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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 66087C28CF6 for ; Wed, 1 Aug 2018 18:32:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24FFD20840 for ; Wed, 1 Aug 2018 18:32:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24FFD20840 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733039AbeHAUTA (ORCPT ); Wed, 1 Aug 2018 16:19:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46076 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404200AbeHATDf (ORCPT ); Wed, 1 Aug 2018 15:03:35 -0400 Received: from localhost (D57E6652.static.ziggozakelijk.nl [213.126.102.82]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 5AA301016; Wed, 1 Aug 2018 17:00:06 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sandipan Das , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.17 137/336] bpf: fix multi-function JITed dump obtained via syscall Date: Wed, 1 Aug 2018 18:47:52 +0200 Message-Id: <20180801165034.371476003@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180801165028.930831994@linuxfoundation.org> References: <20180801165028.930831994@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sandipan Das [ Upstream commit 4d56a76ead2fcd856e677cdc9445ad331a409b8c ] Currently, for multi-function programs, we cannot get the JITed instructions using the bpf system call's BPF_OBJ_GET_INFO_BY_FD command. Because of this, userspace tools such as bpftool fail to identify a multi-function program as being JITed or not. With the JIT enabled and the test program running, this can be verified as follows: # cat /proc/sys/net/core/bpf_jit_enable 1 Before applying this patch: # bpftool prog list 1: kprobe name foo tag b811aab41a39ad3d gpl loaded_at 2018-05-16T11:43:38+0530 uid 0 xlated 216B not jited memlock 65536B ... # bpftool prog dump jited id 1 no instructions returned After applying this patch: # bpftool prog list 1: kprobe name foo tag b811aab41a39ad3d gpl loaded_at 2018-05-16T12:13:01+0530 uid 0 xlated 216B jited 308B memlock 65536B ... # bpftool prog dump jited id 1 0: nop 4: nop 8: mflr r0 c: std r0,16(r1) 10: stdu r1,-112(r1) 14: std r31,104(r1) 18: addi r31,r1,48 1c: li r3,10 ... Signed-off-by: Sandipan Das Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/syscall.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1946,13 +1946,44 @@ static int bpf_prog_get_info_by_fd(struc * for offload. */ ulen = info.jited_prog_len; - info.jited_prog_len = prog->jited_len; + if (prog->aux->func_cnt) { + u32 i; + + info.jited_prog_len = 0; + for (i = 0; i < prog->aux->func_cnt; i++) + info.jited_prog_len += prog->aux->func[i]->jited_len; + } else { + info.jited_prog_len = prog->jited_len; + } + if (info.jited_prog_len && ulen) { if (bpf_dump_raw_ok()) { uinsns = u64_to_user_ptr(info.jited_prog_insns); ulen = min_t(u32, info.jited_prog_len, ulen); - if (copy_to_user(uinsns, prog->bpf_func, ulen)) - return -EFAULT; + + /* for multi-function programs, copy the JITed + * instructions for all the functions + */ + if (prog->aux->func_cnt) { + u32 len, free, i; + u8 *img; + + free = ulen; + for (i = 0; i < prog->aux->func_cnt; i++) { + len = prog->aux->func[i]->jited_len; + len = min_t(u32, len, free); + img = (u8 *) prog->aux->func[i]->bpf_func; + if (copy_to_user(uinsns, img, len)) + return -EFAULT; + uinsns += len; + free -= len; + if (!free) + break; + } + } else { + if (copy_to_user(uinsns, prog->bpf_func, ulen)) + return -EFAULT; + } } else { info.jited_prog_insns = 0; }