Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756763Ab3DXOy4 (ORCPT ); Wed, 24 Apr 2013 10:54:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13460 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752876Ab3DXOyy (ORCPT ); Wed, 24 Apr 2013 10:54:54 -0400 Date: Wed, 24 Apr 2013 10:54:49 -0400 From: Josh Boyer To: Matt Fleming Cc: Matthew Garrett , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] efi: Check EFI revision in setup_efi_vars Message-ID: <20130424145449.GC15272@hansolo.jdub.homelinux.org> References: <20130424143738.GB15272@hansolo.jdub.homelinux.org> <5177EFCE.80104@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5177EFCE.80104@intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2128 Lines: 48 On Wed, Apr 24, 2013 at 03:44:30PM +0100, Matt Fleming wrote: > On 24/04/13 15:37, Josh Boyer wrote: > > We need to check the runtime sys_table for the EFI version the firmware > > specifies instead of just checking for a NULL QueryVariableInfo. Older > > implementations of EFI don't have QueryVariableInfo but the runtime is > > a smaller structure, so the pointer to it may be pointing off into garbage. > > > > This is apparently the case with several Apple firmwares that support EFI > > 1.10, and the current check causes them to no longer boot. Fix based on > > a suggestion from Matthew Garrett. > > > > Signed-off-by: Josh Boyer > > --- > > arch/x86/boot/compressed/eboot.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c > > index 8615f75..b46efbf 100644 > > --- a/arch/x86/boot/compressed/eboot.c > > +++ b/arch/x86/boot/compressed/eboot.c > > @@ -258,7 +258,9 @@ static efi_status_t setup_efi_vars(struct boot_params *params) > > u64 store_size, remaining_size, var_size; > > efi_status_t status; > > > > - if (!sys_table->runtime->query_variable_info) > > + if (sys_table->runtime->hdr.revision < EFI_2_00_SYSTEM_TABLE_REVISION) > > + return EFI_UNSUPPORTED; > > + else if(!sys_table->runtime->query_variable_info) > > return EFI_UNSUPPORTED; > > > > data = (struct setup_data *)(unsigned long)params->hdr.setup_data; > > > > Thanks Josh, that looks correct. > > It's a small point, but does the check against NULL actually make sense? > I don't think we ever check other system table pointers against NULL. That I'm not sure of. I was going off of the assumption that Matthew put it there because someone's EFI 2.0 implementation was crappy and didn't actually implement it. So I left that check in place for now. josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/