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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 AB3E8C43610 for ; Sun, 11 Nov 2018 22:33:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7234B2245E for ; Sun, 11 Nov 2018 22:33:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="e8u/WLRZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7234B2245E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404466AbeKLIXr (ORCPT ); Mon, 12 Nov 2018 03:23:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:58162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404439AbeKLIXq (ORCPT ); Mon, 12 Nov 2018 03:23:46 -0500 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 83F142154B; Sun, 11 Nov 2018 22:33:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975628; bh=qMxs+8MQLreilkSeBFXZPNvN9ndZKbEtrGFHqLhC+18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e8u/WLRZPp53lRY3FFfRArCO03dCLltkGIDswSZ08/wc+FefB5iGa+VtCSuU2a8kR Yvn6F+pGpaaCgXAM8Ql0+t5hmAEM09gBYhYRat8UC/bMa9czX7zWKxTBwl8yoNaBh/ OJs2jG62yF1qW6Qw/zcV/PEC4IORugf++1ZVOG7Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Anil S Keshavamurthy , "David S . Miller" , Linus Torvalds , "Naveen N . Rao" , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 045/141] kprobes: Return error if we fail to reuse kprobe instead of BUG_ON() Date: Sun, 11 Nov 2018 14:25:04 -0800 Message-Id: <20181111221633.648383226@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221627.853046496@linuxfoundation.org> References: <20181111221627.853046496@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu [ Upstream commit 819319fc93461c07b9cdb3064f154bd8cfd48172 ] Make reuse_unused_kprobe() to return error code if it fails to reuse unused kprobe for optprobe instead of calling BUG_ON(). Signed-off-by: Masami Hiramatsu Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Naveen N . Rao Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/kprobes.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -665,9 +665,10 @@ static void unoptimize_kprobe(struct kpr } /* Cancel unoptimizing for reusing */ -static void reuse_unused_kprobe(struct kprobe *ap) +static int reuse_unused_kprobe(struct kprobe *ap) { struct optimized_kprobe *op; + int ret; BUG_ON(!kprobe_unused(ap)); /* @@ -681,8 +682,12 @@ static void reuse_unused_kprobe(struct k /* Enable the probe again */ ap->flags &= ~KPROBE_FLAG_DISABLED; /* Optimize it again (remove from op->list) */ - BUG_ON(!kprobe_optready(ap)); + ret = kprobe_optready(ap); + if (ret) + return ret; + optimize_kprobe(ap); + return 0; } /* Remove optimized instructions */ @@ -894,11 +899,16 @@ static void __disarm_kprobe(struct kprob #define kprobe_disarmed(p) kprobe_disabled(p) #define wait_for_kprobe_optimizer() do {} while (0) -/* There should be no unused kprobes can be reused without optimization */ -static void reuse_unused_kprobe(struct kprobe *ap) +static int reuse_unused_kprobe(struct kprobe *ap) { + /* + * If the optimized kprobe is NOT supported, the aggr kprobe is + * released at the same time that the last aggregated kprobe is + * unregistered. + * Thus there should be no chance to reuse unused kprobe. + */ printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); - BUG_ON(kprobe_unused(ap)); + return -EINVAL; } static void free_aggr_kprobe(struct kprobe *p) @@ -1276,9 +1286,12 @@ static int register_aggr_kprobe(struct k goto out; } init_aggr_kprobe(ap, orig_p); - } else if (kprobe_unused(ap)) + } else if (kprobe_unused(ap)) { /* This probe is going to die. Rescue it */ - reuse_unused_kprobe(ap); + ret = reuse_unused_kprobe(ap); + if (ret) + goto out; + } if (kprobe_gone(ap)) { /*