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 1A33EC5ACD7 for ; Wed, 18 Mar 2020 14:34:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0CDE20774 for ; Wed, 18 Mar 2020 14:34:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="M+sTpZ4I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726958AbgCROel (ORCPT ); Wed, 18 Mar 2020 10:34:41 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:37026 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbgCROel (ORCPT ); Wed, 18 Mar 2020 10:34:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584542080; 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=UDcu1iOa70ydGTzbtxeciqeXori85SoY2pnI41cZUDY=; b=M+sTpZ4Itm2z/5rKyBttp696B82XawqcxlKgQAYC/0X4kcKRmJsnyo2I/LSqzFaOy1vdSW MARFEVbJMbOGvSq0UGAWO8GfJCKPuhtKHc9I1DwVWCU+/XAZdyvc3gRNi4u0RoY+gGiiBy PM3HVN/2n476w5NNHpSIIeaThQtrmOM= 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-435-W8OgMNYEOw6rZG7yJQ1TWA-1; Wed, 18 Mar 2020 10:34:39 -0400 X-MC-Unique: W8OgMNYEOw6rZG7yJQ1TWA-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 D582C189D6C0; Wed, 18 Mar 2020 14:34:36 +0000 (UTC) Received: from llong.remote.csb (ovpn-120-114.rdu2.redhat.com [10.10.120.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id 66E1D19C58; Wed, 18 Mar 2020 14:34:34 +0000 (UTC) Subject: Re: [PATCH v4 4/4] KEYS: Avoid false positive ENOMEM error on key read To: David Howells Cc: Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Mimi Zohar , "David S. Miller" , Jakub Kicinski , keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, netdev@vger.kernel.org, linux-afs@lists.infradead.org, Sumit Garg , Jerry Snitselaar , Roberto Sassu , Eric Biggers , Chris von Recklinghausen References: <20200317194140.6031-5-longman@redhat.com> <20200317194140.6031-1-longman@redhat.com> <2832139.1584520054@warthog.procyon.org.uk> From: Waiman Long Organization: Red Hat Message-ID: Date: Wed, 18 Mar 2020 10:34:33 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <2832139.1584520054@warthog.procyon.org.uk> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 3/18/20 4:27 AM, David Howells wrote: > Waiman Long wrote: > >> +static inline void __kvzfree(const void *addr, size_t len) >> +{ >> + if (addr) { >> + memset((void *)addr, 0, len); >> + kvfree(addr); >> + } >> +} > I wonder if that would be better as "kvfree(memset(...))" as memset() will > return the address parameter. If memset is not inline, it avoids the need for > the compiler to save the parameter. > > David Doing this is micro-optimization. As the keys subsystem is that performance critical, do we need to do that to save a cycle or two while making the code a bit harder to read? Cheers, Longman