From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25B54C3A5A4 for ; Fri, 30 Aug 2019 08:03:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E896B21726 for ; Fri, 30 Aug 2019 08:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727544AbfH3IDy (ORCPT ); Fri, 30 Aug 2019 04:03:54 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:59564 "EHLO fornost.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727417AbfH3IDx (ORCPT ); Fri, 30 Aug 2019 04:03:53 -0400 Received: from gwarestrin.arnor.me.apana.org.au ([192.168.0.7]) by fornost.hmeau.com with smtp (Exim 4.89 #2 (Debian)) id 1i3bsr-0003vO-4o; Fri, 30 Aug 2019 18:03:50 +1000 Received: by gwarestrin.arnor.me.apana.org.au (sSMTP sendmail emulation); Fri, 30 Aug 2019 18:03:48 +1000 Date: Fri, 30 Aug 2019 18:03:48 +1000 From: Herbert Xu To: Ard Biesheuvel Cc: linux-crypto@vger.kernel.org, ebiggers@kernel.org Subject: Re: [PATCH 08/17] crypto: skcipher - add the ability to abort a skcipher walk Message-ID: <20190830080347.GA6677@gondor.apana.org.au> References: <20190821143253.30209-1-ard.biesheuvel@linaro.org> <20190821143253.30209-9-ard.biesheuvel@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190821143253.30209-9-ard.biesheuvel@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Wed, Aug 21, 2019 at 05:32:44PM +0300, Ard Biesheuvel wrote: > After starting a skcipher walk, the only way to ensure that all > resources it has tied up are released is to complete it. In some > cases, it will be useful to be able to abort a walk cleanly after > it has started, so add this ability to the skcipher walk API. > > Signed-off-by: Ard Biesheuvel > --- > crypto/skcipher.c | 3 +++ > include/crypto/internal/skcipher.h | 5 +++++ > 2 files changed, 8 insertions(+) > > diff --git a/crypto/skcipher.c b/crypto/skcipher.c > index 5d836fc3df3e..973ab1c7dcca 100644 > --- a/crypto/skcipher.c > +++ b/crypto/skcipher.c > @@ -140,6 +140,9 @@ int skcipher_walk_done(struct skcipher_walk *walk, int err) > goto already_advanced; > } > > + if (unlikely(!n)) > + goto finish; > + > scatterwalk_advance(&walk->in, n); > scatterwalk_advance(&walk->out, n); > already_advanced: > diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h > index d68faa5759ad..bc488173531f 100644 > --- a/include/crypto/internal/skcipher.h > +++ b/include/crypto/internal/skcipher.h > @@ -148,6 +148,11 @@ int skcipher_walk_aead_decrypt(struct skcipher_walk *walk, > struct aead_request *req, bool atomic); > void skcipher_walk_complete(struct skcipher_walk *walk, int err); > > +static inline void skcipher_walk_abort(struct skcipher_walk *walk) > +{ > + skcipher_walk_done(walk, walk->nbytes); > +} Couldn't you just abort it by supplying an error in place of walk->bytes? IOW I'm fine with this helper but you don't need to touch skcipher_walk_done as just giving it an negative err value should do the trick. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt