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Commit 22426465 authored by Al Viro's avatar Al Viro
Browse files

ppc32: fix copy_from_user() 



should clear on access_ok() failures.  Also remove the useless
range truncation logics.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent aace880f

arch/powerpc/include/asm/uaccess.h

+2 −23
Original line number Diff line number Diff line
@@ -308,40 +308,23 @@ extern unsigned long __copy_tofrom_user(void __user *to, 
static inline unsigned long copy_from_user(void *to,

		const void __user *from, unsigned long n)

{

	unsigned long over;



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

	if (likely(access_ok(VERIFY_READ, from, n))) {

		if (!__builtin_constant_p(n))

			check_object_size(to, n, false);

		return __copy_tofrom_user((__force void __user *)to, from, n);

	}

	if ((unsigned long)from < TASK_SIZE) {

		over = (unsigned long)from + n - TASK_SIZE;

		if (!__builtin_constant_p(n - over))

			check_object_size(to, n - over, false);

		return __copy_tofrom_user((__force void __user *)to, from,

				n - over) + over;

	}

	memset(to, 0, n);

	return n;

}



static inline unsigned long copy_to_user(void __user *to,

		const void *from, unsigned long n)

{

	unsigned long over;



	if (access_ok(VERIFY_WRITE, to, n)) {

		if (!__builtin_constant_p(n))

			check_object_size(from, n, true);

		return __copy_tofrom_user(to, (__force void __user *)from, n);

	}

	if ((unsigned long)to < TASK_SIZE) {

		over = (unsigned long)to + n - TASK_SIZE;

		if (!__builtin_constant_p(n))

			check_object_size(from, n - over, true);

		return __copy_tofrom_user(to, (__force void __user *)from,

				n - over) + over;

	}

	return n;

}
@@ -439,10 +422,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size) 
	might_fault();

	if (likely(access_ok(VERIFY_WRITE, addr, size)))

		return __clear_user(addr, size);

	if ((unsigned long)addr < TASK_SIZE) {

		unsigned long over = (unsigned long)addr + size - TASK_SIZE;

		return __clear_user(addr, size - over) + over;

	}

	return size;

}