From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id EFD656B04EE for ; Tue, 11 Jul 2017 07:25:22 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id v88so31095038wrb.1 for ; Tue, 11 Jul 2017 04:25:22 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id u18si10409679wra.269.2017.07.11.04.25.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Jul 2017 04:25:21 -0700 (PDT) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6BBO7Ww079242 for ; Tue, 11 Jul 2017 07:25:20 -0400 Received: from e23smtp06.au.ibm.com (e23smtp06.au.ibm.com [202.81.31.148]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bmc7nk7gx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 11 Jul 2017 07:25:20 -0400 Received: from localhost by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 11 Jul 2017 21:25:17 +1000 Received: from d23av05.au.ibm.com (d23av05.au.ibm.com [9.190.234.119]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6BBNp4p21430510 for ; Tue, 11 Jul 2017 21:23:59 +1000 Received: from d23av05.au.ibm.com (localhost [127.0.0.1]) by d23av05.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6BBN1Vp015768 for ; Tue, 11 Jul 2017 21:23:03 +1000 Subject: Re: [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper References: <1499289735-14220-1-git-send-email-linuxram@us.ibm.com> <1499289735-14220-32-git-send-email-linuxram@us.ibm.com> <58e0d9ff-727f-c960-5c5f-16d19a89e181@linux.vnet.ibm.com> <20170710055502.GC5713@ram.oc3035372033.ibm.com> From: Anshuman Khandual Date: Tue, 11 Jul 2017 16:52:40 +0530 MIME-Version: 1.0 In-Reply-To: <20170710055502.GC5713@ram.oc3035372033.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: <94b76f58-1002-b3a7-7269-67129c795f25@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ram Pai , Anshuman Khandual Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, dave.hansen@intel.com, hbabu@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com On 07/10/2017 11:25 AM, Ram Pai wrote: > On Mon, Jul 10, 2017 at 08:41:30AM +0530, Anshuman Khandual wrote: >> On 07/06/2017 02:52 AM, Ram Pai wrote: >>> get_pte_pkey() helper returns the pkey associated with >>> a address corresponding to a given mm_struct. >>> >>> Signed-off-by: Ram Pai >>> --- >>> arch/powerpc/include/asm/book3s/64/mmu-hash.h | 5 ++++ >>> arch/powerpc/mm/hash_utils_64.c | 28 +++++++++++++++++++++++++ >>> 2 files changed, 33 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h >>> index f7a6ed3..369f9ff 100644 >>> --- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h >>> +++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h >>> @@ -450,6 +450,11 @@ extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap, >>> int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, >>> pte_t *ptep, unsigned long trap, unsigned long flags, >>> int ssize, unsigned int shift, unsigned int mmu_psize); >>> + >>> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS >>> +u16 get_pte_pkey(struct mm_struct *mm, unsigned long address); >>> +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ >>> + >>> #ifdef CONFIG_TRANSPARENT_HUGEPAGE >>> extern int __hash_page_thp(unsigned long ea, unsigned long access, >>> unsigned long vsid, pmd_t *pmdp, unsigned long trap, >>> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c >>> index 1e74529..591990c 100644 >>> --- a/arch/powerpc/mm/hash_utils_64.c >>> +++ b/arch/powerpc/mm/hash_utils_64.c >>> @@ -1573,6 +1573,34 @@ void hash_preload(struct mm_struct *mm, unsigned long ea, >>> local_irq_restore(flags); >>> } >>> >>> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS >>> +/* >>> + * return the protection key associated with the given address >>> + * and the mm_struct. >>> + */ >>> +u16 get_pte_pkey(struct mm_struct *mm, unsigned long address) >>> +{ >>> + pte_t *ptep; >>> + u16 pkey = 0; >>> + unsigned long flags; >>> + >>> + if (REGION_ID(address) == VMALLOC_REGION_ID) >>> + mm = &init_mm; >> >> IIUC, protection keys are only applicable for user space. This >> function is getting used to populate siginfo structure. Then how >> can we ever request this for any address in VMALLOC region. > > make sense. this check is not needed. > >> >>> + >>> + if (!mm || !mm->pgd) >>> + return 0; >> >> Is this really required at this stage ? > > its a sanity check to gaurd against bad inputs. See a problem? I mean its okay, thought it to be unnecessary. Your call. -- 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