Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752096Ab3CPU4h (ORCPT ); Sat, 16 Mar 2013 16:56:37 -0400 Received: from two.firstfloor.org ([193.170.194.197]:49808 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751325Ab3CPU4g (ORCPT ); Sat, 16 Mar 2013 16:56:36 -0400 Date: Sat, 16 Mar 2013 21:56:34 +0100 From: Andi Kleen To: Oleg Nesterov Cc: Andi Kleen , Andrew Morton , Linus Torvalds , Lucas De Marchi , Benjamin Herrenschmidt , Linux Kernel Mailing List , Paul Mackerras , david@gibson.dropbear.id.au, Kees Cook , Serge Hallyn , "Rafael J. Wysocki" , Feng Hong , Lucas De Marchi Subject: Re: [PATCH 0/2] finx argv_split() vs sysctl race Message-ID: <20130316205634.GU11268@two.firstfloor.org> References: <20130312191118.GA17439@redhat.com> <20130312203514.GA23488@redhat.com> <20130313174641.GA28083@redhat.com> <20130313174705.GB28083@redhat.com> <20130314152819.7fb1242b493e8bad2d34671b@linux-foundation.org> <20130315163916.GA31995@redhat.com> <20130316202327.GA18613@redhat.com> <20130316203221.GT11268@two.firstfloor.org> <20130316204539.GA19462@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130316204539.GA19462@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 884 Lines: 27 > Perhaps rcu can be better, although a global rwsem looks simpler, > I dunno. It's a general problem with lots of sysctls. > > But argv_split() or its usage should be changed anyway, and GFP_KERNEL > won't work under rcu_read_lock(). rcu strings has a helper function to copy the string for sleepy cases. > > To me 1/2 looks as a simplification anyway, but I won't argue if we > decide to add rcu/locking and avoid this patch. Ok I'll revisit. I think the problem last time was that the rcu strings needed a kernel_text_address() function that worked on all architectures. Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/