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=-4.0 required=3.0 tests=MAILING_LIST_MULTI, SIGNED_OFF_BY,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 9AA75C2BA19 for ; Tue, 14 Apr 2020 09:01:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 64014206D5 for ; Tue, 14 Apr 2020 09:01:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64014206D5 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 DCBC88E0003; Tue, 14 Apr 2020 05:01:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D7CED8E0001; Tue, 14 Apr 2020 05:01:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C930A8E0003; Tue, 14 Apr 2020 05:01:33 -0400 (EDT) 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 AF8558E0001 for ; Tue, 14 Apr 2020 05:01:33 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 676D48E58 for ; Tue, 14 Apr 2020 09:01:33 +0000 (UTC) X-FDA: 76705867266.03.heat20_81f39ce74e61f X-HE-Tag: heat20_81f39ce74e61f X-Filterd-Recvd-Size: 5191 Received: from mail-wm1-f67.google.com (mail-wm1-f67.google.com [209.85.128.67]) by imf39.hostedemail.com (Postfix) with ESMTP for ; Tue, 14 Apr 2020 09:01:32 +0000 (UTC) Received: by mail-wm1-f67.google.com with SMTP id r26so13093027wmh.0 for ; Tue, 14 Apr 2020 02:01:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ZSEHFc2eh+N6K60wyVHbBWfK0AmjMN90oe2OMNtMMJ0=; b=Vckr1oUbSansaRpWbZ/NgnebZVPZDZPY/XBu/9mcjRFF06LkTP7eXMq6BVkrKr1+zQ 0xhMORfMZnmZHdzdh613ZCyHAjy0VAmGsPo5g6s8NIYnkxlrvpTg92j009YFUwZKpIl4 ZL53etG53GQ6LbFkPBlkIJfKeKwx2H/UHE8+tJaS54/vTZOZTjMmof7vXhyBGkflUE6A 7JpXMkkC31oJHSgBajuZ0m1fVDm+18MQTcpyAqiv+nLDN63CIKxJmi71pw9Sc+cBpReU 1c5kMbXmxRUW7zyQTGQvRglPUcNBHqpU8OrfM92zvX7CQLewfBNH0LeDNPtSgsxTBagd 6XxA== X-Gm-Message-State: AGi0PubZWFyn8YvQeHXOC0gbFIj5G5zPKJDkWsa35FJYUpgWH/cUtCij F1pGPIBTVvd2Lf/FHVtXw/0= X-Google-Smtp-Source: APiQypIjMMKQ1krTcIb7iRe2Mn/fScrYHKTluZiYEwYRZsrwjhiGsUjKHrgwCKNk20IxGSD17N1euw== X-Received: by 2002:a1c:a913:: with SMTP id s19mr23660673wme.134.1586854891811; Tue, 14 Apr 2020 02:01:31 -0700 (PDT) Received: from localhost (ip-37-188-180-223.eurotel.cz. [37.188.180.223]) by smtp.gmail.com with ESMTPSA id n6sm18637096wrs.81.2020.04.14.02.01.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Apr 2020 02:01:30 -0700 (PDT) Date: Tue, 14 Apr 2020 11:01:29 +0200 From: Michal Hocko To: Waiman Long Cc: Andrew Morton , David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Linus Torvalds , Joe Perches , Matthew Wilcox , David Rientjes , linux-mm@kvack.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-crypto@vger.kernel.org, linux-s390@vger.kernel.org, linux-pm@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-mediatek@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.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, samba-technical@lists.samba.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, cocci@systeme.lip6.fr, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org Subject: Re: [PATCH 1/2] mm, treewide: Rename kzfree() to kfree_sensitive() Message-ID: <20200414090129.GE4629@dhcp22.suse.cz> References: <20200413211550.8307-1-longman@redhat.com> <20200413211550.8307-2-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200413211550.8307-2-longman@redhat.com> 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: On Mon 13-04-20 17:15:49, Waiman Long wrote: > As said by Linus: > > A symmetric naming is only helpful if it implies symmetries in use. > Otherwise it's actively misleading. > > In "kzalloc()", the z is meaningful and an important part of what the > caller wants. > > In "kzfree()", the z is actively detrimental, because maybe in the > future we really _might_ want to use that "memfill(0xdeadbeef)" or > something. The "zero" part of the interface isn't even _relevant_. > > The main reason that kzfree() exists is to clear sensitive information > that should not be leaked to other future users of the same memory > objects. > > Rename kzfree() to kfree_sensitive() to follow the example of the > recently added kvfree_sensitive() and make the intention of the API > more explicit. In addition, memzero_explicit() is used to clear the > memory to make sure that it won't get optimized away by the compiler. > > The renaming is done by using the command sequence: > > git grep -w --name-only kzfree |\ > xargs sed -i 's/\bkzfree\b/kfree_sensitive/' > > followed by some editing of the kfree_sensitive() kerneldoc and the > use of memzero_explicit() instead of memset(). > > Suggested-by: Joe Perches > Signed-off-by: Waiman Long Makes sense. I haven't checked all the conversions and will rely on the script doing the right thing. The core MM part is correct. Acked-by: Michal Hocko -- Michal Hocko SUSE Labs