From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807AbdHJOnh (ORCPT ); Thu, 10 Aug 2017 10:43:37 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:23063 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752362AbdHJOnf (ORCPT ); Thu, 10 Aug 2017 10:43:35 -0400 Subject: Re: [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot() To: Michael Ellerman , akpm@linux-foundation.org, benh@kernel.crashing.org, paulus@samba.org, davem@davemloft.net, dave.hansen@linux.intel.com Cc: bsingharora@gmail.com, dja@axtens.net, tglx@linutronix.de, mgorman@suse.de, aarcange@redhat.com, kirill.shutemov@linux.intel.com, heiko.carstens@de.ibm.com, ak@linux.intel.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, sparclinux@vger.kernel.org, Khalid Aziz References: <43c120f0cbbebd1398997b9521013ced664e5053.1502219353.git.khalid.aziz@oracle.com> <87tw1flftz.fsf@concordia.ellerman.id.au> From: Khalid Aziz Organization: Oracle Corp Message-ID: <2e97b439-dd71-8997-4824-15f2b1f53787@oracle.com> Date: Thu, 10 Aug 2017 08:41:41 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <87tw1flftz.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/10/2017 07:20 AM, Michael Ellerman wrote: > Khalid Aziz writes: > >> A protection flag may not be valid across entire address space and >> hence arch_validate_prot() might need the address a protection bit is >> being set on to ensure it is a valid protection flag. For example, sparc >> processors support memory corruption detection (as part of ADI feature) >> flag on memory addresses mapped on to physical RAM but not on PFN mapped >> pages or addresses mapped on to devices. This patch adds address to the >> parameters being passed to arch_validate_prot() so protection bits can >> be validated in the relevant context. >> >> Signed-off-by: Khalid Aziz >> Cc: Khalid Aziz >> --- >> v7: >> - new patch >> >> arch/powerpc/include/asm/mman.h | 2 +- >> arch/powerpc/kernel/syscalls.c | 2 +- >> include/linux/mman.h | 2 +- >> mm/mprotect.c | 2 +- >> 4 files changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h >> index 30922f699341..bc74074304a2 100644 >> --- a/arch/powerpc/include/asm/mman.h >> +++ b/arch/powerpc/include/asm/mman.h >> @@ -40,7 +40,7 @@ static inline bool arch_validate_prot(unsigned long prot) >> return false; >> return true; >> } >> -#define arch_validate_prot(prot) arch_validate_prot(prot) >> +#define arch_validate_prot(prot, addr) arch_validate_prot(prot) > > This can be simpler, as just: > > #define arch_validate_prot arch_validate_prot > Hi Michael, Thanks for reviewing! My patch expands parameter list for arch_validate_prot() from one to two parameters. Existing powerpc version of arch_validate_prot() is written with one parameter. If I use the above #define, compilation fails with: mm/mprotect.c: In function ‘do_mprotect_pkey’: mm/mprotect.c:399: error: too many arguments to function ‘arch_validate_prot’ Another way to solve it would be to add the new addr parameter to powerpc version of arch_validate_prot() but I chose the less disruptive solution of tackling it through #define and expanded the existing #define to include the new parameter. Make sense? Thanks, Khalid