Commit 73e800ec authored by Al Viro's avatar Al Viro
Browse files

x86_64: csum_..._copy_..._user(): switch to unsafe_..._user() 



We already have stac/clac pair around the calls of csum_partial_copy_generic().
Stretch that area back, so that it covers the preceding loop (and convert
the loop body from __{get,put}_user() to unsafe_{get,put}_user()).
That brings the beginning of the areas to the earlier access_ok(),
which allows to convert them into user_access_{begin,end}() ones.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2a89b674

arch/x86/lib/csum-wrappers_64.c

+12 −11
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst, 
	might_sleep();

	*errp = 0;



	if (!likely(access_ok(src, len)))

	if (!user_access_begin(src, len))

		goto out_err;



	/*
@@ -42,8 +42,7 @@ csum_partial_copy_from_user(const void __user *src, void *dst, 
		while (((unsigned long)src & 6) && len >= 2) {

			__u16 val16;



			if (__get_user(val16, (const __u16 __user *)src))

				goto out_err;

			unsafe_get_user(val16, (const __u16 __user *)src, out);



			*(__u16 *)dst = val16;

			isum = (__force __wsum)add32_with_carry(
@@ -53,15 +52,16 @@ csum_partial_copy_from_user(const void __user *src, void *dst, 
			len -= 2;

		}

	}

	stac();

	isum = csum_partial_copy_generic((__force const void *)src,

				dst, len, isum, errp, NULL);

	clac();

	user_access_end();

	if (unlikely(*errp))

		goto out_err;



	return isum;



out:

	user_access_end();

out_err:

	*errp = -EFAULT;

	memset(dst, 0, len);
@@ -89,7 +89,7 @@ csum_and_copy_to_user(const void *src, void __user *dst, 


	might_sleep();



	if (unlikely(!access_ok(dst, len))) {

	if (!user_access_begin(dst, len)) {

		*errp = -EFAULT;

		return 0;

	}
@@ -100,9 +100,7 @@ csum_and_copy_to_user(const void *src, void __user *dst, 


			isum = (__force __wsum)add32_with_carry(

					(__force unsigned)isum, val16);

			*errp = __put_user(val16, (__u16 __user *)dst);

			if (*errp)

				return isum;

			unsafe_put_user(val16, (__u16 __user *)dst, out);

			src += 2;

			dst += 2;

			len -= 2;
@@ -110,11 +108,14 @@ csum_and_copy_to_user(const void *src, void __user *dst, 
	}



	*errp = 0;

	stac();

	ret = csum_partial_copy_generic(src, (void __force *)dst,

					len, isum, NULL, errp);

	clac();

	user_access_end();

	return ret;

out:

	user_access_end();

	*errp = -EFAULT;

	return isum;

}

EXPORT_SYMBOL(csum_and_copy_to_user);

CRA Git | Maintained and supported by SUSTech CRA and CCSE