From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753051AbdHKMyT (ORCPT ); Fri, 11 Aug 2017 08:54:19 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:36942 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752705AbdHKMyS (ORCPT ); Fri, 11 Aug 2017 08:54:18 -0400 Date: Fri, 11 Aug 2017 14:54:13 +0200 From: Ingo Molnar To: Stuart Hayes Cc: Matt Fleming , Ard Biesheuvel , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v2] x86/efi: page align EFI ROM image ranges Message-ID: <20170811125413.umxgpqos3vmva5cg@gmail.com> References: <4a28637c-d5ff-95ed-5bee-2b1e465f2d79@gmail.com> <20170804120650.GE8187@codeblueprint.co.uk> <20170810144637.qpqqr5rs3lhag6av@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Stuart Hayes wrote: > The kernel's EFI stub locates and copies EFI ROM images into memory, which it allocates using the byte-granular EFI allocate_pool function. These memory ranges are then added to setup_data, and later to e820 (in e820__reserve_setup_data()). The e820 ranges are parsed to create nosave regions (in e820__register_nosave_regions()), but when non-page-aligned e820 regions are parsed, a nosave page is added at the beginning and end of each non-page-aligned region, which results in data not getting saved or restored during a hibernate/resume. This can result in random failures after a hibernate/resume. > > Round up the allocation size to a whole number of pages, and use EFI allocate_pages to ensure that the EFI ROM copy regions are page-aligned. > > On a system with six EFI ROM images, before the patch: > > e820: update [mem 0x64866020-0x6486e05f] usable ==> usable > e820: update [mem 0x6147a020-0x61499c5f] usable ==> usable > e820: update [mem 0x60fff020-0x6105785f] usable ==> usable > e820: update [mem 0x60fa6020-0x60ffe85f] usable ==> usable > e820: update [mem 0x60f4d020-0x60fa585f] usable ==> usable > e820: update [mem 0x60ef4020-0x60f4c85f] usable ==> usable > ... > PM: Registered nosave memory: [mem 0x00000000-0x00000fff] > PM: Registered nosave memory: [mem 0x000a0000-0x000fffff] > PM: Registered nosave memory: [mem 0x60ef4000-0x60ef4fff] > PM: Registered nosave memory: [mem 0x60f4c000-0x60f4cfff] > PM: Registered nosave memory: [mem 0x60f4d000-0x60f4dfff] > PM: Registered nosave memory: [mem 0x60fa5000-0x60fa5fff] > PM: Registered nosave memory: [mem 0x60fa6000-0x60fa6fff] > PM: Registered nosave memory: [mem 0x60ffe000-0x60ffefff] > PM: Registered nosave memory: [mem 0x60fff000-0x60ffffff] > PM: Registered nosave memory: [mem 0x61057000-0x61057fff] > PM: Registered nosave memory: [mem 0x6147a000-0x6147afff] > PM: Registered nosave memory: [mem 0x61499000-0x61499fff] > PM: Registered nosave memory: [mem 0x64866000-0x64866fff] > PM: Registered nosave memory: [mem 0x6486e000-0x6486efff] > PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff] > > After the patch: > > e820: update [mem 0x64866000-0x6486efff] usable ==> usable > e820: update [mem 0x6147a000-0x61499fff] usable ==> usable > e820: update [mem 0x60fff000-0x61057fff] usable ==> usable > e820: update [mem 0x60fa6000-0x60ffefff] usable ==> usable > e820: update [mem 0x60f4d000-0x60fa5fff] usable ==> usable > e820: update [mem 0x60ef4000-0x60f4cfff] usable ==> usable > ... > PM: Registered nosave memory: [mem 0x00000000-0x00000fff] > PM: Registered nosave memory: [mem 0x000a0000-0x000fffff] > PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff] > > Signed-off-by: Stuart Hayes > --- > Changes in V2: > Update the comments in the code. > Add same fix to __setup_efi_pci32() > > --- linux-4.13-rc2/arch/x86/boot/compressed/eboot.c.orig 2017-08-01 12:12:04.696049106 -0400 > +++ linux-4.13-rc2/arch/x86/boot/compressed/eboot.c 2017-08-07 13:00:15.165374388 -0400 > @@ -127,7 +127,13 @@ __setup_efi_pci32(efi_pci_io_protocol_32 > > size = pci->romsize + sizeof(*rom); > > - status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom); > + /* > + * Get whole pages because this will be added to e820, and > + * e820__register_nosave_regions() expects page-aligned regions. BTW., could we please also do a separate robustness fix to e820__register_nosave_regions(), which complains about regions that have bad alignment, and fixes them up if possible? That way if with just the robustness fix applied we'd get the warning on your system - and hibernation should work - and with this second fix we'd get a silent bootup and a working system. Or something like that? Thanks, Ingo