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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 1B1BCC433EF for ; Mon, 18 Jun 2018 08:16:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C16B620864 for ; Mon, 18 Jun 2018 08:16:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C16B620864 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934122AbeFRIQK (ORCPT ); Mon, 18 Jun 2018 04:16:10 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52964 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934242AbeFRIQI (ORCPT ); Mon, 18 Jun 2018 04:16:08 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 63C80C75; Mon, 18 Jun 2018 08:16:07 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Sasha Levin Subject: [PATCH 4.16 031/279] powerpc/64s: Default l1d_size to 64K in RFI fallback flush Date: Mon, 18 Jun 2018 10:10:16 +0200 Message-Id: <20180618080610.113679785@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Madhavan Srinivasan [ Upstream commit 9dfbf78e4114fcaf4ef61c49885c3ab5bad40d0b ] If there is no d-cache-size property in the device tree, l1d_size could be zero. We don't actually expect that to happen, it's only been seen on mambo (simulator) in some configurations. A zero-size l1d_size leads to the loop in the asm wrapping around to 2^64-1, and then walking off the end of the fallback area and eventually causing a page fault which is fatal. Just default to 64K which is correct on some CPUs, and sane enough to not cause a crash on others. Fixes: aa8a5e0062ac9 ('powerpc/64s: Add support for RFI flush of L1-D cache') Signed-off-by: Madhavan Srinivasan [mpe: Rewrite comment and change log] Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/setup_64.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -864,6 +864,17 @@ static void init_fallback_flush(void) int cpu; l1d_size = ppc64_caches.l1d.size; + + /* + * If there is no d-cache-size property in the device tree, l1d_size + * could be zero. That leads to the loop in the asm wrapping around to + * 2^64-1, and then walking off the end of the fallback area and + * eventually causing a page fault which is fatal. Just default to + * something vaguely sane. + */ + if (!l1d_size) + l1d_size = (64 * 1024); + limit = min(ppc64_bolted_size(), ppc64_rma_size); /*