Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751526AbbG3LSo (ORCPT ); Thu, 30 Jul 2015 07:18:44 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:46748 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750734AbbG3LSn (ORCPT ); Thu, 30 Jul 2015 07:18:43 -0400 Date: Thu, 30 Jul 2015 19:18:19 +0800 From: joeyli To: Matt Fleming Cc: Borislav Petkov , "H. Peter Anvin" , "Lee, Chun-Yi" , Thomas Gleixner , Ingo Molnar , x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86_64/efi: Mapping Boot and Runtime EFI memory regions to different starting virtual address Message-ID: <20150730111819.GK15651@linux-rxt1.site> References: <1438230757-30840-1-git-send-email-jlee@suse.com> <55B9D806.7030705@zytor.com> <20150730080323.GD8984@nazgul.tnic> <20150730101131.GB2725@codeblueprint.co.uk> <20150730110959.GJ15651@linux-rxt1.site> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150730110959.GJ15651@linux-rxt1.site> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6949 Lines: 112 On Thu, Jul 30, 2015 at 07:09:59PM +0800, joeyli wrote: > On Thu, Jul 30, 2015 at 11:11:31AM +0100, Matt Fleming wrote: > > On Thu, 30 Jul, at 10:03:23AM, Borislav Petkov wrote: > > > On Thu, Jul 30, 2015 at 12:53:42AM -0700, H. Peter Anvin wrote: > > > > This changelog is at least partially incomprehensive. It also seems > > > > more than a bit aggressive to expect that 1 GB will be sufficient > > > > forever. > > > > > > Right, before we do anything, I'd like for us to figure out first why > > > this is a problem all of a sudden. And why should we even keep boot > > > code/data, if it is fair game, once runtime services get enabled. > > > > > > Matt, can you please chime in first before we even talk about a > > > solution... > > > > Yeah, I do not understand the issue properly. > > > > Why do we care about EfiBoot* regions after hibernate? Surely we've > > already freed those regions in efi_free_boot_services() during boot and > > nobody should be touching them again? If the firmware does, that's a > > whole new bug we've never encountered before. > > > > And we obviously can't allow the runtime regions to move around during > > hibernate/resume because we've already informed the firmware where those > > regions live during SetVirtualAddressMap() at boot. > > > > I admit that I haven't looked at the hibernate code paths. Let me go do > > that now. > > > > -- > > Matt Fleming, Intel Open Source Technology Center > > In efi_map_regions(), kernel mapping EFI_MEMORY_RUNTIME and > EFI_BOOT_SERVICES_CODE/DATA regions to trampoline_pgd. > > UEFI keeps the physical address of Runtime Code/Data were not changed in > hibernate cycle. But the changes of Boot regions causes Runtime Code/Data > mapping to different virtual address in trampoline_pgd. > > The following is a case from Intel DQ57TM. > > Boot: > [ 0.036509] efi: mem11: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b7f7e000-0x00000000b7f9e000) va=[0xfffffffefff7e000-0xfffffffefff9e000) (0MB) > [ 0.051393] efi: mem17: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b8b4f000-0x00000000b8b50000) va=[0xfffffffefff4f000-0xfffffffefff50000) (0MB) > [ 0.066271] efi: mem19: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b8c2f000-0x00000000b9135000) va=[0xfffffffeffa2f000-0xfffffffefff35000) (5MB) > [ 0.081152] efi: mem21: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b9138000-0x00000000baf7d000) va=[0xfffffffefdb38000-0xfffffffeff97d000) (30MB) > [ 0.096120] efi: mem23: [Boot Code | | | | | |WB|WT|WC|UC] pa=[0x00000000bb04b000-0x00000000bb385000) va=[0xfffffffefd64b000-0xfffffffefd985000) (3MB) > [ 0.111002] efi: mem24: [Runtime Code |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb385000-0x00000000bb3e5000) va=[0xfffffffefd585000-0xfffffffefd5e5000) (0MB) > [ 0.125883] efi: mem25: [Runtime Data |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb3e5000-0x00000000bb445000) va=[0xfffffffefd3e5000-0xfffffffefd445000) (0MB) > [ 0.140764] efi: mem29: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000bb7ff000-0x00000000bb800000) va=[0xfffffffefd1ff000-0xfffffffefd200000) (0MB) > > Hibernate resumed: > [ 0.036486] efi: mem11: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b7f7e000-0x00000000b7f9e000) va=[0xfffffffefff7e000-0xfffffffefff9e000) (0MB) > [ 0.051375] efi: mem17: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b8c0d000-0x00000000b9113000) va=[0xfffffffeffa0d000-0xfffffffefff13000) (5MB) <=== order of Boot Data changed > [ 0.066253] efi: mem20: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b9132000-0x00000000b9133000) va=[0xfffffffeff932000-0xfffffffeff933000) (0MB) > [ 0.081135] efi: mem22: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000b9138000-0x00000000baf7d000) va=[0xfffffffefd938000-0xfffffffeff77d000) (30MB) > [ 0.096103] efi: mem24: [Boot Code | | | | | |WB|WT|WC|UC] pa=[0x00000000bb04b000-0x00000000bb385000) va=[0xfffffffefd44b000-0xfffffffefd785000) (3MB) > [ 0.110984] efi: mem25: [Runtime Code |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb385000-0x00000000bb3e5000) va=[0xfffffffefd385000-0xfffffffefd3e5000) (0MB) <=== va changed > [ 0.125865] efi: mem26: [Runtime Data |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb3e5000-0x00000000bb445000) va=[0xfffffffefd1e5000-0xfffffffefd245000) (0MB) > [ 0.140747] efi: mem30: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000bb7ff000-0x00000000bb800000) va=[0xfffffffefcfff000-0xfffffffefd000000) (0MB) > > Look at the origin va of Runtime Code is 0xfffffffefd585000, but after hibernate > result boot, the new va is 0xfffffffefd385000. > > Issue machine's UEFI keeps the PA of Runtime regions unchanged, but Boot regions > moved. That causes Runtime regions mapping to different VA. > > > > Regards > Joey Lee In the above case, just simply accessing EFI variable through efivars to reproduce issue: linux-aiip:~ # hexdump -C /sys/firmware/efi/efivars/SecureBoot-8be4df61-93ca-11d2-aa0d-00e098032b8c Killed [ 257.856185] BUG: unable to handle kernel paging request at fffffffefd244e60 <=== address is in Runtime Data region [ 257.863200] IP: [] virt_efi_get_variable+0x5d/0xa0 [ 257.869586] PGD 1a0c067 PUD 13b0ae063 PMD 13b0bc063 PTE 0 [ 257.875056] Oops: 0000 [#1] SMP [...snip] [ 258.149804] RIP [] virt_efi_get_variable+0x5d/0xa0 [ 258.156273] RSP [ 258.159769] CR2: fffffffefd244e60 [ 258.163090] ---[ end trace 9edb589760c07d3e ]--- 0xfffffffefd244e60 is covered by Runtime Data region after hibernate resumed: [ 0.125865] efi: mem26: [Runtime Data |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb3e5000-0x00000000bb445000) va=[0xfffffffefd1e5000-0xfffffffefd245000) (0MB) 0xfffffffefd244e60 But this va address didn't mapped to any pa in hibernating kernel (image kernel): [ 0.111002] efi: mem24: [Runtime Code |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb385000-0x00000000bb3e5000) va=[0xfffffffefd585000-0xfffffffefd5e5000) (0MB) [ 0.125883] efi: mem25: [Runtime Data |RUN| | | | |WB|WT|WC|UC] pa=[0x00000000bb3e5000-0x00000000bb445000) va=[0xfffffffefd3e5000-0xfffffffefd445000) (0MB) 0xfffffffefd244e60 <=== no mapping [ 0.140764] efi: mem29: [Boot Data | | | | | |WB|WT|WC|UC] pa=[0x00000000bb7ff000-0x00000000bb800000) va=[0xfffffffefd1ff000-0xfffffffefd200000) (0MB) So, when call EFI runtime services, got problem. Regards Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/