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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 82310C433E1 for ; Tue, 21 Jul 2020 20:26:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60EBE2073A for ; Tue, 21 Jul 2020 20:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731149AbgGUU0v (ORCPT ); Tue, 21 Jul 2020 16:26:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730281AbgGUUZv (ORCPT ); Tue, 21 Jul 2020 16:25:51 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02ECFC0619DC; Tue, 21 Jul 2020 13:25:50 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxyph-00HPoa-Mq; Tue, 21 Jul 2020 20:25:49 +0000 From: Al Viro To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH 04/18] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum Date: Tue, 21 Jul 2020 21:25:35 +0100 Message-Id: <20200721202549.4150745-4-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200721202549.4150745-1-viro@ZenIV.linux.org.uk> References: <20200721202425.GA2786714@ZenIV.linux.org.uk> <20200721202549.4150745-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro Preparation for the change of calling conventions; right now all callers pass 0 as initial sum. Passing 0xffffffff instead yields the values comparable mod 0xffff and guarantees that 0 will not be returned on success. Signed-off-by: Al Viro --- lib/iov_iter.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 7405922caaec..d5b7e204fea6 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1451,7 +1451,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, int err = 0; next = csum_and_copy_from_user(v.iov_base, (to += v.iov_len) - v.iov_len, - v.iov_len, 0, &err); + v.iov_len, ~0U, &err); if (!err) { sum = csum_block_add(sum, next, off); off += v.iov_len; @@ -1493,7 +1493,7 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, int err = 0; next = csum_and_copy_from_user(v.iov_base, (to += v.iov_len) - v.iov_len, - v.iov_len, 0, &err); + v.iov_len, ~0U, &err); if (err) return false; sum = csum_block_add(sum, next, off); @@ -1539,7 +1539,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, int err = 0; next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len, v.iov_base, - v.iov_len, 0, &err); + v.iov_len, ~0U, &err); if (!err) { sum = csum_block_add(sum, next, off); off += v.iov_len; -- 2.11.0