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=-1.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 1632FC433DF for ; Thu, 14 May 2020 01:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 162552065D for ; Thu, 14 May 2020 01:13:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589418805; bh=E3TK4XJbiog9RqVvd1coo4BBYDYxNPOeooso1RPW9+o=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=HPidmc4mCw7V1BOBeubYWB6pigmwnnUhvsEYIBPIZBmnChMcWRHN+WHY1CbEzEeJE 0da6wn+8QOPUwM4gkkdpM/9y128tKMybebYNWu/dRG1tEj4vYbvZ8iXn1hEeWXwtNu lzzl92MuVSzJhVrMo8oahxjXRjtrwoGfwCSLYeTU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725977AbgENBNY (ORCPT ); Wed, 13 May 2020 21:13:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:47796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgENBNY (ORCPT ); Wed, 13 May 2020 21:13:24 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 18FB2205ED; Thu, 14 May 2020 01:13:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589418804; bh=E3TK4XJbiog9RqVvd1coo4BBYDYxNPOeooso1RPW9+o=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=b38mEvyZRSzT8rHakz4cXiV/smUzpawoP/W25qu1jycv3OKF/Tee8zvKw12mAkxX2 sMGDcbWVx9Rf4NXP29meINeTtJKaxPsH/WnZQ5G2Y/aMSZwnJKOW6PoAPJkE+Y4yEJ mgEjAnRg8ItCq5lHHZoRmJZSU0MdT1D0NFPbudbQ= Date: Thu, 14 May 2020 10:13:18 +0900 From: Masami Hiramatsu To: Christoph Hellwig Cc: x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , Linus Torvalds , Andrew Morton , linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/18] maccess: unify the probe kernel arch hooks Message-Id: <20200514101318.1c14647e41b7038b99b91fcd@kernel.org> In-Reply-To: <20200513160038.2482415-11-hch@lst.de> References: <20200513160038.2482415-1-hch@lst.de> <20200513160038.2482415-11-hch@lst.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org Hi Christoph, On Wed, 13 May 2020 18:00:30 +0200 Christoph Hellwig wrote: > @@ -36,14 +50,20 @@ long __weak probe_kernel_read(void *dst, const void *src, size_t size) > * probe_kernel_read() suitable for use within regions where the caller > * already holds mmap_sem, or other locks which nest inside mmap_sem. > */ > -long __weak probe_kernel_read_strict(void *dst, const void *src, size_t size) > - __attribute__((alias("__probe_kernel_read"))); > +long probe_kernel_read_strict(void *dst, const void *src, size_t size) > +{ > + return __probe_kernel_read(dst, src, size, true); > +} > > -long __probe_kernel_read(void *dst, const void *src, size_t size) > +static long __probe_kernel_read(void *dst, const void *src, size_t size, > + bool strict) > { > long ret; > mm_segment_t old_fs = get_fs(); > > + if (!probe_kernel_read_allowed(dst, src, size, strict)) > + return -EFAULT; Could you make this return -ERANGE instead of -EFAULT so that the caller can notice that the address might be user space? Thank you, -- Masami Hiramatsu