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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 2AE9DC433DB for ; Wed, 3 Feb 2021 15:00:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8D3864F60 for ; Wed, 3 Feb 2021 15:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233139AbhBCPAN (ORCPT ); Wed, 3 Feb 2021 10:00:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:50488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233002AbhBCPAL (ORCPT ); Wed, 3 Feb 2021 10:00:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9835464F60; Wed, 3 Feb 2021 14:59:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612364371; bh=eR80RgfFYxpw8uTlLQWDfNOedWdFdvjd+BmXvyBOF7M=; h=From:To:Cc:Subject:Date:From; b=dIO/cyRQO8SLlfVPsvnD/467jFQv7RlxdrxPip6hP9B2EGbwZO48DgLULPnv6cmXe nT7p1Zk2dJXyUposOF14X2tZJEDLEHyI/PFWGwBW1oyhXZ3oMn5b2hoaqWpfCjJAAd nPkXBKyzqv/cLnu874lHDm5uO1iSGkegmhuVHRySqpYHWe/8OkmkT6JWHDMi9tFu8b mHuVEUYGXtnOuC+fdLR+hoVFuAtTvlF91UGDGBUE4tugyCz9PGlcHFnjEwQKKZPhtc vW8yaE/XXtVXFIl+yDTN7oa2EdBSizSsemyoV4gS38x0mo7gCIyxauIpGT911KCdVv Rrd2aB8ZdK1+g== From: Masami Hiramatsu To: Ingo Molnar , Steven Rostedt Cc: "Naveen N . Rao" , Ananth N Mavinakayanahalli , Wang ShaoBo , Cheng Jian , linux-kernel@vger.kernel.org, mhiramat@kernel.org Subject: [PATCH] kprobes: Warn if the kprobe is reregistered Date: Wed, 3 Feb 2021 23:59:27 +0900 Message-Id: <161236436734.194052.4058506306336814476.stgit@devnote2> X-Mailer: git-send-email 2.25.1 User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Warn if the kprobe is reregistered, since there must be a software bug (actively used resource must not be re-registered) and caller must be fixed. Signed-off-by: Masami Hiramatsu --- kernel/kprobes.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d5a3eb74a657..dd1d027455c4 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1520,13 +1520,16 @@ static struct kprobe *__get_valid_kprobe(struct kprobe *p) return ap; } -/* Return error if the kprobe is being re-registered */ -static inline int check_kprobe_rereg(struct kprobe *p) +/* + * Warn and return error if the kprobe is being re-registered since + * there must be a software bug. + */ +static inline int warn_kprobe_rereg(struct kprobe *p) { int ret = 0; mutex_lock(&kprobe_mutex); - if (__get_valid_kprobe(p)) + if (WARN_ON_ONCE(__get_valid_kprobe(p))) ret = -EINVAL; mutex_unlock(&kprobe_mutex); @@ -1614,7 +1617,7 @@ int register_kprobe(struct kprobe *p) return PTR_ERR(addr); p->addr = addr; - ret = check_kprobe_rereg(p); + ret = warn_kprobe_rereg(p); if (ret) return ret; @@ -1995,7 +1998,7 @@ int register_kretprobe(struct kretprobe *rp) return ret; /* If only rp->kp.addr is specified, check reregistering kprobes */ - if (rp->kp.addr && check_kprobe_rereg(&rp->kp)) + if (rp->kp.addr && warn_kprobe_rereg(&rp->kp)) return -EINVAL; if (kretprobe_blacklist_size) {