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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3DB9ECAAD1 for ; Thu, 1 Sep 2022 19:21:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233598AbiIATVP (ORCPT ); Thu, 1 Sep 2022 15:21:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231304AbiIATVN (ORCPT ); Thu, 1 Sep 2022 15:21:13 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B3987822B for ; Thu, 1 Sep 2022 12:21:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+roK5D09xrSmOTu3P9Sq1+swSxQSmI55Rozlj/752hc=; b=SA4u3MTjdtlR0YA+gRA5r1ludD tFMeaLbxOMYjCyzsUlZvpXhnZc4YYAS+moqdo47PM5WidLL4S5706TPZjOCTaAc+q0My20kmvYY39 AMHI8bcNaChVJ5vhxGmFOFvqu6WTutPz1gb+a+AZOf/OiqM7bJWaG+eBEaXMe507tvVwSU3kQ+9PR UMudahAcskOEDdsg+B4RhmOmTrxVayyUw1n1EAYDo6BDXX0lei+V2/CqeRPZoI4yBMiLxwpYjFhf0 KsMI/65uOfgkVeJvu1gDAwCq4qvSd0X2PqPYYDcI3sNhxfcYiczEpAcYSNIUXRitYrpiKF2sqHlgc 9DL1ZnHg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oTpk8-008TE7-39; Thu, 01 Sep 2022 19:20:48 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B5DC130010B; Thu, 1 Sep 2022 21:20:47 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A69332B8BD272; Thu, 1 Sep 2022 21:20:47 +0200 (CEST) Date: Thu, 1 Sep 2022 21:20:47 +0200 From: Peter Zijlstra To: Sathvika Vasireddy Cc: linuxppc-dev@lists.ozlabs.org, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, aik@ozlabs.ru, mpe@ellerman.id.au, mingo@redhat.com, christophe.leroy@csgroup.eu, rostedt@goodmis.org, mbenes@suse.cz, npiggin@gmail.com, chenzhongjin@huawei.com, naveen.n.rao@linux.vnet.ibm.com Subject: Re: [PATCH v2 08/16] objtool: Fix SEGFAULT Message-ID: References: <20220829055223.24767-1-sv@linux.ibm.com> <20220829055223.24767-9-sv@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220829055223.24767-9-sv@linux.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 29, 2022 at 11:22:15AM +0530, Sathvika Vasireddy wrote: > From: Christophe Leroy > > find_insn() will return NULL in case of failure. Check insn in order > to avoid a kernel Oops for NULL pointer dereference. > > Signed-off-by: Christophe Leroy > --- > tools/objtool/check.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index 91678252a9b6..ed2fdfeb1d9c 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -205,7 +205,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func, > return false; > > insn = find_insn(file, func->sec, func->offset); > - if (!insn->func) > + if (!insn || !insn->func) > return false; I suppose this is ok, but how can the lookup for func->sec, func->offset *not* find an instruction ?!