From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by kanga.kvack.org (Postfix) with ESMTP id EC3F56B7252 for ; Tue, 4 Dec 2018 23:02:59 -0500 (EST) Received: by mail-wr1-f72.google.com with SMTP id d11so14238466wrq.18 for ; Tue, 04 Dec 2018 20:02:59 -0800 (PST) Received: from pegase1.c-s.fr (pegase1.c-s.fr. [93.17.236.30]) by mx.google.com with ESMTPS id q15si9381987wmf.199.2018.12.04.20.02.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Dec 2018 20:02:58 -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> From: Christophe LEROY Message-ID: Date: Wed, 5 Dec 2018 05:02:56 +0100 MIME-Version: 1.0 In-Reply-To: <20181205030931.12037-3-aneesh.kumar@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 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 ? Christophe > ptent = pte_clear_soft_dirty(ptent); > - ptep_modify_prot_commit(vma, addr, pte, ptent); > + ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); > } else if (is_swap_pte(ptent)) { > ptent = pte_swp_clear_soft_dirty(ptent); > set_pte_at(vma->vm_mm, addr, pte, ptent); > diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h > index c9897dcc46c4..37039e918f17 100644 > --- a/include/asm-generic/pgtable.h > +++ b/include/asm-generic/pgtable.h > @@ -619,7 +619,7 @@ static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma, > */ > 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) > { > __ptep_modify_prot_commit(vma->vm_mm, addr, ptep, pte); > } > diff --git a/mm/memory.c b/mm/memory.c > index d36b0eaa7862..4f3ddaedc764 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3568,7 +3568,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) > int last_cpupid; > int target_nid; > bool migrated = false; > - pte_t pte; > + pte_t pte, old_pte; > bool was_writable = pte_savedwrite(vmf->orig_pte); > int flags = 0; > > @@ -3588,12 +3588,12 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) > * Make it present again, Depending on how arch implementes non > * accessible ptes, some can allow access by kernel mode. > */ > - pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte); > - pte = pte_modify(pte, vma->vm_page_prot); > + old_pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte); > + pte = pte_modify(old_pte, vma->vm_page_prot); > pte = pte_mkyoung(pte); > if (was_writable) > pte = pte_mkwrite(pte); > - ptep_modify_prot_commit(vma, vmf->address, vmf->pte, pte); > + ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte); > update_mmu_cache(vma, vmf->address, vmf->pte); > > page = vm_normal_page(vma, vmf->address, pte); > diff --git a/mm/mprotect.c b/mm/mprotect.c > index a301d4c83d3c..1b46b1b1248d 100644 > --- a/mm/mprotect.c > +++ b/mm/mprotect.c > @@ -110,8 +110,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, > continue; > } > > - ptent = ptep_modify_prot_start(vma, addr, pte); > - ptent = pte_modify(ptent, newprot); > + oldpte = ptep_modify_prot_start(vma, addr, pte); > + ptent = pte_modify(oldpte, newprot); > if (preserve_write) > ptent = pte_mk_savedwrite(ptent); > > @@ -121,7 +121,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, > !(vma->vm_flags & VM_SOFTDIRTY))) { > ptent = pte_mkwrite(ptent); > } > - ptep_modify_prot_commit(vma, addr, pte, ptent); > + ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent); > pages++; > } else if (IS_ENABLED(CONFIG_MIGRATION)) { > swp_entry_t entry = pte_to_swp_entry(oldpte); >