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=-8.3 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,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 4F56AC433FF for ; Mon, 29 Jul 2019 11:39:17 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id A1A1321655 for ; Mon, 29 Jul 2019 11:39:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="CN1IqAJT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1A1321655 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-16608-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 31835 invoked by uid 550); 29 Jul 2019 11:39:10 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 31802 invoked from network); 29 Jul 2019 11:39:10 -0000 Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=CN1IqAJT; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1564400333; bh=nziOx+hsAmSgHaUew2nk7oKkm5bBxFcVZVeuZ8olOds=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=CN1IqAJT5TRTGPGfzxV/ACgvbI3nuqf2174u4PWQd9Ase9/M+vHqjqmWnrCYoIbw6 yE3FBsZeQZsCnTcqZazPFn2WiXxexkLpBBbomM3ozi46ukMJ3IxVZgdpmFES3H2pwh 4ivVSPPMX9Pw+vXzT5OWKhHUUUl7ClwZhgNV8iHg= X-Virus-Scanned: amavisd-new at c-s.fr Subject: Re: [RFC PATCH 09/10] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter 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 Cc: linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, yebin10@huawei.com, thunder.leizhen@huawei.com, jingxiangfeng@huawei.com, fanchengyang@huawei.com References: <20190717080621.40424-1-yanaijie@huawei.com> <20190717080621.40424-10-yanaijie@huawei.com> From: Christophe Leroy Message-ID: Date: Mon, 29 Jul 2019 13:38:57 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190717080621.40424-10-yanaijie@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Le 17/07/2019 à 10:06, Jason Yan a écrit : > One may want to disable kaslr when boot, so provide a cmdline parameter > 'nokaslr' to support this. > > Signed-off-by: Jason Yan > Cc: Diana Craciun > Cc: Michael Ellerman > Cc: Christophe Leroy > Cc: Benjamin Herrenschmidt > Cc: Paul Mackerras > Cc: Nicholas Piggin > Cc: Kees Cook > --- > arch/powerpc/kernel/kaslr_booke.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c > index 00339c05879f..e65a5d9d2ff1 100644 > --- a/arch/powerpc/kernel/kaslr_booke.c > +++ b/arch/powerpc/kernel/kaslr_booke.c > @@ -373,6 +373,18 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size > return kaslr_offset; > } > > +static inline __init bool kaslr_disabled(void) > +{ > + char *str; > + > + str = strstr(early_command_line, "nokaslr"); Why using early_command_line instead of boot_command_line ? > + if ((str == early_command_line) || > + (str > early_command_line && *(str - 1) == ' ')) Is that stuff really needed ? Why not just: return strstr(early_command_line, "nokaslr") != NULL; > + return true; > + > + return false; > +} > + > /* > * To see if we need to relocate the kernel to a random offset > * void *dt_ptr - address of the device tree > @@ -388,6 +400,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) > kernel_sz = (unsigned long)_end - KERNELBASE; > > kaslr_get_cmdline(dt_ptr); > + if (kaslr_disabled()) > + return; > > offset = kaslr_choose_location(dt_ptr, size, kernel_sz); > > Christophe