From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbbC0OIJ (ORCPT ); Fri, 27 Mar 2015 10:08:09 -0400 Received: from www.sr71.net ([198.145.64.142]:53247 "EHLO blackbird.sr71.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752809AbbC0OIH (ORCPT ); Fri, 27 Mar 2015 10:08:07 -0400 Message-ID: <55156445.3000609@sr71.net> Date: Fri, 27 Mar 2015 07:08:05 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Borislav Petkov CC: linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, dave.hansen@linux.intel.com Subject: Re: [PATCH 06/17] x86, mpx: trace attempts to find bounds tables References: <20150326183327.64807530@viggo.jf.intel.com> <20150326183341.A0AA7CBF@viggo.jf.intel.com> <20150327123248.GE18927@pd.tnic> In-Reply-To: <20150327123248.GE18927@pd.tnic> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/27/2015 05:32 AM, Borislav Petkov wrote: >> > This event traces any time we go looking to unmap a bounds table >> > for a given virtual address range. This is useful to ensure >> > that the kernel actually "tried" to free a bounds table versus >> > times it succeeded. >> > >> > It might try and fail if it realized that a table was shared >> > with an adjacent VMA which is not being unmapped. > Would it make sense to extend this tracepoint to also dump the error > values returned from unmap_edge_bts() and unmap_single_bt() inside > mpx_unmap_tables()? Both of the paths below this point (the "real" unmap and the zap) also have tracepoints. It might also get confusing to see -ENOENT in the success case. Also, in practice, you can see the siginfo get generated and tell that something bad happened. I think I'd rather leave it as-is.