From patchwork Fri May 22 04:24:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Fastabend X-Patchwork-Id: 218732 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, URIBL_BLOCKED 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 09EF6C433E0 for ; Fri, 22 May 2020 04:24:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA69C206DD for ; Fri, 22 May 2020 04:24:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cT1HgshI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727855AbgEVEYk (ORCPT ); Fri, 22 May 2020 00:24:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726286AbgEVEYk (ORCPT ); Fri, 22 May 2020 00:24:40 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EB22C061A0E; Thu, 21 May 2020 21:24:40 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id y198so4629806pfb.4; Thu, 21 May 2020 21:24:40 -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=8be0dtX8Bx/Brc6sNGJ5yvfgieIe1YrD5dF5nmEn7pI=; b=cT1HgshI4I0n0b+SflxNfDkbf3zlrNCPRS4X8hXeDgqoYfdLwjOV3W1MWt1xlFmxrA m7iHWHlT+//ig2t27WQ7HdDP97+P5IdCjyMTNb9sXqx5q1O2KA40Q68cs3QbciM8BFXw TwOKaEDCQMxcDCr0SKpeEvRIEvB8J8mwyQrwix0/cHyewP721JR3UBUKdDt88u0QnRaO Y8FECRUQlDk8SNX+ybqNsrnpJYCy6+lqmX8h0RAX7sDC24Moj5K654ebrkMdkPQg/T+J r+xdypLY75GTTRGFZDwP7aUiFgjgAVyD87WG6v6+H5DaSbc+fwV+hhasrtZZoTVUYxlx 3VaQ== 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=8be0dtX8Bx/Brc6sNGJ5yvfgieIe1YrD5dF5nmEn7pI=; b=CtrYaZ9g71ZiWv0EOR1eN/Tz6LDEM/SNnzJ6s9jt6LFhjbTxzihGsb4pgCgGE2wDE+ WykvHsr4pqPiGJjTMJSr5/fap9ZfCFYuuhCqdSLfD11kDfx0Zct3rCmwmjpUAGTe6CZ4 QRhgMTjE3vXPBH5ADMwoAG/udJM7u0TxtgobwiccAhyDTv+OnO1ZSG7662wL4elZcOFd YoFYaxhcmDUt5shHBPuTYdvZKQfsKMWQW5JfQ/RsjlDSvQLSfnvhQ6QOiqyiDXfJk1cl fhlVquX4Gs1IzEMnqYX/BdMgGRdA/P7QdBtwUe/CexBwlzY0Gtg+1mkZRjFLrYH7Irg1 R99w== X-Gm-Message-State: AOAM532MOgTcnNd47JtDuGZrJegqC9FNgInj/RYtrjohtDXfmUcuFTX4 J/IOhmipbaPsXI4DiAG80Hk= X-Google-Smtp-Source: ABdhPJx5ymzSVvKTn0gURA/z/0XsLCCNRlJiQtWV7lcVHXjPgQhzf8ET2yF2LpNvTBw17/HABs+gJQ== X-Received: by 2002:a62:19d5:: with SMTP id 204mr2159724pfz.189.1590121479566; Thu, 21 May 2020 21:24:39 -0700 (PDT) Received: from [127.0.1.1] ([184.63.162.180]) by smtp.gmail.com with ESMTPSA id z23sm4931236pga.86.2020.05.21.21.24.29 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 May 2020 21:24:38 -0700 (PDT) Subject: [bpf-next PATCH v4 2/5] bpf: extend bpf_base_func_proto helpers with probe_* and *current_task* From: John Fastabend To: yhs@fb.com, andrii.nakryiko@gmail.com, ast@kernel.org, daniel@iogearbox.net Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, john.fastabend@gmail.com, jakub@cloudflare.com, lmb@cloudflare.com Date: Thu, 21 May 2020 21:24:23 -0700 Message-ID: <159012146282.14791.7652481804905295417.stgit@john-Precision-5820-Tower> In-Reply-To: <159012108670.14791.18091717338621259928.stgit@john-Precision-5820-Tower> References: <159012108670.14791.18091717338621259928.stgit@john-Precision-5820-Tower> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 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 Acked-by: Yonghong Song --- 0 files changed 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 9531f54..6fabbc4 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, @@ -907,7 +907,7 @@ 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, @@ -928,7 +928,7 @@ 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,