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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 5DF49C04EB9 for ; Wed, 5 Dec 2018 05:25:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28BEB2084C for ; Wed, 5 Dec 2018 05:25:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28BEB2084C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-security-module-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726889AbeLEFZ3 (ORCPT ); Wed, 5 Dec 2018 00:25:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:48587 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726171AbeLEFZ3 (ORCPT ); Wed, 5 Dec 2018 00:25:29 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Dec 2018 21:25:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,316,1539673200"; d="scan'208";a="301122280" Received: from alison-desk.jf.intel.com ([10.54.74.53]) by fmsmga005.fm.intel.com with ESMTP; 04 Dec 2018 21:25:28 -0800 Date: Tue, 4 Dec 2018 21:28:03 -0800 From: Alison Schofield To: Peter Zijlstra Cc: dhowells@redhat.com, tglx@linutronix.de, jmorris@namei.org, mingo@redhat.com, hpa@zytor.com, bp@alien8.de, luto@kernel.org, kirill.shutemov@linux.intel.com, dave.hansen@intel.com, kai.huang@intel.com, jun.nakajima@intel.com, dan.j.williams@intel.com, jarkko.sakkinen@intel.com, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [RFC v2 07/13] x86/mm: Add helpers for reference counting encrypted VMAs Message-ID: <20181205052802.GA18596@alison-desk.jf.intel.com> References: <20181204085835.GO11614@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181204085835.GO11614@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Tue, Dec 04, 2018 at 09:58:35AM +0100, Peter Zijlstra wrote: > On Mon, Dec 03, 2018 at 11:39:54PM -0800, Alison Schofield wrote: > > > +void vma_put_encrypt_ref(struct vm_area_struct *vma) > > +{ > > + if (vma_keyid(vma)) > > + if (refcount_dec_and_test(&encrypt_count[vma_keyid(vma)])) { > > + mktme_map_lock(); > > + mktme_map_free_keyid(vma_keyid(vma)); > > + mktme_map_unlock(); > > + } > > This violates CodingStyle Got it! Will fix this and the other instances where you noticed poorly nested if statements. > > + if (refcount_dec_and_test(&encrypt_count[keyid])) { > > + mktme_map_lock(); > > That smells like it wants to use refcount_dec_and_lock() instead. > > Also, if you write that like: > > if (!refcount_dec_and_lock(&encrypt_count[keyid], &lock)) > return; > > you loose an indent level. Looks good! I need to make sure it's OK to switch to a spinlock to use the *_lock functions.