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=-6.9 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,URIBL_BLOCKED,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 42E8CCA90AF for ; Wed, 13 May 2020 10:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C98B206E5 for ; Wed, 13 May 2020 10:01:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589364108; bh=wN63/d8bY6lKcZMrGG0Tt2Sxn2DQckb0HCInWH1OSmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UxeCi14y8z0v8Aw0CddaVvKPXEHqb3YsPThaxR0e8NlA2mhyqzuwCytTqN3+7+Wxg gPYNNfRWlxB0cnaWfiH6EWjbeob2cIUCXtXqpKtCyBJ8vjIpIofNnpufhF2IrUvutv Z6c1H9kM3ZfclULpTlWIsk94i0GkQkUqEx+pTl7s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732927AbgEMKBr (ORCPT ); Wed, 13 May 2020 06:01:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:50882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732886AbgEMJuq (ORCPT ); Wed, 13 May 2020 05:50:46 -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 12F1720740; Wed, 13 May 2020 09:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589363445; bh=wN63/d8bY6lKcZMrGG0Tt2Sxn2DQckb0HCInWH1OSmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EjSc9uCPvWl4LDsYp0jUYPP50WVoG+jNDSKjknhCIlxJIR0sehaq6V9Gnd/R/0j1g PeY2LTKQcc+1WI2Smy0W/KAk2V6Ypey/zAlxoyIRKnOf0HJZ5EdZOCwt6ntwN5j2tU xYt3tMs2SLSWj6TcLOd2hXJoIsjM8AkIMuUopEmg= 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 5.4 76/90] x86/unwind/orc: Prevent unwinding before ORC initialization Date: Wed, 13 May 2020 11:45:12 +0200 Message-Id: <20200513094417.204174530@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200513094408.810028856@linuxfoundation.org> References: <20200513094408.810028856@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: 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 @@ -142,9 +142,6 @@ static struct orc_entry *orc_find(unsign { static struct orc_entry *orc; - if (!orc_init) - return NULL; - if (ip == 0) return &null_orc_entry; @@ -582,6 +579,9 @@ 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;