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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 56D55C433E3 for ; Tue, 19 May 2020 13:45:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 260B420709 for ; Tue, 19 May 2020 13:45:08 +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="s5jGcOuF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728982AbgESNo6 (ORCPT ); Tue, 19 May 2020 09:44:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726880AbgESNo5 (ORCPT ); Tue, 19 May 2020 09:44:57 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66041C08C5C0; Tue, 19 May 2020 06:44:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:In-Reply-To:References; bh=VA+rkbbJ9Gdu2pIdIJCd0hxkxzOrtfH9/4cfURE97w4=; b=s5jGcOuFcMqXXsAcexu5WkkZpW SqMchNqCMYatHho2iD6t0yuHPPsnOU7ddh0uHbCBrRC1iUo6xwomnsizcFL8lqJCbsH762aqgv9f1 M3UX75xgLM/hLHthh07qF4USOtDaNRjvSnclU4YUozuiTb8LWYOEgjMlNNXPhMl5uBUDJ/VaVA6ju ZYOmK5YEdFlIf5whS9gHwr3RdmlbwgpmqhC40VmWGXUQmYyfNQUPBdsaCPh1TLNjxE1ub3Q8jgTGh VjQUwge2yc4VojVSjpq7694uk3yIBqjzpHN6/RQXB0KByEZY3OhQCrBzDRPhy3k9+ljWwoFcuXPml UbSLfoTA==; Received: from [2001:4bb8:188:1506:c70:4a89:bc61:2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jb2Y7-0000zQ-W6; Tue, 19 May 2020 13:44:52 +0000 From: Christoph Hellwig To: x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , Masami Hiramatsu , Linus Torvalds , Andrew Morton Cc: 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: clean up and streamline probe_kernel_* and friends v3 Date: Tue, 19 May 2020 15:44:29 +0200 Message-Id: <20200519134449.1466624-1-hch@lst.de> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, this series start cleaning up the safe kernel and user memory probing helpers in mm/maccess.c, and then allows architectures to implement the kernel probing without overriding the address space limit and temporarily allowing access to user memory. It then switches x86 over to this new mechanism by reusing the unsafe_* uaccess logic. This version also switches to the saner copy_{from,to}_kernel_nofault naming suggested by Linus. I kept the x86 helprs as-is without calling unsage_{get,put}_user as that avoids a number of hard to trace casts, and it will still work with the asm-goto based version easily. Changes since v2: - rebased on 5.7-rc6 with the bpf trace format string changes - rename arch_kernel_read to __get_kernel_nofault and arch_kernel_write to __put_kernel_nofault - clean up the tracers to only allowd "mixed" reads when the kernel has non-overlapping address spaces