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 62918C3F2D4 for ; Fri, 6 Mar 2020 06:42:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4229D2073D for ; Fri, 6 Mar 2020 06:42:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726108AbgCFGmB (ORCPT ); Fri, 6 Mar 2020 01:42:01 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:11596 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725784AbgCFGl7 (ORCPT ); Fri, 6 Mar 2020 01:41:59 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 490C9FE5135A1EBC16F0; Fri, 6 Mar 2020 14:41:56 +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 14:41:48 +0800 From: Jason Yan To: , , , , , , , , , CC: , , , Jason Yan Subject: [PATCH v4 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init() Date: Fri, 6 Mar 2020 14:40:28 +0800 Message-ID: <20200306064033.3398-2-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 Some code refactor in kaslr_legal_offset() and kaslr_early_init(). No functional change. This is a preparation for KASLR fsl_booke64. 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/mm/nohash/kaslr_booke.c | 34 +++++++++++++++------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 4a75f2d9bf0e..6ebff31fefcc 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -25,6 +25,7 @@ struct regions { unsigned long pa_start; unsigned long pa_end; unsigned long kernel_size; + unsigned long linear_sz; unsigned long dtb_start; unsigned long dtb_end; unsigned long initrd_start; @@ -260,11 +261,23 @@ static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells, *size_cells = fdt32_to_cpu(*prop); } -static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index, - unsigned long offset) +static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long random) { unsigned long koffset = 0; unsigned long start; + unsigned long index; + unsigned long offset; + + /* + * Decide which 64M we want to start + * Only use the low 8 bits of the random seed + */ + index = random & 0xFF; + index %= regions.linear_sz / SZ_64M; + + /* Decide offset inside 64M */ + offset = random % (SZ_64M - regions.kernel_size); + offset = round_down(offset, SZ_16K); while ((long)index >= 0) { offset = memstart_addr + index * SZ_64M + offset; @@ -289,10 +302,9 @@ static inline __init bool kaslr_disabled(void) static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size, unsigned long kernel_sz) { - unsigned long offset, random; + unsigned long random; unsigned long ram, linear_sz; u64 seed; - unsigned long index; kaslr_get_cmdline(dt_ptr); if (kaslr_disabled()) @@ -333,22 +345,12 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size regions.dtb_start = __pa(dt_ptr); regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr); regions.kernel_size = kernel_sz; + regions.linear_sz = linear_sz; get_initrd_range(dt_ptr); get_crash_kernel(dt_ptr, ram); - /* - * Decide which 64M we want to start - * Only use the low 8 bits of the random seed - */ - index = random & 0xFF; - index %= linear_sz / SZ_64M; - - /* Decide offset inside 64M */ - offset = random % (SZ_64M - kernel_sz); - offset = round_down(offset, SZ_16K); - - return kaslr_legal_offset(dt_ptr, index, offset); + return kaslr_legal_offset(dt_ptr, random); } /* -- 2.17.2