From patchwork Thu Nov 1 07:00:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 991843 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="Dd4lVL0L"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42lx234B9Dz9sVq for ; Thu, 1 Nov 2018 18:01:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728090AbeKAQCv (ORCPT ); Thu, 1 Nov 2018 12:02:51 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:50418 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727716AbeKAQCv (ORCPT ); Thu, 1 Nov 2018 12:02:51 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wA16qXvN005388 for ; Thu, 1 Nov 2018 00:01:08 -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=7EBwVpGU6cfoNRqG1P1JQWDDOcAtW/i60Agk+wxGtKY=; b=Dd4lVL0LDFRlG1tVtJ+UldI0vhPI8OgNCHBtscHaM0xn4PM85xQh+yDuTQDlyRHVJ8vf 4v3RU+jL5lTzTojXBFC1hUyV2Z8dC+tXBOmWRizlkojgx/VGar51Upr4fG6ByZMfb10s StXHpO1liWa1h3fsOfxtN+RKBfZrqWF+JXE= Received: from maileast.thefacebook.com ([199.201.65.23]) by mx0a-00082601.pphosted.com with ESMTP id 2nfqhhgme0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 01 Nov 2018 00:01:08 -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; Thu, 1 Nov 2018 00:01:07 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 785FA62E1653; Thu, 1 Nov 2018 00:01:06 -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 bpf 1/3] bpf: show real jited prog address in /proc/kallsyms Date: Thu, 1 Nov 2018 00:00:56 -0700 Message-ID: <20181101070058.2760251-2-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181101070058.2760251-1-songliubraving@fb.com> References: <20181101070058.2760251-1-songliubraving@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-11-01_04:, , 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, /proc/kallsyms shows page address of jited bpf program. This is not ideal for detailed profiling (find hot instructions from stack traces). This patch replaces the page address with real prog start address. Signed-off-by: Song Liu --- kernel/bpf/core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 6377225b2082..1a796e0799ec 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -553,7 +553,6 @@ bool is_bpf_text_address(unsigned long addr) int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *sym) { - unsigned long symbol_start, symbol_end; struct bpf_prog_aux *aux; unsigned int it = 0; int ret = -ERANGE; @@ -566,10 +565,9 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, if (it++ != symnum) continue; - bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); bpf_get_prog_name(aux->prog, sym); - *value = symbol_start; + *value = (unsigned long)aux->prog->bpf_func; *type = BPF_SYM_ELF_TYPE; ret = 0;