From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 3x5VdC5crLzDqXh for ; Mon, 10 Jul 2017 13:12:31 +1000 (AEST) Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6A39FnA118311 for ; Sun, 9 Jul 2017 23:12:29 -0400 Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bjtx5cr1y-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 09 Jul 2017 23:12:29 -0400 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 10 Jul 2017 13:12:27 +1000 Received: from d23av05.au.ibm.com (d23av05.au.ibm.com [9.190.234.119]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6A3CGHE21430424 for ; Mon, 10 Jul 2017 13:12:24 +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 v6A3Bpxh025615 for ; Mon, 10 Jul 2017 13:11:52 +1000 From: Anshuman Khandual Subject: Re: [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper To: Ram Pai , 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 References: <1499289735-14220-1-git-send-email-linuxram@us.ibm.com> <1499289735-14220-32-git-send-email-linuxram@us.ibm.com> Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, 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 Date: Mon, 10 Jul 2017 08:41:30 +0530 MIME-Version: 1.0 In-Reply-To: <1499289735-14220-32-git-send-email-linuxram@us.ibm.com> Content-Type: text/plain; charset=windows-1252 Message-Id: <58e0d9ff-727f-c960-5c5f-16d19a89e181@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. > + > + if (!mm || !mm->pgd) > + return 0; Is this really required at this stage ?