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,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E718CC47404 for ; Wed, 9 Oct 2019 16:09:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA20F2196E for ; Wed, 9 Oct 2019 16:09:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731738AbfJIQJS (ORCPT ); Wed, 9 Oct 2019 12:09:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41922 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731666AbfJIQJR (ORCPT ); Wed, 9 Oct 2019 12:09:17 -0400 Received: from [213.220.153.21] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iIEWW-00034Q-P7; Wed, 09 Oct 2019 16:09:12 +0000 From: Christian Brauner To: Alexei Starovoitov , Daniel Borkmann , bpf@vger.kernel.org Cc: Martin KaFai Lau , Song Liu , Yonghong Song , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: [PATCH 0/3] bpf: switch to new usercopy helpers Date: Wed, 9 Oct 2019 18:09:04 +0200 Message-Id: <20191009160907.10981-1-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hey everyone, In v5.4-rc2 we added two new helpers check_zeroed_user() and copy_struct_from_user() including selftests (cf. [1]). It is a generic interface designed to copy a struct from userspace. The helpers will be especially useful for structs versioned by size of which we have quite a few. The most obvious benefit is that this helper lets us get rid of duplicate code. We've already switched over sched_setattr(), perf_event_open(), and clone3(). More importantly it will also help to ensure that users implementing versioning-by-size end up with the same core semantics. This point is especially crucial since we have at least one case where versioning-by-size is used but with slighly different semantics: sched_setattr(), perf_event_open(), and clone3() all do do similar checks to copy_struct_from_user() while rt_sigprocmask(2) always rejects differently-sized struct arguments. This little series switches over bpf codepaths that have hand-rolled implementations of these helpers. Thanks! Christian /* Reference */ [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Christian Brauner (3): bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() bpf: use copy_struct_from_user() in bpf() syscall kernel/bpf/syscall.c | 38 ++++++++++++-------------------------- 1 file changed, 12 insertions(+), 26 deletions(-) -- 2.23.0