summary refs log tree commit diff
path: root/include/asm-mips/uaccess.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-mips/uaccess.h
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
Diffstat (limited to 'include/asm-mips/uaccess.h')
-rw-r--r--include/asm-mips/uaccess.h830
1 files changed, 830 insertions, 0 deletions
diff --git a/include/asm-mips/uaccess.h b/include/asm-mips/uaccess.h
new file mode 100644
index 000000000000..07114898e065
--- /dev/null
+++ b/include/asm-mips/uaccess.h
@@ -0,0 +1,830 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_UACCESS_H
+#define _ASM_UACCESS_H
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/thread_info.h>
+#include <asm-generic/uaccess.h>
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+#ifdef CONFIG_MIPS32
+
+#define __UA_LIMIT	0x80000000UL
+
+#define __UA_ADDR	".word"
+#define __UA_LA		"la"
+#define __UA_ADDU	"addu"
+#define __UA_t0		"$8"
+#define __UA_t1		"$9"
+
+#endif /* CONFIG_MIPS32 */
+
+#ifdef CONFIG_MIPS64
+
+#define __UA_LIMIT	(- TASK_SIZE)
+
+#define __UA_ADDR	".dword"
+#define __UA_LA		"dla"
+#define __UA_ADDU	"daddu"
+#define __UA_t0		"$12"
+#define __UA_t1		"$13"
+
+#endif /* CONFIG_MIPS64 */
+
+/*
+ * USER_DS is a bitmask that has the bits set that may not be set in a valid
+ * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
+ * the arithmetic we're doing only works if the limit is a power of two, so
+ * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
+ * address in this range it's the process's problem, not ours :-)
+ */
+
+#define KERNEL_DS	((mm_segment_t) { 0UL })
+#define USER_DS		((mm_segment_t) { __UA_LIMIT })
+
+#define VERIFY_READ    0
+#define VERIFY_WRITE   1
+
+#define get_ds()	(KERNEL_DS)
+#define get_fs()	(current_thread_info()->addr_limit)
+#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+
+#define segment_eq(a,b)	((a).seg == (b).seg)
+
+
+/*
+ * Is a address valid? This does a straighforward calculation rather
+ * than tests.
+ *
+ * Address valid if:
+ *  - "addr" doesn't have any high-bits set
+ *  - AND "size" doesn't have any high-bits set
+ *  - AND "addr+size" doesn't have any high-bits set
+ *  - OR we are in kernel mode.
+ *
+ * __ua_size() is a trick to avoid runtime checking of positive constant
+ * sizes; for those we already know at compile time that the size is ok.
+ */
+#define __ua_size(size)							\
+	((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
+
+/*
+ * access_ok: - Checks if a user space pointer is valid
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
+ *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
+ *        to write to a block, it is always safe to read from it.
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
+ *
+ * Note that, depending on architecture, this function probably just
+ * checks that the pointer is in the user space range - after calling
+ * this function, memory access functions may still return -EFAULT.
+ */
+
+#define __access_mask get_fs().seg
+
+#define __access_ok(addr, size, mask)					\
+	(((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)
+
+#define access_ok(type, addr, size)					\
+	likely(__access_ok((unsigned long)(addr), (size),__access_mask))
+
+/*
+ * verify_area: - Obsolete/deprecated and will go away soon,
+ * use access_ok() instead.
+ * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
+ * @addr: User space pointer to start of block to check
+ * @size: Size of block to check
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This function has been replaced by access_ok().
+ *
+ * Checks if a pointer to a block of memory in user space is valid.
+ *
+ * Returns zero if the memory block may be valid, -EFAULT
+ * if it is definitely invalid.
+ *
+ * See access_ok() for more details.
+ */
+static inline int __deprecated verify_area(int type, const void * addr, unsigned long size)
+{
+	return access_ok(type, addr, size) ? 0 : -EFAULT;
+}
+
+/*
+ * put_user: - Write a simple value into user space.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+#define put_user(x,ptr)	\
+	__put_user_check((x),(ptr),sizeof(*(ptr)))
+
+/*
+ * get_user: - Get a simple variable from user space.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ */
+#define get_user(x,ptr) \
+	__get_user_check((x),(ptr),sizeof(*(ptr)))
+
+/*
+ * __put_user: - Write a simple value into user space, with less checking.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+#define __put_user(x,ptr) \
+	__put_user_nocheck((x),(ptr),sizeof(*(ptr)))
+
+/*
+ * __get_user: - Get a simple variable from user space, with less checking.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Caller must check the pointer with access_ok() before calling this
+ * function.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ */
+#define __get_user(x,ptr) \
+	__get_user_nocheck((x),(ptr),sizeof(*(ptr)))
+
+struct __large_struct { unsigned long buf[100]; };
+#define __m(x) (*(struct __large_struct *)(x))
+
+/*
+ * Yuck.  We need two variants, one for 64bit operation and one
+ * for 32 bit mode and old iron.
+ */
+#ifdef __mips64
+#define __GET_USER_DW(__gu_err) __get_user_asm("ld", __gu_err)
+#else
+#define __GET_USER_DW(__gu_err) __get_user_asm_ll32(__gu_err)
+#endif
+
+#define __get_user_nocheck(x,ptr,size)					\
+({									\
+	__typeof(*(ptr)) __gu_val = 0;					\
+	long __gu_addr;							\
+	long __gu_err = 0;						\
+									\
+	might_sleep();							\
+	__gu_addr = (long) (ptr);					\
+	switch (size) {							\
+	case 1: __get_user_asm("lb", __gu_err); break;			\
+	case 2: __get_user_asm("lh", __gu_err); break;			\
+	case 4: __get_user_asm("lw", __gu_err); break;			\
+	case 8: __GET_USER_DW(__gu_err); break;				\
+	default: __get_user_unknown(); break;				\
+	}								\
+	x = (__typeof__(*(ptr))) __gu_val;				\
+	__gu_err;							\
+})
+
+#define __get_user_check(x,ptr,size)					\
+({									\
+	__typeof__(*(ptr)) __gu_val = 0;				\
+	long __gu_addr;							\
+	long __gu_err;							\
+									\
+	might_sleep();							\
+	__gu_addr = (long) (ptr);					\
+	__gu_err = access_ok(VERIFY_READ, (void *) __gu_addr, size)	\
+				? 0 : -EFAULT;				\
+									\
+	if (likely(!__gu_err)) {					\
+		switch (size) {						\
+		case 1: __get_user_asm("lb", __gu_err); break;		\
+		case 2: __get_user_asm("lh", __gu_err); break;		\
+		case 4: __get_user_asm("lw", __gu_err); break;		\
+		case 8: __GET_USER_DW(__gu_err); break;			\
+		default: __get_user_unknown(); break;			\
+		}							\
+	}								\
+	x = (__typeof__(*(ptr))) __gu_val;				\
+	__gu_err;							\
+})
+
+#define __get_user_asm(insn,__gu_err)					\
+({									\
+	__asm__ __volatile__(						\
+	"1:	" insn "	%1, %3				\n"	\
+	"2:							\n"	\
+	"	.section .fixup,\"ax\"				\n"	\
+	"3:	li	%0, %4					\n"	\
+	"	j	2b					\n"	\
+	"	.previous					\n"	\
+	"	.section __ex_table,\"a\"			\n"	\
+	"	"__UA_ADDR "\t1b, 3b				\n"	\
+	"	.previous					\n"	\
+	: "=r" (__gu_err), "=r" (__gu_val)				\
+	: "0" (__gu_err), "o" (__m(__gu_addr)), "i" (-EFAULT));		\
+})
+
+/*
+ * Get a long long 64 using 32 bit registers.
+ */
+#define __get_user_asm_ll32(__gu_err)					\
+({									\
+	__asm__ __volatile__(						\
+	"1:	lw	%1, %3					\n"	\
+	"2:	lw	%D1, %4					\n"	\
+	"	move	%0, $0					\n"	\
+	"3:	.section	.fixup,\"ax\"			\n"	\
+	"4:	li	%0, %5					\n"	\
+	"	move	%1, $0					\n"	\
+	"	move	%D1, $0					\n"	\
+	"	j	3b					\n"	\
+	"	.previous					\n"	\
+	"	.section	__ex_table,\"a\"		\n"	\
+	"	" __UA_ADDR "	1b, 4b				\n"	\
+	"	" __UA_ADDR "	2b, 4b				\n"	\
+	"	.previous					\n"	\
+	: "=r" (__gu_err), "=&r" (__gu_val)				\
+	: "0" (__gu_err), "o" (__m(__gu_addr)),				\
+	  "o" (__m(__gu_addr + 4)), "i" (-EFAULT));			\
+})
+
+extern void __get_user_unknown(void);
+
+/*
+ * Yuck.  We need two variants, one for 64bit operation and one
+ * for 32 bit mode and old iron.
+ */
+#ifdef __mips64
+#define __PUT_USER_DW(__pu_val) __put_user_asm("sd", __pu_val)
+#else
+#define __PUT_USER_DW(__pu_val) __put_user_asm_ll32(__pu_val)
+#endif
+
+#define __put_user_nocheck(x,ptr,size)					\
+({									\
+	__typeof__(*(ptr)) __pu_val;					\
+	long __pu_addr;							\
+	long __pu_err = 0;						\
+									\
+	might_sleep();							\
+	__pu_val = (x);							\
+	__pu_addr = (long) (ptr);					\
+	switch (size) {							\
+	case 1: __put_user_asm("sb", __pu_val); break;			\
+	case 2: __put_user_asm("sh", __pu_val); break;			\
+	case 4: __put_user_asm("sw", __pu_val); break;			\
+	case 8: __PUT_USER_DW(__pu_val); break;				\
+	default: __put_user_unknown(); break;				\
+	}								\
+	__pu_err;							\
+})
+
+#define __put_user_check(x,ptr,size)					\
+({									\
+	__typeof__(*(ptr)) __pu_val;					\
+	long __pu_addr;							\
+	long __pu_err;							\
+									\
+	might_sleep();							\
+	__pu_val = (x);							\
+	__pu_addr = (long) (ptr);					\
+	__pu_err = access_ok(VERIFY_WRITE, (void *) __pu_addr, size)	\
+				? 0 : -EFAULT;				\
+									\
+	if (likely(!__pu_err)) {					\
+		switch (size) {						\
+		case 1: __put_user_asm("sb", __pu_val); break;		\
+		case 2: __put_user_asm("sh", __pu_val); break;		\
+		case 4: __put_user_asm("sw", __pu_val); break;		\
+		case 8: __PUT_USER_DW(__pu_val); break;			\
+		default: __put_user_unknown(); break;			\
+		}							\
+	}								\
+	__pu_err;							\
+})
+
+#define __put_user_asm(insn, __pu_val)					\
+({									\
+	__asm__ __volatile__(						\
+	"1:	" insn "	%z2, %3		# __put_user_asm\n"	\
+	"2:							\n"	\
+	"	.section	.fixup,\"ax\"			\n"	\
+	"3:	li	%0, %4					\n"	\
+	"	j	2b					\n"	\
+	"	.previous					\n"	\
+	"	.section	__ex_table,\"a\"		\n"	\
+	"	" __UA_ADDR "	1b, 3b				\n"	\
+	"	.previous					\n"	\
+	: "=r" (__pu_err)						\
+	: "0" (__pu_err), "Jr" (__pu_val), "o" (__m(__pu_addr)),	\
+	  "i" (-EFAULT));						\
+})
+
+#define __put_user_asm_ll32(__pu_val)					\
+({									\
+	__asm__ __volatile__(						\
+	"1:	sw	%2, %3		# __put_user_asm_ll32	\n"	\
+	"2:	sw	%D2, %4					\n"	\
+	"3:							\n"	\
+	"	.section	.fixup,\"ax\"			\n"	\
+	"4:	li	%0, %5					\n"	\
+	"	j	3b					\n"	\
+	"	.previous					\n"	\
+	"	.section	__ex_table,\"a\"		\n"	\
+	"	" __UA_ADDR "	1b, 4b				\n"	\
+	"	" __UA_ADDR "	2b, 4b				\n"	\
+	"	.previous"						\
+	: "=r" (__pu_err)						\
+	: "0" (__pu_err), "r" (__pu_val), "o" (__m(__pu_addr)),		\
+	  "o" (__m(__pu_addr + 4)), "i" (-EFAULT));			\
+})
+
+extern void __put_user_unknown(void);
+
+/*
+ * We're generating jump to subroutines which will be outside the range of
+ * jump instructions
+ */
+#ifdef MODULE
+#define __MODULE_JAL(destination)					\
+	".set\tnoat\n\t"						\
+	__UA_LA "\t$1, " #destination "\n\t" 				\
+	"jalr\t$1\n\t"							\
+	".set\tat\n\t"
+#else
+#define __MODULE_JAL(destination)					\
+	"jal\t" #destination "\n\t"
+#endif
+
+extern size_t __copy_user(void *__to, const void *__from, size_t __n);
+
+#define __invoke_copy_to_user(to,from,n)				\
+({									\
+	register void *__cu_to_r __asm__ ("$4");			\
+	register const void *__cu_from_r __asm__ ("$5");		\
+	register long __cu_len_r __asm__ ("$6");			\
+									\
+	__cu_to_r = (to);						\
+	__cu_from_r = (from);						\
+	__cu_len_r = (n);						\
+	__asm__ __volatile__(						\
+	__MODULE_JAL(__copy_user)					\
+	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
+	:								\
+	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
+	  "memory");							\
+	__cu_len_r;							\
+})
+
+/*
+ * __copy_to_user: - Copy a block of data into user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from kernel space to user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+#define __copy_to_user(to,from,n)					\
+({									\
+	void *__cu_to;							\
+	const void *__cu_from;						\
+	long __cu_len;							\
+									\
+	might_sleep();							\
+	__cu_to = (to);							\
+	__cu_from = (from);						\
+	__cu_len = (n);							\
+	__cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len);	\
+	__cu_len;							\
+})
+
+#define __copy_to_user_inatomic __copy_to_user
+#define __copy_from_user_inatomic __copy_from_user
+
+/*
+ * copy_to_user: - Copy a block of data into user space.
+ * @to:   Destination address, in user space.
+ * @from: Source address, in kernel space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from kernel space to user space.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ */
+#define copy_to_user(to,from,n)						\
+({									\
+	void *__cu_to;							\
+	const void *__cu_from;						\
+	long __cu_len;							\
+									\
+	might_sleep();							\
+	__cu_to = (to);							\
+	__cu_from = (from);						\
+	__cu_len = (n);							\
+	if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))			\
+		__cu_len = __invoke_copy_to_user(__cu_to, __cu_from,	\
+		                                 __cu_len);		\
+	__cu_len;							\
+})
+
+#define __invoke_copy_from_user(to,from,n)				\
+({									\
+	register void *__cu_to_r __asm__ ("$4");			\
+	register const void *__cu_from_r __asm__ ("$5");		\
+	register long __cu_len_r __asm__ ("$6");			\
+									\
+	__cu_to_r = (to);						\
+	__cu_from_r = (from);						\
+	__cu_len_r = (n);						\
+	__asm__ __volatile__(						\
+	".set\tnoreorder\n\t"						\
+	__MODULE_JAL(__copy_user)					\
+	".set\tnoat\n\t"						\
+	__UA_ADDU "\t$1, %1, %2\n\t"					\
+	".set\tat\n\t"							\
+	".set\treorder"							\
+	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
+	:								\
+	: "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",		\
+	  "memory");							\
+	__cu_len_r;							\
+})
+
+/*
+ * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from user space to kernel space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * If some data could not be copied, this function will pad the copied
+ * data to the requested size using zero bytes.
+ */
+#define __copy_from_user(to,from,n)					\
+({									\
+	void *__cu_to;							\
+	const void *__cu_from;						\
+	long __cu_len;							\
+									\
+	might_sleep();							\
+	__cu_to = (to);							\
+	__cu_from = (from);						\
+	__cu_len = (n);							\
+	__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,		\
+	                                   __cu_len);			\
+	__cu_len;							\
+})
+
+/*
+ * copy_from_user: - Copy a block of data from user space.
+ * @to:   Destination address, in kernel space.
+ * @from: Source address, in user space.
+ * @n:    Number of bytes to copy.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Copy data from user space to kernel space.
+ *
+ * Returns number of bytes that could not be copied.
+ * On success, this will be zero.
+ *
+ * If some data could not be copied, this function will pad the copied
+ * data to the requested size using zero bytes.
+ */
+#define copy_from_user(to,from,n)					\
+({									\
+	void *__cu_to;							\
+	const void *__cu_from;						\
+	long __cu_len;							\
+									\
+	might_sleep();							\
+	__cu_to = (to);							\
+	__cu_from = (from);						\
+	__cu_len = (n);							\
+	if (access_ok(VERIFY_READ, __cu_from, __cu_len))		\
+		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
+		                                   __cu_len);		\
+	__cu_len;							\
+})
+
+#define __copy_in_user(to, from, n)	__copy_from_user(to, from, n)
+
+#define copy_in_user(to,from,n)						\
+({									\
+	void *__cu_to;							\
+	const void *__cu_from;						\
+	long __cu_len;							\
+									\
+	might_sleep();							\
+	__cu_to = (to);							\
+	__cu_from = (from);						\
+	__cu_len = (n);							\
+	if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&	\
+	           access_ok(VERIFY_WRITE, __cu_to, __cu_len)))		\
+		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
+		                                   __cu_len);		\
+	__cu_len;							\
+})
+
+/*
+ * __clear_user: - Zero a block of memory in user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
+static inline __kernel_size_t
+__clear_user(void *addr, __kernel_size_t size)
+{
+	__kernel_size_t res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, $0\n\t"
+		"move\t$6, %2\n\t"
+		__MODULE_JAL(__bzero)
+		"move\t%0, $6"
+		: "=r" (res)
+		: "r" (addr), "r" (size)
+		: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+
+	return res;
+}
+
+#define clear_user(addr,n)						\
+({									\
+	void * __cl_addr = (addr);					\
+	unsigned long __cl_size = (n);					\
+	if (__cl_size && access_ok(VERIFY_WRITE,			\
+		((unsigned long)(__cl_addr)), __cl_size))		\
+		__cl_size = __clear_user(__cl_addr, __cl_size);		\
+	__cl_size;							\
+})
+
+/*
+ * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ * Caller must check the specified block with access_ok() before calling
+ * this function.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+static inline long
+__strncpy_from_user(char *__to, const char *__from, long __len)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		"move\t$6, %3\n\t"
+		__MODULE_JAL(__strncpy_from_user_nocheck_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (__to), "r" (__from), "r" (__len)
+		: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
+
+	return res;
+}
+
+/*
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+static inline long
+strncpy_from_user(char *__to, const char *__from, long __len)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		"move\t$6, %3\n\t"
+		__MODULE_JAL(__strncpy_from_user_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (__to), "r" (__from), "r" (__len)
+		: "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
+
+	return res;
+}
+
+/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
+static inline long __strlen_user(const char *s)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		__MODULE_JAL(__strlen_user_nocheck_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (s)
+		: "$2", "$4", __UA_t0, "$31");
+
+	return res;
+}
+
+/*
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ *
+ * If there is a limit on the length of a valid string, you may wish to
+ * consider using strnlen_user() instead.
+ */
+static inline long strlen_user(const char *s)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		__MODULE_JAL(__strlen_user_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (s)
+		: "$2", "$4", __UA_t0, "$31");
+
+	return res;
+}
+
+/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
+static inline long __strnlen_user(const char *s, long n)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		__MODULE_JAL(__strnlen_user_nocheck_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (s), "r" (n)
+		: "$2", "$4", "$5", __UA_t0, "$31");
+
+	return res;
+}
+
+/*
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ *
+ * If there is a limit on the length of a valid string, you may wish to
+ * consider using strnlen_user() instead.
+ */
+static inline long strnlen_user(const char *s, long n)
+{
+	long res;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"move\t$4, %1\n\t"
+		"move\t$5, %2\n\t"
+		__MODULE_JAL(__strnlen_user_asm)
+		"move\t%0, $2"
+		: "=r" (res)
+		: "r" (s), "r" (n)
+		: "$2", "$4", "$5", __UA_t0, "$31");
+
+	return res;
+}
+
+struct exception_table_entry
+{
+	unsigned long insn;
+	unsigned long nextinsn;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+#endif /* _ASM_UACCESS_H */