From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 5C1A56B0292 for ; Thu, 10 Aug 2017 10:43:08 -0400 (EDT) Received: by mail-pg0-f72.google.com with SMTP id v77so8529422pgb.15 for ; Thu, 10 Aug 2017 07:43:08 -0700 (PDT) Received: from aserp1040.oracle.com (aserp1040.oracle.com. [141.146.126.69]) by mx.google.com with ESMTPS id r15si4265296pfd.505.2017.08.10.07.43.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Aug 2017 07:43:07 -0700 (PDT) Subject: Re: [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot() References: <43c120f0cbbebd1398997b9521013ced664e5053.1502219353.git.khalid.aziz@oracle.com> <87tw1flftz.fsf@concordia.ellerman.id.au> From: Khalid Aziz Message-ID: <2e97b439-dd71-8997-4824-15f2b1f53787@oracle.com> Date: Thu, 10 Aug 2017 08:41:41 -0600 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 Sender: owner-linux-mm@kvack.org List-ID: 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 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 a??do_mprotect_pkeya??: mm/mprotect.c:399: error: too many arguments to function a??arch_validate_prota?? 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org