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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 777DBC4BA11 for ; Wed, 26 Feb 2020 08:59:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45FA724656 for ; Wed, 26 Feb 2020 08:59:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582707598; bh=49tfpGRVnqBQTopxUDbKTPCXsBFDOff5Cwem9g40BwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iILobBhyDhYLZnyV8eMTUUwt1g4m6z693NU4tjqQFbpDjCEYSEQVJ4dRq70UZwtEA FsRMYBjKl9sIoAfo2VuONe0gaDTGdr8uLuOJhq87ax2HepKYBAh6zyVYGojr0RjTTQ HLENAZ3f2SjvDkKQcN/4An/yEpZyFSbxRvOaZZkw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727532AbgBZI74 (ORCPT ); Wed, 26 Feb 2020 03:59:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:49474 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgBZI74 (ORCPT ); Wed, 26 Feb 2020 03:59:56 -0500 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 72AA620732; Wed, 26 Feb 2020 08:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582707595; bh=49tfpGRVnqBQTopxUDbKTPCXsBFDOff5Cwem9g40BwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=grHCW+GTMaYqs3IAf4tKY/ui3x21b3rIUcWd+NzTXwuOn1I81O+RLAvMM6NPusd6J 9LKyDYy3X0R9I8Ag6/mczYan/W9Epn+e5bxoD4Cu5YW6MehYFzmq2cICOIpNPAOUWJ Fqql4fPl/zN4J+EpQNqIfk0zst+ez1pHjiFt39/Y= From: Masami Hiramatsu To: Ingo Molnar Cc: Anders Roxell , paulmck@kernel.org, joel@joelfernandes.org, "Naveen N . Rao" , Anil S Keshavamurthy , David Miller , Masami Hiramatsu , Linux Kernel Mailing List , Steven Rostedt Subject: [PATCH -tip V4 3/4] kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex Date: Wed, 26 Feb 2020 17:59:51 +0900 Message-Id: <158270759113.18966.8938334321921933993.stgit@devnote2> X-Mailer: git-send-email 2.20.1 In-Reply-To: <158270755997.18966.3544449431956918068.stgit@devnote2> References: <158270755997.18966.3544449431956918068.stgit@devnote2> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In kprobe_optimizer() kick_kprobe_optimizer() is called without kprobe_mutex, but this can race with other caller which is protected by kprobe_mutex. To fix that, expand kprobe_mutex protected area to protect kick_kprobe_optimizer() call. Signed-off-by: Masami Hiramatsu --- kernel/kprobes.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 38d9a5d7c8a4..6d76a6e3e1a5 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -592,11 +592,12 @@ static void kprobe_optimizer(struct work_struct *work) mutex_unlock(&module_mutex); mutex_unlock(&text_mutex); cpus_read_unlock(); - mutex_unlock(&kprobe_mutex); /* Step 5: Kick optimizer again if needed */ if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) kick_kprobe_optimizer(); + + mutex_unlock(&kprobe_mutex); } /* Wait for completing optimization and unoptimization */