Commit 6e78ad0b authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: lib - move __crypto_xor into utils 



CRYPTO_LIB_CHACHA depends on CRYPTO for __crypto_xor, defined in
crypto/algapi.c.  This is a layering violation because the dependencies
should only go in the other direction (crypto/ => lib/crypto/).  Also
the correct dependency would be CRYPTO_ALGAPI, not CRYPTO.  Fix this by
moving __crypto_xor into the utils module in lib/crypto/.

Note that CRYPTO_LIB_CHACHA_GENERIC selected XOR_BLOCKS, which is
unrelated and unnecessary.  It was perhaps thought that XOR_BLOCKS was
needed for __crypto_xor, but that's not the case.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Reviewed-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 7033b937

crypto/algapi.c

+0 −71
Original line number Diff line number Diff line
@@ -997,77 +997,6 @@ void crypto_inc(u8 *a, unsigned int size) 
}

EXPORT_SYMBOL_GPL(crypto_inc);



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)src1) |

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

			(size - 1);



		relalign = d ? 1 << __ffs(d) : size;



		/*

		 * If we care about alignment, process as many bytes as

		 * needed to advance dst and src to values whose alignments

		 * equal their relative alignment. This will allow us to

		 * process the remainder of the input using optimal strides.

		 */

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

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

			len--;

		}

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u64 l = get_unaligned((u64 *)src1) ^

				get_unaligned((u64 *)src2);

			put_unaligned(l, (u64 *)dst);

		} else {

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

		}

		dst += 8;

		src1 += 8;

		src2 += 8;

		len -= 8;

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u32 l = get_unaligned((u32 *)src1) ^

				get_unaligned((u32 *)src2);

			put_unaligned(l, (u32 *)dst);

		} else {

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

		}

		dst += 4;

		src1 += 4;

		src2 += 4;

		len -= 4;

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u16 l = get_unaligned((u16 *)src1) ^

				get_unaligned((u16 *)src2);

			put_unaligned(l, (u16 *)dst);

		} else {

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

		}

		dst += 2;

		src1 += 2;

		src2 += 2;

		len -= 2;

	}



	while (len--)

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

}

EXPORT_SYMBOL_GPL(__crypto_xor);



unsigned int crypto_alg_extsize(struct crypto_alg *alg)

{

	return alg->cra_ctxsize +

lib/crypto/Kconfig

+1 −2
Original line number Diff line number Diff line
@@ -36,7 +36,7 @@ config CRYPTO_ARCH_HAVE_LIB_CHACHA 


config CRYPTO_LIB_CHACHA_GENERIC

	tristate

	select XOR_BLOCKS

	select CRYPTO_LIB_UTILS

	help

	  This symbol can be depended upon by arch implementations of the

	  ChaCha library interface that require the generic code as a
@@ -46,7 +46,6 @@ config CRYPTO_LIB_CHACHA_GENERIC 


config CRYPTO_LIB_CHACHA

	tristate "ChaCha library interface"

	depends on CRYPTO

	depends on CRYPTO_ARCH_HAVE_LIB_CHACHA || !CRYPTO_ARCH_HAVE_LIB_CHACHA

	select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n

	help

lib/crypto/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



obj-$(CONFIG_CRYPTO_LIB_UTILS)			+= libcryptoutils.o

libcryptoutils-y				:= memneq.o

libcryptoutils-y				:= memneq.o utils.o



# chacha is used by the /dev/random driver which is always builtin

obj-y						+= chacha.o

lib/crypto/memneq.c

+0 −2
Original line number Diff line number Diff line
@@ -175,5 +175,3 @@ noinline unsigned long __crypto_memneq(const void *a, const void *b, 
EXPORT_SYMBOL(__crypto_memneq);



#endif /* __HAVE_ARCH_CRYPTO_MEMNEQ */
 


MODULE_LICENSE("GPL");

lib/crypto/utils.c

0 → 100644
+88 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Crypto library utility functions

 *

 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>

 */



#include <asm/unaligned.h>

#include <crypto/algapi.h>

#include <linux/module.h>



/*

 * XOR @len bytes from @src1 and @src2 together, writing the result to @dst

 * (which may alias one of the sources).  Don't call this directly; call

 * crypto_xor() or crypto_xor_cpy() instead.

 */

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)src1) |

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

			(size - 1);



		relalign = d ? 1 << __ffs(d) : size;



		/*

		 * If we care about alignment, process as many bytes as

		 * needed to advance dst and src to values whose alignments

		 * equal their relative alignment. This will allow us to

		 * process the remainder of the input using optimal strides.

		 */

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

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

			len--;

		}

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u64 l = get_unaligned((u64 *)src1) ^

				get_unaligned((u64 *)src2);

			put_unaligned(l, (u64 *)dst);

		} else {

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

		}

		dst += 8;

		src1 += 8;

		src2 += 8;

		len -= 8;

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u32 l = get_unaligned((u32 *)src1) ^

				get_unaligned((u32 *)src2);

			put_unaligned(l, (u32 *)dst);

		} else {

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

		}

		dst += 4;

		src1 += 4;

		src2 += 4;

		len -= 4;

	}



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

		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {

			u16 l = get_unaligned((u16 *)src1) ^

				get_unaligned((u16 *)src2);

			put_unaligned(l, (u16 *)dst);

		} else {

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

		}

		dst += 2;

		src1 += 2;

		src2 += 2;

		len -= 2;

	}



	while (len--)

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

}

EXPORT_SYMBOL_GPL(__crypto_xor);



MODULE_LICENSE("GPL");