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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,USER_AGENT_SANE_1 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 3B602C11D05 for ; Thu, 20 Feb 2020 13:40:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1091A208C4 for ; Thu, 20 Feb 2020 13:40:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="YWHTXkfG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728180AbgBTNkf (ORCPT ); Thu, 20 Feb 2020 08:40:35 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:15436 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728028AbgBTNkf (ORCPT ); Thu, 20 Feb 2020 08:40:35 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 48NbM36ysPz9txrk; Thu, 20 Feb 2020 14:40:31 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=YWHTXkfG; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id hbJhFWvUXX38; Thu, 20 Feb 2020 14:40:31 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 48NbM35T14z9txrh; Thu, 20 Feb 2020 14:40:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1582206031; bh=Ey2+g9lGzZa+YpnSVqQPtdcZpHXPa/MkjNUS6tI4A50=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=YWHTXkfGYULWjCzpxJ4aJed4CCe5/NvB7c8ruOxwGI+oYB+UydgpWU1vNgwzK6FLr sBjuADkg+TKg8Z6wwsthh+MM6O2FfXnhIO1BuKLrWqWnQRuKDl7MTd9LotDr3wUyYa uz4yBBQmY4PrMwGmIrFxxpTLToGtdK9nM4+QDwlQ= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id F33388B86E; Thu, 20 Feb 2020 14:40:32 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id SxQ2wcihBuVZ; Thu, 20 Feb 2020 14:40:32 +0100 (CET) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B52B28B866; Thu, 20 Feb 2020 14:40:31 +0100 (CET) Subject: Re: [PATCH v3 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init() To: Jason Yan , mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, diana.craciun@nxp.com, benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com, keescook@chromium.org, kernel-hardening@lists.openwall.com, oss@buserror.net Cc: linux-kernel@vger.kernel.org, zhaohongjiang@huawei.com References: <20200206025825.22934-1-yanaijie@huawei.com> <20200206025825.22934-2-yanaijie@huawei.com> From: Christophe Leroy Message-ID: <6c0b0720-6998-f43a-a2b6-0632d4df1126@c-s.fr> Date: Thu, 20 Feb 2020 14:40:31 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200206025825.22934-2-yanaijie@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 06/02/2020 à 03:58, Jason Yan a écrit : > 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 | 40 ++++++++++++++-------------- > 1 file changed, 20 insertions(+), 20 deletions(-) > > diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c > index 4a75f2d9bf0e..07b036e98353 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); > } > > /* > @@ -358,8 +360,6 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size > */ > notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > { > - unsigned long tlb_virt; > - phys_addr_t tlb_phys; > unsigned long offset; > unsigned long kernel_sz; > > @@ -375,8 +375,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > is_second_reloc = 1; > > if (offset >= SZ_64M) { > - tlb_virt = round_down(kernstart_virt_addr, SZ_64M); > - tlb_phys = round_down(kernstart_addr, SZ_64M); > + unsigned long tlb_virt = round_down(kernstart_virt_addr, SZ_64M); > + phys_addr_t tlb_phys = round_down(kernstart_addr, SZ_64M); That looks like cleanup unrelated to the patch itself. > > /* Create kernel map to relocate in */ > create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); > Christophe