From patchwork Fri Jun 21 16:59:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 806396 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E06AF172761; Fri, 21 Jun 2024 17:00:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718989221; cv=none; b=RDLSn8r0TTH2bpBZJYuKYp9JOyYaEhkAjaKodSq+W0xOWBXB+AQUK022qySNZJoOZDDU0JnUOKvMjYNDH069KtUQVNtUW+RL0/P3y1bjcE1EhgbHPshpV7/Z+H6M6iiDRrP2t80XbeyH64gQcGtrTDxyCZYO9590AfqdJawAR18= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718989221; c=relaxed/simple; bh=FQIlGe1ODogKmI2ftbLTyX6pGZq9j7L+IwPSLI+6oQE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C0WtB73M3J32Jk4JjGcZYm9oQ12Btrlr2hTbRTpWTO6aYjhFv9t1VJFalIik7vVt6oZD56hP/Mxa6rT2A2xhzG9kAFOcvs91ysUHYHFpy44bqW9JiRnT1ZfeCOxcNRLH6BFR8clSKBml11/LzBwlgOxB0398320oUvd/Kdicr9s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jrPFiXKi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jrPFiXKi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2090CC3277B; Fri, 21 Jun 2024 17:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718989220; bh=FQIlGe1ODogKmI2ftbLTyX6pGZq9j7L+IwPSLI+6oQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jrPFiXKi4LvCNOgnzw+phKBA5RMKNvKjBEYelo/7go6XV8yi4vFGII9AS/EJkWvdd GDOuq2HZ63To6E3tgcjpWX9Dcsar7WBntHgV6iRE/v0bTWlCGXk8f2THnUMc221xSJ DmaUJBepd428UBiTB3dqkMvg87ZQLgfdPsvBEllsUTsjwtBl7PhAzCUup2kmVwvAZq SccO2T5TsxGGtff0hPnRwsiJACJlRzRpvTdCDNy5+dLKvB4Ul2hjmvVV/DD8kHfE0j +0x2CBv9sWxCqIJdnBHhpQvnFbgCRSCIMS0D1DCyDjncDmOwWiKx08b+qbwJjYk6Gh Z6l5e45qmzHXQ== From: Eric Biggers To: linux-crypto@vger.kernel.org, fsverity@lists.linux.dev, dm-devel@lists.linux.dev Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Sami Tolvanen , Bart Van Assche , Herbert Xu , Alasdair Kergon , Mike Snitzer , Mikulas Patocka Subject: [PATCH v6 09/15] dm-verity: make real_digest and want_digest fixed-length Date: Fri, 21 Jun 2024 09:59:16 -0700 Message-ID: <20240621165922.77672-10-ebiggers@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240621165922.77672-1-ebiggers@kernel.org> References: <20240621165922.77672-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers Change the digest fields in struct dm_verity_io from variable-length to fixed-length, since their maximum length is fixed at HASH_MAX_DIGESTSIZE, i.e. 64 bytes, which is not too big. This is simpler and makes the fields a bit faster to access. (HASH_MAX_DIGESTSIZE did not exist when this code was written, which may explain why it wasn't used.) This makes the verity_io_real_digest() and verity_io_want_digest() functions trivial, but this patch leaves them in place temporarily since most of their callers will go away in a later patch anyway. Reviewed-by: Sami Tolvanen Acked-by: Ard Biesheuvel Signed-off-by: Eric Biggers --- drivers/md/dm-verity-target.c | 3 +-- drivers/md/dm-verity.h | 17 +++++++---------- 2 files changed, 8 insertions(+), 12 deletions(-) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 796d85526696..4ef814a7faf4 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -1527,12 +1527,11 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv) ti->error = "Cannot allocate workqueue"; r = -ENOMEM; goto bad; } - ti->per_io_data_size = sizeof(struct dm_verity_io) + - v->ahash_reqsize + v->digest_size * 2; + ti->per_io_data_size = sizeof(struct dm_verity_io) + v->ahash_reqsize; r = verity_fec_ctr(v); if (r) goto bad; diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h index 20b1bcf03474..5d3da9f5fc95 100644 --- a/drivers/md/dm-verity.h +++ b/drivers/md/dm-verity.h @@ -89,19 +89,16 @@ struct dm_verity_io { struct work_struct work; struct work_struct bh_work; char *recheck_buffer; + u8 real_digest[HASH_MAX_DIGESTSIZE]; + u8 want_digest[HASH_MAX_DIGESTSIZE]; + /* - * Three variably-size fields follow this struct: - * - * u8 hash_req[v->ahash_reqsize]; - * u8 real_digest[v->digest_size]; - * u8 want_digest[v->digest_size]; - * - * To access them use: verity_io_hash_req(), verity_io_real_digest() - * and verity_io_want_digest(). + * This struct is followed by a variable-sized struct ahash_request of + * size v->ahash_reqsize. To access it, use verity_io_hash_req(). */ }; static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v, struct dm_verity_io *io) @@ -110,17 +107,17 @@ static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v, } static inline u8 *verity_io_real_digest(struct dm_verity *v, struct dm_verity_io *io) { - return (u8 *)(io + 1) + v->ahash_reqsize; + return io->real_digest; } static inline u8 *verity_io_want_digest(struct dm_verity *v, struct dm_verity_io *io) { - return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size; + return io->want_digest; } extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, struct bvec_iter *iter, int (*process)(struct dm_verity *v,