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=-3.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 3E049C6778D for ; Tue, 11 Sep 2018 10:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7BD220867 for ; Tue, 11 Sep 2018 10:21:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ugcYa6nI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7BD220867 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727623AbeIKPTn (ORCPT ); Tue, 11 Sep 2018 11:19:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:52556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726569AbeIKPTn (ORCPT ); Tue, 11 Sep 2018 11:19:43 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 8332620839; Tue, 11 Sep 2018 10:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1536661263; bh=b70k6hylNV4gTFKNqqCQWGr6hs4NFyt8sFzYt9QXHYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ugcYa6nIp9PiM3KUxMHSXrh/qv6SN+Sc3pAkXhE8R23sCgye/7TSyRuvkALS9OD27 82qRFOdXCiBhRyR6G560CvD0V+fsarn2dZJcHuqzwuD3ygnTKEbwQX4P2NWNfoSZGV yMK3GTL1k04G39tzB5u8E9QFW6NuFy9zv/D3KAgg= From: Masami Hiramatsu To: Ingo Molnar Cc: "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" , Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [PATCH -tip v2 4/5] kprobes: Return error if fail to reuse kprobe instead of BUG_ON Date: Tue, 11 Sep 2018 19:20:40 +0900 Message-Id: <153666124040.21306.14150398706331307654.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <153666112297.21306.4621579144717171778.stgit@devbox> References: <153666112297.21306.4621579144717171778.stgit@devbox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- kernel/kprobes.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 277a6cbe83db..63c342e5e6c3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -700,9 +700,10 @@ static void unoptimize_kprobe(struct kprobe *p, bool force) } /* 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; /* * Unused kprobe MUST be on the way of delayed unoptimizing (means @@ -713,8 +714,12 @@ static void reuse_unused_kprobe(struct kprobe *ap) /* 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 */ @@ -939,11 +944,16 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) #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) @@ -1315,9 +1325,12 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) 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)) { /*