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 E5B64C433DF for ; Tue, 16 Jun 2020 19:44:04 +0000 (UTC) Received: from krantz.zx2c4.com (krantz.zx2c4.com [192.95.5.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 581F0208B8 for ; Tue, 16 Jun 2020 19:44:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XoScRIB/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 581F0208B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 157f9c7a; Tue, 16 Jun 2020 19:25:37 +0000 (UTC) Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 768a0e00 for ; Tue, 16 Jun 2020 19:25:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592336613; 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=7Z6fHUpD/YKa1+K4csbSQ8hpcds1t8FVRWhxbaMjfP4=; b=XoScRIB/OUnlC6iHUifIbbqw0nMqyGT44ncKlwjVJ6EzmytEYHukuC+9GeA6NoD4Ia58ob zdgyRIA/jM0/wFteh1WPXwdM2my8JrDTe/bGsTs4vlNv/sl6PkBIRr4W0nOkg7Wx8FBO6/ claoyJXO0QkMR++u/1025GkuGUGIKy8= 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-144-TJgrp6WMNr--nG8NkXkVIQ-1; Tue, 16 Jun 2020 15:43:29 -0400 X-MC-Unique: TJgrp6WMNr--nG8NkXkVIQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0BAEEE91A; Tue, 16 Jun 2020 19:43:23 +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 72FAE5C1BD; Tue, 16 Jun 2020 19:43:17 +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: <5c70746c-ecfc-316f-f1ff-ab432cf9f32d@redhat.com> Date: Tue, 16 Jun 2020 15:43:16 -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 2.79 on 10.5.11.16 X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" 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? I am not sure about that, but both of them can be slow. > > 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); > } > is_kernel_rodata() is inlined, but is_vmalloc_addr() isn't. So the overhead can be a bit bigger. Cheers, Longman