From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755573AbcARPkK (ORCPT ); Mon, 18 Jan 2016 10:40:10 -0500 Received: from mail-pf0-f175.google.com ([209.85.192.175]:33079 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755375AbcARPkH (ORCPT ); Mon, 18 Jan 2016 10:40:07 -0500 Date: Mon, 18 Jan 2016 15:40:01 +0000 From: Matt Fleming To: Srikar Dronamraju Cc: Ingo Molnar , Ingo Molnar , LKML , linux-efi@vger.kernel.org, Linus Torvalds Subject: Re: v4.4-rc8 based tip tree kernel hangs on boot. Message-ID: <20160118154001.GA2607@codeblueprint.co.uk> References: <20160110192921.GD17012@linux.vnet.ibm.com> <20160111140140.GA2644@codeblueprint.co.uk> <20160112103043.GA5707@gmail.com> <20160115162011.GA2935@linux.vnet.ibm.com> <20160115222921.GA5378@codeblueprint.co.uk> <20160117173248.GA28841@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160117173248.GA28841@linux.vnet.ibm.com> User-Agent: Mutt/1.5.24+41 (02bc14ed1569) (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 17 Jan, at 11:02:48PM, Srikar Dronamraju wrote: > > Unfortunately even with your below patch on top of c9f2a9a ("x86/efi: > Hoist page table switching code into efi_call_virt()" also fails to boot > with and without CONFIG_DEBUG_WX=y. I have added CONFIG_EFI_PGT_DUMP. What about if you comment out the call to efi_dump_pagetable()? What if you return early from efi_sync_low_kernel_mappings(), e.g. diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 71121a9d06cf..e1f8ebb88f84 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -177,6 +177,8 @@ void efi_sync_low_kernel_mappings(void) init_mm.pgd + pgd_index(PAGE_OFFSET), sizeof(pgd_t) * num_pgds); + return; + /* * We can share all PGD entries apart from the one entry that * covers the EFI runtime mapping space. Do either of those modifications make your kernel boot when you apply the patch I sent on Friday? If so, which one? I'm struggling to find hardware that's similar enough to reproduce this.