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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) IBM Corporation, 2010
*
* Author: Anton Blanchard <anton@au.ibm.com>
*/
#include <linux/export.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/checksum.h>
#include <linux/uaccess.h>
__wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len)
{
unsigned int csum;
int err = 0;
might_sleep();
if (unlikely(!access_ok(src, len)))
return 0;
allow_read_from_user(src, len);
csum = csum_partial_copy_generic((void __force *)src, dst,
len, ~0U, &err, NULL);
if (unlikely(err)) {
int missing = __copy_from_user(dst, src, len);
if (missing)
csum = 0;
else
csum = csum_partial(dst, len, ~0U);
}
prevent_read_from_user(src, len);
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_from_user);
__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
{
unsigned int csum;
int err = 0;
might_sleep();
if (unlikely(!access_ok(dst, len)))
return 0;
allow_write_to_user(dst, len);
csum = csum_partial_copy_generic(src, (void __force *)dst,
len, ~0U, NULL, &err);
if (unlikely(err)) {
csum = csum_partial(src, len, ~0U);
if (copy_to_user(dst, src, len))
csum = 0;
}
prevent_write_to_user(dst, len);
return (__force __wsum)csum;
}
EXPORT_SYMBOL(csum_and_copy_to_user);
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