Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758713Ab1ELVJY (ORCPT ); Thu, 12 May 2011 17:09:24 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:56305 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758633Ab1ELVJX (ORCPT ); Thu, 12 May 2011 17:09:23 -0400 Date: Thu, 12 May 2011 17:08:45 -0400 (EDT) Message-Id: <20110512.170845.1074260586094306244.davem@davemloft.net> To: mingo@elte.hu Cc: torvalds@linux-foundation.org, eranian@google.com, acme@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] vsprintf: Turn kptr_restrict off by default From: David Miller In-Reply-To: <20110512210028.GA16600@elte.hu> References: <20110512.164319.1770509419224900253.davem@davemloft.net> <20110512210028.GA16600@elte.hu> X-Mailer: Mew version 6.3 on Emacs 23.2 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Thu, 12 May 2011 14:08:47 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1048 Lines: 28 From: Ingo Molnar Date: Thu, 12 May 2011 23:00:28 +0200 > Subject: vsprintf: Turn kptr_restrict off by default > > kptr_restrict has been triggering bugs in apps such as perf, and it also makes > the system less useful by default, so turn it off by default. > > This is how we generally handle security features that remove functionality, > such as firewall code or SELinux - they have to be configured and activated > from user-space. > > Distributions can turn kptr_restrict on again via this line in > /etc/sysctrl.conf: > > kernel.kptr_restrict = 1 > > ( Also mark the variable __read_mostly while at it, as it's typically modified > only once per bootup, or not at all. ) > > Signed-off-by: Ingo Molnar Acked-by: David S. Miller -- 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/