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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 2AB6FC3A59F for ; Thu, 29 Aug 2019 15:59:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 074F7205ED for ; Thu, 29 Aug 2019 15:59:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726739AbfH2P7P (ORCPT ); Thu, 29 Aug 2019 11:59:15 -0400 Received: from mga12.intel.com ([192.55.52.136]:49368 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbfH2P7P (ORCPT ); Thu, 29 Aug 2019 11:59:15 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Aug 2019 08:59:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,443,1559545200"; d="scan'208";a="175307620" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga008.jf.intel.com with ESMTP; 29 Aug 2019 08:59:14 -0700 Date: Thu, 29 Aug 2019 08:59:14 -0700 From: Sean Christopherson To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org Subject: Re: [PATCH v2 1/5] x86/sgx: Convert encl->flags from an unsigned int to an atomic Message-ID: <20190829155914.GC26580@linux.intel.com> References: <20190827192717.27312-1-sean.j.christopherson@intel.com> <20190827192717.27312-2-sean.j.christopherson@intel.com> <20190829000600.jkk7aih7j4cwzejp@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829000600.jkk7aih7j4cwzejp@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Thu, Aug 29, 2019 at 04:09:29PM +0300, Jarkko Sakkinen wrote: > On Tue, Aug 27, 2019 at 12:27:13PM -0700, Sean Christopherson wrote: > > @@ -77,7 +78,7 @@ static int sgx_release(struct inode *inode, struct file *file) > > }; > > > > mutex_lock(&encl->lock); > > - encl->flags |= SGX_ENCL_DEAD; > > + atomic_or(SGX_ENCL_DEAD, &encl->flags); > > mutex_unlock(&encl->lock); > > Had a couple of checkpatch.pl errors (not a biggie, just a remark). > > Is there reason to keep lock there? Yes, I couldn't convince myself the reclaim flows would work correctly if SGX_ENCL_DEAD could be set while the reclaimer held encl->lock. But I'm also not 100% certain holding encl->lock is strictly necessary in this case, so I didn't add a comment either.