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 DAE10ECAAD5 for ; Fri, 2 Sep 2022 08:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235933AbiIBInI (ORCPT ); Fri, 2 Sep 2022 04:43:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235889AbiIBIm7 (ORCPT ); Fri, 2 Sep 2022 04:42:59 -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 7646DAFADC for ; Fri, 2 Sep 2022 01:42:52 -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-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=kyUq76Ekypnho/k0EISFYQkD5KK5rKzGsuomfL+eaXc=; b=lC/XLdh8VjG1swl38+yATsXvz3 r6gwmqc2fYBtTbRW1eo85+4AMiO6E6/2aJ6THbpInNUlmeMKt3GhkNVy2uLq0QMz+pkw6c62y+5zs 4Jgtt20xoA/PrrpZqKIkEr/sTdS1C/DfXr7RioekxoS3gM/c+KxYShn+KBf+CYQVBYyTz6sOSYPKr zA/fuz/3o7pf4KQyujptDcXRVlo///hpm7j+x9IpOZfxbdNB6r8/SbI8eOgz/vAODNX2wKEvUhZ/s /6tGqbWCZ32XiTaSegBK5VgHc2thAUjL+TvtDwt6McfUTx0ctUU/rJPbw8FyC7SF6HP1XJNbNZHox W7X7E9Nw==; 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 1oU2Fo-008cnp-OP; Fri, 02 Sep 2022 08:42:21 +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) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DC8003002C7; Fri, 2 Sep 2022 10:42:17 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C62CB2B8A3BCB; Fri, 2 Sep 2022 10:42:17 +0200 (CEST) Date: Fri, 2 Sep 2022 10:42:17 +0200 From: Peter Zijlstra To: Christophe Leroy Cc: Sathvika Vasireddy , "linuxppc-dev@lists.ozlabs.org" , "jpoimboe@redhat.com" , "linux-kernel@vger.kernel.org" , "aik@ozlabs.ru" , "mpe@ellerman.id.au" , "mingo@redhat.com" , "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> <66a3976b-48c1-f8c4-aee0-d04c2c11f5af@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <66a3976b-48c1-f8c4-aee0-d04c2c11f5af@csgroup.eu> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 02, 2022 at 08:06:28AM +0000, Christophe Leroy wrote: > > > Le 01/09/2022 à 21:20, Peter Zijlstra a écrit : > > 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 ?! > > That happened to me at the begining when the port to powerpc was not > fully functionnal. > > I guess that could also happen with a corrupted object file so better > safe than sorry. Fair enough. Acked-by: Peter Zijlstra (Intel) 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8A2CEECAAD5 for ; Fri, 2 Sep 2022 08:43:23 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MJrzF5zbbz3bkm for ; Fri, 2 Sep 2022 18:43:21 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=desiato.20200630 header.b=lC/XLdh8; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=infradead.org (client-ip=2001:8b0:10b:1:d65d:64ff:fe57:4e05; helo=desiato.infradead.org; envelope-from=peterz@infradead.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=desiato.20200630 header.b=lC/XLdh8; dkim-atps=neutral Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4MJryZ2NlFz2xn3 for ; Fri, 2 Sep 2022 18:42:43 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=kyUq76Ekypnho/k0EISFYQkD5KK5rKzGsuomfL+eaXc=; b=lC/XLdh8VjG1swl38+yATsXvz3 r6gwmqc2fYBtTbRW1eo85+4AMiO6E6/2aJ6THbpInNUlmeMKt3GhkNVy2uLq0QMz+pkw6c62y+5zs 4Jgtt20xoA/PrrpZqKIkEr/sTdS1C/DfXr7RioekxoS3gM/c+KxYShn+KBf+CYQVBYyTz6sOSYPKr zA/fuz/3o7pf4KQyujptDcXRVlo///hpm7j+x9IpOZfxbdNB6r8/SbI8eOgz/vAODNX2wKEvUhZ/s /6tGqbWCZ32XiTaSegBK5VgHc2thAUjL+TvtDwt6McfUTx0ctUU/rJPbw8FyC7SF6HP1XJNbNZHox W7X7E9Nw==; 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 1oU2Fo-008cnp-OP; Fri, 02 Sep 2022 08:42:21 +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) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DC8003002C7; Fri, 2 Sep 2022 10:42:17 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C62CB2B8A3BCB; Fri, 2 Sep 2022 10:42:17 +0200 (CEST) Date: Fri, 2 Sep 2022 10:42:17 +0200 From: Peter Zijlstra To: Christophe Leroy 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> <66a3976b-48c1-f8c4-aee0-d04c2c11f5af@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <66a3976b-48c1-f8c4-aee0-d04c2c11f5af@csgroup.eu> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "aik@ozlabs.ru" , "chenzhongjin@huawei.com" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "mingo@redhat.com" , Sathvika Vasireddy , "npiggin@gmail.com" , "jpoimboe@redhat.com" , "naveen.n.rao@linux.vnet.ibm.com" , "mbenes@suse.cz" , "linuxppc-dev@lists.ozlabs.org" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Sep 02, 2022 at 08:06:28AM +0000, Christophe Leroy wrote: > > > Le 01/09/2022 à 21:20, Peter Zijlstra a écrit : > > 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 ?! > > That happened to me at the begining when the port to powerpc was not > fully functionnal. > > I guess that could also happen with a corrupted object file so better > safe than sorry. Fair enough. Acked-by: Peter Zijlstra (Intel)