[deliverable/linux.git] / arch / x86 / include / asm / uaccess.h

#ifndef _ASM_X86_UACCESS_H
#define _ASM_X86_UACCESS_H
/*
 * User space memory access functions
 */
#include <linux/errno.h>
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <linux/string.h>
#include <asm/asm.h>
#include <asm/page.h>
#include <asm/smap.h>

#define VERIFY_READ 0
#define VERIFY_WRITE 1

/*
 * 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.
 */

#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })

#define KERNEL_DS	MAKE_MM_SEG(-1UL)
#define USER_DS 	MAKE_MM_SEG(TASK_SIZE_MAX)

#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)

#define user_addr_max() (current_thread_info()->addr_limit.seg)
#define __addr_ok(addr) 	\
	((unsigned long __force)(addr) < user_addr_max())

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 0 if the range is valid, nonzero otherwise.
 *
 * This is equivalent to the following test:
 * (u33)addr + (u33)size > (u33)current->addr_limit.seg (u65 for x86_64)
 *
 * This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry...
 */

#define __range_not_ok(addr, size, limit)				\
({									\
	unsigned long flag, roksum;					\
	__chk_user_ptr(addr);						\
	asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0"		\
	    : "=&r" (flag), "=r" (roksum)				\
	    : "1" (addr), "g" ((long)(size)),				\
	      "rm" (limit));						\
	flag;								\
})

/**
 * 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_ok(type, addr, size) \
	(likely(__range_not_ok(addr, size, user_addr_max()) == 0))

/*
 * The exception table consists of pairs of addresses relative to the
 * exception table enty itself: the first is the address of an
 * instruction that is allowed to fault, and the second is the address
 * at which the program should continue.  No registers are modified,
 * so it is entirely up to the continuation code to figure out what to
 * do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry {
	int insn, fixup;
};
/* This is not the generic standard exception_table_entry format */
#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE

extern int fixup_exception(struct pt_regs *regs);
extern int early_fixup_exception(unsigned long *ip);

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the ugliness from the user.
 *
 * The "__xxx" versions of the user access functions are versions that
 * do not verify the address space, that must have been done previously
 * with a separate "access_ok()" call (this is used when we do multiple
 * accesses to the same area of user memory).
 */

extern int __get_user_1(void);
extern int __get_user_2(void);
extern int __get_user_4(void);
extern int __get_user_8(void);
extern int __get_user_bad(void);

#define __get_user_x(size, ret, x, ptr)		      \
	asm volatile("call __get_user_" #size	      \
		     : "=a" (ret), "=d" (x)	      \
		     : "0" (ptr))		      \

/* Careful: we have to cast the result to the type of the pointer
 * for sign reasons */

/**
 * 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.
 */
#ifdef CONFIG_X86_32
#define __get_user_8(__ret_gu, __val_gu, ptr)				\
		__get_user_x(X, __ret_gu, __val_gu, ptr)
#else
#define __get_user_8(__ret_gu, __val_gu, ptr)				\
		__get_user_x(8, __ret_gu, __val_gu, ptr)
#endif

#define get_user(x, ptr)						\
({									\
	int __ret_gu;							\
	unsigned long __val_gu;						\
	__chk_user_ptr(ptr);						\
	might_fault();							\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_x(1, __ret_gu, __val_gu, ptr);		\
		break;							\
	case 2:								\
		__get_user_x(2, __ret_gu, __val_gu, ptr);		\
		break;							\
	case 4:								\
		__get_user_x(4, __ret_gu, __val_gu, ptr);		\
		break;							\
	case 8:								\
		__get_user_8(__ret_gu, __val_gu, ptr);			\
		break;							\
	default:							\
		__get_user_x(X, __ret_gu, __val_gu, ptr);		\
		break;							\
	}								\
	(x) = (__typeof__(*(ptr)))__val_gu;				\
	__ret_gu;							\
})

#define __put_user_x(size, x, ptr, __ret_pu)			\
	asm volatile("call __put_user_" #size : "=a" (__ret_pu)	\
		     : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")


#ifdef CONFIG_X86_32
#define __put_user_asm_u64(x, addr, err, errret)			\
	asm volatile(ASM_STAC "\n"					\
		     "1:	movl %%eax,0(%2)\n"			\
		     "2:	movl %%edx,4(%2)\n"			\
		     "3: " ASM_CLAC "\n"				\
		     ".section .fixup,\"ax\"\n"				\
		     "4:	movl %3,%0\n"				\
		     "	jmp 3b\n"					\
		     ".previous\n"					\
		     _ASM_EXTABLE(1b, 4b)				\
		     _ASM_EXTABLE(2b, 4b)				\
		     : "=r" (err)					\
		     : "A" (x), "r" (addr), "i" (errret), "0" (err))

#define __put_user_asm_ex_u64(x, addr)					\
	asm volatile(ASM_STAC "\n"					\
		     "1:	movl %%eax,0(%1)\n"			\
		     "2:	movl %%edx,4(%1)\n"			\
		     "3: " ASM_CLAC "\n"				\
		     _ASM_EXTABLE_EX(1b, 2b)				\
		     _ASM_EXTABLE_EX(2b, 3b)				\
		     : : "A" (x), "r" (addr))

#define __put_user_x8(x, ptr, __ret_pu)				\
	asm volatile("call __put_user_8" : "=a" (__ret_pu)	\
		     : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
#else
#define __put_user_asm_u64(x, ptr, retval, errret) \
	__put_user_asm(x, ptr, retval, "q", "", "er", errret)
#define __put_user_asm_ex_u64(x, addr)	\
	__put_user_asm_ex(x, addr, "q", "", "er")
#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
#endif

extern void __put_user_bad(void);

/*
 * Strange magic calling convention: pointer in %ecx,
 * value in %eax(:%edx), return value in %eax. clobbers %rbx
 */
extern void __put_user_1(void);
extern void __put_user_2(void);
extern void __put_user_4(void);
extern void __put_user_8(void);

/**
 * 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)					\
({								\
	int __ret_pu;						\
	__typeof__(*(ptr)) __pu_val;				\
	__chk_user_ptr(ptr);					\
	might_fault();						\
	__pu_val = x;						\
	switch (sizeof(*(ptr))) {				\
	case 1:							\
		__put_user_x(1, __pu_val, ptr, __ret_pu);	\
		break;						\
	case 2:							\
		__put_user_x(2, __pu_val, ptr, __ret_pu);	\
		break;						\
	case 4:							\
		__put_user_x(4, __pu_val, ptr, __ret_pu);	\
		break;						\
	case 8:							\
		__put_user_x8(__pu_val, ptr, __ret_pu);		\
		break;						\
	default:						\
		__put_user_x(X, __pu_val, ptr, __ret_pu);	\
		break;						\
	}							\
	__ret_pu;						\
})

#define __put_user_size(x, ptr, size, retval, errret)			\
do {									\
	retval = 0;							\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	case 1:								\
		__put_user_asm(x, ptr, retval, "b", "b", "iq", errret);	\
		break;							\
	case 2:								\
		__put_user_asm(x, ptr, retval, "w", "w", "ir", errret);	\
		break;							\
	case 4:								\
		__put_user_asm(x, ptr, retval, "l", "k", "ir", errret);	\
		break;							\
	case 8:								\
		__put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval,	\
				   errret);				\
		break;							\
	default:							\
		__put_user_bad();					\
	}								\
} while (0)

#define __put_user_size_ex(x, ptr, size)				\
do {									\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	case 1:								\
		__put_user_asm_ex(x, ptr, "b", "b", "iq");		\
		break;							\
	case 2:								\
		__put_user_asm_ex(x, ptr, "w", "w", "ir");		\
		break;							\
	case 4:								\
		__put_user_asm_ex(x, ptr, "l", "k", "ir");		\
		break;							\
	case 8:								\
		__put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr);	\
		break;							\
	default:							\
		__put_user_bad();					\
	}								\
} while (0)

#ifdef CONFIG_X86_32
#define __get_user_asm_u64(x, ptr, retval, errret)	(x) = __get_user_bad()
#define __get_user_asm_ex_u64(x, ptr)			(x) = __get_user_bad()
#else
#define __get_user_asm_u64(x, ptr, retval, errret) \
	 __get_user_asm(x, ptr, retval, "q", "", "=r", errret)
#define __get_user_asm_ex_u64(x, ptr) \
	 __get_user_asm_ex(x, ptr, "q", "", "=r")
#endif

#define __get_user_size(x, ptr, size, retval, errret)			\
do {									\
	retval = 0;							\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	case 1:								\
		__get_user_asm(x, ptr, retval, "b", "b", "=q", errret);	\
		break;							\
	case 2:								\
		__get_user_asm(x, ptr, retval, "w", "w", "=r", errret);	\
		break;							\
	case 4:								\
		__get_user_asm(x, ptr, retval, "l", "k", "=r", errret);	\
		break;							\
	case 8:								\
		__get_user_asm_u64(x, ptr, retval, errret);		\
		break;							\
	default:							\
		(x) = __get_user_bad();					\
	}								\
} while (0)

#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret)	\
	asm volatile(ASM_STAC "\n"					\
		     "1:	mov"itype" %2,%"rtype"1\n"		\
		     "2: " ASM_CLAC "\n"				\
		     ".section .fixup,\"ax\"\n"				\
		     "3:	mov %3,%0\n"				\
		     "	xor"itype" %"rtype"1,%"rtype"1\n"		\
		     "	jmp 2b\n"					\
		     ".previous\n"					\
		     _ASM_EXTABLE(1b, 3b)				\
		     : "=r" (err), ltype(x)				\
		     : "m" (__m(addr)), "i" (errret), "0" (err))

#define __get_user_size_ex(x, ptr, size)				\
do {									\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	case 1:								\
		__get_user_asm_ex(x, ptr, "b", "b", "=q");		\
		break;							\
	case 2:								\
		__get_user_asm_ex(x, ptr, "w", "w", "=r");		\
		break;							\
	case 4:								\
		__get_user_asm_ex(x, ptr, "l", "k", "=r");		\
		break;							\
	case 8:								\
		__get_user_asm_ex_u64(x, ptr);				\
		break;							\
	default:							\
		(x) = __get_user_bad();					\
	}								\
} while (0)

#define __get_user_asm_ex(x, addr, itype, rtype, ltype)			\
	asm volatile("1:	mov"itype" %1,%"rtype"0\n"		\
		     "2:\n"						\
		     _ASM_EXTABLE_EX(1b, 2b)				\
		     : ltype(x) : "m" (__m(addr)))

#define __put_user_nocheck(x, ptr, size)			\
({								\
	int __pu_err;						\
	__put_user_size((x), (ptr), (size), __pu_err, -EFAULT);	\
	__pu_err;						\
})

#define __get_user_nocheck(x, ptr, size)				\
({									\
	int __gu_err;							\
	unsigned long __gu_val;						\
	__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT);	\
	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
	__gu_err;							\
})

/* FIXME: this hack is definitely wrong -AK */
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))

/*
 * Tell gcc we read from memory instead of writing: this is because
 * we do not write to any memory gcc knows about, so there are no
 * aliasing issues.
 */
#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret)	\
	asm volatile(ASM_STAC "\n"					\
		     "1:	mov"itype" %"rtype"1,%2\n"		\
		     "2: " ASM_CLAC "\n"				\
		     ".section .fixup,\"ax\"\n"				\
		     "3:	mov %3,%0\n"				\
		     "	jmp 2b\n"					\
		     ".previous\n"					\
		     _ASM_EXTABLE(1b, 3b)				\
		     : "=r"(err)					\
		     : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err))

#define __put_user_asm_ex(x, addr, itype, rtype, ltype)			\
	asm volatile("1:	mov"itype" %"rtype"0,%1\n"		\
		     "2:\n"						\
		     _ASM_EXTABLE_EX(1b, 2b)				\
		     : : ltype(x), "m" (__m(addr)))

/*
 * uaccess_try and catch
 */
#define uaccess_try	do {						\
	current_thread_info()->uaccess_err = 0;				\
	stac();								\
	barrier();

#define uaccess_catch(err)						\
	clac();								\
	(err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0);	\
} while (0)

/**
 * __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)))

/**
 * __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((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

#define __get_user_unaligned __get_user
#define __put_user_unaligned __put_user

/*
 * {get|put}_user_try and catch
 *
 * get_user_try {
 *	get_user_ex(...);
 * } get_user_catch(err)
 */
#define get_user_try		uaccess_try
#define get_user_catch(err)	uaccess_catch(err)

#define get_user_ex(x, ptr)	do {					\
	unsigned long __gue_val;					\
	__get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr))));	\
	(x) = (__force __typeof__(*(ptr)))__gue_val;			\
} while (0)

#define put_user_try		uaccess_try
#define put_user_catch(err)	uaccess_catch(err)

#define put_user_ex(x, ptr)						\
	__put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

extern unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
extern __must_check long
strncpy_from_user(char *dst, const char __user *src, long count);

extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);

unsigned long __must_check clear_user(void __user *mem, unsigned long len);
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);

/*
 * movsl can be slow when source and dest are not both 8-byte aligned
 */
#ifdef CONFIG_X86_INTEL_USERCOPY
extern struct movsl_mask {
	int mask;
} ____cacheline_aligned_in_smp movsl_mask;
#endif

#define ARCH_HAS_NOCACHE_UACCESS 1

#ifdef CONFIG_X86_32
# include <asm/uaccess_32.h>
#else
# include <asm/uaccess_64.h>
#endif

#endif /* _ASM_X86_UACCESS_H */
Commit	Line	Data
1965aae3 PA	1	#ifndef _ASM_X86_UACCESS_H
1965aae3 PA	2	#define _ASM_X86_UACCESS_H
ca233862 GC	3	/*
	4	* User space memory access functions
	5	*/
	6	#include <linux/errno.h>
	7	#include <linux/compiler.h>
	8	#include <linux/thread_info.h>
ca233862 GC	9	#include <linux/string.h>
	10	#include <asm/asm.h>
	11	#include <asm/page.h>
63bcff2a	12	#include <asm/smap.h>
ca233862 GC	13
	14	#define VERIFY_READ 0
	15	#define VERIFY_WRITE 1
	16
	17	/*
	18	* The fs value determines whether argument validity checking should be
	19	* performed or not. If get_fs() == USER_DS, checking is performed, with
	20	* get_fs() == KERNEL_DS, checking is bypassed.
	21	*
	22	* For historical reasons, these macros are grossly misnamed.
	23	*/
	24
	25	#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
	26
	27	#define KERNEL_DS MAKE_MM_SEG(-1UL)
9063c61f	28	#define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX)
ca233862 GC	29
	30	#define get_ds() (KERNEL_DS)
	31	#define get_fs() (current_thread_info()->addr_limit)
	32	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	33
	34	#define segment_eq(a, b) ((a).seg == (b).seg)
	35
4ae73f2d	36	#define user_addr_max() (current_thread_info()->addr_limit.seg)
bc6ca7b3 AS	37	#define __addr_ok(addr) \
bc6ca7b3 AS	38	((unsigned long __force)(addr) < user_addr_max())
002ca169	39
ca233862 GC	40	/*
	41	* Test whether a block of memory is a valid user space address.
	42	* Returns 0 if the range is valid, nonzero otherwise.
	43	*
	44	* This is equivalent to the following test:
26afb7c6	45	* (u33)addr + (u33)size > (u33)current->addr_limit.seg (u65 for x86_64)
ca233862 GC	46	*
	47	* This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry...
	48	*/
	49
bc6ca7b3	50	#define __range_not_ok(addr, size, limit) \
ca233862 GC	51	({ \
	52	unsigned long flag, roksum; \
	53	__chk_user_ptr(addr); \
	54	asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0" \
	55	: "=&r" (flag), "=r" (roksum) \
	56	: "1" (addr), "g" ((long)(size)), \
bc6ca7b3	57	"rm" (limit)); \
ca233862 GC	58	flag; \
	59	})
	60
	61	/**
	62	* access_ok: - Checks if a user space pointer is valid
	63	* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
	64	* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
	65	* to write to a block, it is always safe to read from it.
	66	* @addr: User space pointer to start of block to check
	67	* @size: Size of block to check
	68	*
	69	* Context: User context only. This function may sleep.
	70	*
	71	* Checks if a pointer to a block of memory in user space is valid.
	72	*
	73	* Returns true (nonzero) if the memory block may be valid, false (zero)
	74	* if it is definitely invalid.
	75	*
	76	* Note that, depending on architecture, this function probably just
	77	* checks that the pointer is in the user space range - after calling
	78	* this function, memory access functions may still return -EFAULT.
	79	*/
bc6ca7b3 AS	80	#define access_ok(type, addr, size) \
bc6ca7b3 AS	81	(likely(__range_not_ok(addr, size, user_addr_max()) == 0))
ca233862 GC	82
ca233862 GC	83	/*
70627654 PA	84	* The exception table consists of pairs of addresses relative to the
	85	* exception table enty itself: the first is the address of an
	86	* instruction that is allowed to fault, and the second is the address
	87	* at which the program should continue. No registers are modified,
	88	* so it is entirely up to the continuation code to figure out what to
	89	* do.
ca233862 GC	90	*
	91	* All the routines below use bits of fixup code that are out of line
	92	* with the main instruction path. This means when everything is well,
	93	* we don't even have to jump over them. Further, they do not intrude
	94	* on our cache or tlb entries.
	95	*/
	96
	97	struct exception_table_entry {
70627654	98	int insn, fixup;
ca233862	99	};
70627654 PA	100	/* This is not the generic standard exception_table_entry format */
	101	#define ARCH_HAS_SORT_EXTABLE
	102	#define ARCH_HAS_SEARCH_EXTABLE
ca233862 GC	103
ca233862 GC	104	extern int fixup_exception(struct pt_regs *regs);
70627654	105	extern int early_fixup_exception(unsigned long *ip);
ca233862 GC	106
	107	/*
	108	* These are the main single-value transfer routines. They automatically
	109	* use the right size if we just have the right pointer type.
	110	*
	111	* This gets kind of ugly. We want to return _two_ values in "get_user()"
	112	* and yet we don't want to do any pointers, because that is too much
	113	* of a performance impact. Thus we have a few rather ugly macros here,
	114	* and hide all the ugliness from the user.
	115	*
	116	* The "__xxx" versions of the user access functions are versions that
	117	* do not verify the address space, that must have been done previously
	118	* with a separate "access_ok()" call (this is used when we do multiple
	119	* accesses to the same area of user memory).
	120	*/
	121
	122	extern int __get_user_1(void);
	123	extern int __get_user_2(void);
	124	extern int __get_user_4(void);
	125	extern int __get_user_8(void);
	126	extern int __get_user_bad(void);
	127
	128	#define __get_user_x(size, ret, x, ptr) \
	129	asm volatile("call __get_user_" #size \
4d5d7838	130	: "=a" (ret), "=d" (x) \
ca233862 GC	131	: "0" (ptr)) \
ca233862 GC	132
865e5b76 GC	133	/* Careful: we have to cast the result to the type of the pointer
	134	* for sign reasons */
	135
	136	/**
	137	* get_user: - Get a simple variable from user space.
	138	* @x: Variable to store result.
	139	* @ptr: Source address, in user space.
	140	*
	141	* Context: User context only. This function may sleep.
	142	*
	143	* This macro copies a single simple variable from user space to kernel
	144	* space. It supports simple types like char and int, but not larger
	145	* data types like structures or arrays.
	146	*
	147	* @ptr must have pointer-to-simple-variable type, and the result of
	148	* dereferencing @ptr must be assignable to @x without a cast.
	149	*
	150	* Returns zero on success, or -EFAULT on error.
	151	* On error, the variable @x is set to zero.
	152	*/
	153	#ifdef CONFIG_X86_32
	154	#define __get_user_8(__ret_gu, __val_gu, ptr) \
	155	__get_user_x(X, __ret_gu, __val_gu, ptr)
	156	#else
	157	#define __get_user_8(__ret_gu, __val_gu, ptr) \
	158	__get_user_x(8, __ret_gu, __val_gu, ptr)
	159	#endif
	160
	161	#define get_user(x, ptr) \
	162	({ \
	163	int __ret_gu; \
	164	unsigned long __val_gu; \
	165	__chk_user_ptr(ptr); \
3ee1afa3	166	might_fault(); \
865e5b76 GC	167	switch (sizeof(*(ptr))) { \
	168	case 1: \
	169	__get_user_x(1, __ret_gu, __val_gu, ptr); \
	170	break; \
	171	case 2: \
	172	__get_user_x(2, __ret_gu, __val_gu, ptr); \
	173	break; \
	174	case 4: \
	175	__get_user_x(4, __ret_gu, __val_gu, ptr); \
	176	break; \
	177	case 8: \
	178	__get_user_8(__ret_gu, __val_gu, ptr); \
	179	break; \
	180	default: \
	181	__get_user_x(X, __ret_gu, __val_gu, ptr); \
	182	break; \
	183	} \
	184	(x) = (__typeof__(*(ptr)))__val_gu; \
	185	__ret_gu; \
	186	})
	187
e30a44fd GC	188	#define __put_user_x(size, x, ptr, __ret_pu) \
e30a44fd GC	189	asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
4d5d7838	190	: "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
e30a44fd GC	191
	192
	193
dc70ddf4	194	#ifdef CONFIG_X86_32
18114f61	195	#define __put_user_asm_u64(x, addr, err, errret) \
63bcff2a PA	196	asm volatile(ASM_STAC "\n" \
63bcff2a PA	197	"1: movl %%eax,0(%2)\n" \
dc70ddf4	198	"2: movl %%edx,4(%2)\n" \
63bcff2a	199	"3: " ASM_CLAC "\n" \
dc70ddf4 GC	200	".section .fixup,\"ax\"\n" \
	201	"4: movl %3,%0\n" \
	202	" jmp 3b\n" \
	203	".previous\n" \
	204	_ASM_EXTABLE(1b, 4b) \
	205	_ASM_EXTABLE(2b, 4b) \
	206	: "=r" (err) \
18114f61	207	: "A" (x), "r" (addr), "i" (errret), "0" (err))
e30a44fd	208
fe40c0af	209	#define __put_user_asm_ex_u64(x, addr) \
63bcff2a PA	210	asm volatile(ASM_STAC "\n" \
63bcff2a PA	211	"1: movl %%eax,0(%1)\n" \
fe40c0af	212	"2: movl %%edx,4(%1)\n" \
63bcff2a	213	"3: " ASM_CLAC "\n" \
535c0c34 PA	214	_ASM_EXTABLE_EX(1b, 2b) \
535c0c34 PA	215	_ASM_EXTABLE_EX(2b, 3b) \
fe40c0af HS	216	: : "A" (x), "r" (addr))
fe40c0af HS	217
e30a44fd GC	218	#define __put_user_x8(x, ptr, __ret_pu) \
	219	asm volatile("call __put_user_8" : "=a" (__ret_pu) \
	220	: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
dc70ddf4	221	#else
18114f61	222	#define __put_user_asm_u64(x, ptr, retval, errret) \
ebe119cd	223	__put_user_asm(x, ptr, retval, "q", "", "er", errret)
fe40c0af	224	#define __put_user_asm_ex_u64(x, addr) \
ebe119cd	225	__put_user_asm_ex(x, addr, "q", "", "er")
e30a44fd	226	#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
dc70ddf4 GC	227	#endif
dc70ddf4 GC	228
e30a44fd GC	229	extern void __put_user_bad(void);
	230
	231	/*
	232	* Strange magic calling convention: pointer in %ecx,
	233	* value in %eax(:%edx), return value in %eax. clobbers %rbx
	234	*/
	235	extern void __put_user_1(void);
	236	extern void __put_user_2(void);
	237	extern void __put_user_4(void);
	238	extern void __put_user_8(void);
	239
e30a44fd GC	240	/**
	241	* put_user: - Write a simple value into user space.
	242	* @x: Value to copy to user space.
	243	* @ptr: Destination address, in user space.
	244	*
	245	* Context: User context only. This function may sleep.
	246	*
	247	* This macro copies a single simple value from kernel space to user
	248	* space. It supports simple types like char and int, but not larger
	249	* data types like structures or arrays.
	250	*
	251	* @ptr must have pointer-to-simple-variable type, and @x must be assignable
	252	* to the result of dereferencing @ptr.
	253	*
	254	* Returns zero on success, or -EFAULT on error.
	255	*/
	256	#define put_user(x, ptr) \
	257	({ \
	258	int __ret_pu; \
	259	__typeof__(*(ptr)) __pu_val; \
	260	__chk_user_ptr(ptr); \
3ee1afa3	261	might_fault(); \
e30a44fd GC	262	__pu_val = x; \
	263	switch (sizeof(*(ptr))) { \
	264	case 1: \
	265	__put_user_x(1, __pu_val, ptr, __ret_pu); \
	266	break; \
	267	case 2: \
	268	__put_user_x(2, __pu_val, ptr, __ret_pu); \
	269	break; \
	270	case 4: \
	271	__put_user_x(4, __pu_val, ptr, __ret_pu); \
	272	break; \
	273	case 8: \
	274	__put_user_x8(__pu_val, ptr, __ret_pu); \
	275	break; \
	276	default: \
	277	__put_user_x(X, __pu_val, ptr, __ret_pu); \
	278	break; \
	279	} \
	280	__ret_pu; \
	281	})
	282
dc70ddf4 GC	283	#define __put_user_size(x, ptr, size, retval, errret) \
	284	do { \
	285	retval = 0; \
	286	__chk_user_ptr(ptr); \
	287	switch (size) { \
	288	case 1: \
	289	__put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \
	290	break; \
	291	case 2: \
	292	__put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \
	293	break; \
	294	case 4: \
4d5d7838	295	__put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \
dc70ddf4 GC	296	break; \
dc70ddf4 GC	297	case 8: \
18114f61 HS	298	__put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \
18114f61 HS	299	errret); \
dc70ddf4 GC	300	break; \
	301	default: \
	302	__put_user_bad(); \
	303	} \
	304	} while (0)
	305
fe40c0af HS	306	#define __put_user_size_ex(x, ptr, size) \
	307	do { \
	308	__chk_user_ptr(ptr); \
	309	switch (size) { \
	310	case 1: \
	311	__put_user_asm_ex(x, ptr, "b", "b", "iq"); \
	312	break; \
	313	case 2: \
	314	__put_user_asm_ex(x, ptr, "w", "w", "ir"); \
	315	break; \
	316	case 4: \
	317	__put_user_asm_ex(x, ptr, "l", "k", "ir"); \
	318	break; \
	319	case 8: \
	320	__put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \
	321	break; \
	322	default: \
	323	__put_user_bad(); \
	324	} \
	325	} while (0)
	326
3f168221 GC	327	#ifdef CONFIG_X86_32
3f168221 GC	328	#define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad()
fe40c0af	329	#define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad()
3f168221 GC	330	#else
	331	#define __get_user_asm_u64(x, ptr, retval, errret) \
	332	__get_user_asm(x, ptr, retval, "q", "", "=r", errret)
fe40c0af HS	333	#define __get_user_asm_ex_u64(x, ptr) \
fe40c0af HS	334	__get_user_asm_ex(x, ptr, "q", "", "=r")
3f168221 GC	335	#endif
	336
	337	#define __get_user_size(x, ptr, size, retval, errret) \
	338	do { \
	339	retval = 0; \
	340	__chk_user_ptr(ptr); \
	341	switch (size) { \
	342	case 1: \
	343	__get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \
	344	break; \
	345	case 2: \
	346	__get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \
	347	break; \
	348	case 4: \
	349	__get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \
	350	break; \
	351	case 8: \
	352	__get_user_asm_u64(x, ptr, retval, errret); \
	353	break; \
	354	default: \
	355	(x) = __get_user_bad(); \
	356	} \
	357	} while (0)
	358
	359	#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
63bcff2a PA	360	asm volatile(ASM_STAC "\n" \
	361	"1: mov"itype" %2,%"rtype"1\n" \
	362	"2: " ASM_CLAC "\n" \
3f168221 GC	363	".section .fixup,\"ax\"\n" \
	364	"3: mov %3,%0\n" \
	365	" xor"itype" %"rtype"1,%"rtype"1\n" \
	366	" jmp 2b\n" \
	367	".previous\n" \
	368	_ASM_EXTABLE(1b, 3b) \
	369	: "=r" (err), ltype(x) \
	370	: "m" (__m(addr)), "i" (errret), "0" (err))
	371
fe40c0af HS	372	#define __get_user_size_ex(x, ptr, size) \
	373	do { \
	374	__chk_user_ptr(ptr); \
	375	switch (size) { \
	376	case 1: \
	377	__get_user_asm_ex(x, ptr, "b", "b", "=q"); \
	378	break; \
	379	case 2: \
	380	__get_user_asm_ex(x, ptr, "w", "w", "=r"); \
	381	break; \
	382	case 4: \
	383	__get_user_asm_ex(x, ptr, "l", "k", "=r"); \
	384	break; \
	385	case 8: \
	386	__get_user_asm_ex_u64(x, ptr); \
	387	break; \
	388	default: \
	389	(x) = __get_user_bad(); \
	390	} \
	391	} while (0)
	392
	393	#define __get_user_asm_ex(x, addr, itype, rtype, ltype) \
5e88353d PA	394	asm volatile("1: mov"itype" %1,%"rtype"0\n" \
5e88353d PA	395	"2:\n" \
535c0c34	396	_ASM_EXTABLE_EX(1b, 2b) \
fe40c0af HS	397	: ltype(x) : "m" (__m(addr)))
fe40c0af HS	398
dc70ddf4 GC	399	#define __put_user_nocheck(x, ptr, size) \
dc70ddf4 GC	400	({ \
16855f87	401	int __pu_err; \
dc70ddf4 GC	402	__put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
	403	__pu_err; \
	404	})
	405
3f168221 GC	406	#define __get_user_nocheck(x, ptr, size) \
3f168221 GC	407	({ \
16855f87	408	int __gu_err; \
3f168221 GC	409	unsigned long __gu_val; \
	410	__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
	411	(x) = (__force __typeof__(*(ptr)))__gu_val; \
	412	__gu_err; \
	413	})
dc70ddf4 GC	414
	415	/* FIXME: this hack is definitely wrong -AK */
	416	struct __large_struct { unsigned long buf[100]; };
	417	#define __m(x) ((struct __large_struct __user )(x))
	418
	419	/*
	420	* Tell gcc we read from memory instead of writing: this is because
	421	* we do not write to any memory gcc knows about, so there are no
	422	* aliasing issues.
	423	*/
	424	#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \
63bcff2a PA	425	asm volatile(ASM_STAC "\n" \
	426	"1: mov"itype" %"rtype"1,%2\n" \
	427	"2: " ASM_CLAC "\n" \
dc70ddf4 GC	428	".section .fixup,\"ax\"\n" \
	429	"3: mov %3,%0\n" \
	430	" jmp 2b\n" \
	431	".previous\n" \
	432	_ASM_EXTABLE(1b, 3b) \
	433	: "=r"(err) \
	434	: ltype(x), "m" (__m(addr)), "i" (errret), "0" (err))
fe40c0af HS	435
fe40c0af HS	436	#define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
5e88353d PA	437	asm volatile("1: mov"itype" %"rtype"0,%1\n" \
5e88353d PA	438	"2:\n" \
535c0c34	439	_ASM_EXTABLE_EX(1b, 2b) \
fe40c0af HS	440	: : ltype(x), "m" (__m(addr)))
	441
	442	/*
	443	* uaccess_try and catch
	444	*/
	445	#define uaccess_try do { \
fe40c0af	446	current_thread_info()->uaccess_err = 0; \
5e88353d	447	stac(); \
fe40c0af HS	448	barrier();
	449
	450	#define uaccess_catch(err) \
5e88353d	451	clac(); \
4fc34901	452	(err) \|= (current_thread_info()->uaccess_err ? -EFAULT : 0); \
fe40c0af HS	453	} while (0)
fe40c0af HS	454
8cb834e9 GC	455	/**
	456	* __get_user: - Get a simple variable from user space, with less checking.
	457	* @x: Variable to store result.
	458	* @ptr: Source address, in user space.
	459	*
	460	* Context: User context only. This function may sleep.
	461	*
	462	* This macro copies a single simple variable from user space to kernel
	463	* space. It supports simple types like char and int, but not larger
	464	* data types like structures or arrays.
	465	*
	466	* @ptr must have pointer-to-simple-variable type, and the result of
	467	* dereferencing @ptr must be assignable to @x without a cast.
	468	*
	469	* Caller must check the pointer with access_ok() before calling this
	470	* function.
	471	*
	472	* Returns zero on success, or -EFAULT on error.
	473	* On error, the variable @x is set to zero.
	474	*/
	475
	476	#define __get_user(x, ptr) \
	477	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
fe40c0af	478
8cb834e9 GC	479	/**
	480	* __put_user: - Write a simple value into user space, with less checking.
	481	* @x: Value to copy to user space.
	482	* @ptr: Destination address, in user space.
	483	*
	484	* Context: User context only. This function may sleep.
	485	*
	486	* This macro copies a single simple value from kernel space to user
	487	* space. It supports simple types like char and int, but not larger
	488	* data types like structures or arrays.
	489	*
	490	* @ptr must have pointer-to-simple-variable type, and @x must be assignable
	491	* to the result of dereferencing @ptr.
	492	*
	493	* Caller must check the pointer with access_ok() before calling this
	494	* function.
	495	*
	496	* Returns zero on success, or -EFAULT on error.
	497	*/
	498
	499	#define __put_user(x, ptr) \
	500	__put_user_nocheck((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
dc70ddf4	501
8cb834e9 GC	502	#define __get_user_unaligned __get_user
8cb834e9 GC	503	#define __put_user_unaligned __put_user
865e5b76	504
fe40c0af HS	505	/*
	506	* {get\|put}_user_try and catch
	507	*
	508	* get_user_try {
	509	* get_user_ex(...);
	510	* } get_user_catch(err)
	511	*/
	512	#define get_user_try uaccess_try
	513	#define get_user_catch(err) uaccess_catch(err)
fe40c0af HS	514
	515	#define get_user_ex(x, ptr) do { \
	516	unsigned long __gue_val; \
	517	__get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \
	518	(x) = (__force __typeof__(*(ptr)))__gue_val; \
	519	} while (0)
	520
019a1369 HS	521	#define put_user_try uaccess_try
	522	#define put_user_catch(err) uaccess_catch(err)
	523
fe40c0af HS	524	#define put_user_ex(x, ptr) \
	525	__put_user_size_ex((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
	526
1ac2e6ca RR	527	extern unsigned long
1ac2e6ca RR	528	copy_from_user_nmi(void to, const void __user from, unsigned long n);
92ae03f2 LT	529	extern __must_check long
92ae03f2 LT	530	strncpy_from_user(char dst, const char __user src, long count);
1ac2e6ca	531
5723aa99 LT	532	extern __must_check long strlen_user(const char __user *str);
	533	extern __must_check long strnlen_user(const char __user *str, long n);
	534
a052858f PA	535	unsigned long __must_check clear_user(void __user *mem, unsigned long len);
	536	unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
	537
8bc7de0c GC	538	/*
	539	* movsl can be slow when source and dest are not both 8-byte aligned
	540	*/
	541	#ifdef CONFIG_X86_INTEL_USERCOPY
	542	extern struct movsl_mask {
	543	int mask;
	544	} ____cacheline_aligned_in_smp movsl_mask;
	545	#endif
	546
22cac167 GC	547	#define ARCH_HAS_NOCACHE_UACCESS 1
22cac167 GC	548
96a388de	549	#ifdef CONFIG_X86_32
a1ce3928	550	# include <asm/uaccess_32.h>
96a388de	551	#else
a1ce3928	552	# include <asm/uaccess_64.h>
96a388de	553	#endif
ca233862	554
1965aae3	555	#endif /* _ASM_X86_UACCESS_H */
8174c430	556