From patchwork Thu Oct 22 08:21:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1386047 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=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CH0hS5LMwz9sSW for ; Thu, 22 Oct 2020 19:22:00 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2895131AbgJVIV7 convert rfc822-to-8bit (ORCPT ); Thu, 22 Oct 2020 04:21:59 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:32529 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2895065AbgJVIV6 (ORCPT ); Thu, 22 Oct 2020 04:21:58 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-162-ZLP9DZhuMCaTUgbcWPi4aw-1; Thu, 22 Oct 2020 04:21:51 -0400 X-MC-Unique: ZLP9DZhuMCaTUgbcWPi4aw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 333C9846375; Thu, 22 Oct 2020 08:21:49 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.195.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1659F60BFA; Thu, 22 Oct 2020 08:21:45 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Daniel Xu , Steven Rostedt , Jesper Brouer , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Viktor Malik Subject: [RFC bpf-next 01/16] ftrace: Add check_direct_entry function Date: Thu, 22 Oct 2020 10:21:23 +0200 Message-Id: <20201022082138.2322434-2-jolsa@kernel.org> In-Reply-To: <20201022082138.2322434-1-jolsa@kernel.org> References: <20201022082138.2322434-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Move code that checks on valid direct ip into separate check_direct_entry function. It will be used in following patches, there's no functional change. Signed-off-by: Jiri Olsa --- kernel/trace/ftrace.c | 55 +++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 23 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8185f7240095..27e9210073d3 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5025,6 +5025,36 @@ struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) return NULL; } +static int check_direct_ip(unsigned long ip) +{ + struct dyn_ftrace *rec; + + /* See if there's a direct function at @ip already */ + if (ftrace_find_rec_direct(ip)) + return -EBUSY; + + rec = lookup_rec(ip, ip); + if (!rec) + return -ENODEV; + + /* + * Check if the rec says it has a direct call but we didn't + * find one earlier? + */ + if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) + return -ENODEV; + + /* Make sure the ip points to the exact record */ + if (ip != rec->ip) { + ip = rec->ip; + /* Need to check this ip for a direct. */ + if (ftrace_find_rec_direct(ip)) + return -EBUSY; + } + + return 0; +} + /** * register_ftrace_direct - Call a custom trampoline directly * @ip: The address of the nop at the beginning of a function @@ -5047,35 +5077,14 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) struct ftrace_direct_func *direct; struct ftrace_func_entry *entry; struct ftrace_hash *free_hash = NULL; - struct dyn_ftrace *rec; int ret = -EBUSY; mutex_lock(&direct_mutex); - /* See if there's a direct function at @ip already */ - if (ftrace_find_rec_direct(ip)) - goto out_unlock; - - ret = -ENODEV; - rec = lookup_rec(ip, ip); - if (!rec) - goto out_unlock; - - /* - * Check if the rec says it has a direct call but we didn't - * find one earlier? - */ - if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) + ret = check_direct_ip(ip); + if (ret) goto out_unlock; - /* Make sure the ip points to the exact record */ - if (ip != rec->ip) { - ip = rec->ip; - /* Need to check this ip for a direct. */ - if (ftrace_find_rec_direct(ip)) - goto out_unlock; - } - ret = -ENOMEM; if (ftrace_hash_empty(direct_functions) || direct_functions->count > 2 * (1 << direct_functions->size_bits)) {