From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031431Ab3HIWwV (ORCPT ); Fri, 9 Aug 2013 18:52:21 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53897 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031398Ab3HIWwT (ORCPT ); Fri, 9 Aug 2013 18:52:19 -0400 Date: Fri, 9 Aug 2013 15:51:58 -0700 From: tip-bot for Daniel Drake Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, yinghai@kernel.org, dsd@laptop.org, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, yinghai@kernel.org, dsd@laptop.org, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <20130809221420.618E6FAB03@dev.laptop.org> References: <20130809221420.618E6FAB03@dev.laptop.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86: Don' t clear olpc_ofw_header when sentinel is detected Git-Commit-ID: d55e37bb0f51316e552376ddc0a3fff34ca7108b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Fri, 09 Aug 2013 15:52:06 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: d55e37bb0f51316e552376ddc0a3fff34ca7108b Gitweb: http://git.kernel.org/tip/d55e37bb0f51316e552376ddc0a3fff34ca7108b Author: Daniel Drake AuthorDate: Fri, 9 Aug 2013 18:14:20 -0400 Committer: H. Peter Anvin CommitDate: Fri, 9 Aug 2013 15:29:48 -0700 x86: Don't clear olpc_ofw_header when sentinel is detected OpenFirmware wasn't quite following the protocol described in boot.txt and the kernel has detected this through use of the sentinel value in boot_params. OFW does zero out almost all of the stuff that it should do, but not the sentinel. This causes the kernel to clear olpc_ofw_header, which breaks x86 OLPC support. OpenFirmware has now been fixed. However, it would be nice if we could maintain Linux compatibility with old firmware versions. To do that, we just have to avoid zeroing out olpc_ofw_header. OFW does not write to any other parts of the header that are being zapped by the sentinel-detection code, and all users of olpc_ofw_header are somewhat protected through checking for the OLPC_OFW_SIG magic value before using it. So this should not cause any problems for anyone. Signed-off-by: Daniel Drake Link: http://lkml.kernel.org/r/20130809221420.618E6FAB03@dev.laptop.org Acked-by: Yinghai Lu Signed-off-by: H. Peter Anvin Cc: # v3.9+ --- arch/x86/include/asm/bootparam_utils.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h index 653668d..4a8cb8d 100644 --- a/arch/x86/include/asm/bootparam_utils.h +++ b/arch/x86/include/asm/bootparam_utils.h @@ -35,9 +35,9 @@ static void sanitize_boot_params(struct boot_params *boot_params) */ if (boot_params->sentinel) { /* fields in boot_params are left uninitialized, clear them */ - memset(&boot_params->olpc_ofw_header, 0, + memset(&boot_params->ext_ramdisk_image, 0, (char *)&boot_params->efi_info - - (char *)&boot_params->olpc_ofw_header); + (char *)&boot_params->ext_ramdisk_image); memset(&boot_params->kbd_status, 0, (char *)&boot_params->hdr - (char *)&boot_params->kbd_status);