326 строки
7.0 KiB
C
326 строки
7.0 KiB
C
#ifndef __ASM_GENERIC_UACCESS_H
|
|
#define __ASM_GENERIC_UACCESS_H
|
|
|
|
/*
|
|
* User space memory access functions, these should work
|
|
* on a ny machine that has kernel and user data in the same
|
|
* address space, e.g. all NOMMU machines.
|
|
*/
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/string.h>
|
|
|
|
#include <asm/segment.h>
|
|
|
|
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
|
|
|
|
#ifndef KERNEL_DS
|
|
#define KERNEL_DS MAKE_MM_SEG(~0UL)
|
|
#endif
|
|
|
|
#ifndef USER_DS
|
|
#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
|
|
#endif
|
|
|
|
#ifndef get_fs
|
|
#define get_ds() (KERNEL_DS)
|
|
#define get_fs() (current_thread_info()->addr_limit)
|
|
|
|
static inline void set_fs(mm_segment_t fs)
|
|
{
|
|
current_thread_info()->addr_limit = fs;
|
|
}
|
|
#endif
|
|
|
|
#define segment_eq(a, b) ((a).seg == (b).seg)
|
|
|
|
#define VERIFY_READ 0
|
|
#define VERIFY_WRITE 1
|
|
|
|
#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
|
|
|
|
/*
|
|
* The architecture should really override this if possible, at least
|
|
* doing a check on the get_fs()
|
|
*/
|
|
#ifndef __access_ok
|
|
static inline int __access_ok(unsigned long addr, unsigned long size)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* The exception table consists of pairs of addresses: 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
|
|
{
|
|
unsigned long insn, fixup;
|
|
};
|
|
|
|
/* Returns 0 if exception not found and fixup otherwise. */
|
|
extern unsigned long search_exception_table(unsigned long);
|
|
|
|
/*
|
|
* architectures with an MMU should override these two
|
|
*/
|
|
#ifndef __copy_from_user
|
|
static inline __must_check long __copy_from_user(void *to,
|
|
const void __user * from, unsigned long n)
|
|
{
|
|
if (__builtin_constant_p(n)) {
|
|
switch(n) {
|
|
case 1:
|
|
*(u8 *)to = *(u8 __force *)from;
|
|
return 0;
|
|
case 2:
|
|
*(u16 *)to = *(u16 __force *)from;
|
|
return 0;
|
|
case 4:
|
|
*(u32 *)to = *(u32 __force *)from;
|
|
return 0;
|
|
#ifdef CONFIG_64BIT
|
|
case 8:
|
|
*(u64 *)to = *(u64 __force *)from;
|
|
return 0;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
memcpy(to, (const void __force *)from, n);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __copy_to_user
|
|
static inline __must_check long __copy_to_user(void __user *to,
|
|
const void *from, unsigned long n)
|
|
{
|
|
if (__builtin_constant_p(n)) {
|
|
switch(n) {
|
|
case 1:
|
|
*(u8 __force *)to = *(u8 *)from;
|
|
return 0;
|
|
case 2:
|
|
*(u16 __force *)to = *(u16 *)from;
|
|
return 0;
|
|
case 4:
|
|
*(u32 __force *)to = *(u32 *)from;
|
|
return 0;
|
|
#ifdef CONFIG_64BIT
|
|
case 8:
|
|
*(u64 __force *)to = *(u64 *)from;
|
|
return 0;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
memcpy((void __force *)to, from, n);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* These are the main single-value transfer routines. They automatically
|
|
* use the right size if we just have the right pointer type.
|
|
* This version just falls back to copy_{from,to}_user, which should
|
|
* provide a fast-path for small values.
|
|
*/
|
|
#define __put_user(x, ptr) \
|
|
({ \
|
|
__typeof__(*(ptr)) __x = (x); \
|
|
int __pu_err = -EFAULT; \
|
|
__chk_user_ptr(ptr); \
|
|
switch (sizeof (*(ptr))) { \
|
|
case 1: \
|
|
case 2: \
|
|
case 4: \
|
|
case 8: \
|
|
__pu_err = __put_user_fn(sizeof (*(ptr)), \
|
|
ptr, &__x); \
|
|
break; \
|
|
default: \
|
|
__put_user_bad(); \
|
|
break; \
|
|
} \
|
|
__pu_err; \
|
|
})
|
|
|
|
#define put_user(x, ptr) \
|
|
({ \
|
|
might_sleep(); \
|
|
__access_ok(ptr, sizeof (*ptr)) ? \
|
|
__put_user(x, ptr) : \
|
|
-EFAULT; \
|
|
})
|
|
|
|
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
|
|
{
|
|
size = __copy_to_user(ptr, x, size);
|
|
return size ? -EFAULT : size;
|
|
}
|
|
|
|
extern int __put_user_bad(void) __attribute__((noreturn));
|
|
|
|
#define __get_user(x, ptr) \
|
|
({ \
|
|
int __gu_err = -EFAULT; \
|
|
__chk_user_ptr(ptr); \
|
|
switch (sizeof(*(ptr))) { \
|
|
case 1: { \
|
|
unsigned char __x; \
|
|
__gu_err = __get_user_fn(sizeof (*(ptr)), \
|
|
ptr, &__x); \
|
|
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
|
|
break; \
|
|
}; \
|
|
case 2: { \
|
|
unsigned short __x; \
|
|
__gu_err = __get_user_fn(sizeof (*(ptr)), \
|
|
ptr, &__x); \
|
|
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
|
|
break; \
|
|
}; \
|
|
case 4: { \
|
|
unsigned int __x; \
|
|
__gu_err = __get_user_fn(sizeof (*(ptr)), \
|
|
ptr, &__x); \
|
|
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
|
|
break; \
|
|
}; \
|
|
case 8: { \
|
|
unsigned long long __x; \
|
|
__gu_err = __get_user_fn(sizeof (*(ptr)), \
|
|
ptr, &__x); \
|
|
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
|
|
break; \
|
|
}; \
|
|
default: \
|
|
__get_user_bad(); \
|
|
break; \
|
|
} \
|
|
__gu_err; \
|
|
})
|
|
|
|
#define get_user(x, ptr) \
|
|
({ \
|
|
might_sleep(); \
|
|
__access_ok(ptr, sizeof (*ptr)) ? \
|
|
__get_user(x, ptr) : \
|
|
-EFAULT; \
|
|
})
|
|
|
|
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
|
|
{
|
|
size = __copy_from_user(x, ptr, size);
|
|
return size ? -EFAULT : size;
|
|
}
|
|
|
|
extern int __get_user_bad(void) __attribute__((noreturn));
|
|
|
|
#ifndef __copy_from_user_inatomic
|
|
#define __copy_from_user_inatomic __copy_from_user
|
|
#endif
|
|
|
|
#ifndef __copy_to_user_inatomic
|
|
#define __copy_to_user_inatomic __copy_to_user
|
|
#endif
|
|
|
|
static inline long copy_from_user(void *to,
|
|
const void __user * from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
if (__access_ok(from, n))
|
|
return __copy_from_user(to, from, n);
|
|
else
|
|
return n;
|
|
}
|
|
|
|
static inline long copy_to_user(void __user *to,
|
|
const void *from, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
if (__access_ok(to, n))
|
|
return __copy_to_user(to, from, n);
|
|
else
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
* Copy a null terminated string from userspace.
|
|
*/
|
|
#ifndef __strncpy_from_user
|
|
static inline long
|
|
__strncpy_from_user(char *dst, const char __user *src, long count)
|
|
{
|
|
char *tmp;
|
|
strncpy(dst, (const char __force *)src, count);
|
|
for (tmp = dst; *tmp && count > 0; tmp++, count--)
|
|
;
|
|
return (tmp - dst);
|
|
}
|
|
#endif
|
|
|
|
static inline long
|
|
strncpy_from_user(char *dst, const char __user *src, long count)
|
|
{
|
|
if (!__access_ok(src, 1))
|
|
return -EFAULT;
|
|
return __strncpy_from_user(dst, src, count);
|
|
}
|
|
|
|
/*
|
|
* Return the size of a string (including the ending 0)
|
|
*
|
|
* Return 0 on exception, a value greater than N if too long
|
|
*/
|
|
#ifndef strnlen_user
|
|
static inline long strnlen_user(const char __user *src, long n)
|
|
{
|
|
return strlen((void * __force)src) + 1;
|
|
}
|
|
#endif
|
|
|
|
static inline long strlen_user(const char __user *src)
|
|
{
|
|
return strnlen_user(src, 32767);
|
|
}
|
|
|
|
/*
|
|
* Zero Userspace
|
|
*/
|
|
#ifndef __clear_user
|
|
static inline __must_check unsigned long
|
|
__clear_user(void __user *to, unsigned long n)
|
|
{
|
|
memset((void __force *)to, 0, n);
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static inline __must_check unsigned long
|
|
clear_user(void __user *to, unsigned long n)
|
|
{
|
|
might_sleep();
|
|
if (!__access_ok(to, n))
|
|
return n;
|
|
|
|
return __clear_user(to, n);
|
|
}
|
|
|
|
#endif /* __ASM_GENERIC_UACCESS_H */
|