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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1DE8BC433E1 for ; Mon, 18 May 2020 15:09:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E5B0F20671 for ; Mon, 18 May 2020 15:09:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E5B0F20671 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 65CC1900003; Mon, 18 May 2020 11:09:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5E632900002; Mon, 18 May 2020 11:09:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4AEAA900003; Mon, 18 May 2020 11:09:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0210.hostedemail.com [216.40.44.210]) by kanga.kvack.org (Postfix) with ESMTP id 282FF900002 for ; Mon, 18 May 2020 11:09:08 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id DA3968248068 for ; Mon, 18 May 2020 15:09:07 +0000 (UTC) X-FDA: 76830172734.09.flag97_4fa68c88f5f04 X-HE-Tag: flag97_4fa68c88f5f04 X-Filterd-Recvd-Size: 2055 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf24.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 May 2020 15:09:07 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 27D5268B02; Mon, 18 May 2020 17:09:04 +0200 (CEST) Date: Mon, 18 May 2020 17:09:03 +0200 From: Christoph Hellwig To: Masami Hiramatsu Cc: Christoph Hellwig , 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 14/18] maccess: allow architectures to provide kernel probing directly Message-ID: <20200518150903.GD8871@lst.de> References: <20200513160038.2482415-1-hch@lst.de> <20200513160038.2482415-15-hch@lst.de> <20200516124259.5b68a4e1d4670efa1397a1e0@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200516124259.5b68a4e1d4670efa1397a1e0@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) 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 Sat, May 16, 2020 at 12:42:59PM +0900, Masami Hiramatsu wrote: > > Provide alternative versions of probe_kernel_read, probe_kernel_write > > and strncpy_from_kernel_unsafe that don't need set_fs magic, but instead > > use arch hooks that are modelled after unsafe_{get,put}_user to access > > kernel memory in an exception safe way. > > This patch seems to introduce new implementation of probe_kernel_read/write() > and strncpy_from_kernel_unsafe(), but also drops copy_from/to_kernel_nofault() > and strncpy_from_kernel_nofault() if HAVE_ARCH_PROBE_KERNEL is defined. > In the result, this cause a link error with BPF and kprobe events. That was just a bug as I didn't commit the changes to switch everything to _nofault and remove _unsafe entirely, sorry.