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 7E4E26B02FA for ; Mon, 10 Jul 2017 01:55:22 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id p64so21656990wrc.8 for ; Sun, 09 Jul 2017 22:55:22 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id d9si7562015wrc.290.2017.07.09.22.55.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 09 Jul 2017 22:55:21 -0700 (PDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6A5sYIL042240 for ; Mon, 10 Jul 2017 01:55:20 -0400 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0b-001b2d01.pphosted.com with ESMTP id 2bjujyqpmf-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 10 Jul 2017 01:55:20 -0400 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 9 Jul 2017 23:55:18 -0600 Date: Sun, 9 Jul 2017 22:55:02 -0700 From: Ram Pai Subject: Re: [RFC v5 31/38] powerpc: introduce get_pte_pkey() helper Reply-To: Ram Pai 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58e0d9ff-727f-c960-5c5f-16d19a89e181@linux.vnet.ibm.com> Message-Id: <20170710055502.GC5713@ram.oc3035372033.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: 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 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? RP -- Ram Pai -- 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