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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 A66F2C433E2 for ; Tue, 16 Jun 2020 20:01:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FE7C206F1 for ; Tue, 16 Jun 2020 20:01:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gwuk/kzd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731442AbgFPUBm (ORCPT ); Tue, 16 Jun 2020 16:01:42 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:39971 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731220AbgFPUBl (ORCPT ); Tue, 16 Jun 2020 16:01:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592337700; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IZuHuVBorvvnUwBUanoxn5EJfFFGTbG0F4JYxmnKd8I=; b=gwuk/kzdb3Ik/Dhd6PCUCPRmNEObII+9CwrZ/qJl/8ZMzV9Julk2/PzPS1Kt5wSfmj85JW GcpiGRFXoqunERmt75RXVaWyPWzbgwxA9xXkyR72DbZB1LRzKAyBx7Ars6UjCB0BBiDDAL Uk6QmjDdivEAi3x3XULlpxOBCWEX8XA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-195-RsA5jiRVM622hegDVDAGvA-1; Tue, 16 Jun 2020 16:01:36 -0400 X-MC-Unique: RsA5jiRVM622hegDVDAGvA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AD51C8035E9; Tue, 16 Jun 2020 20:01:28 +0000 (UTC) Received: from llong.remote.csb (ovpn-114-156.rdu2.redhat.com [10.10.114.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4F41719D71; Tue, 16 Jun 2020 20:01:20 +0000 (UTC) Subject: Re: [PATCH v4 0/3] mm, treewide: Rename kzfree() to kfree_sensitive() To: Joe Perches , Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Matthew Wilcox , David Rientjes Cc: Michal Hocko , Johannes Weiner , Dan Carpenter , David Sterba , "Jason A . Donenfeld" , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-pm@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-amlogic@lists.infradead.org, linux-mediatek@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-ppp@vger.kernel.org, wireguard@lists.zx2c4.com, linux-wireless@vger.kernel.org, devel@driverdev.osuosl.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-fscrypt@vger.kernel.org, ecryptfs@vger.kernel.org, kasan-dev@googlegroups.com, linux-bluetooth@vger.kernel.org, linux-wpan@vger.kernel.org, linux-sctp@vger.kernel.org, linux-nfs@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org References: <20200616015718.7812-1-longman@redhat.com> From: Waiman Long Organization: Red Hat Message-ID: <7662bfe8-b279-f98c-3ae3-c3b889aea1f5@redhat.com> Date: Tue, 16 Jun 2020 16:01:19 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On 6/16/20 2:53 PM, Joe Perches wrote: > On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: >> v4: >> - Break out the memzero_explicit() change as suggested by Dan Carpenter >> so that it can be backported to stable. >> - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for >> now as there can be a bit more discussion on what is best. It will be >> introduced as a separate patch later on after this one is merged. > To this larger audience and last week without reply: > https://lore.kernel.org/lkml/573b3fbd5927c643920e1364230c296b23e7584d.camel@perches.com/ > > Are there _any_ fastpath uses of kfree or vfree? > > Many patches have been posted recently to fix mispairings > of specific types of alloc and free functions. > > To eliminate these mispairings at a runtime cost of four > comparisons, should the kfree/vfree/kvfree/kfree_const > functions be consolidated into a single kfree? > > Something like the below: > > void kfree(const void *addr) > { > if (is_kernel_rodata((unsigned long)addr)) > return; > > if (is_vmalloc_addr(addr)) > _vfree(addr); > else > _kfree(addr); > } > > #define kvfree kfree > #define vfree kfree > #define kfree_const kfree > > How about adding CONFIG_DEBUG_VM code to check for invalid address ranges in kfree() and vfree()? By doing this, we can catch unmatched pairing in debug mode, but won't have the overhead when debug mode is off. Thought? Cheers, Longman