Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759115Ab3DZItn (ORCPT ); Fri, 26 Apr 2013 04:49:43 -0400 Received: from mail-wi0-f177.google.com ([209.85.212.177]:48856 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758863Ab3DZItl (ORCPT ); Fri, 26 Apr 2013 04:49:41 -0400 Message-ID: <517A3FA0.8030702@intel.com> Date: Fri, 26 Apr 2013 09:49:36 +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> <517A28D7.3010707@intel.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: 2246 Lines: 59 On 26/04/13 08:43, Michel Lespinasse wrote: > Still seeing the crash. > > I went and compared the crash dump with the vmlinux disassembly; the > issue is a NULL pointer dereference in list_for_each_entry_safe(). > list_empty() checks that the head node points to itself, but here the > head node has NULL. I think this may be due to gsmi_init() being > called before efivars_init(). Not sure what's the proper fix though. Ohh... I see what you mean. The bug is in variable_is_present() because it accesses __efivars directly, which a) isn't the struct efivars gsmi.c uses and b) hasn't been initialised. Something like this might work. --- diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 182ce94..f4baa11 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -1628,10 +1628,11 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, return count; } -static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) +static bool variable_is_present(struct efivars *efivars, + efi_char16_t *variable_name, + efi_guid_t *vendor) { struct efivar_entry *entry, *n; - struct efivars *efivars = &__efivars; unsigned long strsize1, strsize2; bool found = false; @@ -1703,8 +1704,8 @@ static void efivar_update_sysfs_entries(struct work_struct *work) if (status != EFI_SUCCESS) { break; } else { - if (!variable_is_present(variable_name, - &vendor)) { + if (!variable_is_present(efivars, + variable_name, &vendor)) { found = true; break; } @@ -2008,7 +2009,8 @@ int register_efivars(struct efivars *efivars, * we'll ever see a different variable name, * and may end up looping here forever. */ - if (variable_is_present(variable_name, &vendor_guid)) { + if (variable_is_present(efivars, variable_name, + &vendor_guid)) { dup_variable_bug(variable_name, &vendor_guid, variable_name_size); status = EFI_NOT_FOUND; -- 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/