Commit f10b7897 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] api: Align tfm context as wide as possible 



Since tfm contexts can contain arbitrary types we should provide at least
natural alignment (__attribute__ ((__aligned__))) for them.  In particular,
this is needed on the Xscale which is a 32-bit architecture with a u64 type
that requires 64-bit alignment.  This problem was reported by Ronen Shitrit.

The crypto_tfm structure's size was 44 bytes on 32-bit architectures and
80 bytes on 64-bit architectures.  So adding this requirement only means
that we have to add an extra 4 bytes on 32-bit architectures.

On i386 the natural alignment is 16 bytes which also benefits the VIA
Padlock as it no longer has to manually align its context structure to
128 bits.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a5f8c473

crypto/api.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -165,7 +165,7 @@ static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags) 
		break;

		break;

	}

	}





	return len + alg->cra_alignmask;

	return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));

}

}





struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)

struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)

drivers/crypto/padlock-aes.c

+5 −1
Original line number Original line Diff line number Diff line
@@ -284,7 +284,11 @@ aes_hw_extkey_available(uint8_t key_len) 




static inline struct aes_ctx *aes_ctx(void *ctx)

static inline struct aes_ctx *aes_ctx(void *ctx)

{

{

	return (struct aes_ctx *)ALIGN((unsigned long)ctx, PADLOCK_ALIGNMENT);

	unsigned long align = PADLOCK_ALIGNMENT;



	if (align <= crypto_tfm_ctx_alignment())

		align = 1;

	return (struct aes_ctx *)ALIGN((unsigned long)ctx, align);

}

}





static int

static int

include/linux/crypto.h

+9 −1
Original line number Original line Diff line number Diff line
@@ -229,6 +229,8 @@ struct crypto_tfm { 
	} crt_u;

	} crt_u;

	

	

	struct crypto_alg *__crt_alg;

	struct crypto_alg *__crt_alg;



	char __crt_ctx[] __attribute__ ((__aligned__));

};

};





/* 

/*
@@ -301,7 +303,13 @@ static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm) 




static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)

static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)

{

{

	return (void *)&tfm[1];

	return tfm->__crt_ctx;

}



static inline unsigned int crypto_tfm_ctx_alignment(void)

{

	struct crypto_tfm *tfm;

	return __alignof__(tfm->__crt_ctx);

}

}





/*

/*

CRA Git | Maintained and supported by SUSTech CRA and CCSE