(&mm->page_table_lock);
	return done + 1;
fault:
	spin_unlock(&mm->page_table_lock);
	if (__handle_fault(uaddr, (unsigned long) pte, 0))
		return 0;
	goto retry;
}

static size_t strncpy_from_user_pt(size_t count, const char __user *src,
				   char *dst)
{
	size_t n = strnlen_user_pt(count, src);

	if (!n)
		return -EFAULT;
	if (n > count)
		n = count;
	if (segment_eq(get_fs(), KERNEL_DS)) {
		memcpy(dst, (const char __kernel __force *) src, n);
		if (dst[n-1] == '\0')
			return n-1;
		else
			return n;
	}
	if (__user_copy_pt((unsigned long) src, dst, n, 0))
		return -EFAULT;
	if (dst[n-1] == '\0')
		return n-1;
	else
		return n;
}

static size_t copy_in_user_pt(size_t n, void __user *to,
			      const void __user *from)
{
	struct mm_struct *mm = current->mm;
	unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
		      uaddr, done, size, error_code;
	unsigned long uaddr_from = (unsigned long) from;
	unsigned long uaddr_to = (unsigned long) to;
	pte_t *pte_from, *pte_to;
	int write_user;

	if (segment_eq(get_fs(), KERNEL_DS)) {
		memcpy((void __force *) to, (void __force *) from, n);
		return 0;
	}
	done = 0;
retry:
	spin_lock(&mm->page_table_lock);
	do {
		write_user = 0;
		uaddr = uaddr_from;
		pte_from = follow_table(mm, uaddr_from);
		error_code = (unsigned long) pte_from;
		if (error_code < 0x1000)
			goto fault;
		if (!pte_present(*pte_from)) {
			error_code = 0x11;
			goto fault;
		}

		write_user = 1;
		uaddr = uaddr_to;
		pte_to = follow_table(mm, uaddr_to);
		error_code = (unsigned long) pte_to;
		if (error_code < 0x1000)
			goto fault;
		if (!pte_present(*pte_to)) {
			error_code = 0x11;
			goto fault;
		} else if (!pte_write(*pte_to)) {
			error_code = 0x04;
			goto fault;
		}

		pfn_from = pte_pfn(*pte_from);
		pfn_to = pte_pfn(*pte_to);
		offset_from = uaddr_from & (PAGE_SIZE-1);
		offset_to = uaddr_from & (PAGE_SIZE-1);
		offset_max = max(offset_from, offset_to);
		size = min(n - done, PAGE_SIZE - offset_max);

		memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to,
		       (void *)(pfn_from << PAGE_SHIFT) + offset_from, size);
		done += size;
		uaddr_from += size;
		uaddr_to += size;
	} while (done < n);
	spin_unlock(&mm->page_table_lock);
	return n - done;
fault:
	spin_unlock(&mm->page_table_lock);
	if (__handle_fault(uaddr, error_code, write_user))
		return n - done;
	goto retry;
}

#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
	asm volatile("0: l   %1,0(%6)\n"				\
		     "1: " insn						\
		     "2: cs  %1,%2,0(%6)\n"				\
		     "3: jl  1b\n"					\
		     "   lhi %0,0\n"					\
		     "4:\n"						\
		     EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)	\
		     : "=d" (ret), "=&d" (oldval), "=&d" (newval),	\
		       "=m" (*uaddr)					\
		     : "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
		       "m" (*uaddr) : "cc" );

static int __futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
{
	int oldval = 0, newval, ret;

	switch (op) {
	case FUTEX_OP_SET:
		__futex_atomic_op("lr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_ADD:
		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_OR:
		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_ANDN:
		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_XOR:
		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	default:
		ret = -ENOSYS;
	}
	if (ret == 0)
		*old = oldval;
	return ret;
}

int futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
{
	int ret;

	if (segment_eq(get_fs(), KERNEL_DS))
		return __futex_atomic_op_pt(op, uaddr, oparg, old);
	spin_lock(&current->mm->page_table_lock);
	uaddr = (u32 __force __user *)
		__dat_user_addr((__force unsigned long) uaddr);
	if (!uaddr) {
		spin_unlock(&current->mm->page_table_lock);
		return -EFAULT;
	}
	get_page(virt_to_page(uaddr));
	spin_unlock(&current->mm->page_table_lock);
	ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
	put_page(virt_to_page(uaddr));
	return ret;
}

static int __futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
				     u32 oldval, u32 newval)
{
	int ret;

	asm volatile("0: cs   %1,%4,0(%5)\n"
		     "1: la   %0,0\n"
		     "2:\n"
		     EX_TABLE(0b,2b) EX_TABLE(1b,2b)
		     : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
		     : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
		     : "cc", "memory" );
	*uval = oldval;
	return ret;
}

int futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
			    u32 oldval, u32 newval)
{
	int ret;

	if (segment_eq(get_fs(), KERNEL_DS))
		return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
	spin_lock(&current->mm->page_table_lock);
	uaddr = (u32 __force __user *)
		__dat_user_addr((__force unsigned long) uaddr);
	if (!uaddr) {
		spin_unlock(&current->mm->page_table_lock);
		return -EFAULT;
	}
	get_page(virt_to_page(uaddr));
	spin_unlock(&current->mm->page_table_lock);
	ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
	put_page(virt_to_page(uaddr));
	return ret;
}

struct uaccess_ops uaccess_pt = {
	.copy_from_user		= copy_from_user_pt,
	.copy_from_user_small	= copy_from_user_pt,
	.copy_to_user		= copy_to_user_pt,
	.copy_to_user_small	= copy_to_user_pt,
	.copy_in_user		= copy_in_user_pt,
	.clear_user		= clear_user_pt,
	.strnlen_user		= strnlen_user_pt,
	.strncpy_from_user	= strncpy_from_user_pt,
	.futex_atomic_op	= futex_atomic_op_pt,
	.futex_atomic_cmpxchg	= futex_atomic_cmpxchg_pt,
};
Commit	Line	Data
59f35d53	1	/*
c1821c2e GS	2	* User access functions based on page table walks for enhanced
c1821c2e GS	3	* system layout without hardware support.
59f35d53 GS	4	*
	5	* Copyright IBM Corp. 2006
	6	* Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com)
	7	*/
	8
	9	#include <linux/errno.h>
d8ad075e	10	#include <linux/hardirq.h>
59f35d53	11	#include <linux/mm.h>
22155914	12	#include <asm/uaccess.h>
59f35d53	13	#include <asm/futex.h>
2b67fc46	14	#include "uaccess.h"
59f35d53	15
e4aa402e MS	16	static inline pte_t follow_table(struct mm_struct mm, unsigned long addr)
	17	{
	18	pgd_t *pgd;
190a1d72	19	pud_t *pud;
e4aa402e MS	20	pmd_t *pmd;
	21
	22	pgd = pgd_offset(mm, addr);
	23	if (pgd_none(pgd) \|\| unlikely(pgd_bad(pgd)))
6c1e3e79	24	return (pte_t *) 0x3a;
e4aa402e	25
190a1d72 MS	26	pud = pud_offset(pgd, addr);
190a1d72 MS	27	if (pud_none(pud) \|\| unlikely(pud_bad(pud)))
6c1e3e79	28	return (pte_t *) 0x3b;
190a1d72 MS	29
190a1d72 MS	30	pmd = pmd_offset(pud, addr);
e4aa402e	31	if (pmd_none(pmd) \|\| unlikely(pmd_bad(pmd)))
6c1e3e79	32	return (pte_t *) 0x10;
e4aa402e MS	33
	34	return pte_offset_map(pmd, addr);
	35	}
	36
6c1e3e79 GS	37	static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
6c1e3e79 GS	38	size_t n, int write_user)
59f35d53 GS	39	{
	40	struct mm_struct *mm = current->mm;
	41	unsigned long offset, pfn, done, size;
59f35d53 GS	42	pte_t *pte;
	43	void from, to;
	44
	45	done = 0;
	46	retry:
	47	spin_lock(&mm->page_table_lock);
	48	do {
e4aa402e	49	pte = follow_table(mm, uaddr);
6c1e3e79 GS	50	if ((unsigned long) pte < 0x1000)
	51	goto fault;
	52	if (!pte_present(*pte)) {
	53	pte = (pte_t *) 0x11;
59f35d53	54	goto fault;
6c1e3e79 GS	55	} else if (write_user && !pte_write(*pte)) {
	56	pte = (pte_t *) 0x04;
	57	goto fault;
	58	}
59f35d53 GS	59
59f35d53 GS	60	pfn = pte_pfn(*pte);
59f35d53 GS	61	offset = uaddr & (PAGE_SIZE - 1);
	62	size = min(n - done, PAGE_SIZE - offset);
	63	if (write_user) {
	64	to = (void *)((pfn << PAGE_SHIFT) + offset);
	65	from = kptr + done;
	66	} else {
	67	from = (void *)((pfn << PAGE_SHIFT) + offset);
	68	to = kptr + done;
	69	}
	70	memcpy(to, from, size);
	71	done += size;
	72	uaddr += size;
	73	} while (done < n);
59f35d53 GS	74	spin_unlock(&mm->page_table_lock);
	75	return n - done;
	76	fault:
	77	spin_unlock(&mm->page_table_lock);
6c1e3e79	78	if (__handle_fault(uaddr, (unsigned long) pte, write_user))
59f35d53 GS	79	return n - done;
	80	goto retry;
	81	}
	82
c1821c2e GS	83	/*
	84	* Do DAT for user address by page table walk, return kernel address.
	85	* This function needs to be called with current->mm->page_table_lock held.
	86	*/
6c1e3e79	87	static __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
c1821c2e GS	88	{
c1821c2e GS	89	struct mm_struct *mm = current->mm;
6c1e3e79	90	unsigned long pfn;
c1821c2e GS	91	pte_t *pte;
	92	int rc;
	93
c1821c2e	94	retry:
e4aa402e	95	pte = follow_table(mm, uaddr);
6c1e3e79 GS	96	if ((unsigned long) pte < 0x1000)
	97	goto fault;
	98	if (!pte_present(*pte)) {
	99	pte = (pte_t *) 0x11;
c1821c2e	100	goto fault;
6c1e3e79	101	}
c1821c2e GS	102
c1821c2e GS	103	pfn = pte_pfn(*pte);
6c1e3e79	104	return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
c1821c2e GS	105	fault:
c1821c2e GS	106	spin_unlock(&mm->page_table_lock);
6c1e3e79	107	rc = __handle_fault(uaddr, (unsigned long) pte, 0);
c1821c2e	108	spin_lock(&mm->page_table_lock);
6c1e3e79 GS	109	if (!rc)
	110	goto retry;
	111	return 0;
c1821c2e GS	112	}
c1821c2e GS	113
59f35d53 GS	114	size_t copy_from_user_pt(size_t n, const void __user from, void to)
	115	{
	116	size_t rc;
	117
	118	if (segment_eq(get_fs(), KERNEL_DS)) {
	119	memcpy(to, (void __kernel __force *) from, n);
	120	return 0;
	121	}
	122	rc = __user_copy_pt((unsigned long) from, to, n, 0);
	123	if (unlikely(rc))
	124	memset(to + n - rc, 0, rc);
	125	return rc;
	126	}
	127
	128	size_t copy_to_user_pt(size_t n, void __user to, const void from)
	129	{
	130	if (segment_eq(get_fs(), KERNEL_DS)) {
	131	memcpy((void __kernel __force *) to, from, n);
	132	return 0;
	133	}
	134	return __user_copy_pt((unsigned long) to, (void *) from, n, 1);
	135	}
c1821c2e GS	136
	137	static size_t clear_user_pt(size_t n, void __user *to)
	138	{
	139	long done, size, ret;
	140
	141	if (segment_eq(get_fs(), KERNEL_DS)) {
	142	memset((void __kernel __force *) to, 0, n);
	143	return 0;
	144	}
	145	done = 0;
	146	do {
	147	if (n - done > PAGE_SIZE)
	148	size = PAGE_SIZE;
	149	else
	150	size = n - done;
	151	ret = __user_copy_pt((unsigned long) to + done,
	152	&empty_zero_page, size, 1);
	153	done += size;
	154	if (ret)
	155	return ret + n - done;
	156	} while (done < n);
	157	return 0;
	158	}
	159
	160	static size_t strnlen_user_pt(size_t count, const char __user *src)
	161	{
	162	char *addr;
	163	unsigned long uaddr = (unsigned long) src;
	164	struct mm_struct *mm = current->mm;
	165	unsigned long offset, pfn, done, len;
c1821c2e GS	166	pte_t *pte;
	167	size_t len_str;
	168
	169	if (segment_eq(get_fs(), KERNEL_DS))
	170	return strnlen((const char __kernel __force *) src, count) + 1;
	171	done = 0;
	172	retry:
	173	spin_lock(&mm->page_table_lock);
	174	do {
e4aa402e	175	pte = follow_table(mm, uaddr);
6c1e3e79	176	if ((unsigned long) pte < 0x1000)
c1821c2e	177	goto fault;
6c1e3e79 GS	178	if (!pte_present(*pte)) {
	179	pte = (pte_t *) 0x11;
	180	goto fault;
	181	}
c1821c2e GS	182
c1821c2e GS	183	pfn = pte_pfn(*pte);
c1821c2e GS	184	offset = uaddr & (PAGE_SIZE-1);
	185	addr = (char *)(pfn << PAGE_SHIFT) + offset;
	186	len = min(count - done, PAGE_SIZE - offset);
	187	len_str = strnlen(addr, len);
	188	done += len_str;
	189	uaddr += len_str;
	190	} while ((len_str == len) && (done < count));
c1821c2e GS	191	spin_unlock(&mm->page_table_lock);
	192	return done + 1;
	193	fault:
	194	spin_unlock(&mm->page_table_lock);
6c1e3e79	195	if (__handle_fault(uaddr, (unsigned long) pte, 0))
c1821c2e	196	return 0;
c1821c2e GS	197	goto retry;
	198	}
	199
	200	static size_t strncpy_from_user_pt(size_t count, const char __user *src,
	201	char *dst)
	202	{
	203	size_t n = strnlen_user_pt(count, src);
	204
	205	if (!n)
	206	return -EFAULT;
	207	if (n > count)
	208	n = count;
	209	if (segment_eq(get_fs(), KERNEL_DS)) {
	210	memcpy(dst, (const char __kernel __force *) src, n);
	211	if (dst[n-1] == '\0')
	212	return n-1;
	213	else
	214	return n;
	215	}
	216	if (__user_copy_pt((unsigned long) src, dst, n, 0))
	217	return -EFAULT;
	218	if (dst[n-1] == '\0')
	219	return n-1;
	220	else
	221	return n;
	222	}
	223
	224	static size_t copy_in_user_pt(size_t n, void __user *to,
	225	const void __user *from)
	226	{
	227	struct mm_struct *mm = current->mm;
	228	unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
6c1e3e79	229	uaddr, done, size, error_code;
c1821c2e GS	230	unsigned long uaddr_from = (unsigned long) from;
c1821c2e GS	231	unsigned long uaddr_to = (unsigned long) to;
c1821c2e GS	232	pte_t pte_from, pte_to;
	233	int write_user;
	234
3f12ebce HC	235	if (segment_eq(get_fs(), KERNEL_DS)) {
	236	memcpy((void __force ) to, (void __force ) from, n);
	237	return 0;
	238	}
c1821c2e GS	239	done = 0;
	240	retry:
	241	spin_lock(&mm->page_table_lock);
	242	do {
6c1e3e79 GS	243	write_user = 0;
6c1e3e79 GS	244	uaddr = uaddr_from;
e4aa402e	245	pte_from = follow_table(mm, uaddr_from);
6c1e3e79 GS	246	error_code = (unsigned long) pte_from;
	247	if (error_code < 0x1000)
	248	goto fault;
	249	if (!pte_present(*pte_from)) {
	250	error_code = 0x11;
c1821c2e GS	251	goto fault;
c1821c2e GS	252	}
e4aa402e	253
6c1e3e79 GS	254	write_user = 1;
6c1e3e79 GS	255	uaddr = uaddr_to;
e4aa402e	256	pte_to = follow_table(mm, uaddr_to);
6c1e3e79 GS	257	error_code = (unsigned long) pte_to;
	258	if (error_code < 0x1000)
	259	goto fault;
	260	if (!pte_present(*pte_to)) {
	261	error_code = 0x11;
	262	goto fault;
	263	} else if (!pte_write(*pte_to)) {
	264	error_code = 0x04;
c1821c2e GS	265	goto fault;
	266	}
	267
	268	pfn_from = pte_pfn(*pte_from);
c1821c2e	269	pfn_to = pte_pfn(*pte_to);
c1821c2e GS	270	offset_from = uaddr_from & (PAGE_SIZE-1);
	271	offset_to = uaddr_from & (PAGE_SIZE-1);
	272	offset_max = max(offset_from, offset_to);
	273	size = min(n - done, PAGE_SIZE - offset_max);
	274
	275	memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to,
	276	(void *)(pfn_from << PAGE_SHIFT) + offset_from, size);
	277	done += size;
	278	uaddr_from += size;
	279	uaddr_to += size;
	280	} while (done < n);
c1821c2e GS	281	spin_unlock(&mm->page_table_lock);
	282	return n - done;
	283	fault:
	284	spin_unlock(&mm->page_table_lock);
6c1e3e79	285	if (__handle_fault(uaddr, error_code, write_user))
c1821c2e GS	286	return n - done;
	287	goto retry;
	288	}
	289
	290	#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
	291	asm volatile("0: l %1,0(%6)\n" \
	292	"1: " insn \
	293	"2: cs %1,%2,0(%6)\n" \
	294	"3: jl 1b\n" \
	295	" lhi %0,0\n" \
	296	"4:\n" \
	297	EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
	298	: "=d" (ret), "=&d" (oldval), "=&d" (newval), \
	299	"=m" (*uaddr) \
	300	: "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
	301	"m" (*uaddr) : "cc" );
	302
8d7718aa	303	static int __futex_atomic_op_pt(int op, u32 __user uaddr, int oparg, int old)
c1821c2e GS	304	{
	305	int oldval = 0, newval, ret;
	306
c1821c2e GS	307	switch (op) {
	308	case FUTEX_OP_SET:
	309	__futex_atomic_op("lr %2,%5\n",
	310	ret, oldval, newval, uaddr, oparg);
	311	break;
	312	case FUTEX_OP_ADD:
	313	__futex_atomic_op("lr %2,%1\nar %2,%5\n",
	314	ret, oldval, newval, uaddr, oparg);
	315	break;
	316	case FUTEX_OP_OR:
	317	__futex_atomic_op("lr %2,%1\nor %2,%5\n",
	318	ret, oldval, newval, uaddr, oparg);
	319	break;
	320	case FUTEX_OP_ANDN:
	321	__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
	322	ret, oldval, newval, uaddr, oparg);
	323	break;
	324	case FUTEX_OP_XOR:
	325	__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
	326	ret, oldval, newval, uaddr, oparg);
	327	break;
	328	default:
	329	ret = -ENOSYS;
	330	}
3f12ebce HC	331	if (ret == 0)
3f12ebce HC	332	*old = oldval;
c1821c2e GS	333	return ret;
	334	}
	335
8d7718aa	336	int futex_atomic_op_pt(int op, u32 __user uaddr, int oparg, int old)
c1821c2e GS	337	{
	338	int ret;
	339
3f12ebce HC	340	if (segment_eq(get_fs(), KERNEL_DS))
3f12ebce HC	341	return __futex_atomic_op_pt(op, uaddr, oparg, old);
c1821c2e	342	spin_lock(&current->mm->page_table_lock);
3c52e49d MS	343	uaddr = (u32 __force __user *)
3c52e49d MS	344	__dat_user_addr((__force unsigned long) uaddr);
c1821c2e GS	345	if (!uaddr) {
	346	spin_unlock(&current->mm->page_table_lock);
	347	return -EFAULT;
	348	}
	349	get_page(virt_to_page(uaddr));
	350	spin_unlock(&current->mm->page_table_lock);
3f12ebce HC	351	ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
	352	put_page(virt_to_page(uaddr));
	353	return ret;
	354	}
	355
8d7718aa ML	356	static int __futex_atomic_cmpxchg_pt(u32 uval, u32 __user uaddr,
8d7718aa ML	357	u32 oldval, u32 newval)
3f12ebce HC	358	{
	359	int ret;
	360
	361	asm volatile("0: cs %1,%4,0(%5)\n"
37a9d912	362	"1: la %0,0\n"
3f12ebce HC	363	"2:\n"
3f12ebce HC	364	EX_TABLE(0b,2b) EX_TABLE(1b,2b)
c1821c2e GS	365	: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
	366	: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
	367	: "cc", "memory" );
37a9d912	368	*uval = oldval;
3f12ebce HC	369	return ret;
	370	}
	371
8d7718aa ML	372	int futex_atomic_cmpxchg_pt(u32 uval, u32 __user uaddr,
8d7718aa ML	373	u32 oldval, u32 newval)
3f12ebce HC	374	{
	375	int ret;
	376
	377	if (segment_eq(get_fs(), KERNEL_DS))
37a9d912	378	return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
3f12ebce	379	spin_lock(&current->mm->page_table_lock);
3c52e49d MS	380	uaddr = (u32 __force __user *)
3c52e49d MS	381	__dat_user_addr((__force unsigned long) uaddr);
3f12ebce HC	382	if (!uaddr) {
	383	spin_unlock(&current->mm->page_table_lock);
	384	return -EFAULT;
	385	}
	386	get_page(virt_to_page(uaddr));
	387	spin_unlock(&current->mm->page_table_lock);
37a9d912	388	ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
c1821c2e GS	389	put_page(virt_to_page(uaddr));
	390	return ret;
	391	}
	392
	393	struct uaccess_ops uaccess_pt = {
	394	.copy_from_user = copy_from_user_pt,
	395	.copy_from_user_small = copy_from_user_pt,
	396	.copy_to_user = copy_to_user_pt,
	397	.copy_to_user_small = copy_to_user_pt,
	398	.copy_in_user = copy_in_user_pt,
	399	.clear_user = clear_user_pt,
	400	.strnlen_user = strnlen_user_pt,
	401	.strncpy_from_user = strncpy_from_user_pt,
	402	.futex_atomic_op = futex_atomic_op_pt,
	403	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
	404	};