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=-6.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 4F9B0C2D0A3 for ; Wed, 4 Nov 2020 06:51:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1BFF2072E for ; Wed, 4 Nov 2020 06:51:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="U+oNG1i1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727214AbgKDGvk (ORCPT ); Wed, 4 Nov 2020 01:51:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726152AbgKDGvk (ORCPT ); Wed, 4 Nov 2020 01:51:40 -0500 Received: from mail-oi1-x242.google.com (mail-oi1-x242.google.com [IPv6:2607:f8b0:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32BCDC061A4D; Tue, 3 Nov 2020 22:51:40 -0800 (PST) Received: by mail-oi1-x242.google.com with SMTP id s21so21191642oij.0; Tue, 03 Nov 2020 22:51:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=ww8C00KkabtDLxcKDhOCeqOXU2u0UX9A1QT4C+4IqFg=; b=U+oNG1i1btw1zXWh+bm57bzcwFK4mYE4QByksZ31ZOpagHl1C+v/SOUHCSg7CswSd6 PTALrp62R1Zd8o9Y2R4V+5pfOT3M3V17TSN4pIWQYirQTCsraF9BmMCa9HTYEcOhzRI6 rGK786eMxm2RXA5HdI85KXlzyUyZDPdQ/K3LpagBqDCjooWEpQC47PVpuET5ReKHkqAN yPH5rnqhxev3jEnC9f/hYHs/HCsNCd06op0/ksCYK/NFIkHeh27ebS8RmQNk4AUYSS/y gQ2zSOgJ4tkFBwdR5yXoOf82s3pQt86EctYNMw+0zoXy0dANx6Y1gV4hE99tet0przAN dhhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=ww8C00KkabtDLxcKDhOCeqOXU2u0UX9A1QT4C+4IqFg=; b=OmHFjjwYCA/8mCMNtWhy1eZecHveNnO1E6YFoNocxjA9QnIjjjnrv6UM5E+scgxM6M kUR+LtICxHt2efgWRbFPTSU2v0uBCOW376pHsw33q4a0ZdO6VOtFSEoyqOFlKQQ28w7C THcCsuAnTd4VlQIY5zMq2PIHN+3ydzDO3/prBOIs+PLnKxpOO09dimyiB2OqrA33MCbh YLxEZeiCK8Vs+QDvShkgx2gw1agvmhHdMUgMece3eEDr0XwofONYky6bvhBUFju4FMcM PrJVN4F2bI9M/1goSzeb2BTvL4Q18kGA+bDjnJXdiqY9A58bY4cO/IGZ22U/MJsOX64b Xp4g== X-Gm-Message-State: AOAM530tA6crOrZUcqqeMgyz4MnHlOyeN/7TEtqT/DurJHm71wYGr8Il UzRcUeuwmmeNM9f3P1VticDl1qtE16EGtA== X-Google-Smtp-Source: ABdhPJzyun/H7Hi4rEAyd54p/J+uvbUT3Lpvv2RlIVlAbVFszhVzGqMO/sgbsnF8KixxOElEmKZGPQ== X-Received: by 2002:aca:5b85:: with SMTP id p127mr1872802oib.34.1604472699568; Tue, 03 Nov 2020 22:51:39 -0800 (PST) Received: from localhost ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id h15sm303563ots.31.2020.11.03.22.51.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Nov 2020 22:51:38 -0800 (PST) Date: Tue, 03 Nov 2020 22:51:30 -0800 From: John Fastabend To: Alexei Starovoitov , KP Singh Cc: open list , bpf , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Paul Turner , Jann Horn , Hao Luo Message-ID: <5fa24f72dd48e_9fa0e20871@john-XPS-13-9370.notmuch> In-Reply-To: References: <20201103153132.2717326-1-kpsingh@chromium.org> <20201103153132.2717326-8-kpsingh@chromium.org> <20201103184714.iukuqfw2byls3s4k@ast-mbp.dhcp.thefacebook.com> Subject: Re: [PATCH bpf-next v2 7/8] bpf: Add tests for task_local_storage Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexei Starovoitov wrote: > On Tue, Nov 3, 2020 at 5:55 PM KP Singh wrote: > > > > [...] > > > > > > > > > > I saw the docs mention that these are not exposed to tracing programs due to > > > > insufficient preemption checks. Do you think it would be okay to allow them > > > > for LSM programs? > > > > > > hmm. Isn't it allowed already? > > > The verifier does: > > > if ((is_tracing_prog_type(prog_type) || > > > prog_type == BPF_PROG_TYPE_SOCKET_FILTER) && > > > map_value_has_spin_lock(map)) { > > > verbose(env, "tracing progs cannot use bpf_spin_lock yet\n"); > > > return -EINVAL; > > > } > > > > > > BPF_PROG_TYPE_LSM is not in this list. > > > > The verifier does not have any problem, it's just that the helpers are not > > exposed to LSM programs via bpf_lsm_func_proto. > > > > So all we need is: > > > > diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c > > index 61f8cc52fd5b..93383df2140b 100644 > > --- a/kernel/bpf/bpf_lsm.c > > +++ b/kernel/bpf/bpf_lsm.c > > @@ -63,6 +63,10 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const > > struct bpf_prog *prog) > > return &bpf_task_storage_get_proto; > > case BPF_FUNC_task_storage_delete: > > return &bpf_task_storage_delete_proto; > > + case BPF_FUNC_spin_lock: > > + return &bpf_spin_lock_proto; > > + case BPF_FUNC_spin_unlock: > > + return &bpf_spin_unlock_proto; > > Ahh. Yes. That should do it. Right now I don't see concerns with safety > of the bpf_spin_lock in bpf_lsm progs. What about sleepable lsm hooks? Normally we wouldn't expect to sleep with a spinlock held. Should we have a check to ensure programs bpf_spin_lock are not also sleepable?