Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754761AbaGVMcE (ORCPT ); Tue, 22 Jul 2014 08:32:04 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:8792 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbaGVMcB (ORCPT ); Tue, 22 Jul 2014 08:32:01 -0400 Message-ID: <53CE59BE.104@imgtec.com> Date: Tue, 22 Jul 2014 13:31:58 +0100 From: Markos Chandras User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Aaro Koskinen , Ralf Baechle , David Daney , , CC: Subject: Re: [PATCH] MIPS: OCTEON: make get_system_type() thread-safe References: <1406029868-6210-1-git-send-email-aaro.koskinen@nsn.com> In-Reply-To: <1406029868-6210-1-git-send-email-aaro.koskinen@nsn.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.158] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/22/2014 12:51 PM, Aaro Koskinen wrote: > get_system_type() is not thread-safe on OCTEON. It uses static data, > also more dangerous issue is that it's calling cvmx_fuse_read_byte() > every time without any synchronization. Currently it's possible to get > processes stuck looping forever in kernel simply by launching multiple > readers of /proc/cpuinfo: > > (while true; do cat /proc/cpuinfo > /dev/null; done) & > (while true; do cat /proc/cpuinfo > /dev/null; done) & > ... > > Fix by initializing the system type string only once during the early > boot. > > Signed-off-by: Aaro Koskinen > Cc: stable@vger.kernel.org > --- > arch/mips/cavium-octeon/setup.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > It looks reasonable to me. Reviewed-by: Markos Chandras -- markos -- 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/