From patchwork Mon May 18 17:36:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 225587 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=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 AAD42C433E0 for ; Mon, 18 May 2020 18:25:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83FE720643 for ; Mon, 18 May 2020 18:25:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589826321; bh=iZoVEaznfcLc5KPtg9brvQf4P2LvgoMn81YSjkt2QUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=043nmgjtNrDZWL3szt3F+WvoEQlqrnv5tVe2nODb6N0ycARG523MyfHZ2dqVBZhf3 JqTq2ZGGoWscmB/Zp607oawyJXB3osa+33U3oGN7J3WwgNuoaJviUKiQkNnbDyJZlf ds67RoUVS8zw5acCNmdUALWIaf0DraD8ZnlE3Fw4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730637AbgERSZT (ORCPT ); Mon, 18 May 2020 14:25:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:46682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729583AbgERRqr (ORCPT ); Mon, 18 May 2020 13:46:47 -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 D07FE20671; Mon, 18 May 2020 17:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589824006; bh=iZoVEaznfcLc5KPtg9brvQf4P2LvgoMn81YSjkt2QUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kw+dJuUPLd7EvWTkVGYk6T2v6cKVuk8WFplHQW4+wOvMWUFqa8LGI3xNeLCGOhI66 O4TYFK8OLp/HVm/Sakd36Gdmzm5wgnQOlhUO3N1/xPiE6XbqBvYiBAq15kDNMgayWs slA9ZCJtGVal9y4c/Udv2TAx+7m4V3p/0dMAlDU4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miroslav Benes , Josh Poimboeuf , Ingo Molnar , Andy Lutomirski , Dave Jones , Jann Horn , Peter Zijlstra , Thomas Gleixner , Vince Weaver Subject: [PATCH 4.14 032/114] x86/unwind/orc: Prevent unwinding before ORC initialization Date: Mon, 18 May 2020 19:36:04 +0200 Message-Id: <20200518173509.513162349@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173503.033975649@linuxfoundation.org> References: <20200518173503.033975649@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josh Poimboeuf commit 98d0c8ebf77e0ba7c54a9ae05ea588f0e9e3f46e upstream. If the unwinder is called before the ORC data has been initialized, orc_find() returns NULL, and it tries to fall back to using frame pointers. This can cause some unexpected warnings during boot. Move the 'orc_init' check from orc_find() to __unwind_init(), so that it doesn't even try to unwind from an uninitialized state. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Andy Lutomirski Cc: Dave Jones Cc: Jann Horn Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vince Weaver Link: https://lore.kernel.org/r/069d1499ad606d85532eb32ce39b2441679667d5.1587808742.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/unwind_orc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -90,9 +90,6 @@ static struct orc_entry null_orc_entry = static struct orc_entry *orc_find(unsigned long ip) { - if (!orc_init) - return NULL; - if (ip == 0) return &null_orc_entry; @@ -508,6 +505,9 @@ EXPORT_SYMBOL_GPL(unwind_next_frame); void __unwind_start(struct unwind_state *state, struct task_struct *task, struct pt_regs *regs, unsigned long *first_frame) { + if (!orc_init) + goto done; + memset(state, 0, sizeof(*state)); state->task = task;