Release 4.14 arch/x86/lib/csum-wrappers_64.c

/*
 * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
 * Subject to the GNU Public License v.2
 *
 * Wrappers of assembly checksum functions for x86-64.
 */
#include <asm/checksum.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/smap.h>

/**
 * csum_partial_copy_from_user - Copy and checksum from user space.
 * @src: source address (user space)
 * @dst: destination address
 * @len: number of bytes to be copied.
 * @isum: initial sum that is added into the result (32bit unfolded)
 * @errp: set to -EFAULT for an bad source address.
 *
 * Returns an 32bit unfolded checksum of the buffer.
 * src and dst are best aligned to 64bits.
 */

__wsum

csum_partial_copy_from_user(const void __user *src, void *dst,
			    int len, __wsum isum, int *errp)
{
	might_sleep();
	*errp = 0;

	if (!likely(access_ok(VERIFY_READ, src, len)))
		goto out_err;

	/*
         * Why 6, not 7? To handle odd addresses aligned we
         * would need to do considerable complications to fix the
         * checksum which is defined as an 16bit accumulator. The
         * fix alignment code is primarily for performance
         * compatibility with 32bit and that will handle odd
         * addresses slowly too.
         */
	if (unlikely((unsigned long)src & 6)) {
		while (((unsigned long)src & 6) && len >= 2) {
			__u16 val16;

			if (__get_user(val16, (const __u16 __user *)src))
				goto out_err;

			*(__u16 *)dst = val16;
			isum = (__force __wsum)add32_with_carry(
					(__force unsigned)isum, val16);
			src += 2;
			dst += 2;
			len -= 2;
		}
	}
	stac();
	isum = csum_partial_copy_generic((__force const void *)src,
				dst, len, isum, errp, NULL);
	clac();
	if (unlikely(*errp))
		goto out_err;

	return isum;

out_err:
	*errp = -EFAULT;
	memset(dst, 0, len);

	return isum;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
164
79.23%
3
33.33%
Al Viro
21
10.14%
3
33.33%
Ingo Molnar
11
5.31%
1
11.11%
H. Peter Anvin
6
2.90%
1
11.11%
Linus Torvalds
5
2.42%
1
11.11%
Total
207
100.00%
9
100.00%


EXPORT_SYMBOL(csum_partial_copy_from_user);

/**
 * csum_partial_copy_to_user - Copy and checksum to user space.
 * @src: source address
 * @dst: destination address (user space)
 * @len: number of bytes to be copied.
 * @isum: initial sum that is added into the result (32bit unfolded)
 * @errp: set to -EFAULT for an bad destination address.
 *
 * Returns an 32bit unfolded checksum of the buffer.
 * src and dst are best aligned to 64bits.
 */

__wsum

csum_partial_copy_to_user(const void *src, void __user *dst,
			  int len, __wsum isum, int *errp)
{
	__wsum ret;

	might_sleep();

	if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
		*errp = -EFAULT;
		return 0;
	}

	if (unlikely((unsigned long)dst & 6)) {
		while (((unsigned long)dst & 6) && len >= 2) {
			__u16 val16 = *(__u16 *)src;

			isum = (__force __wsum)add32_with_carry(
					(__force unsigned)isum, val16);
			*errp = __put_user(val16, (__u16 __user *)dst);
			if (*errp)
				return isum;
			src += 2;
			dst += 2;
			len -= 2;
		}
	}

	*errp = 0;
	stac();
	ret = csum_partial_copy_generic(src, (void __force *)dst,
					len, isum, NULL, errp);
	clac();
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
155
82.45%
3
42.86%
Al Viro
19
10.11%
3
42.86%
H. Peter Anvin
14
7.45%
1
14.29%
Total
188
100.00%
7
100.00%


EXPORT_SYMBOL(csum_partial_copy_to_user);

/**
 * csum_partial_copy_nocheck - Copy and checksum.
 * @src: source address
 * @dst: destination address
 * @len: number of bytes to be copied.
 * @sum: initial sum that is added into the result (32bit unfolded)
 *
 * Returns an 32bit unfolded checksum of the buffer.
 */

__wsum

csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
{
	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
32
88.89%
1
50.00%
Al Viro
4
11.11%
1
50.00%
Total
36
100.00%
2
100.00%


EXPORT_SYMBOL(csum_partial_copy_nocheck);



__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
			const struct in6_addr *daddr,
			__u32 len, __u8 proto, __wsum sum)
{
	__u64 rest, sum64;

	rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
		(__force __u64)sum;

	asm("   addq (%[saddr]),%[sum]\n"
            "   adcq 8(%[saddr]),%[sum]\n"
            "   adcq (%[daddr]),%[sum]\n"
            "   adcq 8(%[daddr]),%[sum]\n"
            "   adcq $0,%[sum]\n"

            : [sum] "=r" (sum64)
            : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));

	return csum_fold(
	       (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
64
83.12%
2
40.00%
Al Viro
11
14.29%
1
20.00%
Alexander Duyck
1
1.30%
1
20.00%
Ingo Molnar
1
1.30%
1
20.00%
Total
77
100.00%
5
100.00%


EXPORT_SYMBOL(csum_ipv6_magic);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Andi Kleen
440
80.88%
4
26.67%
Al Viro
55
10.11%
3
20.00%
H. Peter Anvin
23
4.23%
1
6.67%
Ingo Molnar
13
2.39%
1
6.67%
Linus Torvalds
5
0.92%
1
6.67%
Andrew Lutomirski
3
0.55%
1
6.67%
Paolo Ciarrocchi
2
0.37%
1
6.67%
Alexander Duyck
1
0.18%
1
6.67%
Wanpeng Li
1
0.18%
1
6.67%
Paul Gortmaker
1
0.18%
1
6.67%
Total
544
100.00%
15
100.00%
Directory: arch/x86/lib

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