8cb834e99f
We also carry the unaligned version with us. Only x86_64 uses it, but there's no problem in defining it. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
229 lines
6.7 KiB
C
229 lines
6.7 KiB
C
#ifndef __i386_UACCESS_H
|
|
#define __i386_UACCESS_H
|
|
|
|
/*
|
|
* User space memory access functions
|
|
*/
|
|
#include <linux/errno.h>
|
|
#include <linux/thread_info.h>
|
|
#include <linux/prefetch.h>
|
|
#include <linux/string.h>
|
|
#include <asm/asm.h>
|
|
#include <asm/page.h>
|
|
|
|
/*
|
|
* 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
|
|
|
|
unsigned long __must_check __copy_to_user_ll
|
|
(void __user *to, const void *from, unsigned long n);
|
|
unsigned long __must_check __copy_from_user_ll
|
|
(void *to, const void __user *from, unsigned long n);
|
|
unsigned long __must_check __copy_from_user_ll_nozero
|
|
(void *to, const void __user *from, unsigned long n);
|
|
unsigned long __must_check __copy_from_user_ll_nocache
|
|
(void *to, const void __user *from, unsigned long n);
|
|
unsigned long __must_check __copy_from_user_ll_nocache_nozero
|
|
(void *to, const void __user *from, unsigned long n);
|
|
|
|
/**
|
|
* __copy_to_user_inatomic: - 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.
|
|
*
|
|
* Copy data from kernel space to user space. Caller must check
|
|
* the specified block with access_ok() before calling this function.
|
|
* The caller should also make sure he pins the user space address
|
|
* so that the we don't result in page fault and sleep.
|
|
*
|
|
* Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault
|
|
* we return the initial request size (1, 2 or 4), as copy_*_user should do.
|
|
* If a store crosses a page boundary and gets a fault, the x86 will not write
|
|
* anything, so this is accurate.
|
|
*/
|
|
|
|
static __always_inline unsigned long __must_check
|
|
__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
|
|
{
|
|
if (__builtin_constant_p(n)) {
|
|
unsigned long ret;
|
|
|
|
switch (n) {
|
|
case 1:
|
|
__put_user_size(*(u8 *)from, (u8 __user *)to,
|
|
1, ret, 1);
|
|
return ret;
|
|
case 2:
|
|
__put_user_size(*(u16 *)from, (u16 __user *)to,
|
|
2, ret, 2);
|
|
return ret;
|
|
case 4:
|
|
__put_user_size(*(u32 *)from, (u32 __user *)to,
|
|
4, ret, 4);
|
|
return ret;
|
|
}
|
|
}
|
|
return __copy_to_user_ll(to, from, n);
|
|
}
|
|
|
|
/**
|
|
* __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.
|
|
*/
|
|
static __always_inline unsigned long __must_check
|
|
__copy_to_user(void __user *to, const void *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
return __copy_to_user_inatomic(to, from, n);
|
|
}
|
|
|
|
static __always_inline unsigned long
|
|
__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
|
|
{
|
|
/* Avoid zeroing the tail if the copy fails..
|
|
* If 'n' is constant and 1, 2, or 4, we do still zero on a failure,
|
|
* but as the zeroing behaviour is only significant when n is not
|
|
* constant, that shouldn't be a problem.
|
|
*/
|
|
if (__builtin_constant_p(n)) {
|
|
unsigned long ret;
|
|
|
|
switch (n) {
|
|
case 1:
|
|
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
|
return ret;
|
|
case 2:
|
|
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
|
return ret;
|
|
case 4:
|
|
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
|
return ret;
|
|
}
|
|
}
|
|
return __copy_from_user_ll_nozero(to, from, n);
|
|
}
|
|
|
|
/**
|
|
* __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.
|
|
*
|
|
* An alternate version - __copy_from_user_inatomic() - may be called from
|
|
* atomic context and will fail rather than sleep. In this case the
|
|
* uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h
|
|
* for explanation of why this is needed.
|
|
*/
|
|
static __always_inline unsigned long
|
|
__copy_from_user(void *to, const void __user *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
if (__builtin_constant_p(n)) {
|
|
unsigned long ret;
|
|
|
|
switch (n) {
|
|
case 1:
|
|
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
|
return ret;
|
|
case 2:
|
|
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
|
return ret;
|
|
case 4:
|
|
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
|
return ret;
|
|
}
|
|
}
|
|
return __copy_from_user_ll(to, from, n);
|
|
}
|
|
|
|
#define ARCH_HAS_NOCACHE_UACCESS
|
|
|
|
static __always_inline unsigned long __copy_from_user_nocache(void *to,
|
|
const void __user *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
if (__builtin_constant_p(n)) {
|
|
unsigned long ret;
|
|
|
|
switch (n) {
|
|
case 1:
|
|
__get_user_size(*(u8 *)to, from, 1, ret, 1);
|
|
return ret;
|
|
case 2:
|
|
__get_user_size(*(u16 *)to, from, 2, ret, 2);
|
|
return ret;
|
|
case 4:
|
|
__get_user_size(*(u32 *)to, from, 4, ret, 4);
|
|
return ret;
|
|
}
|
|
}
|
|
return __copy_from_user_ll_nocache(to, from, n);
|
|
}
|
|
|
|
static __always_inline unsigned long
|
|
__copy_from_user_inatomic_nocache(void *to, const void __user *from,
|
|
unsigned long n)
|
|
{
|
|
return __copy_from_user_ll_nocache_nozero(to, from, n);
|
|
}
|
|
|
|
unsigned long __must_check copy_to_user(void __user *to,
|
|
const void *from, unsigned long n);
|
|
unsigned long __must_check copy_from_user(void *to,
|
|
const void __user *from,
|
|
unsigned long n);
|
|
long __must_check strncpy_from_user(char *dst, const char __user *src,
|
|
long count);
|
|
long __must_check __strncpy_from_user(char *dst,
|
|
const char __user *src, long count);
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
#define strlen_user(str) strnlen_user(str, LONG_MAX)
|
|
|
|
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);
|
|
|
|
#endif /* __i386_UACCESS_H */
|