From patchwork Sun Feb 14 16:13:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timur Tabi X-Patchwork-Id: 12087275 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=-11.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 36A39C433E0 for ; Sun, 14 Feb 2021 16:13:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A89EE64E6A for ; Sun, 14 Feb 2021 16:13:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A89EE64E6A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DC2FC8D00D2; Sun, 14 Feb 2021 11:13:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D737A8D0060; Sun, 14 Feb 2021 11:13:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CAF548D00D2; Sun, 14 Feb 2021 11:13:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) by kanga.kvack.org (Postfix) with ESMTP id B58738D0060 for ; Sun, 14 Feb 2021 11:13:54 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 753938248047 for ; Sun, 14 Feb 2021 16:13:54 +0000 (UTC) X-FDA: 77817369588.27.957645A Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf27.hostedemail.com (Postfix) with ESMTP id 09BF680192CE for ; Sun, 14 Feb 2021 16:13:51 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 333E264DAD; Sun, 14 Feb 2021 16:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613319232; bh=oHf15gSHKcdfrEuxcuEmshOdx1i9DIeGN5nSxvWb/No=; h=From:To:Subject:Date:From; b=O00k2kQ07nI0dSl2MUzumJwYSH1LWk6XWq2zYi1z1zxrGtqBxnLrwv0udEZb5j/Br xgezU5+xgLN5qGdt9t3IIM8LKMtDC8RNqbJd3Zp/ADvGfYnaZ9DAKG6mBUn+QaNFzB fFF5cHZ+6XRRt97tswNUL6njcYd283UQgEUiJKfdK9fbo5Md8rwDdWpcl2hTScAY9a 0o9rZEnVY63o3OTraf33OKNLxNm4MKVIA1/3iNm3PCqnvrCbntdVCiaqGuG9elHGr8 iduzTsrlfo9/nrbsaXuDnUu8Tkj5gSYo4a/jsV/WVqLRD+ML2wQx9Ab/YnF87eTB7t gWMJ18zYRaraA== From: Timur Tabi To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Vlastimil Babka , Andy Shevchenko , Matthew Wilcox , akpm@linux-foundation.org, Linus Torvalds , roman.fietze@magna.com, Kees Cook , John Ogness , akinobu.mita@gmail.com, glider@google.com, Andrey Konovalov , Marco Elver , Rasmus Villemoes , Pavel Machek , Tetsuo Handa , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 0/3][v4] add support for never printing hashed addresses Date: Sun, 14 Feb 2021 10:13:45 -0600 Message-Id: <20210214161348.369023-1-timur@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 09BF680192CE X-Stat-Signature: zp5rhfughgwtmmzb51k1b58t5ikj493c Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf27; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1613319231-658981 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: Although hashing addresses printed via printk does make the kernel more secure, it interferes with debugging, especially with some functions like print_hex_dump() which always uses hashed addresses. To avoid having to choose between %p and %px, it's easier to add a kernel command line that treats all %p as %px. This encourages developers to use %p more without making debugging more difficult. Patches #1 and #2 upgrade the kselftest framework so that it can report on tests that were skipped outright. This is needed for the test_printf module which will now skip %p hashing tests if hashing is disabled. Patch #2 upgrades the printf library to check the command line. It also updates test_printf(). Timur Tabi (3): [v4] lib: use KSTM_MODULE_GLOBALS macro in kselftest drivers [v4] kselftest: add support for skipped tests [v4] lib/vsprintf: debug_never_hash_pointers prints all addresses as unhashed .../admin-guide/kernel-parameters.txt | 15 ++++++++ lib/test_bitmap.c | 3 +- lib/test_printf.c | 12 +++++- lib/vsprintf.c | 38 ++++++++++++++++++- tools/testing/selftests/kselftest_module.h | 18 ++++++--- 5 files changed, 74 insertions(+), 12 deletions(-)