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Commit eb47e029 authored by Al Viro's avatar Al Viro
Browse files

cris: buggered copy_from_user/copy_to_user/clear_user 



* copy_from_user() on access_ok() failure ought to zero the destination
* none of those primitives should skip the access_ok() check in case of
small constant size.

Cc: stable@vger.kernel.org
Acked-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9ad18b75

arch/cris/include/asm/uaccess.h

+32 −39
Original line number Original line Diff line number Diff line
@@ -194,30 +194,6 @@ extern unsigned long __copy_user(void __user *to, const void *from, unsigned lon 
extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n);

extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n);

extern unsigned long __do_clear_user(void __user *to, unsigned long n);

extern unsigned long __do_clear_user(void __user *to, unsigned long n);





static inline unsigned long

__generic_copy_to_user(void __user *to, const void *from, unsigned long n)

{

	if (access_ok(VERIFY_WRITE, to, n))

		return __copy_user(to, from, n);

	return n;

}



static inline unsigned long

__generic_copy_from_user(void *to, const void __user *from, unsigned long n)

{

	if (access_ok(VERIFY_READ, from, n))

		return __copy_user_zeroing(to, from, n);

	return n;

}



static inline unsigned long

__generic_clear_user(void __user *to, unsigned long n)

{

	if (access_ok(VERIFY_WRITE, to, n))

		return __do_clear_user(to, n);

	return n;

}



static inline long

static inline long

__strncpy_from_user(char *dst, const char __user *src, long count)

__strncpy_from_user(char *dst, const char __user *src, long count)

{

{
@@ -282,7 +258,7 @@ __constant_copy_from_user(void *to, const void __user *from, unsigned long n) 
	else if (n == 24)

	else if (n == 24)

		__asm_copy_from_user_24(to, from, ret);

		__asm_copy_from_user_24(to, from, ret);

	else

	else

		ret = __generic_copy_from_user(to, from, n);

		ret = __copy_user_zeroing(to, from, n);





	return ret;

	return ret;

}

}
@@ -333,7 +309,7 @@ __constant_copy_to_user(void __user *to, const void *from, unsigned long n) 
	else if (n == 24)

	else if (n == 24)

		__asm_copy_to_user_24(to, from, ret);

		__asm_copy_to_user_24(to, from, ret);

	else

	else

		ret = __generic_copy_to_user(to, from, n);

		ret = __copy_user(to, from, n);





	return ret;

	return ret;

}

}
@@ -366,26 +342,43 @@ __constant_clear_user(void __user *to, unsigned long n) 
	else if (n == 24)

	else if (n == 24)

		__asm_clear_24(to, ret);

		__asm_clear_24(to, ret);

	else

	else

		ret = __generic_clear_user(to, n);

		ret = __do_clear_user(to, n);





	return ret;

	return ret;

}

}









#define clear_user(to, n)				\

static inline size_t clear_user(void __user *to, size_t n)

	(__builtin_constant_p(n) ?			\

{

	 __constant_clear_user(to, n) :			\

	if (unlikely(!access_ok(VERIFY_WRITE, to, n)))

	 __generic_clear_user(to, n))

		return n;

	if (__builtin_constant_p(n))

		return __constant_clear_user(to, n);

	else

		return __do_clear_user(to, n);

}





#define copy_from_user(to, from, n)			\

static inline size_t copy_from_user(void *to, const void __user *from, size_t n)

	(__builtin_constant_p(n) ?			\

{

	 __constant_copy_from_user(to, from, n) :	\

	if (unlikely(!access_ok(VERIFY_READ, from, n))) {

	 __generic_copy_from_user(to, from, n))

		memset(to, 0, n);

		return n;

	}

	if (__builtin_constant_p(n))

		return __constant_copy_from_user(to, from, n);

	else

		return __copy_user_zeroing(to, from, n);

}





#define copy_to_user(to, from, n)			\

static inline size_t copy_to_user(void __user *to, const void *from, size_t n)

	(__builtin_constant_p(n) ?			\

{

	 __constant_copy_to_user(to, from, n) :		\

	if (unlikely(!access_ok(VERIFY_WRITE, to, n)))

	 __generic_copy_to_user(to, from, n))

		return n;

	if (__builtin_constant_p(n))

		return __constant_copy_to_user(to, from, n);

	else

		return __copy_user(to, from, n);

}





/* We let the __ versions of copy_from/to_user inline, because they're often

/* 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.

 * used in fast paths and have only a small space overhead.