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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: A64C4C0005 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: wgd3mr38q8q1agdttiknfb574frp4fjt X-HE-Tag: 1745992201-620088 X-HE-Meta: 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 8djjV+jJ +Y5/mjHEbGWUIGFnb18uGz1TbURWjzs1EYI8z00ty7BdSvReEb4sduQcp4pxwc3KoZuAoBF7WvjvWpFbE9HO65DmjiokmOdanKAe0qQJCVHC+bjz1AA6HqutKkTBv7wAmPG2ZmPT08QN25bjV6/WWzLjzhTKIANEMXeY8hqO768T0QT8vRxD8DIF04owSf2yopaHc2GLhrFeboGfWp/F1RPV+1vAaCiI5hUJA6nA3L0Ix15J9+DOosJhDBQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 30/04/25 11:13 am, Anshuman Khandual wrote: > On 4/29/25 10:53, Dev Jain wrote: >> Override the generic definition to use get_and_clear_full_ptes(), so that >> we do a TLBI possibly only on the "contpte-edges" of the large PTE block, >> instead of doing it for every contpte block, which happens for ptep_get_and_clear(). > > Could you please explain what does "contpte-edges" really signify in the > context of large PTE blocks ? Also how TLBI operation only on these edges > will never run into the risk of missing TLB invalidation of some other > mapped areas ? We are doing a TLBI over the whole range already, in the mprotect code: see tlb_flush_pte_range. What the arm64 internal API does, irrespective of the caller, is to do a TLBI for every contpte block in case of unfolding. We don't need that for the intermediate blocks because the caller does that. We do need a TLBI for the start and end contpte block, because in case the range we are invalidating partially covers them, then the caller will not do a TLBI for the non-overlapped PTEs of the block. I'll explain some more in the changelog next version. > >> >> Signed-off-by: Dev Jain >> --- >> arch/arm64/include/asm/pgtable.h | 5 +++++ >> arch/arm64/mm/mmu.c | 12 +++++++++--- >> include/linux/pgtable.h | 4 ++++ >> mm/pgtable-generic.c | 16 +++++++++++----- >> 4 files changed, 29 insertions(+), 8 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index 2a77f11b78d5..8872ea5f0642 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -1553,6 +1553,11 @@ extern void ptep_modify_prot_commit(struct vm_area_struct *vma, >> unsigned long addr, pte_t *ptep, >> pte_t old_pte, pte_t new_pte); >> >> +#define modify_prot_start_ptes modify_prot_start_ptes >> +extern pte_t modify_prot_start_ptes(struct vm_area_struct *vma, >> + unsigned long addr, pte_t *ptep, >> + unsigned int nr); >> + >> #ifdef CONFIG_ARM64_CONTPTE >> >> /* >> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >> index 8fcf59ba39db..fe60be8774f4 100644 >> --- a/arch/arm64/mm/mmu.c >> +++ b/arch/arm64/mm/mmu.c >> @@ -1523,7 +1523,8 @@ static int __init prevent_bootmem_remove_init(void) >> early_initcall(prevent_bootmem_remove_init); >> #endif >> >> -pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) >> +pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long addr, >> + pte_t *ptep, unsigned int nr) >> { >> if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) { >> /* >> @@ -1532,9 +1533,14 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte >> * in cases where cpu is affected with errata #2645198. >> */ >> if (pte_user_exec(ptep_get(ptep))) >> - return ptep_clear_flush(vma, addr, ptep); >> + return clear_flush_ptes(vma, addr, ptep, nr); >> } >> - return ptep_get_and_clear(vma->vm_mm, addr, ptep); >> + return get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, 0); >> +} >> + >> +pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) >> +{ >> + return modify_prot_start_ptes(vma, addr, ptep, 1); >> } >> >> void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, >> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h >> index ed287289335f..10cdb87ccecf 100644 >> --- a/include/linux/pgtable.h >> +++ b/include/linux/pgtable.h >> @@ -828,6 +828,10 @@ extern pte_t ptep_clear_flush(struct vm_area_struct *vma, >> pte_t *ptep); >> #endif >> >> +extern pte_t clear_flush_ptes(struct vm_area_struct *vma, >> + unsigned long address, >> + pte_t *ptep, unsigned int nr); >> + >> #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH >> extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, >> unsigned long address, >> diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c >> index 5a882f2b10f9..e238f88c3cac 100644 >> --- a/mm/pgtable-generic.c >> +++ b/mm/pgtable-generic.c >> @@ -90,17 +90,23 @@ int ptep_clear_flush_young(struct vm_area_struct *vma, >> } >> #endif >> >> -#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH >> -pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, >> - pte_t *ptep) >> +pte_t clear_flush_ptes(struct vm_area_struct *vma, unsigned long address, >> + pte_t *ptep, unsigned int nr) >> { >> struct mm_struct *mm = (vma)->vm_mm; >> pte_t pte; >> - pte = ptep_get_and_clear(mm, address, ptep); >> + pte = get_and_clear_full_ptes(mm, address, ptep, nr, 0); >> if (pte_accessible(mm, pte)) >> - flush_tlb_page(vma, address); >> + flush_tlb_range(vma, address, address + nr * PAGE_SIZE); >> return pte; >> } >> + >> +#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH >> +pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, >> + pte_t *ptep) >> +{ >> + return clear_flush_ptes(vma, address, ptep, 1); >> +} >> #endif >> >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE