uaccess.h

来自「Linux Kernel 2.6.9 for OMAP1710」· C头文件 代码 · 共 753 行 · 第 1/2 页

		".previous"						\
		: "=r"(err)						\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)		\
		: "r14", "memory")
#else
#error no endian defined
#endif

#define __put_user_size(x,ptr,size,retval)				\
do {									\
	retval = 0;							\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	  case 1: __put_user_asm(x,ptr,retval,"b"); break;		\
	  case 2: __put_user_asm(x,ptr,retval,"h"); break;		\
	  case 4: __put_user_asm(x,ptr,retval,""); break;		\
	  case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
	  default: __put_user_bad();					\
	}								\
} while (0)

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)				\
	__asm__ __volatile__(						\
		"	.fillinsn\n"					\
		"1:	st"itype" %1,@%2\n"				\
		"	.fillinsn\n"					\
		"2:\n"							\
		".section .fixup,\"ax\"\n"				\
		"	.balign 4\n"					\
		"3:	ldi %0,%3\n"					\
		"	seth r14,#high(2b)\n"				\
		"	or3 r14,r14,#low(2b)\n"				\
		"	jmp r14\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.balign 4\n"					\
		"	.long 1b,3b\n"					\
		".previous"						\
		: "=r"(err)						\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)		\
		: "r14", "memory")

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

extern long __get_user_bad(void);

#define __get_user_size(x,ptr,size,retval)				\
do {									\
	retval = 0;							\
	__chk_user_ptr(ptr);						\
	switch (size) {							\
	  case 1: __get_user_asm(x,ptr,retval,"ub"); break;		\
	  case 2: __get_user_asm(x,ptr,retval,"uh"); break;		\
	  case 4: __get_user_asm(x,ptr,retval,""); break;		\
	  default: (x) = __get_user_bad();				\
	}								\
} while (0)

#define __get_user_asm(x, addr, err, itype)				\
	__asm__ __volatile__(						\
		"	.fillinsn\n"					\
		"1:	ld"itype" %1,@%2\n"				\
		"	.fillinsn\n"					\
		"2:\n"							\
		".section .fixup,\"ax\"\n"				\
		"	.balign 4\n"					\
		"3:	ldi %0,%3\n"					\
		"	seth r14,#high(2b)\n"				\
		"	or3 r14,r14,#low(2b)\n"				\
		"	jmp r14\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.balign 4\n"					\
		"	.long 1b,3b\n"					\
		".previous"						\
		: "=r"(err), "=&r"(x)					\
		: "r"(addr), "i"(-EFAULT), "0"(err)			\
		: "r14", "memory")

/*
 * 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 m32r will not write
 * anything, so this is accurate.
 */


/*
 * Copy To/From Userspace
 */

/* Generic arbitrary sized copy.  */
/* Return the number of bytes NOT copied.  */
#define __copy_user(to,from,size)					\
do {									\
	unsigned long __dst, __src, __c;				\
	__asm__ __volatile__ (						\
		"	mv	r14, %0\n"				\
		"	or	r14, %1\n"				\
		"	beq	%0, %1, 9f\n"				\
		"	beqz	%2, 9f\n"				\
		"	and3	r14, r14, #3\n"				\
		"	bnez	r14, 2f\n"				\
		"	and3	%2, %2, #3\n"				\
		"	beqz	%3, 2f\n"				\
		"	addi	%0, #-4		; word_copy \n"		\
		"	.fillinsn\n"					\
		"0:	ld	r14, @%1+\n"				\
		"	addi	%3, #-1\n"				\
		"	.fillinsn\n"					\
		"1:	st	r14, @+%0\n"				\
		"	bnez	%3, 0b\n"				\
		"	beqz	%2, 9f\n"				\
		"	addi	%0, #4\n"				\
		"	.fillinsn\n"					\
		"2:	ldb	r14, @%1	; byte_copy \n"		\
		"	.fillinsn\n"					\
		"3:	stb	r14, @%0\n"				\
		"	addi	%1, #1\n"				\
		"	addi	%2, #-1\n"				\
		"	addi	%0, #1\n"				\
		"	bnez	%2, 2b\n"				\
		"	.fillinsn\n"					\
		"9:\n"							\
		".section .fixup,\"ax\"\n"				\
		"	.balign 4\n"					\
		"5:	addi	%3, #1\n"				\
		"	addi	%1, #-4\n"				\
		"	.fillinsn\n"					\
		"6:	slli	%3, #2\n"				\
		"	add	%2, %3\n"				\
		"	addi	%0, #4\n"				\
		"	.fillinsn\n"					\
		"7:	seth	r14, #high(9b)\n"			\
		"	or3	r14, r14, #low(9b)\n"			\
		"	jmp	r14\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.balign 4\n"					\
		"	.long 0b,6b\n"					\
		"	.long 1b,5b\n"					\
		"	.long 2b,9b\n"					\
		"	.long 3b,9b\n"					\
		".previous\n"						\
		: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)	\
		: "0"(to), "1"(from), "2"(size), "3"(size / 4)		\
		: "r14", "memory");					\
} while (0)

#define __copy_user_zeroing(to,from,size)				\
do {									\
	unsigned long __dst, __src, __c;				\
	__asm__ __volatile__ (						\
		"	mv	r14, %0\n"				\
		"	or	r14, %1\n"				\
		"	beq	%0, %1, 9f\n"				\
		"	beqz	%2, 9f\n"				\
		"	and3	r14, r14, #3\n"				\
		"	bnez	r14, 2f\n"				\
		"	and3	%2, %2, #3\n"				\
		"	beqz	%3, 2f\n"				\
		"	addi	%0, #-4		; word_copy \n"		\
		"	.fillinsn\n"					\
		"0:	ld	r14, @%1+\n"				\
		"	addi	%3, #-1\n"				\
		"	.fillinsn\n"					\
		"1:	st	r14, @+%0\n"				\
		"	bnez	%3, 0b\n"				\
		"	beqz	%2, 9f\n"				\
		"	addi	%0, #4\n"				\
		"	.fillinsn\n"					\
		"2:	ldb	r14, @%1	; byte_copy \n"		\
		"	.fillinsn\n"					\
		"3:	stb	r14, @%0\n"				\
		"	addi	%1, #1\n"				\
		"	addi	%2, #-1\n"				\
		"	addi	%0, #1\n"				\
		"	bnez	%2, 2b\n"				\
		"	.fillinsn\n"					\
		"9:\n"							\
		".section .fixup,\"ax\"\n"				\
		"	.balign 4\n"					\
		"5:	addi	%3, #1\n"				\
		"	addi	%1, #-4\n"				\
		"	.fillinsn\n"					\
		"6:	slli	%3, #2\n"				\
		"	add	%2, %3\n"				\
		"	addi	%0, #4\n"				\
		"	.fillinsn\n"					\
		"7:	ldi	r14, #0		; store zero \n"	\
		"	.fillinsn\n"					\
		"8:	addi	%2, #-1\n"				\
		"	stb	r14, @%0	; ACE? \n"		\
		"	addi	%0, #1\n"				\
		"	bnez	%2, 8b\n"				\
		"	seth	r14, #high(9b)\n"			\
		"	or3	r14, r14, #low(9b)\n"			\
		"	jmp	r14\n"					\
		".previous\n"						\
		".section __ex_table,\"a\"\n"				\
		"	.balign 4\n"					\
		"	.long 0b,6b\n"					\
		"	.long 1b,5b\n"					\
		"	.long 2b,7b\n"					\
		"	.long 3b,7b\n"					\
		".previous\n"						\
		: "=&r"(__dst), "=&r"(__src), "=&r"(size), "=&r"(__c)	\
		: "0"(to), "1"(from), "2"(size), "3"(size / 4)		\
		: "r14", "memory");					\
} while (0)


/* We let the __ versions of copy_from/to_user inline, because they're often
 * used in fast paths and have only a small space overhead.
 */
static inline unsigned long __generic_copy_from_user_nocheck(void *to,
	const void __user *from, unsigned long n)
{
	__copy_user_zeroing(to,from,n);
	return n;
}

static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
	const void *from, unsigned long n)
{
	__copy_user(to,from,n);
	return n;
}

unsigned long __generic_copy_to_user(void *, const void *, unsigned long);
unsigned long __generic_copy_from_user(void *, const void *, unsigned long);

/**
 * __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.
 */
#define __copy_to_user(to,from,n)			\
	__generic_copy_to_user_nocheck((to),(from),(n))

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

/**
 * copy_to_user: - Copy a block of data into user space.
 * @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.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
#define copy_to_user(to,from,n)				\
({							\
	might_sleep();					\
	__generic_copy_to_user((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.
 */
#define __copy_from_user(to,from,n)			\
	__generic_copy_from_user_nocheck((to),(from),(n))

/**
 * copy_from_user: - Copy a block of data from user space.
 * @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.
 *
 * 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.
 */
#define copy_from_user(to,from,n)			\
({							\
	might_sleep();					\
__generic_copy_from_user((to),(from),(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);

/**
 * __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.
 */
unsigned long __clear_user(void __user *mem, unsigned long len);

/**
 * clear_user: - Zero a block of memory in user space.
 * @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.
 */
unsigned long clear_user(void __user *mem, unsigned long len);

/**
 * 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);

#endif /* _ASM_M32R_UACCESS_H */