Commit ee3c9c7e authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: powerpc/p10-aes-gcm - simplify handling of linear associated data 



p10_aes_gcm_crypt() is abusing the scatter_walk API to get the virtual
address for the first source scatterlist element.  But this code is only
built for PPC64 which is a !HIGHMEM platform, and it can read past a
page boundary from the address returned by scatterwalk_map() which means
it already assumes the address is from the kernel's direct map.  Thus,
just use sg_virt() instead to get the same result in a simpler way.

Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Danny Tsen <dtsen@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 1742b0a0

arch/powerpc/crypto/aes-gcm-p10-glue.c

+2 −7
Original line number Diff line number Diff line
@@ -214,7 +214,6 @@ static int p10_aes_gcm_crypt(struct aead_request *req, u8 *riv, 
	struct gcm_ctx *gctx = PTR_ALIGN((void *)databuf, PPC_ALIGN);

	u8 hashbuf[sizeof(struct Hash_ctx) + PPC_ALIGN];

	struct Hash_ctx *hash = PTR_ALIGN((void *)hashbuf, PPC_ALIGN);

	struct scatter_walk assoc_sg_walk;

	struct skcipher_walk walk;

	u8 *assocmem = NULL;

	u8 *assoc;
@@ -234,8 +233,7 @@ static int p10_aes_gcm_crypt(struct aead_request *req, u8 *riv, 


	/* Linearize assoc, if not already linear */

	if (req->src->length >= assoclen && req->src->length) {

		scatterwalk_start(&assoc_sg_walk, req->src);

		assoc = scatterwalk_map(&assoc_sg_walk);

		assoc = sg_virt(req->src); /* ppc64 is !HIGHMEM */

	} else {

		gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?

			      GFP_KERNEL : GFP_ATOMIC;
@@ -253,9 +251,6 @@ static int p10_aes_gcm_crypt(struct aead_request *req, u8 *riv, 
	gcmp10_init(gctx, iv, (unsigned char *) &ctx->enc_key, hash, assoc, assoclen);

	vsx_end();



	if (!assocmem)

		scatterwalk_unmap(assoc);

	else

	kfree(assocmem);



	if (enc)