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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 31779C433DF for ; Fri, 15 May 2020 22:06:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04BF320709 for ; Fri, 15 May 2020 22:06:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SxzT6nzH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726492AbgEOWGd (ORCPT ); Fri, 15 May 2020 18:06:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726179AbgEOWGd (ORCPT ); Fri, 15 May 2020 18:06:33 -0400 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1132DC061A0C; Fri, 15 May 2020 15:06:33 -0700 (PDT) Received: by mail-il1-x143.google.com with SMTP id c20so1925608ilk.6; Fri, 15 May 2020 15:06:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=tERCCKiIKjEOnssno9mpcVZCO2wmElRDazrTiC4NWhc=; b=SxzT6nzH53RfnGEZPsqknVJuHoICyb9rZPzQ7437b1+CiLKdVFzjPL8ecKFhHW/7Y0 hHeki8WSCL9l3GnzlwVYDCLkDKD4M8OTwBAlGt89JFRykzRSn5OFt9VXRO3PfBma+Qje Yexk2vdHU/qBxStUMigyYUKQyDbim7QJ0fyaf7MopdrDN4ZL5w+NuRfyzTB/skcq2KuP nmRz3zDU68HZVsgUCSnq79741d3t+1aE2zkuIo+tLXPjz171+nwNH6k6hMdyCQQwWOKo w3bzGx8xW3YY+b6CmzoN2Du8rQpmn3JxZTzJoVya8uy0qgiKWMJEmhmtYlqD9YANXQci CZuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=tERCCKiIKjEOnssno9mpcVZCO2wmElRDazrTiC4NWhc=; b=V1wlLaEkzM7AuSz7Lhp85AOXH7xlMNgNt1nkXspcu22flP85F3004Cs17QljYRmd1O KX9wmmp+JbKkwf3qnjSccupw728BoqGjkzRIOHW0qXsxmbW/0supG6HtdcvJQQn/tza/ Z5ALhjCdghAjYOx4u+QVajJM9u/ZrystLuPAQm5w+B4KlnwOYUGmstDo7I77xU8RtoXT +RbksAk6mHURAbvvDVDvwaEBwJpUOA/IR1hbwSguFNCxojA68bQBZ0pfua1nJBT/Dh4l rKBL1t06VniKjkwc2+FuVI5gQimQbYikiYWyldzMeaFg8tYX8r0vnET0JB+BKztxgAan FHHw== X-Gm-Message-State: AOAM531MUO4d7WYgvFWqo/yGO8+O6H+f+/3VNljM2vNzBbFSiuennwUb v3HqRMjbuUB/oCr0ttQQ+fw= X-Google-Smtp-Source: ABdhPJx1zhZSh7bwpqkECWQRvF3kqTYnQ7hkWZA+FrFoOXcDOz5FAIoBQlEOaFNkeWztXGHYV8BhoA== X-Received: by 2002:a92:bb55:: with SMTP id w82mr5558479ili.211.1589580392500; Fri, 15 May 2020 15:06:32 -0700 (PDT) Received: from [127.0.1.1] ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id l7sm1402407ilh.54.2020.05.15.15.06.23 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 May 2020 15:06:31 -0700 (PDT) Subject: [bpf-next PATCH v2 2/5] bpf: extend bpf_base_func_proto helpers with probe_* and *current_task* From: John Fastabend To: yhs@fb.com, ast@kernel.org, daniel@iogearbox.net Cc: lmb@cloudflare.com, bpf@vger.kernel.org, john.fastabend@gmail.com, jakub@cloudflare.com, netdev@vger.kernel.org Date: Fri, 15 May 2020 15:06:17 -0700 Message-ID: <158958037715.12532.12473092995203096801.stgit@john-Precision-5820-Tower> In-Reply-To: <158958022865.12532.5430684453474460041.stgit@john-Precision-5820-Tower> References: <158958022865.12532.5430684453474460041.stgit@john-Precision-5820-Tower> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Often it is useful when applying policy to know something about the task. If the administrator has CAP_SYS_ADMIN rights then they can use kprobe + networking hook and link the two programs together to accomplish this. However, this is a bit clunky and also means we have to call both the network program and kprobe program when we could just use a single program and avoid passing metadata through sk_msg/skb->cb, socket, maps, etc. To accomplish this add probe_* helpers to bpf_base_func_proto programs guarded by a perfmon_capable() check. New supported helpers are the following, BPF_FUNC_get_current_task BPF_FUNC_current_task_under_cgroup BPF_FUNC_probe_read_user BPF_FUNC_probe_read_kernel BPF_FUNC_probe_read_user_str BPF_FUNC_probe_read_kernel_str Signed-off-by: John Fastabend --- kernel/bpf/helpers.c | 27 +++++++++++++++++++++++++++ kernel/trace/bpf_trace.c | 16 ++++++++-------- 2 files changed, 35 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 886949f..ee992dd 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -601,6 +601,13 @@ const struct bpf_func_proto bpf_event_output_data_proto = { .arg5_type = ARG_CONST_SIZE_OR_ZERO, }; +const struct bpf_func_proto bpf_current_task_under_cgroup_proto __weak; +const struct bpf_func_proto bpf_get_current_task_proto __weak; +const struct bpf_func_proto bpf_probe_read_user_proto __weak; +const struct bpf_func_proto bpf_probe_read_user_str_proto __weak; +const struct bpf_func_proto bpf_probe_read_kernel_proto __weak; +const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak; + const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -648,6 +655,26 @@ bpf_base_func_proto(enum bpf_func_id func_id) case BPF_FUNC_jiffies64: return &bpf_jiffies64_proto; default: + break; + } + + if (!perfmon_capable()) + return NULL; + + switch (func_id) { + case BPF_FUNC_get_current_task: + return &bpf_get_current_task_proto; + case BPF_FUNC_current_task_under_cgroup: + return &bpf_current_task_under_cgroup_proto; + case BPF_FUNC_probe_read_user: + return &bpf_probe_read_user_proto; + case BPF_FUNC_probe_read_kernel: + return &bpf_probe_read_kernel_proto; + case BPF_FUNC_probe_read_user_str: + return &bpf_probe_read_user_str_proto; + case BPF_FUNC_probe_read_kernel_str: + return &bpf_probe_read_kernel_str_proto; + default: return NULL; } } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 9a84d7f..60e54be 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -147,7 +147,7 @@ BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, return ret; } -static const struct bpf_func_proto bpf_probe_read_user_proto = { +const struct bpf_func_proto bpf_probe_read_user_proto = { .func = bpf_probe_read_user, .gpl_only = true, .ret_type = RET_INTEGER, @@ -167,7 +167,7 @@ BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, return ret; } -static const struct bpf_func_proto bpf_probe_read_user_str_proto = { +const struct bpf_func_proto bpf_probe_read_user_str_proto = { .func = bpf_probe_read_user_str, .gpl_only = true, .ret_type = RET_INTEGER, @@ -198,7 +198,7 @@ BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, false); } -static const struct bpf_func_proto bpf_probe_read_kernel_proto = { +const struct bpf_func_proto bpf_probe_read_kernel_proto = { .func = bpf_probe_read_kernel, .gpl_only = true, .ret_type = RET_INTEGER, @@ -213,7 +213,7 @@ BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, return bpf_probe_read_kernel_common(dst, size, unsafe_ptr, true); } -static const struct bpf_func_proto bpf_probe_read_compat_proto = { +const struct bpf_func_proto bpf_probe_read_compat_proto = { .func = bpf_probe_read_compat, .gpl_only = true, .ret_type = RET_INTEGER, @@ -253,7 +253,7 @@ BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, false); } -static const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { +const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { .func = bpf_probe_read_kernel_str, .gpl_only = true, .ret_type = RET_INTEGER, @@ -268,7 +268,7 @@ BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr, true); } -static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { +const struct bpf_func_proto bpf_probe_read_compat_str_proto = { .func = bpf_probe_read_compat_str, .gpl_only = true, .ret_type = RET_INTEGER, @@ -877,7 +877,7 @@ BPF_CALL_0(bpf_get_current_task) return (long) current; } -static const struct bpf_func_proto bpf_get_current_task_proto = { +const struct bpf_func_proto bpf_get_current_task_proto = { .func = bpf_get_current_task, .gpl_only = true, .ret_type = RET_INTEGER, @@ -898,7 +898,7 @@ BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) return task_under_cgroup_hierarchy(current, cgrp); } -static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { +const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { .func = bpf_current_task_under_cgroup, .gpl_only = false, .ret_type = RET_INTEGER,