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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 3A287C432C2 for ; Wed, 25 Sep 2019 23:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 181D520640 for ; Wed, 25 Sep 2019 23:04:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730757AbfIYXEQ (ORCPT ); Wed, 25 Sep 2019 19:04:16 -0400 Received: from mx2.mailbox.org ([80.241.60.215]:26388 "EHLO mx2.mailbox.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726206AbfIYXEQ (ORCPT ); Wed, 25 Sep 2019 19:04:16 -0400 Received: from smtp2.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:105:465:1:1:0]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by mx2.mailbox.org (Postfix) with ESMTPS id 690E0A2271; Thu, 26 Sep 2019 01:04:13 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.240]) by spamfilter02.heinlein-hosting.de (spamfilter02.heinlein-hosting.de [80.241.56.116]) (amavisd-new, port 10030) with ESMTP id dnEiLNSDRYRu; Thu, 26 Sep 2019 01:04:10 +0200 (CEST) From: Aleksa Sarai To: Ingo Molnar , Peter Zijlstra , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Christian Brauner Cc: Aleksa Sarai , Rasmus Villemoes , Al Viro , Linus Torvalds , libc-alpha@sourceware.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 0/4] lib: introduce copy_struct_from_user() helper Date: Thu, 26 Sep 2019 01:03:28 +0200 Message-Id: <20190925230332.18690-1-cyphar@cyphar.com> 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 Patch changelog: v2: * Switch to less buggy handling of alignment. [Linus Torvalds, Al Viro] * Move is_zeroed_user() to lib/usercopy.c. [kbuild test robot] * Move copy_struct_to_user() to lib/usercopy.c. [Christian Brauner] * Add self-tests for is_zeroed_user() to lib/test_user_copy.c. [Christian Brauner] v1: This series was split off from the openat2(2) syscall discussion[1]. However, the copy_struct_to_user() helper has been dropped, because after some discussion it appears that there is no really obvious semantics for how copy_struct_to_user() should work on mixed-vintages (for instance, whether [2] is the correct semantics for all syscalls). A common pattern for syscall extensions is increasing the size of a struct passed from userspace, such that the zero-value of the new fields result in the old kernel behaviour (allowing for a mix of userspace and kernel vintages to operate on one another in most cases). Previously there was no common lib/ function that implemented the necessary extension-checking semantics (and different syscalls implemented them slightly differently or incompletely[3]). This series implements the helper and ports several syscalls to use it. [1]: https://lore.kernel.org/lkml/20190904201933.10736-1-cyphar@cyphar.com/ [2]: commit 1251201c0d34 ("sched/core: Fix uclamp ABI bug, clean up and robustify sched_read_attr() ABI logic and code") [3]: For instance {sched_setattr,perf_event_open,clone3}(2) all do do similar checks to copy_struct_from_user() while rt_sigprocmask(2) always rejects differently-sized struct arguments. Aleksa Sarai (4): lib: introduce copy_struct_from_user() helper clone3: switch to copy_struct_from_user() sched_setattr: switch to copy_struct_from_user() perf_event_open: switch to copy_struct_from_user() include/linux/bitops.h | 7 +++ include/linux/uaccess.h | 4 ++ include/uapi/linux/sched.h | 2 + kernel/events/core.c | 47 +++------------ kernel/fork.c | 34 +++-------- kernel/sched/core.c | 43 +++----------- lib/strnlen_user.c | 8 +-- lib/test_user_copy.c | 59 +++++++++++++++++-- lib/usercopy.c | 115 +++++++++++++++++++++++++++++++++++++ 9 files changed, 205 insertions(+), 114 deletions(-) -- 2.23.0