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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 F0F5CC31E40 for ; Tue, 30 Jul 2019 17:32:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEC94204FD for ; Tue, 30 Jul 2019 17:32:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731243AbfG3Rct (ORCPT ); Tue, 30 Jul 2019 13:32:49 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:52554 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731017AbfG3Rcs (ORCPT ); Tue, 30 Jul 2019 13:32:48 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id A7ACA126598EE; Tue, 30 Jul 2019 10:32:47 -0700 (PDT) Date: Tue, 30 Jul 2019 10:32:45 -0700 (PDT) Message-Id: <20190730.103245.831770564486791326.davem@davemloft.net> To: dhowells@redhat.com Cc: netdev@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, arnd@arndb.de, keescook@chromium.org Subject: Re: [PATCH net-next] rxrpc: Fix -Wframe-larger-than= warnings from on-stack crypto From: David Miller In-Reply-To: <156449861697.10315.4666924841804740487.stgit@warthog.procyon.org.uk> References: <156449861697.10315.4666924841804740487.stgit@warthog.procyon.org.uk> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 30 Jul 2019 10:32:48 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: David Howells Date: Tue, 30 Jul 2019 15:56:57 +0100 > rxkad sometimes triggers a warning about oversized stack frames when > building with clang for a 32-bit architecture: > > net/rxrpc/rxkad.c:243:12: error: stack frame size of 1088 bytes in function 'rxkad_secure_packet' [-Werror,-Wframe-larger-than=] > net/rxrpc/rxkad.c:501:12: error: stack frame size of 1088 bytes in function 'rxkad_verify_packet' [-Werror,-Wframe-larger-than=] > > The problem is the combination of SYNC_SKCIPHER_REQUEST_ON_STACK() in > rxkad_verify_packet()/rxkad_secure_packet() with the relatively large > scatterlist in rxkad_verify_packet_1()/rxkad_secure_packet_encrypt(). > > The warning does not show up when using gcc, which does not inline the > functions as aggressively, but the problem is still the same. > > Allocate the cipher buffers from the slab instead, caching the allocated > packet crypto request memory used for DATA packet crypto in the rxrpc_call > struct. > > Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") > Reported-by: Arnd Bergmann > Signed-off-by: David Howells > Acked-by: Arnd Bergmann > cc: Herbert Xu Applied.