Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751230AbcLDObk (ORCPT ); Sun, 4 Dec 2016 09:31:40 -0500 Received: from mail-io0-f173.google.com ([209.85.223.173]:34860 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750867AbcLDObi (ORCPT ); Sun, 4 Dec 2016 09:31:38 -0500 MIME-Version: 1.0 In-Reply-To: <20161204141746.GL20785@codeblueprint.co.uk> References: <1480010543-25709-2-git-send-email-ard.biesheuvel@linaro.org> <20161204141746.GL20785@codeblueprint.co.uk> From: Ard Biesheuvel Date: Sun, 4 Dec 2016 14:31:23 +0000 Message-ID: Subject: Re: [tip:efi/core] efi/libstub: Make efi_random_alloc() allocate below 4 GB on 32-bit To: Matt Fleming Cc: "tglx@linutronix.de" , Peter Zijlstra , Arnd Bergmann , Ingo Molnar , Linus Torvalds , "linux-kernel@vger.kernel.org" , "hpa@zytor.com" , linux-tip-commits@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2371 Lines: 49 On 4 December 2016 at 14:17, Matt Fleming wrote: > On Thu, 24 Nov, at 10:47:15PM, tip-bot for Ard Biesheuvel wrote: >> Commit-ID: 018edcfac4c3b140366ad51b0907f3becb5bb624 >> Gitweb: http://git.kernel.org/tip/018edcfac4c3b140366ad51b0907f3becb5bb624 >> Author: Ard Biesheuvel >> AuthorDate: Thu, 24 Nov 2016 18:02:23 +0000 >> Committer: Ingo Molnar >> CommitDate: Fri, 25 Nov 2016 07:15:23 +0100 >> >> efi/libstub: Make efi_random_alloc() allocate below 4 GB on 32-bit >> >> The UEFI stub executes in the context of the firmware, which identity >> maps the available system RAM, which implies that only memory below >> 4 GB can be used for allocations on 32-bit architectures, even on [L]PAE >> capable hardware. >> >> So ignore any reported memory above 4 GB in efi_random_alloc(). This >> also fixes a reported build problem on ARM under -Os, where the 64-bit >> logical shift relies on a software routine that the ARM decompressor does >> not provide. >> >> A second [minor] issue is also fixed, where the '+ 1' is moved out of >> the shift, where it belongs: the reason for its presence is that a >> memory region where start == end should count as a single slot, given >> that 'end' takes the desired size and alignment of the allocation into >> account. >> >> To clarify the code in this regard, rename start/end to 'first_slot' and >> 'last_slot', respectively, and introduce 'region_end' to describe the >> last usable address of the current region. >> >> Reported-by: Arnd Bergmann >> Signed-off-by: Ard Biesheuvel >> Cc: Linus Torvalds >> Cc: Matt Fleming >> Cc: Peter Zijlstra >> Cc: Thomas Gleixner >> Cc: linux-efi@vger.kernel.org >> Link: http://lkml.kernel.org/r/1480010543-25709-2-git-send-email-ard.biesheuvel@linaro.org >> Signed-off-by: Ingo Molnar >> --- >> drivers/firmware/efi/libstub/random.c | 13 +++++++------ >> 1 file changed, 7 insertions(+), 6 deletions(-) > > Ard, was this picked up for the correct tip branch? If it fixes a > build failure it should have gone into tip/efi/urgent, right? The failure was in -next, with a patch queued up for v4.10, so that is where the fix went as well.