From: behanw@converseincode.com Subject: [PATCH RFC 2/6] crypto: LLVMLinux: Remove VLAIS usage from crypto/hmac.c Date: Tue, 2 Sep 2014 15:32:29 -0700 Message-ID: <1409697153-7006-3-git-send-email-behanw@converseincode.com> References: <1409697153-7006-1-git-send-email-behanw@converseincode.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: akpm@linux-foundation.org, james.l.morris@oracle.com, john.johansen@canonical.com, linux-btrfs@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-security-module@vger.kernel.org, neilb@suse.de, serge@hallyn.com, torvalds@linux-foundation.org, =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= , Behan Webster , pageexec@freemail.hu To: agk@redhat.com, clm@fb.com, davem@davemloft.net, dm-devel@redhat.com, fabf@skynet.be, herbert@gondor.apana.org.au, jbacik@fb.com, snitzer@redhat.com Return-path: In-Reply-To: <1409697153-7006-1-git-send-email-behanw@converseincode.com> Sender: linux-btrfs-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org =46rom: Jan-Simon M=C3=B6ller The use of variable length arrays in structs (VLAIS) in the Linux Kerne= l code precludes the use of compilers which don't implement VLAIS (for instanc= e the Clang compiler). This patch instead allocates the appropriate amount of= memory using an char array. struct shash_desc contains a flexible array member member ctx declared = with CRYPTO_MINALIGN_ATTR, so sizeof(struct shash_desc) aligns the beginning of the array declared after struct shash_desc with long long. No trailing padding is required because it is not a struct type that ca= n be used in an array. The CRYPTO_MINALIGN_ATTR is required so that desc is aligned with long = long as would be the case for a struct containing a member with CRYPTO_MINALIGN_ATTR. Signed-off-by: Jan-Simon M=C3=B6ller Signed-off-by: Behan Webster Cc: pageexec@freemail.hu --- crypto/hmac.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/crypto/hmac.c b/crypto/hmac.c index 8d9544c..00ce204 100644 --- a/crypto/hmac.c +++ b/crypto/hmac.c @@ -52,20 +52,19 @@ static int hmac_setkey(struct crypto_shash *parent, struct hmac_ctx *ctx =3D align_ptr(opad + ss, crypto_tfm_ctx_alignment()); struct crypto_shash *hash =3D ctx->hash; - struct { - struct shash_desc shash; - char ctx[crypto_shash_descsize(hash)]; - } desc; + char desc[sizeof(struct shash_desc) + + crypto_shash_descsize(hash)] CRYPTO_MINALIGN_ATTR; + struct shash_desc *shash =3D (struct shash_desc *)desc; unsigned int i; =20 - desc.shash.tfm =3D hash; - desc.shash.flags =3D crypto_shash_get_flags(parent) & - CRYPTO_TFM_REQ_MAY_SLEEP; + shash->tfm =3D hash; + shash->flags =3D crypto_shash_get_flags(parent) + & CRYPTO_TFM_REQ_MAY_SLEEP; =20 if (keylen > bs) { int err; =20 - err =3D crypto_shash_digest(&desc.shash, inkey, keylen, ipad); + err =3D crypto_shash_digest(shash, inkey, keylen, ipad); if (err) return err; =20 @@ -81,12 +80,12 @@ static int hmac_setkey(struct crypto_shash *parent, opad[i] ^=3D 0x5c; } =20 - return crypto_shash_init(&desc.shash) ?: - crypto_shash_update(&desc.shash, ipad, bs) ?: - crypto_shash_export(&desc.shash, ipad) ?: - crypto_shash_init(&desc.shash) ?: - crypto_shash_update(&desc.shash, opad, bs) ?: - crypto_shash_export(&desc.shash, opad); + return crypto_shash_init(shash) ?: + crypto_shash_update(shash, ipad, bs) ?: + crypto_shash_export(shash, ipad) ?: + crypto_shash_init(shash) ?: + crypto_shash_update(shash, opad, bs) ?: + crypto_shash_export(shash, opad); } =20 static int hmac_export(struct shash_desc *pdesc, void *out) --=20 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html