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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 23470C433E0 for ; Thu, 28 May 2020 05:41:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8EAC20899 for ; Thu, 28 May 2020 05:41:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Zn6qhVBM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728109AbgE1FlY (ORCPT ); Thu, 28 May 2020 01:41:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728069AbgE1FlV (ORCPT ); Thu, 28 May 2020 01:41:21 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77084C05BD1E; Wed, 27 May 2020 22:41:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=RKgk8zViaf8A5u7/beCuCOI0498LURgV/aa2JhdiYjs=; b=Zn6qhVBMpAn77GXpcuKN/iHPMA RbRTTRBammj4MrsO8AhNVVSuA0xsSJSsIlU8dOckiWeZ2FXN1+ty9K4+RR90K6u33N8xrKChrqQkb PwSsuITP+jEHA2q84Lxc3Uc3SGlPHG2HSK+fvMsnSPRXMyO+lGTf0rZxtCr54e8LTXDCJEIPdDL39 6Nmg4vnARVXBh55dKoyPG5OEzrZRfZIUf5xncLNpj9SlvCp1eGWhS9jySc1peFI7eOVwkUZwdhSbD ui3LQbBjdHrJ3zEYg7ikFoVUuPOiZsz8+5NO3ug/7J/qII85sH2qNsEfBw0lXznhEentn4RdTEnwy un2XVTVQ==; Received: from p4fdb1ad2.dip0.t-ipconnect.de ([79.219.26.210] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jeBI6-0002RT-Hj; Thu, 28 May 2020 05:41:18 +0000 From: Christoph Hellwig To: Al Viro Cc: Linus Torvalds , Ian Kent , David Howells , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: [PATCH 12/14] fs: implement kernel_read using __kernel_read Date: Thu, 28 May 2020 07:40:41 +0200 Message-Id: <20200528054043.621510-13-hch@lst.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200528054043.621510-1-hch@lst.de> References: <20200528054043.621510-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Consolidate the two in-kernel read helpers to make upcoming changes easier. The only difference are the missing call to rw_verify_area in kernel_read, and an access_ok check that doesn't make sense for kernel buffers to start with. Signed-off-by: Christoph Hellwig --- fs/read_write.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index bd12af8a895c8..4e19152a7efe0 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -453,15 +453,12 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { - mm_segment_t old_fs; - ssize_t result; + ssize_t ret; - old_fs = get_fs(); - set_fs(KERNEL_DS); - /* The cast to a user pointer is valid due to the set_fs() */ - result = vfs_read(file, (void __user *)buf, count, pos); - set_fs(old_fs); - return result; + ret = rw_verify_area(READ, file, pos, count); + if (ret) + return ret; + return __kernel_read(file, buf, count, pos); } EXPORT_SYMBOL(kernel_read); -- 2.26.2