From patchwork Fri Nov 2 17:16:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 992448 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="LMA8CMBf"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42mpf80Y1HzB4Xd for ; Sat, 3 Nov 2018 04:17:04 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728109AbeKCCYy (ORCPT ); Fri, 2 Nov 2018 22:24:54 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:37650 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726085AbeKCCYx (ORCPT ); Fri, 2 Nov 2018 22:24:53 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.22/8.16.0.22) with SMTP id wA2HBNHm028175 for ; Fri, 2 Nov 2018 10:17:01 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=i9l5XKG3LcNRXebfKblGdVPL7HgmGqsCV4u3xdILCtk=; b=LMA8CMBfjJXAWFnxVncp3p7RUGo/O2ggHxhYeLM4pn53d9NP5obWoy3MEYDURnm+BWlS RyemvboNY+y7bkifxw/Vm4PwDrc8ll7unUnWKQQB83uNDLhebBOtyFAhfdLVmpJSItzy XPIyh0nxupMTaIqZJ2JrWI7pTX2vvDcDwig= Received: from maileast.thefacebook.com ([199.201.65.23]) by m0001303.ppops.net with ESMTP id 2ngscw8ahr-18 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Fri, 02 Nov 2018 10:17:01 -0700 Received: from mx-out.facebook.com (2620:10d:c0a1:3::13) by mail.thefacebook.com (2620:10d:c021:18::174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1531.3; Fri, 2 Nov 2018 10:16:27 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id DB00762E1315; Fri, 2 Nov 2018 10:16:22 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: CC: , Song Liu , , , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v2 bpf 2/3] bpf: show real jited address in bpf_prog_info->jited_ksyms Date: Fri, 2 Nov 2018 10:16:16 -0700 Message-ID: <20181102171617.310178-3-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181102171617.310178-1-songliubraving@fb.com> References: <20181102171617.310178-1-songliubraving@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-11-02_10:, , signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Currently, jited_ksyms in bpf_prog_info shows page addresses of jited bpf program. The main reason here is to not expose randomized start address. However, this is not ideal for detailed profiling (find hot instructions from stack traces). This patch replaces the page address with real prog start address. This change is OK because bpf_prog_get_info_by_fd() is only available to root. Signed-off-by: Song Liu --- kernel/bpf/syscall.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ccb93277aae2..34a9eef5992c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2172,7 +2172,6 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, user_ksyms = u64_to_user_ptr(info.jited_ksyms); for (i = 0; i < ulen; i++) { ksym_addr = (ulong) prog->aux->func[i]->bpf_func; - ksym_addr &= PAGE_MASK; if (put_user((u64) ksym_addr, &user_ksyms[i])) return -EFAULT; }