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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE725C43381 for ; Wed, 27 Feb 2019 08:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8AC4218D9 for ; Wed, 27 Feb 2019 08:01:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="XYB4w9HS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727078AbfB0IBM (ORCPT ); Wed, 27 Feb 2019 03:01:12 -0500 Received: from merlin.infradead.org ([205.233.59.134]:60468 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726702AbfB0IBM (ORCPT ); Wed, 27 Feb 2019 03:01:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=eOaSEjVF3dTmLFou+OG1uoIHG1sWUtxIukluUJvK3iM=; b=XYB4w9HSYY3bjQd1EdcQzIWJa KCn9U9BuJtQ7bytbJbdv3N8v27hlq4poDikC5kWzBuu1cWHbABYmb71EQn3YvZsC8XI7UuDHPmfeg emR8jaL64uXxto3sPW6UaDENBlTWvZNlJDWjd0L3D6mGg8+xx6Q3llbp63tLugNIMFVYzkefmfy22 V38C+tft2xQ6p9C3MsXHxtYiUp20usZZeynCWcOGgmFy6JT9gU4WR5T9ty2ij2wPM4iGcsCwIvg0/ seuYB1yIN7ekwRtitXWXTJpwYTPrFb6gIH8DTq66foxJaceXZLi3BZZPyMM4tt1owRZwgqvqFzpNH PY50iAqcA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gyu8r-0006FT-2k; Wed, 27 Feb 2019 08:00:37 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 747F023D03C7A; Wed, 27 Feb 2019 09:00:34 +0100 (CET) Date: Wed, 27 Feb 2019 09:00:34 +0100 From: Peter Zijlstra To: Masami Hiramatsu Cc: Joel Fernandes , Steven Rostedt , Linus Torvalds , linux-kernel@vger.kernel.org, Andy Lutomirski , Ingo Molnar , Andrew Morton , Changbin Du , Jann Horn , Kees Cook , Andy Lutomirski , Alexei Starovoitov , Nadav Amit Subject: Re: [RFC PATCH 0/4] tracing/probes: uaccess: Add support user-space access Message-ID: <20190227080034.GJ32494@hirez.programming.kicks-ass.net> References: <155110348217.21156.3874419272673328527.stgit@devbox> <20190226213850.GA219025@google.com> <20190227164104.5f53f029a7fec898204e9b67@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227164104.5f53f029a7fec898204e9b67@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 04:41:04PM +0900, Masami Hiramatsu wrote: > > IMHO, checking in access_ok() inside it is reasonable, but as it > commented, it is for "if pagefaults are enabled.". What we need another > access_ok() for the case when pagefaults are disabled, that is what PeterZ > suggested in below mail. > > https://lore.kernel.org/lkml/20190225150603.GE32494@hirez.programming.kicks-ass.net/T/#u FWIW, feel free to carry that patch with your other changes that require it. You can add my SoB if you write the Changelog ;-)