From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id 3B3286B000E for ; Wed, 25 Jul 2018 12:19:32 -0400 (EDT) Received: by mail-ed1-f70.google.com with SMTP id g5-v6so3327970edp.1 for ; Wed, 25 Jul 2018 09:19:32 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id n6-v6si1346353edb.59.2018.07.25.09.19.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jul 2018 09:19:31 -0700 (PDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6PGERvk008270 for ; Wed, 25 Jul 2018 12:19:29 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kevj206tr-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 25 Jul 2018 12:19:28 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Jul 2018 12:19:27 -0400 From: "Aneesh Kumar K.V" Subject: [PATCH V2 4/6] arch/powerpc/mm/hash: validate the pte entries before handling the hash fault Date: Wed, 25 Jul 2018 21:49:01 +0530 In-Reply-To: <20180725161903.31257-1-aneesh.kumar@linux.ibm.com> References: <20180725161903.31257-1-aneesh.kumar@linux.ibm.com> Message-Id: <20180725161903.31257-4-aneesh.kumar@linux.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: npiggin@gmail.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, Naoya Horiguchi Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, "Aneesh Kumar K.V" Make sure we are operating on THP and hugetlb entries in the respective hash fault handling routines. No functional change in this patch. If we walked the table wrongly before, we will retry the access. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/hugepage-hash64.c | 6 ++++++ arch/powerpc/mm/hugetlbpage-hash64.c | 4 ++++ 2 files changed, 10 insertions(+) diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c index f20d16f849c5..049dcb8c95c2 100644 --- a/arch/powerpc/mm/hugepage-hash64.c +++ b/arch/powerpc/mm/hugepage-hash64.c @@ -51,6 +51,12 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid, new_pmd |= _PAGE_DIRTY; } while (!pmd_xchg(pmdp, __pmd(old_pmd), __pmd(new_pmd))); + /* + * Make sure this is thp or devmap entry + */ + if (!(old_pmd & (H_PAGE_THP_HUGE | _PAGE_DEVMAP))) + return 0; + rflags = htab_convert_pte_flags(new_pmd); #if 0 diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c index b320f5097a06..2e6a8f9345d3 100644 --- a/arch/powerpc/mm/hugetlbpage-hash64.c +++ b/arch/powerpc/mm/hugetlbpage-hash64.c @@ -62,6 +62,10 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, new_pte |= _PAGE_DIRTY; } while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); + /* Make sure this is a hugetlb entry */ + if (old_pte & (H_PAGE_THP_HUGE | _PAGE_DEVMAP)) + return 0; + rflags = htab_convert_pte_flags(new_pte); if (unlikely(mmu_psize == MMU_PAGE_16G)) offset = PTRS_PER_PUD; -- 2.17.1