1c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifndef __i386_UACCESS_H
2c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __i386_UACCESS_H
3c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
4c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
5c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * User space memory access functions
6c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
7c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/errno.h>
8c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/thread_info.h>
9c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/prefetch.h>
10c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <linux/string.h>
11c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#include <asm/page.h>
12c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
13c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define VERIFY_READ 0
14c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define VERIFY_WRITE 1
15c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
16c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
17c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The fs value determines whether argument validity checking should be
18c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * performed or not.  If get_fs() == USER_DS, checking is performed, with
19c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * get_fs() == KERNEL_DS, checking is bypassed.
20c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
21c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * For historical reasons, these macros are grossly misnamed.
22c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
23c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
24c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })
25c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
26c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
27c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFFUL)
28c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)
29c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
30c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define get_ds()	(KERNEL_DS)
31c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define get_fs()	(current_thread_info()->addr_limit)
32c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define set_fs(x)	(current_thread_info()->addr_limit = (x))
33c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
34c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define segment_eq(a,b)	((a).seg == (b).seg)
35c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
36c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
37c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * movsl can be slow when source and dest are not both 8-byte aligned
38c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
39c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef CONFIG_X86_INTEL_USERCOPY
40c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern struct movsl_mask {
41c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	int mask;
42c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} ____cacheline_aligned_in_smp movsl_mask;
43c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif
44c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
45c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __addr_ok(addr) ((unsigned long __force)(addr) < (current_thread_info()->addr_limit.seg))
46c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
47c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
48c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Test whether a block of memory is a valid user space address.
49c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns 0 if the range is valid, nonzero otherwise.
50c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
51c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This is equivalent to the following test:
52c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
53c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
54c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This needs 33-bit arithmetic. We have a carry...
55c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
56c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __range_ok(addr,size) ({ \
57c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	unsigned long flag,roksum; \
58c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__chk_user_ptr(addr); \
59c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \
60c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		:"=&r" (flag), "=r" (roksum) \
61c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		:"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \
62c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	flag; })
63c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
64c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
65c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * access_ok: - Checks if a user space pointer is valid
66c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
67c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
68c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *        to write to a block, it is always safe to read from it.
69c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @addr: User space pointer to start of block to check
70c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @size: Size of block to check
71c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
72c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
73c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
74c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Checks if a pointer to a block of memory in user space is valid.
75c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
76c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns true (nonzero) if the memory block may be valid, false (zero)
77c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * if it is definitely invalid.
78c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
79c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Note that, depending on architecture, this function probably just
80c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * checks that the pointer is in the user space range - after calling
81c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * this function, memory access functions may still return -EFAULT.
82c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
83c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
84c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
85c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
86c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The exception table consists of pairs of addresses: the first is the
87c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * address of an instruction that is allowed to fault, and the second is
88c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * the address at which the program should continue.  No registers are
89c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * modified, so it is entirely up to the continuation code to figure out
90c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * what to do.
91c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
92c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * All the routines below use bits of fixup code that are out of line
93c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * with the main instruction path.  This means when everything is well,
94c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * we don't even have to jump over them.  Further, they do not intrude
95c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * on our cache or tlb entries.
96c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
97c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
98c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct exception_table_entry
99c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
100c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	unsigned long insn, fixup;
101c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru};
102c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
103c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern int fixup_exception(struct pt_regs *regs);
104c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
105c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
106c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * These are the main single-value transfer routines.  They automatically
107c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * use the right size if we just have the right pointer type.
108c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
109c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This gets kind of ugly. We want to return _two_ values in "get_user()"
110c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * and yet we don't want to do any pointers, because that is too much
111c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * of a performance impact. Thus we have a few rather ugly macros here,
112c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * and hide all the ugliness from the user.
113c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
114c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The "__xxx" versions of the user access functions are versions that
115c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * do not verify the address space, that must have been done previously
116c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * with a separate "access_ok()" call (this is used when we do multiple
117c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * accesses to the same area of user memory).
118c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
119c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
120c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __get_user_1(void);
121c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __get_user_2(void);
122c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __get_user_4(void);
123c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
124c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __get_user_x(size,ret,x,ptr) \
125c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__asm__ __volatile__("call __get_user_" #size \
126c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		:"=a" (ret),"=d" (x) \
127c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		:"0" (ptr))
128c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
129c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
130c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/* Careful: we have to cast the result to the type of the pointer for sign reasons */
131c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
132c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * get_user: - Get a simple variable from user space.
133c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @x:   Variable to store result.
134c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr: Source address, in user space.
135c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
136c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
137c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
138c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This macro copies a single simple variable from user space to kernel
139c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * space.  It supports simple types like char and int, but not larger
140c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * data types like structures or arrays.
141c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
142c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr must have pointer-to-simple-variable type, and the result of
143c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * dereferencing @ptr must be assignable to @x without a cast.
144c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
145c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns zero on success, or -EFAULT on error.
146c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * On error, the variable @x is set to zero.
147c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
148c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define get_user(x,ptr)							\
149c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru({	int __ret_gu;							\
150c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	unsigned long __val_gu;						\
151c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__chk_user_ptr(ptr);						\
152c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	switch(sizeof (*(ptr))) {					\
153c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 1:  __get_user_x(1,__ret_gu,__val_gu,ptr); break;		\
154c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 2:  __get_user_x(2,__ret_gu,__val_gu,ptr); break;		\
155c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 4:  __get_user_x(4,__ret_gu,__val_gu,ptr); break;		\
156c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	default: __get_user_x(X,__ret_gu,__val_gu,ptr); break;		\
157c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}								\
158c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	(x) = (__typeof__(*(ptr)))__val_gu;				\
159c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__ret_gu;							\
160c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru})
161c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
162c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __put_user_bad(void);
163c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
164c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
165c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Strange magic calling convention: pointer in %ecx,
166c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * value in %eax(:%edx), return value in %eax, no clobbers.
167c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
168c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __put_user_1(void);
169c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __put_user_2(void);
170c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __put_user_4(void);
171c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern void __put_user_8(void);
172c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
173c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
174c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
175c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr))
176c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr))
177c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr))
178c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
179c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
180c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * put_user: - Write a simple value into user space.
181c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @x:   Value to copy to user space.
182c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr: Destination address, in user space.
183c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
184c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
185c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
186c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This macro copies a single simple value from kernel space to user
187c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * space.  It supports simple types like char and int, but not larger
188c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * data types like structures or arrays.
189c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
190c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr must have pointer-to-simple-variable type, and @x must be assignable
191c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * to the result of dereferencing @ptr.
192c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
193c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns zero on success, or -EFAULT on error.
194c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
195c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef CONFIG_X86_WP_WORKS_OK
196c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
197c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define put_user(x,ptr)						\
198c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru({	int __ret_pu;						\
199c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__typeof__(*(ptr)) __pu_val;				\
200c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__chk_user_ptr(ptr);					\
201c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__pu_val = x;						\
202c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	switch(sizeof(*(ptr))) {				\
203c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 1: __put_user_1(__pu_val, ptr); break;		\
204c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 2: __put_user_2(__pu_val, ptr); break;		\
205c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 4: __put_user_4(__pu_val, ptr); break;		\
206c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 8: __put_user_8(__pu_val, ptr); break;		\
207c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	default:__put_user_X(__pu_val, ptr); break;		\
208c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}							\
209c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__ret_pu;						\
210c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru})
211c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
212c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#else
213c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define put_user(x,ptr)						\
214c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru({								\
215c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 	int __ret_pu;						\
216c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__typeof__(*(ptr)) __pus_tmp = x;			\
217c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__ret_pu=0;						\
218c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp,		\
219c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				sizeof(*(ptr))) != 0))		\
220c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 		__ret_pu=-EFAULT;				\
221c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru 	__ret_pu;						\
222c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru })
223c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
224c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
225c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif
226c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
227c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
228c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * __get_user: - Get a simple variable from user space, with less checking.
229c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @x:   Variable to store result.
230c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr: Source address, in user space.
231c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
232c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
233c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
234c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This macro copies a single simple variable from user space to kernel
235c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * space.  It supports simple types like char and int, but not larger
236c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * data types like structures or arrays.
237c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
238c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr must have pointer-to-simple-variable type, and the result of
239c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * dereferencing @ptr must be assignable to @x without a cast.
240c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
241c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Caller must check the pointer with access_ok() before calling this
242c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * function.
243c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
244c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns zero on success, or -EFAULT on error.
245c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * On error, the variable @x is set to zero.
246c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
247c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __get_user(x,ptr) \
248c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru  __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
249c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
250c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
251c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
252c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * __put_user: - Write a simple value into user space, with less checking.
253c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @x:   Value to copy to user space.
254c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr: Destination address, in user space.
255c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
256c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
257c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
258c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * This macro copies a single simple value from kernel space to user
259c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * space.  It supports simple types like char and int, but not larger
260c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * data types like structures or arrays.
261c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
262c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @ptr must have pointer-to-simple-variable type, and @x must be assignable
263c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * to the result of dereferencing @ptr.
264c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
265c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Caller must check the pointer with access_ok() before calling this
266c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * function.
267c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
268c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns zero on success, or -EFAULT on error.
269c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
270c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user(x,ptr) \
271c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru  __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
272c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
273c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_nocheck(x,ptr,size)				\
274c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru({								\
275c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	long __pu_err;						\
276c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__put_user_size((x),(ptr),(size),__pu_err,-EFAULT);	\
277c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__pu_err;						\
278c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru})
279c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
280c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
281c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_u64(x, addr, err)				\
282c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__asm__ __volatile__(					\
283c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"1:	movl %%eax,0(%2)\n"			\
284c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"2:	movl %%edx,4(%2)\n"			\
285c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"3:\n"						\
286c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section .fixup,\"ax\"\n"			\
287c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"4:	movl %3,%0\n"				\
288c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	jmp 3b\n"				\
289c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous\n"					\
290c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section __ex_table,\"a\"\n"			\
291c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.align 4\n"				\
292c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.long 1b,4b\n"				\
293c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.long 2b,4b\n"				\
294c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous"					\
295c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: "=r"(err)					\
296c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: "A" (x), "r" (addr), "i"(-EFAULT), "0"(err))
297c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
298c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#ifdef CONFIG_X86_WP_WORKS_OK
299c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
300c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_size(x,ptr,size,retval,errret)			\
301c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querudo {									\
302c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	retval = 0;							\
303c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__chk_user_ptr(ptr);						\
304c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	switch (size) {							\
305c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 1: __put_user_asm(x,ptr,retval,"b","b","iq",errret);break;	\
306c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 2: __put_user_asm(x,ptr,retval,"w","w","ir",errret);break; \
307c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 4: __put_user_asm(x,ptr,retval,"l","","ir",errret); break;	\
308c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
309c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	  default: __put_user_bad();					\
310c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}								\
311c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} while (0)
312c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
313c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#else
314c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
315c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_size(x,ptr,size,retval,errret)			\
316c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querudo {									\
317c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__typeof__(*(ptr)) __pus_tmp = x;				\
318c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	retval = 0;							\
319c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru									\
320c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0))	\
321c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		retval = errret;					\
322c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} while (0)
323c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
324c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif
325c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustruct __large_struct { unsigned long buf[100]; };
326c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __m(x) (*(struct __large_struct __user *)(x))
327c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
328c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/*
329c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Tell gcc we read from memory instead of writing: this is because
330c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * we do not write to any memory gcc knows about, so there are no
331c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * aliasing issues.
332c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
333c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret)	\
334c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__asm__ __volatile__(						\
335c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"1:	mov"itype" %"rtype"1,%2\n"			\
336c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"2:\n"							\
337c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section .fixup,\"ax\"\n"				\
338c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"3:	movl %3,%0\n"					\
339c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	jmp 2b\n"					\
340c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous\n"						\
341c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section __ex_table,\"a\"\n"				\
342c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.align 4\n"					\
343c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.long 1b,3b\n"					\
344c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous"						\
345c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: "=r"(err)						\
346c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: ltype (x), "m"(__m(addr)), "i"(errret), "0"(err))
347c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
348c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
349c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __get_user_nocheck(x,ptr,size)				\
350c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru({								\
351c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	long __gu_err;						\
352c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	unsigned long __gu_val;					\
353c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\
354c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	(x) = (__typeof__(*(ptr)))__gu_val;			\
355c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__gu_err;						\
356c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru})
357c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
358c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruextern long __get_user_bad(void);
359c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
360c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __get_user_size(x,ptr,size,retval,errret)			\
361c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querudo {									\
362c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	retval = 0;							\
363c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__chk_user_ptr(ptr);						\
364c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	switch (size) {							\
365c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 1: __get_user_asm(x,ptr,retval,"b","b","=q",errret);break;	\
366c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 2: __get_user_asm(x,ptr,retval,"w","w","=r",errret);break;	\
367c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	case 4: __get_user_asm(x,ptr,retval,"l","","=r",errret);break;	\
368c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	default: (x) = __get_user_bad();				\
369c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}								\
370c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru} while (0)
371c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
372c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret)	\
373c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	__asm__ __volatile__(						\
374c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"1:	mov"itype" %2,%"rtype"1\n"			\
375c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"2:\n"							\
376c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section .fixup,\"ax\"\n"				\
377c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"3:	movl %3,%0\n"					\
378c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	xor"itype" %"rtype"1,%"rtype"1\n"		\
379c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	jmp 2b\n"					\
380c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous\n"						\
381c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".section __ex_table,\"a\"\n"				\
382c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.align 4\n"					\
383c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		"	.long 1b,3b\n"					\
384c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		".previous"						\
385c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: "=r"(err), ltype (x)					\
386c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		: "m"(__m(addr)), "i"(errret), "0"(err))
387c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
388c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
389c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __copy_to_user_ll(void __user *to,
390c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void *from, unsigned long n);
391c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __copy_from_user_ll(void *to,
392c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n);
393c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __copy_from_user_ll_nozero(void *to,
394c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n);
395c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __copy_from_user_ll_nocache(void *to,
396c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n);
397c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to,
398c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n);
399c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
400c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
401c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking.
402c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @to:   Destination address, in user space.
403c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @from: Source address, in kernel space.
404c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @n:    Number of bytes to copy.
405c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
406c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.
407c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
408c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Copy data from kernel space to user space.  Caller must check
409c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * the specified block with access_ok() before calling this function.
410c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * The caller should also make sure he pins the user space address
411c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * so that the we don't result in page fault and sleep.
412c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
413c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
414c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * we return the initial request size (1, 2 or 4), as copy_*_user should do.
415c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * If a store crosses a page boundary and gets a fault, the x86 will not write
416c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * anything, so this is accurate.
417c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
418c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
419c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long __must_check
420c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
421c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
422c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if (__builtin_constant_p(n)) {
423c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		unsigned long ret;
424c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
425c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		switch (n) {
426c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 1:
427c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1);
428c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
429c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 2:
430c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2);
431c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
432c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 4:
433c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4);
434c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
435c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		}
436c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}
437c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	return __copy_to_user_ll(to, from, n);
438c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
439c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
440c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
441c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * __copy_to_user: - Copy a block of data into user space, with less checking.
442c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @to:   Destination address, in user space.
443c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @from: Source address, in kernel space.
444c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @n:    Number of bytes to copy.
445c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
446c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
447c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
448c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Copy data from kernel space to user space.  Caller must check
449c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * the specified block with access_ok() before calling this function.
450c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
451c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns number of bytes that could not be copied.
452c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * On success, this will be zero.
453c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
454c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long __must_check
455c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru__copy_to_user(void __user *to, const void *from, unsigned long n)
456c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
457c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru       might_sleep();
458c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru       return __copy_to_user_inatomic(to, from, n);
459c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
460c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
461c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long
462c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
463c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
464c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	/* Avoid zeroing the tail if the copy fails..
465c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	 * If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
466c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	 * but as the zeroing behaviour is only significant when n is not
467c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	 * constant, that shouldn't be a problem.
468c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	 */
469c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if (__builtin_constant_p(n)) {
470c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		unsigned long ret;
471c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
472c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		switch (n) {
473c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 1:
474c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u8 *)to, from, 1, ret, 1);
475c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
476c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 2:
477c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u16 *)to, from, 2, ret, 2);
478c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
479c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 4:
480c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u32 *)to, from, 4, ret, 4);
481c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
482c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		}
483c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}
484c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	return __copy_from_user_ll_nozero(to, from, n);
485c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
486c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
487c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
488c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * __copy_from_user: - Copy a block of data from user space, with less checking.
489c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @to:   Destination address, in kernel space.
490c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @from: Source address, in user space.
491c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @n:    Number of bytes to copy.
492c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
493c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
494c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
495c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Copy data from user space to kernel space.  Caller must check
496c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * the specified block with access_ok() before calling this function.
497c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
498c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns number of bytes that could not be copied.
499c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * On success, this will be zero.
500c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
501c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * If some data could not be copied, this function will pad the copied
502c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * data to the requested size using zero bytes.
503c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
504c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * An alternate version - __copy_from_user_inatomic() - may be called from
505c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * atomic context and will fail rather than sleep.  In this case the
506c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * uncopied bytes will *NOT* be padded with zeros.  See fs/filemap.h
507c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * for explanation of why this is needed.
508c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
509c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long
510c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru__copy_from_user(void *to, const void __user *from, unsigned long n)
511c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
512c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	might_sleep();
513c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if (__builtin_constant_p(n)) {
514c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		unsigned long ret;
515c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
516c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		switch (n) {
517c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 1:
518c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u8 *)to, from, 1, ret, 1);
519c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
520c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 2:
521c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u16 *)to, from, 2, ret, 2);
522c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
523c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 4:
524c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u32 *)to, from, 4, ret, 4);
525c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
526c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		}
527c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}
528c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	return __copy_from_user_ll(to, from, n);
529c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
530c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
531c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define ARCH_HAS_NOCACHE_UACCESS
532c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
533c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long __copy_from_user_nocache(void *to,
534c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n)
535c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
536c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	might_sleep();
537c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	if (__builtin_constant_p(n)) {
538c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		unsigned long ret;
539c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
540c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		switch (n) {
541c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 1:
542c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u8 *)to, from, 1, ret, 1);
543c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
544c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 2:
545c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u16 *)to, from, 2, ret, 2);
546c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
547c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		case 4:
548c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			__get_user_size(*(u32 *)to, from, 4, ret, 4);
549c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru			return ret;
550c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru		}
551c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	}
552c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru	return __copy_from_user_ll_nocache(to, from, n);
553c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
554c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
555c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querustatic __always_inline unsigned long
556c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru__copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n)
557c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru{
558c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru       return __copy_from_user_ll_nocache_nozero(to, from, n);
559c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru}
560c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
561c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check copy_to_user(void __user *to,
562c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void *from, unsigned long n);
563c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check copy_from_user(void *to,
564c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const void __user *from, unsigned long n);
565c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querulong __must_check strncpy_from_user(char *dst, const char __user *src,
566c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				long count);
567c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querulong __must_check __strncpy_from_user(char *dst,
568c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru				const char __user *src, long count);
569c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
570c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru/**
571c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * strlen_user: - Get the size of a string in user space.
572c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * @str: The string to measure.
573c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
574c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Context: User context only.  This function may sleep.
575c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
576c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Get the size of a NUL-terminated string in user space.
577c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
578c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * Returns the size of the string INCLUDING the terminating NUL.
579c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * On exception, returns 0.
580c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru *
581c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * If there is a limit on the length of a valid string, you may wish to
582c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru * consider using strnlen_user() instead.
583c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru */
584c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#define strlen_user(str) strnlen_user(str, LONG_MAX)
585c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
586c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Querulong strnlen_user(const char __user *str, long n);
587c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check clear_user(void __user *mem, unsigned long len);
588c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queruunsigned long __must_check __clear_user(void __user *mem, unsigned long len);
589c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru
590c559cd81139f97cecad1ad91a0b2e25a5936d53Jean-Baptiste Queru#endif /* __i386_UACCESS_H */
591