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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 C7220C3F2D5 for ; Fri, 6 Mar 2020 06:42:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5ABD2084E for ; Fri, 6 Mar 2020 06:42:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726307AbgCFGmF (ORCPT ); Fri, 6 Mar 2020 01:42:05 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:11185 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726129AbgCFGmC (ORCPT ); Fri, 6 Mar 2020 01:42:02 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 43F80B97B73A86E1D99C; Fri, 6 Mar 2020 14:42:01 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Mar 2020 14:41:50 +0800 From: Jason Yan To: , , , , , , , , , CC: , , , Jason Yan Subject: [PATCH v4 4/6] powerpc/fsl_booke/64: do not clear the BSS for the second pass Date: Fri, 6 Mar 2020 14:40:31 +0800 Message-ID: <20200306064033.3398-5-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200306064033.3398-1-yanaijie@huawei.com> References: <20200306064033.3398-1-yanaijie@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The BSS section has already cleared out in the first pass. No need to clear it again. This can save some time when booting with KASLR enabled. Signed-off-by: Jason Yan Cc: Scott Wood Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook --- arch/powerpc/kernel/head_64.S | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 454129a3c259..9354c292b709 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -913,6 +913,13 @@ start_here_multiplatform: bl relative_toc tovirt(r2,r2) + /* Do not clear the BSS for the second pass if randomized */ + LOAD_REG_ADDR(r3, kernstart_virt_addr) + ld r3,0(r3) + LOAD_REG_IMMEDIATE(r4, KERNELBASE) + cmpd r3,r4 + bne 4f + /* Clear out the BSS. It may have been done in prom_init, * already but that's irrelevant since prom_init will soon * be detached from the kernel completely. Besides, we need -- 2.17.2