Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942037AbcJ0N4I (ORCPT ); Thu, 27 Oct 2016 09:56:08 -0400 Received: from mail.skyhub.de ([78.46.96.112]:50977 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941950AbcJ0Nzy (ORCPT ); Thu, 27 Oct 2016 09:55:54 -0400 Date: Thu, 27 Oct 2016 14:36:23 +0200 From: Borislav Petkov To: Bob Peterson Cc: Linus Torvalds , Andy Lutomirski , Andreas Gruenbacher , Peter Zijlstra , Andy Lutomirski , LKML , Steven Whitehouse , Mel Gorman , linux-mm Subject: Re: CONFIG_VMAP_STACK, on-stack struct, and wake_up_bit Message-ID: <20161027123623.j2jri5bandimboff@pd.tnic> References: <996124132.13035408.1477505043741.JavaMail.zimbra@redhat.com> <1731570270.13088320.1477515684152.JavaMail.zimbra@redhat.com> <20161026231358.36jysz2wycdf4anf@pd.tnic> <624629879.13118306.1477528645189.JavaMail.zimbra@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <624629879.13118306.1477528645189.JavaMail.zimbra@redhat.com> User-Agent: NeoMutt/20161014 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2277 Lines: 69 On Wed, Oct 26, 2016 at 08:37:25PM -0400, Bob Peterson wrote: > Attached, but as Linus suggested, I turned off the AMD microcode driver, > so it should be the same if you turn it back on. If you want, I can > do it and re-send so you have a more pristine .config. Let me know. Thanks, but I was able to reproduce in a VM. Here's a fix which works here - I'd appreciate it if you ran it and checked the microcode was applied correctly, i.e.: $ dmesg | grep -i microcode before and after the patch. Please paste that output in a mail too. Thanks! --- From: Borislav Petkov Date: Thu, 27 Oct 2016 14:03:59 +0200 Subject: [PATCH] x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY We needed the physical address of the container in order to compute the offset within the relocated ramdisk. And we did this by doing __pa() on the virtual address. However, __pa() does checks whether the physical address is within PAGE_OFFSET and __START_KERNEL_map - see __phys_addr() - which fail if we have CONFIG_RANDOMIZE_MEMORY enabled: we feed a virtual address which *doesn't* have the randomization offset into a function which uses PAGE_OFFSET which *does* have that offset. This makes this check fire: VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x)); ^^^^^^ due to the randomization offset. The fix is as simple as using __pa_nodebug() because we do that randomization offset accounting later in that function ourselves. Reported-by: Bob Peterson Signed-off-by: Borislav Petkov Cc: stable@vger.kernel.org # 4.9 --- arch/x86/kernel/cpu/microcode/amd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 620ab06bcf45..017bda12caae 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -429,7 +429,7 @@ int __init save_microcode_in_initrd_amd(void) * We need the physical address of the container for both bitness since * boot_params.hdr.ramdisk_image is a physical address. */ - cont = __pa(container); + cont = __pa_nodebug(container); cont_va = container; #endif -- 2.10.0 -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.