diff options
Diffstat (limited to 'mm/mprotect.c')
-rw-r--r-- | mm/mprotect.c | 151 |
1 files changed, 120 insertions, 31 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index a40992610ab6..94722a4d6b43 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -35,12 +35,16 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) } #endif -static void change_pte_range(struct mm_struct *mm, pmd_t *pmd, +static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable) + int dirty_accountable, int prot_numa, bool *ret_all_same_node) { + struct mm_struct *mm = vma->vm_mm; pte_t *pte, oldpte; spinlock_t *ptl; + unsigned long pages = 0; + bool all_same_node = true; + int last_nid = -1; pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); @@ -48,17 +52,43 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd, oldpte = *pte; if (pte_present(oldpte)) { pte_t ptent; + bool updated = false; ptent = ptep_modify_prot_start(mm, addr, pte); - ptent = pte_modify(ptent, newprot); + if (!prot_numa) { + ptent = pte_modify(ptent, newprot); + updated = true; + } else { + struct page *page; + + page = vm_normal_page(vma, addr, oldpte); + if (page) { + int this_nid = page_to_nid(page); + if (last_nid == -1) + last_nid = this_nid; + if (last_nid != this_nid) + all_same_node = false; + + /* only check non-shared pages */ + if (!pte_numa(oldpte) && + page_mapcount(page) == 1) { + ptent = pte_mknuma(ptent); + updated = true; + } + } + } /* * Avoid taking write faults for pages we know to be * dirty. */ - if (dirty_accountable && pte_dirty(ptent)) + if (dirty_accountable && pte_dirty(ptent)) { ptent = pte_mkwrite(ptent); + updated = true; + } + if (updated) + pages++; ptep_modify_prot_commit(mm, addr, pte, ptent); } else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) { swp_entry_t entry = pte_to_swp_entry(oldpte); @@ -72,61 +102,101 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd, set_pte_at(mm, addr, pte, swp_entry_to_pte(entry)); } + pages++; } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); pte_unmap_unlock(pte - 1, ptl); + + *ret_all_same_node = all_same_node; + return pages; } -static inline void change_pmd_range(struct vm_area_struct *vma, pud_t *pud, - unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable) +#ifdef CONFIG_NUMA_BALANCING +static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, + pmd_t *pmd) +{ + spin_lock(&mm->page_table_lock); + set_pmd_at(mm, addr & PMD_MASK, pmd, pmd_mknuma(*pmd)); + spin_unlock(&mm->page_table_lock); +} +#else +static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, + pmd_t *pmd) +{ + BUG(); +} +#endif /* CONFIG_NUMA_BALANCING */ + +static inline unsigned long change_pmd_range(struct vm_area_struct *vma, + pud_t *pud, unsigned long addr, unsigned long end, + pgprot_t newprot, int dirty_accountable, int prot_numa) { pmd_t *pmd; unsigned long next; + unsigned long pages = 0; + bool all_same_node; pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) - split_huge_page_pmd(vma->vm_mm, pmd); - else if (change_huge_pmd(vma, pmd, addr, newprot)) + split_huge_page_pmd(vma, addr, pmd); + else if (change_huge_pmd(vma, pmd, addr, newprot, + prot_numa)) { + pages += HPAGE_PMD_NR; continue; + } /* fall through */ } if (pmd_none_or_clear_bad(pmd)) continue; - change_pte_range(vma->vm_mm, pmd, addr, next, newprot, - dirty_accountable); + pages += change_pte_range(vma, pmd, addr, next, newprot, + dirty_accountable, prot_numa, &all_same_node); + + /* + * If we are changing protections for NUMA hinting faults then + * set pmd_numa if the examined pages were all on the same + * node. This allows a regular PMD to be handled as one fault + * and effectively batches the taking of the PTL + */ + if (prot_numa && all_same_node) + change_pmd_protnuma(vma->vm_mm, addr, pmd); } while (pmd++, addr = next, addr != end); + + return pages; } -static inline void change_pud_range(struct vm_area_struct *vma, pgd_t *pgd, - unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable) +static inline unsigned long change_pud_range(struct vm_area_struct *vma, + pgd_t *pgd, unsigned long addr, unsigned long end, + pgprot_t newprot, int dirty_accountable, int prot_numa) { pud_t *pud; unsigned long next; + unsigned long pages = 0; pud = pud_offset(pgd, addr); do { next = pud_addr_end(addr, end); if (pud_none_or_clear_bad(pud)) continue; - change_pmd_range(vma, pud, addr, next, newprot, - dirty_accountable); + pages += change_pmd_range(vma, pud, addr, next, newprot, + dirty_accountable, prot_numa); } while (pud++, addr = next, addr != end); + + return pages; } -static void change_protection(struct vm_area_struct *vma, +static unsigned long change_protection_range(struct vm_area_struct *vma, unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable) + int dirty_accountable, int prot_numa) { struct mm_struct *mm = vma->vm_mm; pgd_t *pgd; unsigned long next; unsigned long start = addr; + unsigned long pages = 0; BUG_ON(addr >= end); pgd = pgd_offset(mm, addr); @@ -135,10 +205,32 @@ static void change_protection(struct vm_area_struct *vma, next = pgd_addr_end(addr, end); if (pgd_none_or_clear_bad(pgd)) continue; - change_pud_range(vma, pgd, addr, next, newprot, - dirty_accountable); + pages += change_pud_range(vma, pgd, addr, next, newprot, + dirty_accountable, prot_numa); } while (pgd++, addr = next, addr != end); - flush_tlb_range(vma, start, end); + + /* Only flush the TLB if we actually modified any entries: */ + if (pages) + flush_tlb_range(vma, start, end); + + return pages; +} + +unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, + unsigned long end, pgprot_t newprot, + int dirty_accountable, int prot_numa) +{ + struct mm_struct *mm = vma->vm_mm; + unsigned long pages; + + mmu_notifier_invalidate_range_start(mm, start, end); + if (is_vm_hugetlb_page(vma)) + pages = hugetlb_change_protection(vma, start, end, newprot); + else + pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); + mmu_notifier_invalidate_range_end(mm, start, end); + + return pages; } int @@ -213,12 +305,9 @@ success: dirty_accountable = 1; } - mmu_notifier_invalidate_range_start(mm, start, end); - if (is_vm_hugetlb_page(vma)) - hugetlb_change_protection(vma, start, end, vma->vm_page_prot); - else - change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable); - mmu_notifier_invalidate_range_end(mm, start, end); + change_protection(vma, start, end, vma->vm_page_prot, + dirty_accountable, 0); + vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); vm_stat_account(mm, newflags, vma->vm_file, nrpages); perf_event_mmap(vma); @@ -274,8 +363,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, error = -EINVAL; if (!(vma->vm_flags & VM_GROWSDOWN)) goto out; - } - else { + } else { if (vma->vm_start > start) goto out; if (unlikely(grows & PROT_GROWSUP)) { @@ -291,9 +379,10 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, for (nstart = start ; ; ) { unsigned long newflags; - /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ + /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ - newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); + newflags = vm_flags; + newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); /* newflags >> 4 shift VM_MAY% in place of VM_% */ if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { |