From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4030Rb60VlzF0Qs for ; Sat, 17 Mar 2018 09:26:19 +1100 (AEDT) Subject: Re: [PATCH v12 15/22] selftests/vm: powerpc implementation to check support for pkey To: Ram Pai , shuahkh@osg.samsung.com, linux-kselftest@vger.kernel.org References: <1519264541-7621-1-git-send-email-linuxram@us.ibm.com> <1519264541-7621-16-git-send-email-linuxram@us.ibm.com> Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, akpm@linux-foundation.org, benh@kernel.crashing.org, paulus@samba.org, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, hbabu@us.ibm.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com, ebiederm@xmission.com, arnd@arndb.de From: Dave Hansen Message-ID: Date: Fri, 16 Mar 2018 15:26:09 -0700 MIME-Version: 1.0 In-Reply-To: <1519264541-7621-16-git-send-email-linuxram@us.ibm.com> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/21/2018 05:55 PM, Ram Pai wrote: > #define PAGE_SIZE (0x1UL << 16) > -static inline int cpu_has_pku(void) > +static inline bool is_pkey_supported(void) > { > - return 1; > + /* > + * No simple way to determine this. > + * lets try allocating a key and see if it succeeds. > + */ > + int ret = sys_pkey_alloc(0, 0); > + > + if (ret > 0) { > + sys_pkey_free(ret); > + return true; > + } > + return false; > } The point of doing this was to have a test for the CPU that way separate from the syscalls. Can you leave cpu_has_pkeys() in place?