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 199DEC433FF for ; Mon, 29 Jul 2019 11:08:27 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 6379021655 for ; Mon, 29 Jul 2019 11:08:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="arONxYLf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6379021655 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-16604-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 5975 invoked by uid 550); 29 Jul 2019 11:08:20 -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 5943 invoked from network); 29 Jul 2019 11:08:20 -0000 Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=arONxYLf; 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=1564398483; bh=5INwHw7XbuC/K2OjMZ4KYRax0cv2G+pbjXkMo1syWiI=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=arONxYLfYazH1Zuv1sjYhl+98rYh7/IMm8wcB9t915KfBP0mg7p23qtwKyOzwnotp W40nOf8zFdXdk+whAYptqqCcrHrHC6a8ulMz3YYeOFBKwQhFMNHEzDbTqPDV1UtWXJ Wm699DyCi1utuj1uMB5IRkKVDDV3wBaTlHP6sh5E= X-Virus-Scanned: amavisd-new at c-s.fr Subject: Re: [RFC PATCH 05/10] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper 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> <20190717080621.40424-6-yanaijie@huawei.com> From: Christophe Leroy Message-ID: Date: Mon, 29 Jul 2019 13:08:08 +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: <20190717080621.40424-6-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 : > Add a new helper reloc_kernel_entry() to jump back to the start of the > new kernel. After we put the new kernel in a randomized place we can use > this new helper to enter the kernel and begin to relocate again. > > 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/head_fsl_booke.S | 16 ++++++++++++++++ > arch/powerpc/mm/mmu_decl.h | 1 + > 2 files changed, 17 insertions(+) > > diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S > index a57d44638031..ce40f96dae20 100644 > --- a/arch/powerpc/kernel/head_fsl_booke.S > +++ b/arch/powerpc/kernel/head_fsl_booke.S > @@ -1144,6 +1144,22 @@ _GLOBAL(create_tlb_entry) > sync > blr > > +/* > + * Return to the start of the relocated kernel and run again > + * r3 - virtual address of fdt > + * r4 - entry of the kernel > + */ > +_GLOBAL(reloc_kernel_entry) > + mfmsr r7 > + li r8,(MSR_IS | MSR_DS) > + andc r7,r7,r8 Instead of the li/andc, what about the following: rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) > + > + mtspr SPRN_SRR0,r4 > + mtspr SPRN_SRR1,r7 > + isync > + sync > + rfi Are the isync/sync really necessary ? AFAIK, rfi is context synchronising. > + > /* > * Create a tlb entry with the same effective and physical address as > * the tlb entry used by the current running code. But set the TS to 1. > diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h > index d7737cf97cee..dae8e9177574 100644 > --- a/arch/powerpc/mm/mmu_decl.h > +++ b/arch/powerpc/mm/mmu_decl.h > @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); > extern int switch_to_as1(void); > extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); > extern void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry); > +extern void reloc_kernel_entry(void *fdt, int addr); No new 'extern' please, see https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/8125//artifact/linux/checkpatch.log > #endif > extern void loadcam_entry(unsigned int index); > extern void loadcam_multi(int first_idx, int num, int tmp_idx); > Christophe