From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Pai Subject: Re: [PATCH v13 22/24] selftests/vm: testcases must restore pkey-permissions Date: Tue, 17 Jul 2018 09:09:10 -0700 Message-ID: <20180717160910.GG5790@ram.oc3035372033.ibm.com> References: <1528937115-10132-1-git-send-email-linuxram@us.ibm.com> <1528937115-10132-23-git-send-email-linuxram@us.ibm.com> Reply-To: Ram Pai Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Dave Hansen Cc: linux-arch@vger.kernel.org, fweimer@redhat.com, x86@kernel.org, shuahkh@osg.samsung.com, mhocko@kernel.org, linux-mm@kvack.org, mingo@redhat.com, aneesh.kumar@linux.vnet.ibm.com, linux-kselftest@vger.kernel.org, bauerman@linux.vnet.ibm.com, msuchanek@suse.de, linuxppc-dev@lists.ozlabs.org List-Id: linux-arch.vger.kernel.org On Wed, Jun 20, 2018 at 08:20:22AM -0700, Dave Hansen wrote: > On 06/13/2018 05:45 PM, Ram Pai wrote: > > Generally the signal handler restores the state of the pkey register > > before returning. However there are times when the read/write operation > > can legitamely fail without invoking the signal handler. Eg: A > > sys_read() operaton to a write-protected page should be disallowed. In > > such a case the state of the pkey register is not restored to its > > original state. The test case is responsible for restoring the key > > register state to its original value. > > Seems fragile. Can't we just do this in common code? We could just > loop through and restore the default permissions. That seems much more > resistant to a bad test case. Yes. done. fixed it the way you suggested in the new version. -- Ram Pai From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37728 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729508AbeGQQnn (ORCPT ); Tue, 17 Jul 2018 12:43:43 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6HGACNX076816 for ; Tue, 17 Jul 2018 12:10:20 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2k9jsujsrh-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 17 Jul 2018 12:10:18 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 17 Jul 2018 17:09:21 +0100 Date: Tue, 17 Jul 2018 09:09:10 -0700 From: Ram Pai Subject: Re: [PATCH v13 22/24] selftests/vm: testcases must restore pkey-permissions Reply-To: Ram Pai References: <1528937115-10132-1-git-send-email-linuxram@us.ibm.com> <1528937115-10132-23-git-send-email-linuxram@us.ibm.com> MIME-Version: 1.0 In-Reply-To: Message-ID: <20180717160910.GG5790@ram.oc3035372033.ibm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Content-Disposition: inline Sender: linux-arch-owner@vger.kernel.org List-ID: To: Dave Hansen Cc: shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, mingo@redhat.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com, fweimer@redhat.com, msuchanek@suse.de, aneesh.kumar@linux.vnet.ibm.com Message-ID: <20180717160910.mHCnauq2GWV8PoETj-JRq6OkIXF9W2bIWNVsMvuI4nw@z> On Wed, Jun 20, 2018 at 08:20:22AM -0700, Dave Hansen wrote: > On 06/13/2018 05:45 PM, Ram Pai wrote: > > Generally the signal handler restores the state of the pkey register > > before returning. However there are times when the read/write operation > > can legitamely fail without invoking the signal handler. Eg: A > > sys_read() operaton to a write-protected page should be disallowed. In > > such a case the state of the pkey register is not restored to its > > original state. The test case is responsible for restoring the key > > register state to its original value. > > Seems fragile. Can't we just do this in common code? We could just > loop through and restore the default permissions. That seems much more > resistant to a bad test case. Yes. done. fixed it the way you suggested in the new version. -- Ram Pai