From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [PATCH 19/22] arm64: mte: Allow user control of the tag check mode via prctl() Date: Wed, 12 Feb 2020 11:45:17 +0000 Message-ID: <20200212114517.GF488264@arrakis.emea.arm.com> References: <20191211184027.20130-1-catalin.marinas@arm.com> <20191211184027.20130-20-catalin.marinas@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from foss.arm.com ([217.140.110.172]:59952 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728247AbgBLLpV (ORCPT ); Wed, 12 Feb 2020 06:45:21 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Kevin Brodsky Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Marc Zyngier , Vincenzo Frascino , Szabolcs Nagy , Richard Earnshaw , Andrey Konovalov , linux-mm@kvack.org, linux-arch@vger.kernel.org On Fri, Dec 27, 2019 at 02:34:32PM +0000, Kevin Brodsky wrote: > Not just related to this patch, but here goes. While trying to debug an > MTE-enabled process, I realised that there's no way to tell the tagged addr > / MTE thread configuration from outside of the thread. At this point I > thought it'd be really nice if this were to be exposed in /proc/pid, maybe > in /proc/pid/status. Unfortunately there seems to be no precedent for an > arch-specific feature to be exposed there. I guess a ptrace call would work > as well, although it wouldn't be as practical without using a debugger. There is proc_pid_arch_status(), currently only used by x86 to report the avx512 status. We could do the same on arm64 and provide information information on the MTE status, SVE configuration, ptrauth. I think this can be a separate patch covering all these. -- Catalin