Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757867Ab3DZHM2 (ORCPT ); Fri, 26 Apr 2013 03:12:28 -0400 Received: from mail-we0-f182.google.com ([74.125.82.182]:60469 "EHLO mail-we0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757078Ab3DZHM0 (ORCPT ); Fri, 26 Apr 2013 03:12:26 -0400 Message-ID: <517A28D7.3010707@intel.com> Date: Fri, 26 Apr 2013 08:12:23 +0100 From: Matt Fleming Organization: Intel Corporation (UK) Ltd. - Registered No. 1134945 - Pipers Way, Swindon SN3 1RJ User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Michel Lespinasse CC: "H. Peter Anvin" , Matthew Garrett , Linus Torvalds , "H. Peter Anvin" , Borislav Petkov , Ingo Molnar , Josh Boyer , Linux Kernel Mailing List , Paul Bolle , Thomas Gleixner Subject: Re: [GIT PULL] x86 fixes for 3.9 References: <201304252144.r3PLihDe025383@terminus.zytor.com> <1366928604.9976.3.camel@x230> <5179B435.1000404@zytor.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2561 Lines: 59 On 26/04/13 00:11, Michel Lespinasse wrote: > On Thu, Apr 25, 2013 at 3:54 PM, H. Peter Anvin wrote: >> On 04/25/2013 03:53 PM, Michel Lespinasse wrote: >>> On Thu, Apr 25, 2013 at 3:23 PM, Matthew Garrett >>> wrote: >>>> On Thu, 2013-04-25 at 15:20 -0700, Linus Torvalds wrote: >>>>> On Thu, Apr 25, 2013 at 2:44 PM, H. Peter Anvin wrote: >>>>>> >>>>>> - if (!sys_table->runtime->query_variable_info) >>>>>> + if (sys_table->runtime->hdr.revision < EFI_2_00_SYSTEM_TABLE_REVISION) >>>>>> return EFI_UNSUPPORTED; >>>>> >>>>> Is a EFI 2.00 system table *guaranteed* to have that >>>>> "query_variable_info" function? The above adds the version check, but >>>>> removes the check for a NULL pointer. >>>> >>>> As far as the spec's concerned, yes. As far as reality's concerned - if >>>> anything doesn't provide it, we're already crashing when >>>> efi_virt_query_variable_info() gets called. Nobody's complained so far. >>> >>> Well, I don't know if this is related, but commit e971318bbed6 broke >>> the google EFI SMI driver with >>> BUG: unable to handle kernel NULL pointer dereference at (null) >>> IP: [] variable_is_present+0x55/0x170 >>> Call Trace: >>> [] register_efivars+0x106/0x370 >>> [] ? firmware_map_add_early+0xb1/0xb1 >>> [] gsmi_init+0x2ad/0x3da >>> [] do_one_initcall+0x3f/0x170 >>> ... >> >> I don't know either. Could you test this patch and see if it does anything? > > Nope, still seeing the crash with this patch applied. Could you try the following patch against Linus' tree? The bug you've found and the changes in the pull request are unrelated. --- diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 182ce94..2a4f619 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1635,6 +1635,9 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) unsigned long strsize1, strsize2; bool found = false; + if (list_empty(&efivars->list)) + return false; + strsize1 = ucs2_strsize(variable_name, 1024); list_for_each_entry_safe(entry, n, &efivars->list, list) { strsize2 = ucs2_strsize(entry->var.VariableName, 1024); -- 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/