From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B665C433F5 for ; Tue, 25 Jan 2022 15:16:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 439F66B0087; Tue, 25 Jan 2022 10:16:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3EA796B0089; Tue, 25 Jan 2022 10:16:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2D8026B008A; Tue, 25 Jan 2022 10:16:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 1DF326B0087 for ; Tue, 25 Jan 2022 10:16:18 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id BEC27120872 for ; Tue, 25 Jan 2022 15:16:17 +0000 (UTC) X-FDA: 79069160394.01.28D1871 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id CB65E40007 for ; Tue, 25 Jan 2022 15:16:10 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8A7916167E; Tue, 25 Jan 2022 15:16:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE21BC340E0; Tue, 25 Jan 2022 15:16:07 +0000 (UTC) Date: Tue, 25 Jan 2022 10:16:06 -0500 From: Steven Rostedt To: Matthew Wilcox Cc: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org, naoya.horiguchi@linux.dev, Ingo Molnar , Zi Yan , Naoya Horiguchi , John Hubbard , linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 2/2] mm/migration: Add trace events for base page and HugeTLB migrations Message-ID: <20220125101606.3cfb5561@gandalf.local.home> In-Reply-To: References: <1643080105-11416-1-git-send-email-anshuman.khandual@arm.com> <1643080105-11416-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: pxuouzq7ht1mu6cbdn35j11gygkgs1z7 X-Rspam-User: nil Authentication-Results: imf11.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf11.hostedemail.com: domain of "SRS0=elGn=SJ=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=elGn=SJ=goodmis.org=rostedt@kernel.org" X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: CB65E40007 X-HE-Tag: 1643123770-381345 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 25 Jan 2022 13:28:49 +0000 Matthew Wilcox wrote: > On Tue, Jan 25, 2022 at 08:38:25AM +0530, Anshuman Khandual wrote: > > + TP_printk("addr=%lx, pte=%lx order=%d", __entry->addr, __entry->pte, __entry->order) > > In these days of increasingly advanced Rowhammer attacks, is it wise > to let userspace know exactly which physical addresses are being > used for virtual addresses? Is it an issue if this is only available for privileged users? With tracing, you can just create a kprobe to get the same information for you as well, so this isn't giving a user anything they do not already have. -- Steve