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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PULL_REQUEST,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EB5B8ECE59D for ; Wed, 16 Oct 2019 00:48:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3EAD2067B for ; Wed, 16 Oct 2019 00:48:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726379AbfJPAsN (ORCPT ); Tue, 15 Oct 2019 20:48:13 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:53490 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726362AbfJPAsN (ORCPT ); Tue, 15 Oct 2019 20:48:13 -0400 Received: from [213.220.153.21] (helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iKXU2-0006Y2-T7; Wed, 16 Oct 2019 00:48:10 +0000 Date: Wed, 16 Oct 2019 02:48:10 +0200 From: Christian Brauner To: ast@kernel.org Cc: bpf@vger.kernel.org, daniel@iogearbox.net, kafai@fb.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, songliubraving@fb.com, yhs@fb.com Subject: Re: [PATCH v2 0/3] bpf: switch to new usercopy helpers Message-ID: <20191016004809.tgw6zznr6ukppplp@wittgenstein> References: <20191009160907.10981-1-christian.brauner@ubuntu.com> <20191016004138.24845-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191016004138.24845-1-christian.brauner@ubuntu.com> User-Agent: NeoMutt/20180716 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, Oct 16, 2019 at 02:41:35AM +0200, Christian Brauner wrote: > 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 > > /* v1 */ > Link: https://lore.kernel.org/r/20191009160907.10981-1-christian.brauner@ubuntu.com > > /* v2 */ > - rebase onto bpf-next > > /* Reference */ > [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Alexei, instead of applying the series you can also just pull from me: The following changes since commit 5bc60de50dfea235634fdf38cbc992fb968d113b: selftests: bpf: Don't try to read files without read permission (2019-10-15 16:27:25 -0700) are available in the Git repository at: git@gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux tags/bpf-copy-struct-from-user for you to fetch changes up to da1699b959d182bb161be3ffc17eab063b2aedd2: bpf: use copy_struct_from_user() in bpf() syscall (2019-10-16 02:35:11 +0200) ---------------------------------------------------------------- bpf-copy-struct-from-user ---------------------------------------------------------------- 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 | 46 ++++++++++++++++++---------------------------- 1 file changed, 18 insertions(+), 28 deletions(-)