From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH] drivers/iommu: don't select DEBUG_FS for AMD_IOMMU_STATS Date: Wed, 6 Apr 2016 00:41:52 +0200 Message-ID: <20160405224152.GK17838@8bytes.org> References: <1459041524-30929-1-git-send-email-paul.gortmaker@windriver.com> <20160405151951.GG11519@8bytes.org> <20160405123754.30786ede@grimm.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160405123754.30786ede-2kNGR76GQU9OHLTnHDQRgA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Steven Rostedt Cc: Paul Gortmaker , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, Apr 05, 2016 at 12:37:54PM -0400, Steven Rostedt wrote: > I will argue that people have asked me to move tracing out of debugfs > (which is why I created tracefs) because the problem with debugfs is > that it opens up a entire system that is not well scrutinized, and > holds lots of possible ways to crack the kernel. > > Disabling debugfs does help with the "security" point you mentioned > above. Yes, that reasoning makes more sense than "debug features are bad for production". It should've been part of the commit message. The AMD_IOMMU_STATS feature is on my list of things to remove anyway, it is mostly disabled and should be done differently (via per-device sysfs stats). So I am just going to remove it for now. Joerg