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=-7.8 required=3.0 tests=DATE_IN_PAST_12_24, DKIMWL_WL_MED,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_IN_DEF_DKIM_WL 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 6EF2EC43381 for ; Fri, 1 Mar 2019 18:01:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41D5A20857 for ; Fri, 1 Mar 2019 18:01:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="EFLBva0R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389057AbfCASBs (ORCPT ); Fri, 1 Mar 2019 13:01:48 -0500 Received: from mail-oi1-f195.google.com ([209.85.167.195]:46778 "EHLO mail-oi1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728507AbfCASBs (ORCPT ); Fri, 1 Mar 2019 13:01:48 -0500 Received: by mail-oi1-f195.google.com with SMTP id j135so20228371oib.13 for ; Fri, 01 Mar 2019 10:01:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+r82PNNK4S55yUQzJgD/fkG0icmVvlFt/MZlHiovndA=; b=EFLBva0RLP5a/haLL2eAdJBRkV8FmWosns5nRq2FrWRX9ZnIocGJUttD0sk4Wzb/+w zpifjLtI+Ckv6iqtl9oIR/OQ+puNgrBQ79rpvkzxdpuxtOf29ITXFFI/gI7qHVLIibJ/ 997P4LKdXH6E4vIB3/kAQ21UEhHGo5LxznGYtzerDiMgdwg8ULanxxlUmRfF58oS5Ixq mQ+KW0p5RfWteF5f0NhGqIsezyR4j/lm6OP7iCAw0FTYAtfOgxwhYOdoyUhQpG2ktvXY QTZ1+hb8HO8S+RwvdrGBFBUYWncQ4rQgMiFUQ8B0euMRqaMfNmUTdvmR5RXiVuZZo12i RCiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+r82PNNK4S55yUQzJgD/fkG0icmVvlFt/MZlHiovndA=; b=Eaf2K3BGYv1S76MlLii292uZzP2krWSqXLa8tMJHzPvlNklUUBVK7vKIJkQsKGtYKO EgXzAFL4kqg1WRg1Q7cejBzFcaIW0Ztlh6koUR22d1iSbIDfdUPE2gm7W93ZD24+ILut m9ZW8LcYcFv6IaX6e4s0FAFJu6maBUc0Eh9Jd811gCiMt2Zn1rmFrEUCBcukd3ii7DHH DH+sCMf1ThvSsOY/4jrNS9Ka9KUszDARlPvQlaRo9R4OcwIKzoWOB+SzteZUrMC9iWeS x0Jg3bf960p4L/z9VEWBnNuAlnJ0Kx863PNZcbedEZEwZpKPmC1wFd+21GWZbk81DxZL CaSA== X-Gm-Message-State: APjAAAXhJRLJey0TIWGrulSBD2I2zywBasMan6gCIT+7AgI4ajUSUpny +1iECiamt538lFF8cu0hDxoCqeSBsyd5TxNO7Pyf5Q== X-Google-Smtp-Source: APXvYqzcEXRLSZ+gSa9475qH55naz08aI+0sxYVaf8xECQABgXWhNu4dXXbOnWWBFxbUZ6wX/Yugw13re6mDtYdUj04= X-Received: by 2002:aca:360a:: with SMTP id d10mr2017174oia.68.1551411250705; Thu, 28 Feb 2019 19:34:10 -0800 (PST) MIME-Version: 1.0 References: <20190228231829.11993-1-daniel@iogearbox.net> <20190228231829.11993-2-daniel@iogearbox.net> In-Reply-To: <20190228231829.11993-2-daniel@iogearbox.net> From: Jann Horn Date: Fri, 1 Mar 2019 04:33:44 +0100 Message-ID: Subject: Re: [PATCH bpf-next v2 1/7] bpf: implement lookup-free direct value access To: Daniel Borkmann Cc: Alexei Starovoitov , bpf@vger.kernel.org, Network Development , joe@wand.net.nz, john.fastabend@gmail.com, tgraf@suug.ch, yhs@fb.com, andriin@fb.com, jakub.kicinski@netronome.com, lmb@cloudflare.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Mar 1, 2019 at 12:19 AM Daniel Borkmann wrote: > This generic extension to BPF maps allows for directly loading an > address residing inside a BPF map value as a single BPF ldimm64 > instruction. [...] > @@ -6698,16 +6705,44 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env) > return err; > } > > - /* store map pointer inside BPF_LD_IMM64 instruction */ > - insn[0].imm = (u32) (unsigned long) map; > - insn[1].imm = ((u64) (unsigned long) map) >> 32; > + aux = &env->insn_aux_data[i]; > + if (insn->src_reg == BPF_PSEUDO_MAP_FD) { > + addr = (unsigned long)map; > + } else { > + u32 off = insn[1].imm; > + > + if (off >= BPF_MAX_VAR_OFF) { > + verbose(env, "direct value offset of %u is not allowed\n", > + off); > + return -EINVAL; > + } > + if (!map->ops->map_direct_value_access) { > + verbose(env, "no direct value access support for this map type\n"); > + return -EINVAL; > + } > + > + err = map->ops->map_direct_value_access(map, off, &addr); > + if (err) { > + verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n", > + map->value_size, off); > + return err; > + } All these error returns need fdput(f), I think.