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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT 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 53A09C4363A for ; Tue, 20 Oct 2020 19:15:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E71632224A for ; Tue, 20 Oct 2020 19:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438037AbgJTTPw (ORCPT ); Tue, 20 Oct 2020 15:15:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438033AbgJTTPw (ORCPT ); Tue, 20 Oct 2020 15:15:52 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91576C0613CE; Tue, 20 Oct 2020 12:15:51 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 4722E1F44C34 From: Gabriel Krisman Bertazi To: dhowells@redhat.com Cc: viro@zeniv.linux.org.uk, tytso@mit.edu, khazhy@google.com, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, kernel@collabora.com, Miklos Szeredi , Gabriel Krisman Bertazi Subject: [PATCH RFC 1/7] watch_queue: Make watch_sizeof() check record size Date: Tue, 20 Oct 2020 15:15:37 -0400 Message-Id: <20201020191543.601784-2-krisman@collabora.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201020191543.601784-1-krisman@collabora.com> References: <20201020191543.601784-1-krisman@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: David Howells Make watch_sizeof() give a build error if the size of the struct won't fit into the size field in the header. Reported-by: Miklos Szeredi Signed-off-by: David Howells [Rebase to 5.10] Signed-off-by: Gabriel Krisman Bertazi --- include/linux/watch_queue.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h index c994d1b2cdba..f1086d12cd03 100644 --- a/include/linux/watch_queue.h +++ b/include/linux/watch_queue.h @@ -120,7 +120,12 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id) * watch_sizeof - Calculate the information part of the size of a watch record, * given the structure size. */ -#define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT) +#define watch_sizeof(STRUCT) \ + ({ \ + size_t max = WATCH_INFO_LENGTH >> WATCH_INFO_LENGTH__SHIFT; \ + BUILD_BUG_ON(sizeof(STRUCT) > max); \ + sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT; \ + }) #else static inline int watch_queue_init(struct pipe_inode_info *pipe) -- 2.28.0