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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BDB29C2BB1D for ; Tue, 17 Mar 2020 11:11:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D0D0206EC for ; Tue, 17 Mar 2020 11:11:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584443516; bh=oBIkwvkWSfSaIPFaRd38+MCP5MdNKN11rWJETiWECyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H5cHYKGvuZul0F3V7ydXHLv6s40cPBQAzsadOEmF7mmB5X0oLEYlFVDzti1Pg6c5+ Yu3EzKcBjwTzhceIV4xPXUC0zzLxqfQZy4HgQzxd8Wmt3IhlRDRnu+rkHQC1Y0pqvp hqAGMvU+GZNsxaqsCxNYebx/JZ0srX/3uJLMRdRw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729073AbgCQLLz (ORCPT ); Tue, 17 Mar 2020 07:11:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:55412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727244AbgCQLLv (ORCPT ); Tue, 17 Mar 2020 07:11:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 CC76C20719; Tue, 17 Mar 2020 11:11:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584443511; bh=oBIkwvkWSfSaIPFaRd38+MCP5MdNKN11rWJETiWECyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r/Tb7Nmxq0g4j2xY0xUzD8IZj8EGMkCg4LtNg6aax3vraDJbMwkv9O/5UIdN7VE0J Ehp28uOk/Jh8N/ItN/c1AirDVw7xExSQKy09Vz1aRi/dt36WALq9K34tz0HwHRV39a NmHo/QQGqagPw3MVGC2zDpGG5JKHmcbnrrGcvKwA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Artem Savkov , "Steven Rostedt (VMware)" Subject: [PATCH 5.5 107/151] ftrace: Return the first found result in lookup_rec() Date: Tue, 17 Mar 2020 11:55:17 +0100 Message-Id: <20200317103334.059635900@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200317103326.593639086@linuxfoundation.org> References: <20200317103326.593639086@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Artem Savkov commit d9815bff6b379ff46981bea9dfeb146081eab314 upstream. It appears that ip ranges can overlap so. In that case lookup_rec() returns whatever results it got last even if it found nothing in last searched page. This breaks an obscure livepatch late module patching usecase: - load livepatch - load the patched module - unload livepatch - try to load livepatch again To fix this return from lookup_rec() as soon as it found the record containing searched-for ip. This used to be this way prior lookup_rec() introduction. Link: http://lkml.kernel.org/r/20200306174317.21699-1-asavkov@redhat.com Cc: stable@vger.kernel.org Fixes: 7e16f581a817 ("ftrace: Separate out functionality from ftrace_location_range()") Signed-off-by: Artem Savkov Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ftrace.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1552,6 +1552,8 @@ static struct dyn_ftrace *lookup_rec(uns rec = bsearch(&key, pg->records, pg->index, sizeof(struct dyn_ftrace), ftrace_cmp_recs); + if (rec) + break; } return rec; }