426 строки
12 KiB
C
426 строки
12 KiB
C
#ifndef __SCORE_UACCESS_H
|
|
#define __SCORE_UACCESS_H
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/thread_info.h>
|
|
#include <asm/extable.h>
|
|
|
|
#define VERIFY_READ 0
|
|
#define VERIFY_WRITE 1
|
|
|
|
#define get_ds() (KERNEL_DS)
|
|
#define get_fs() (current_thread_info()->addr_limit)
|
|
#define segment_eq(a, b) ((a).seg == (b).seg)
|
|
|
|
/*
|
|
* Is a address valid? This does a straighforward calculation rather
|
|
* than tests.
|
|
*
|
|
* Address valid if:
|
|
* - "addr" doesn't have any high-bits set
|
|
* - AND "size" doesn't have any high-bits set
|
|
* - AND "addr+size" doesn't have any high-bits set
|
|
* - OR we are in kernel mode.
|
|
*
|
|
* __ua_size() is a trick to avoid runtime checking of positive constant
|
|
* sizes; for those we already know at compile time that the size is ok.
|
|
*/
|
|
#define __ua_size(size) \
|
|
((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
|
|
|
|
/*
|
|
* access_ok: - Checks if a user space pointer is valid
|
|
* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
|
|
* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
|
|
* to write to a block, it is always safe to read from it.
|
|
* @addr: User space pointer to start of block to check
|
|
* @size: Size of block to check
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* 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(addr, size) \
|
|
(((long)((get_fs().seg) & \
|
|
((addr) | ((addr) + (size)) | \
|
|
__ua_size(size)))) == 0)
|
|
|
|
#define access_ok(type, addr, size) \
|
|
likely(__access_ok((unsigned long)(addr), (size)))
|
|
|
|
/*
|
|
* 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 if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
*/
|
|
#define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
|
|
|
|
/*
|
|
* get_user: - Get a simple variable from user space.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
|
|
|
|
/*
|
|
* __put_user: - Write a simple value into user space, with less checking.
|
|
* @x: Value to copy to user space.
|
|
* @ptr: Destination address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
*/
|
|
#define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
|
|
|
|
/*
|
|
* __get_user: - Get a simple variable from user space, with less checking.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
|
|
|
|
struct __large_struct { unsigned long buf[100]; };
|
|
#define __m(x) (*(struct __large_struct __user *)(x))
|
|
|
|
/*
|
|
* Yuck. We need two variants, one for 64bit operation and one
|
|
* for 32 bit mode and old iron.
|
|
*/
|
|
extern void __get_user_unknown(void);
|
|
|
|
#define __get_user_common(val, size, ptr) \
|
|
do { \
|
|
switch (size) { \
|
|
case 1: \
|
|
__get_user_asm(val, "lb", ptr); \
|
|
break; \
|
|
case 2: \
|
|
__get_user_asm(val, "lh", ptr); \
|
|
break; \
|
|
case 4: \
|
|
__get_user_asm(val, "lw", ptr); \
|
|
break; \
|
|
case 8: \
|
|
if (__copy_from_user((void *)&val, ptr, 8) == 0) \
|
|
__gu_err = 0; \
|
|
else \
|
|
__gu_err = -EFAULT; \
|
|
break; \
|
|
default: \
|
|
__get_user_unknown(); \
|
|
break; \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __get_user_nocheck(x, ptr, size) \
|
|
({ \
|
|
long __gu_err = 0; \
|
|
__get_user_common((x), size, ptr); \
|
|
__gu_err; \
|
|
})
|
|
|
|
#define __get_user_check(x, ptr, size) \
|
|
({ \
|
|
long __gu_err = -EFAULT; \
|
|
const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
|
|
\
|
|
if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \
|
|
__get_user_common((x), size, __gu_ptr); \
|
|
else \
|
|
(x) = 0; \
|
|
\
|
|
__gu_err; \
|
|
})
|
|
|
|
#define __get_user_asm(val, insn, addr) \
|
|
{ \
|
|
long __gu_tmp; \
|
|
\
|
|
__asm__ __volatile__( \
|
|
"1:" insn " %1, %3\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:li %0, %4\n" \
|
|
"li %1, 0\n" \
|
|
"j 2b\n" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n" \
|
|
".word 1b, 3b\n" \
|
|
".previous\n" \
|
|
: "=r" (__gu_err), "=r" (__gu_tmp) \
|
|
: "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \
|
|
\
|
|
(val) = (__typeof__(*(addr))) __gu_tmp; \
|
|
}
|
|
|
|
/*
|
|
* Yuck. We need two variants, one for 64bit operation and one
|
|
* for 32 bit mode and old iron.
|
|
*/
|
|
#define __put_user_nocheck(val, ptr, size) \
|
|
({ \
|
|
__typeof__(*(ptr)) __pu_val; \
|
|
long __pu_err = 0; \
|
|
\
|
|
__pu_val = (val); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_asm("sb", ptr); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_asm("sh", ptr); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_asm("sw", ptr); \
|
|
break; \
|
|
case 8: \
|
|
if ((__copy_to_user((void *)ptr, &__pu_val, 8)) == 0) \
|
|
__pu_err = 0; \
|
|
else \
|
|
__pu_err = -EFAULT; \
|
|
break; \
|
|
default: \
|
|
__put_user_unknown(); \
|
|
break; \
|
|
} \
|
|
__pu_err; \
|
|
})
|
|
|
|
|
|
#define __put_user_check(val, ptr, size) \
|
|
({ \
|
|
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
|
|
__typeof__(*(ptr)) __pu_val = (val); \
|
|
long __pu_err = -EFAULT; \
|
|
\
|
|
if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_asm("sb", __pu_addr); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_asm("sh", __pu_addr); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_asm("sw", __pu_addr); \
|
|
break; \
|
|
case 8: \
|
|
if ((__copy_to_user((void *)__pu_addr, &__pu_val, 8)) == 0)\
|
|
__pu_err = 0; \
|
|
else \
|
|
__pu_err = -EFAULT; \
|
|
break; \
|
|
default: \
|
|
__put_user_unknown(); \
|
|
break; \
|
|
} \
|
|
} \
|
|
__pu_err; \
|
|
})
|
|
|
|
#define __put_user_asm(insn, ptr) \
|
|
__asm__ __volatile__( \
|
|
"1:" insn " %2, %3\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:li %0, %4\n" \
|
|
"j 2b\n" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n" \
|
|
".word 1b, 3b\n" \
|
|
".previous\n" \
|
|
: "=r" (__pu_err) \
|
|
: "0" (0), "r" (__pu_val), "o" (__m(ptr)), \
|
|
"i" (-EFAULT));
|
|
|
|
extern void __put_user_unknown(void);
|
|
extern int __copy_tofrom_user(void *to, const void *from, unsigned long len);
|
|
|
|
static inline unsigned long
|
|
copy_from_user(void *to, const void *from, unsigned long len)
|
|
{
|
|
unsigned long res = len;
|
|
|
|
if (likely(access_ok(VERIFY_READ, from, len)))
|
|
res = __copy_tofrom_user(to, from, len);
|
|
|
|
if (unlikely(res))
|
|
memset(to + (len - res), 0, res);
|
|
|
|
return res;
|
|
}
|
|
|
|
static inline unsigned long
|
|
copy_to_user(void *to, const void *from, unsigned long len)
|
|
{
|
|
if (likely(access_ok(VERIFY_WRITE, to, len)))
|
|
len = __copy_tofrom_user(to, from, len);
|
|
|
|
return len;
|
|
}
|
|
|
|
static inline unsigned long
|
|
__copy_from_user(void *to, const void *from, unsigned long len)
|
|
{
|
|
unsigned long left = __copy_tofrom_user(to, from, len);
|
|
if (unlikely(left))
|
|
memset(to + (len - left), 0, left);
|
|
return left;
|
|
}
|
|
|
|
#define __copy_to_user(to, from, len) \
|
|
__copy_tofrom_user((to), (from), (len))
|
|
|
|
static inline unsigned long
|
|
__copy_to_user_inatomic(void *to, const void *from, unsigned long len)
|
|
{
|
|
return __copy_to_user(to, from, len);
|
|
}
|
|
|
|
static inline unsigned long
|
|
__copy_from_user_inatomic(void *to, const void *from, unsigned long len)
|
|
{
|
|
return __copy_tofrom_user(to, from, len);
|
|
}
|
|
|
|
#define __copy_in_user(to, from, len) __copy_tofrom_user(to, from, len)
|
|
|
|
static inline unsigned long
|
|
copy_in_user(void *to, const void *from, unsigned long len)
|
|
{
|
|
if (access_ok(VERIFY_READ, from, len) &&
|
|
access_ok(VERFITY_WRITE, to, len))
|
|
return __copy_tofrom_user(to, from, len);
|
|
}
|
|
|
|
/*
|
|
* __clear_user: - Zero a block of memory in user space, with less checking.
|
|
* @to: Destination address, in user space.
|
|
* @n: Number of bytes to zero.
|
|
*
|
|
* Zero a block of memory in user space. Caller must check
|
|
* the specified block with access_ok() before calling this function.
|
|
*
|
|
* Returns number of bytes that could not be cleared.
|
|
* On success, this will be zero.
|
|
*/
|
|
extern unsigned long __clear_user(void __user *src, unsigned long size);
|
|
|
|
static inline unsigned long clear_user(char *src, unsigned long size)
|
|
{
|
|
if (access_ok(VERIFY_WRITE, src, size))
|
|
return __clear_user(src, size);
|
|
|
|
return -EFAULT;
|
|
}
|
|
/*
|
|
* __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
|
|
* @dst: Destination address, in kernel space. This buffer must be at
|
|
* least @count bytes long.
|
|
* @src: Source address, in user space.
|
|
* @count: Maximum number of bytes to copy, including the trailing NUL.
|
|
*
|
|
* Copies a NUL-terminated string from userspace to kernel space.
|
|
* Caller must check the specified block with access_ok() before calling
|
|
* this function.
|
|
*
|
|
* On success, returns the length of the string (not including the trailing
|
|
* NUL).
|
|
*
|
|
* If access to userspace fails, returns -EFAULT (some data may have been
|
|
* copied).
|
|
*
|
|
* If @count is smaller than the length of the string, copies @count bytes
|
|
* and returns @count.
|
|
*/
|
|
extern int __strncpy_from_user(char *dst, const char *src, long len);
|
|
|
|
static inline int strncpy_from_user(char *dst, const char *src, long len)
|
|
{
|
|
if (access_ok(VERIFY_READ, src, 1))
|
|
return __strncpy_from_user(dst, src, len);
|
|
|
|
return -EFAULT;
|
|
}
|
|
|
|
extern int __strlen_user(const char *src);
|
|
static inline long strlen_user(const char __user *src)
|
|
{
|
|
return __strlen_user(src);
|
|
}
|
|
|
|
extern int __strnlen_user(const char *str, long len);
|
|
static inline long strnlen_user(const char __user *str, long len)
|
|
{
|
|
if (!access_ok(VERIFY_READ, str, 0))
|
|
return 0;
|
|
else
|
|
return __strnlen_user(str, len);
|
|
}
|
|
|
|
#endif /* __SCORE_UACCESS_H */
|
|
|