uaccess.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 506 行 · 第 1/2 页

({								\
	long __pu_err;						\
	__put_user_size((x),(ptr),(size),__pu_err,-EFAULT);	\
	__pu_err;						\
})


#define __put_user_check(x,ptr,size)					\
({									\
	long __pu_err = -EFAULT;					\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
	might_sleep();						\
	if (access_ok(VERIFY_WRITE,__pu_addr,size))			\
		__put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT);	\
	__pu_err;							\
})							

#define __put_user_u64(x, addr, err)				\
	__asm__ __volatile__(					\
		"1:	movl %%eax,0(%2)\n"			\
		"2:	movl %%edx,4(%2)\n"			\
		"3:\n"						\
		".section .fixup,\"ax\"\n"			\
		"4:	movl %3,%0\n"				\
		"	jmp 3b\n"				\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.align 4\n"				\
		"	.long 1b,4b\n"				\
		"	.long 2b,4b\n"				\
		".previous"					\
		: "=r"(err)					\
		: "A" (x), "r" (addr), "i"(-EFAULT), "0"(err))

#ifdef CONFIG_X86_WP_WORKS_OK

#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","","ir",errret); break;	\
	case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
	  default: __put_user_bad();					\
	}								\
} while (0)

#else

#define __put_user_size(x,ptr,size,retval,errret)			\
do {									\
	__typeof__(*(ptr)) __pus_tmp = x;				\
	retval = 0;							\
									\
	if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0))	\
		retval = errret;					\
} while (0)

#endif
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(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__(						\
		"1:	mov"itype" %"rtype"1,%2\n"			\
		"2:\n"							\
		".section .fixup,\"ax\"\n"				\
		"3:	movl %3,%0\n"					\
		"	jmp 2b\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.align 4\n"					\
		"	.long 1b,3b\n"					\
		".previous"						\
		: "=r"(err)						\
		: ltype (x), "m"(__m(addr)), "i"(errret), "0"(err))


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

extern long __get_user_bad(void);

#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","","=r",errret);break;	\
	default: (x) = __get_user_bad();				\
	}								\
} while (0)

#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret)	\
	__asm__ __volatile__(						\
		"1:	mov"itype" %2,%"rtype"1\n"			\
		"2:\n"							\
		".section .fixup,\"ax\"\n"				\
		"3:	movl %3,%0\n"					\
		"	xor"itype" %"rtype"1,%"rtype"1\n"		\
		"	jmp 2b\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.align 4\n"					\
		"	.long 1b,3b\n"					\
		".previous"						\
		: "=r"(err), ltype (x)					\
		: "m"(__m(addr)), "i"(errret), "0"(err))


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);

/*
 * 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.
 */

/**
 * __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 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);
}

static 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);
}

/**
 * __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.
 */
static inline unsigned long
__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
{
	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);
}

static inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
       might_sleep();
       return __copy_from_user_inatomic(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, ~0UL >> 1)

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 */