usercopy.c 764 Bytes
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/uaccess.h>

/* out-of-line parts */

#ifndef INLINE_COPY_FROM_USER
unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
{
	unsigned long res = n;
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	might_fault();
	if (likely(access_ok(VERIFY_READ, from, n))) {
		kasan_check_write(to, n);
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		res = raw_copy_from_user(to, from, n);
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	}
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	if (unlikely(res))
		memset(to + (n - res), 0, res);
	return res;
}
EXPORT_SYMBOL(_copy_from_user);
#endif

#ifndef INLINE_COPY_TO_USER
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unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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	might_fault();
	if (likely(access_ok(VERIFY_WRITE, to, n))) {
		kasan_check_read(from, n);
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		n = raw_copy_to_user(to, from, n);
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	}
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	return n;
}
EXPORT_SYMBOL(_copy_to_user);
#endif