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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 ADA66C433E7 for ; Fri, 16 Oct 2020 06:54:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E1B7207C4 for ; Fri, 16 Oct 2020 06:54:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ndM3N2H9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394500AbgJPGyV (ORCPT ); Fri, 16 Oct 2020 02:54:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394162AbgJPGyV (ORCPT ); Fri, 16 Oct 2020 02:54:21 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6D0DC061755 for ; Thu, 15 Oct 2020 23:54:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=6qmV6T/fkjw04YEk4tETd5MpPwH/0OOPAH2ymP/DpVc=; b=ndM3N2H9UJgv0dwSmm6hAx628h Hf6/x7fwbqfjb71sajdhWuHIdexSlUT6qZmoBnrUPftILWZJrSxKRkHQOKRFr/SL0J5xsFisirEHu XXl3i4wFRhBxPGO8cF0ilc88GjbGphNnwUCVQ723Pr1nYon64Qxx3WfPINc+aGQKDubqhm75AWa19 0AMOAp/6O2St/+im05QN0aok38sjTB9vYYjApnZRfJy7GIfEuVUuI/yz6h/Unz6l53LdkYP0o4Bx4 lx6sbKjnUDN1wnpe1yHIIDarGrOUyQ/PoTWRdETrUjQfdl4bNsG85Xiucbhc6bpQMBcyKwaZToyWz WqxkeE+w==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kTJcp-0002W2-I9; Fri, 16 Oct 2020 06:54:03 +0000 Date: Fri, 16 Oct 2020 07:54:03 +0100 From: Christoph Hellwig To: "Christopher M. Riedl" Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Subject: Re: [PATCH 1/8] powerpc/uaccess: Add unsafe_copy_from_user Message-ID: <20201016065403.GA9343@infradead.org> References: <20201015150159.28933-1-cmr@codefail.de> <20201015150159.28933-2-cmr@codefail.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201015150159.28933-2-cmr@codefail.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 15, 2020 at 10:01:52AM -0500, Christopher M. Riedl wrote: > Implement raw_copy_from_user_allowed() which assumes that userspace read > access is open. Use this new function to implement raw_copy_from_user(). > Finally, wrap the new function to follow the usual "unsafe_" convention > of taking a label argument. The new raw_copy_from_user_allowed() calls > __copy_tofrom_user() internally, but this is still safe to call in user > access blocks formed with user_*_access_begin()/user_*_access_end() > since asm functions are not instrumented for tracing. Please also add a fallback unsafe_copy_from_user to linux/uaccess.h so this can be used as a generic API.