Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754338AbbDTXuY (ORCPT ); Mon, 20 Apr 2015 19:50:24 -0400 Received: from mail-db3on0080.outbound.protection.outlook.com ([157.55.234.80]:58774 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752038AbbDTXuW convert rfc822-to-8bit (ORCPT ); Mon, 20 Apr 2015 19:50:22 -0400 From: Chris Metcalf To: Andrew Morton CC: Rasmus Villemoes , Tejun Heo , "Peter Zijlstra (Intel)" , Sudeep Holla , Michal Nazarewicz , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: Re: [PATCH] __bitmap_parselist: fix bug in empty string handling Thread-Topic: [PATCH] __bitmap_parselist: fix bug in empty string handling Thread-Index: AQHQeThZnA7rNYY3GEG3uk4NKR/e3Z1WW5eAgAA7fM8= Date: Mon, 20 Apr 2015 23:50:19 +0000 Message-ID: <20FD3D67-54CF-45E6-81A9-273E25B8A154@ezchip.com> References: <1429293604-5210-1-git-send-email-cmetcalf@ezchip.com>,<20150420131725.3491233d901f1231af8fbc5d@linux-foundation.org> In-Reply-To: <20150420131725.3491233d901f1231af8fbc5d@linux-foundation.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: linux-foundation.org; dkim=none (message not signed) header.d=none; x-originating-ip: [70.210.230.79] x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:DB5PR02MB0776; x-forefront-antispam-report: BMV:1;SFV:NSPM;SFS:(10009020)(6009001)(24454002)(51704005)(377454003)(2950100001)(102836002)(46102003)(33656002)(82746002)(87936001)(19580405001)(2656002)(92566002)(66066001)(106116001)(122556002)(19580395003)(50986999)(76176999)(77156002)(86362001)(62966003)(83716003)(40100003)(54356999)(110136001)(36756003)(104396002);DIR:OUT;SFP:1101;SCL:1;SRVR:DB5PR02MB0776;H:DB5PR02MB0776.eurprd02.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(601004)(5002010)(5005006);SRVR:DB5PR02MB0776;BCL:0;PCL:0;RULEID:;SRVR:DB5PR02MB0776; x-forefront-prvs: 05529C6FDB Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: ezchip.com X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Apr 2015 23:50:19.8058 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 0fc16e0a-3cd3-4092-8b2f-0a42cff122c3 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB5PR02MB0776 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1241 Lines: 27 > On Apr 20, 2015, at 1:17 PM, Andrew Morton wrote: > >> On Fri, 17 Apr 2015 14:00:04 -0400 Chris Metcalf wrote: >> >> bitmap_parselist("", &mask, nmaskbits) will erroneously set bit >> zero in the mask. The same bug is visible in cpumask_parselist() >> since it is layered on top of the bitmask code, e.g. if you boot with >> "isolcpus=", you will actually end up with cpu zero isolated. >> >> The bug was introduced in commit 4b060420a596 ("bitmap, irq: add >> smp_affinity_list interface to /proc/irq") when bitmap_parselist() >> was generalized to support userspace as well as kernelspace. >> >> Signed-off-by: Chris Metcalf >> Cc: stable@vger.kernel.org > > I don't think we need to backport a fix for a 4 year old bug which has > very minor consequences. Am I wrong? I don't have a strong feeling on this one. My guess is it's trivial to backport but also very low impact so either way is pretty reasonable. -- 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/