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=-10.0 required=3.0 tests=BAYES_00,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 3B0C6C433E0 for ; Wed, 5 Aug 2020 20:06:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D42E22B42 for ; Wed, 5 Aug 2020 20:06:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596658014; bh=yFYTa998NKrtDfXdDzp1QLN7+n8qgvxQI8H6upuXPM0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uDbNTT1GUgAOCGXfi/7qM8C/F13POeEskGiynlVUjgSULeIsbyes+06sv77HDHMth jkyPLarkp086PrgiJlat3NMPMQPqY4x2MfZ9Vh+HUBu4T0Ph+vsKXpULz/iuoB9vzW MipHL1OHUEA4kBYbV4Bjxr4X+nOHm1W/vfHbmlqk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727880AbgHEUGv (ORCPT ); Wed, 5 Aug 2020 16:06:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:50662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727004AbgHEQeg (ORCPT ); Wed, 5 Aug 2020 12:34:36 -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 01A7B233FA; Wed, 5 Aug 2020 15:53:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596642827; bh=yFYTa998NKrtDfXdDzp1QLN7+n8qgvxQI8H6upuXPM0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q2CAA+zLs41rHPezyGRZksu6+YhrO0485Rcl6azROb/J4aLyHFqROJyFENqOPgnh2 SNPJiK4nvOeqzCXVd1QLtZRN8s4RrWQ9lcCoYmf97ky9Q6n8ETo25yLewbQIRNZg+d xWc1h0MPStsqfvMMlOKf/CO9tv5aH7p9Naeft+Js= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Geert Uytterhoeven , Nicolas Pitre , Russell King , Nick Desaulniers Subject: [PATCH 4.14 8/8] ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel() Date: Wed, 5 Aug 2020 17:53:34 +0200 Message-Id: <20200805153507.382671788@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200805153507.005753845@linuxfoundation.org> References: <20200805153507.005753845@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: Geert Uytterhoeven commit 59b6359dd92d18f5dc04b14a4c926fa08ab66f7c upstream. If CONFIG_DEBUG_LOCK_ALLOC=y, the kernel log is spammed with a few hundred identical messages: unwind: Unknown symbol address c0800300 unwind: Index not found c0800300 c0800300 is the return address from the last subroutine call (to __memzero()) in __mmap_switched(). Apparently having this address in the link register confuses the unwinder. To fix this, reset the link register to zero before jumping to start_kernel(). Fixes: 9520b1a1b5f7a348 ("ARM: head-common.S: speed up startup code") Suggested-by: Ard Biesheuvel Signed-off-by: Geert Uytterhoeven Acked-by: Nicolas Pitre Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman Signed-off-by: Nick Desaulniers --- arch/arm/kernel/head-common.S | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -101,6 +101,7 @@ __mmap_switched: str r2, [r6] @ Save atags pointer cmp r7, #0 strne r0, [r7] @ Save control register values + mov lr, #0 b start_kernel ENDPROC(__mmap_switched)