From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by kanga.kvack.org (Postfix) with ESMTP id B60896B727C for ; Tue, 4 Dec 2018 23:42:46 -0500 (EST) Received: by mail-wr1-f71.google.com with SMTP id w12so14492054wru.20 for ; Tue, 04 Dec 2018 20:42:46 -0800 (PST) Received: from pegase1.c-s.fr (pegase1.c-s.fr. [93.17.236.30]) by mx.google.com with ESMTPS id f23si9414193wml.194.2018.12.04.20.42.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Dec 2018 20:42:45 -0800 (PST) Subject: Re: [PATCH V3 2/5] mm: update ptep_modify_prot_commit to take old pte value as arg References: <20181205030931.12037-1-aneesh.kumar@linux.ibm.com> <20181205030931.12037-3-aneesh.kumar@linux.ibm.com> <48f13462-1695-a759-9df8-1ef60fd88196@linux.ibm.com> From: Christophe LEROY Message-ID: <3c1395e0-8a06-e407-80ba-2d634a9e01e9@c-s.fr> Date: Wed, 5 Dec 2018 05:42:43 +0100 MIME-Version: 1.0 In-Reply-To: <48f13462-1695-a759-9df8-1ef60fd88196@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" , npiggin@gmail.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org Le 05/12/2018 à 05:06, Aneesh Kumar K.V a écrit : > On 12/5/18 9:32 AM, Christophe LEROY wrote: >> >> >> Le 05/12/2018 à 04:09, Aneesh Kumar K.V a écrit : >>> Architectures like ppc64 requires to do a conditional tlb flush based >>> on the old >>> and new value of pte. Enable that by passing old pte value as the arg. >>> >>> Signed-off-by: Aneesh Kumar K.V >>> --- >>>   arch/s390/include/asm/pgtable.h | 3 ++- >>>   arch/s390/mm/pgtable.c          | 2 +- >>>   arch/x86/include/asm/paravirt.h | 2 +- >>>   fs/proc/task_mmu.c              | 8 +++++--- >>>   include/asm-generic/pgtable.h   | 2 +- >>>   mm/memory.c                     | 8 ++++---- >>>   mm/mprotect.c                   | 6 +++--- >>>   7 files changed, 17 insertions(+), 14 deletions(-) >>> >>> diff --git a/arch/s390/include/asm/pgtable.h >>> b/arch/s390/include/asm/pgtable.h >>> index 5d730199e37b..76dc344edb8c 100644 >>> --- a/arch/s390/include/asm/pgtable.h >>> +++ b/arch/s390/include/asm/pgtable.h >>> @@ -1070,7 +1070,8 @@ static inline pte_t ptep_get_and_clear(struct >>> mm_struct *mm, >>>   #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION >>>   pte_t ptep_modify_prot_start(struct vm_area_struct *, unsigned >>> long, pte_t *); >>> -void ptep_modify_prot_commit(struct vm_area_struct *, unsigned long, >>> pte_t *, pte_t); >>> +void ptep_modify_prot_commit(struct vm_area_struct *, unsigned long, >>> +                 pte_t *, pte_t, pte_t); >>>   #define __HAVE_ARCH_PTEP_CLEAR_FLUSH >>>   static inline pte_t ptep_clear_flush(struct vm_area_struct *vma, >>> diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c >>> index 29c0a21cd34a..b283b92722cc 100644 >>> --- a/arch/s390/mm/pgtable.c >>> +++ b/arch/s390/mm/pgtable.c >>> @@ -322,7 +322,7 @@ pte_t ptep_modify_prot_start(struct >>> vm_area_struct *vma, unsigned long addr, >>>   EXPORT_SYMBOL(ptep_modify_prot_start); >>>   void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned >>> long addr, >>> -                 pte_t *ptep, pte_t pte) >>> +                 pte_t *ptep, pte_t old_pte, pte_t pte) >>>   { >>>       pgste_t pgste; >>>       struct mm_struct *mm = vma->vm_mm; >>> diff --git a/arch/x86/include/asm/paravirt.h >>> b/arch/x86/include/asm/paravirt.h >>> index 1154f154025d..0d75a4f60500 100644 >>> --- a/arch/x86/include/asm/paravirt.h >>> +++ b/arch/x86/include/asm/paravirt.h >>> @@ -429,7 +429,7 @@ static inline pte_t ptep_modify_prot_start(struct >>> vm_area_struct *vma, unsigned >>>   } >>>   static inline void ptep_modify_prot_commit(struct vm_area_struct >>> *vma, unsigned long addr, >>> -                       pte_t *ptep, pte_t pte) >>> +                       pte_t *ptep, pte_t old_pte, pte_t pte) >>>   { >>>       struct mm_struct *mm = vma->vm_mm; >>> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c >>> index 9952d7185170..8d62891d38a8 100644 >>> --- a/fs/proc/task_mmu.c >>> +++ b/fs/proc/task_mmu.c >>> @@ -940,10 +940,12 @@ static inline void clear_soft_dirty(struct >>> vm_area_struct *vma, >>>       pte_t ptent = *pte; >>>       if (pte_present(ptent)) { >>> -        ptent = ptep_modify_prot_start(vma, addr, pte); >>> -        ptent = pte_wrprotect(ptent); >>> +        pte_t old_pte; >>> + >>> +        old_pte = ptep_modify_prot_start(vma, addr, pte); >>> +        ptent = pte_wrprotect(old_pte); >> >> This change doesn't seem to fit with the commit description. Why write >> protecting in addition to clearing dirty ? >> >> > > The hunk above use a new variable old_pte. There is no functional change > in that hunk. > Oops, sorry, I misread the patch, don't know why. Christophe