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Commit a7c391f0 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
Browse files

crypto: algapi - use separate dst and src operands for __crypto_xor() 



In preparation of introducing crypto_xor_cpy(), which will use separate
operands for input and output, modify the __crypto_xor() implementation,
which it will share with the existing crypto_xor(), which provides the
actual functionality when not using the inline version.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 9a42e4ee

crypto/algapi.c

+15 −10
Original line number Diff line number Diff line
@@ -975,13 +975,15 @@ void crypto_inc(u8 *a, unsigned int size) 
}

EXPORT_SYMBOL_GPL(crypto_inc);



void __crypto_xor(u8 *dst, const u8 *src, unsigned int len)

void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len)

{

	int relalign = 0;



	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

		int size = sizeof(unsigned long);

		int d = ((unsigned long)dst ^ (unsigned long)src) & (size - 1);

		int d = (((unsigned long)dst ^ (unsigned long)src1) |

			 ((unsigned long)dst ^ (unsigned long)src2)) &

			(size - 1);



		relalign = d ? 1 << __ffs(d) : size;
@@ -992,34 +994,37 @@ void __crypto_xor(u8 *dst, const u8 *src, unsigned int len) 
		 * process the remainder of the input using optimal strides.

		 */

		while (((unsigned long)dst & (relalign - 1)) && len > 0) {

			*dst++ ^= *src++;

			*dst++ = *src1++ ^ *src2++;

			len--;

		}

	}



	while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) {

		*(u64 *)dst ^= *(u64 *)src;

		*(u64 *)dst = *(u64 *)src1 ^  *(u64 *)src2;

		dst += 8;

		src += 8;

		src1 += 8;

		src2 += 8;

		len -= 8;

	}



	while (len >= 4 && !(relalign & 3)) {

		*(u32 *)dst ^= *(u32 *)src;

		*(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2;

		dst += 4;

		src += 4;

		src1 += 4;

		src2 += 4;

		len -= 4;

	}



	while (len >= 2 && !(relalign & 1)) {

		*(u16 *)dst ^= *(u16 *)src;

		*(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2;

		dst += 2;

		src += 2;

		src1 += 2;

		src2 += 2;

		len -= 2;

	}



	while (len--)

		*dst++ ^= *src++;

		*dst++ = *src1++ ^ *src2++;

}

EXPORT_SYMBOL_GPL(__crypto_xor);

include/crypto/algapi.h

+2 −2
Original line number Diff line number Diff line
@@ -192,7 +192,7 @@ static inline unsigned int crypto_queue_len(struct crypto_queue *queue) 
}



void crypto_inc(u8 *a, unsigned int size);

void __crypto_xor(u8 *dst, const u8 *src, unsigned int size);

void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int size);



static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size)

{
@@ -207,7 +207,7 @@ static inline void crypto_xor(u8 *dst, const u8 *src, unsigned int size) 
			size -= sizeof(unsigned long);

		}

	} else {

		__crypto_xor(dst, src, size);

		__crypto_xor(dst, dst, src, size);

	}

}