diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 72 |
1 files changed, 53 insertions, 19 deletions
diff --git a/mm/memory.c b/mm/memory.c index 106ae6439..96d64ceb6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -61,6 +61,7 @@ #include <linux/string.h> #include <linux/dma-debug.h> #include <linux/debugfs.h> +#include <linux/userfaultfd_k.h> #include <asm/io.h> #include <asm/pgalloc.h> @@ -203,22 +204,22 @@ static void check_sync_rss_stat(struct task_struct *task) #ifdef HAVE_GENERIC_MMU_GATHER -static int tlb_next_batch(struct mmu_gather *tlb) +static bool tlb_next_batch(struct mmu_gather *tlb) { struct mmu_gather_batch *batch; batch = tlb->active; if (batch->next) { tlb->active = batch->next; - return 1; + return true; } if (tlb->batch_count == MAX_GATHER_BATCH_COUNT) - return 0; + return false; batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); if (!batch) - return 0; + return false; tlb->batch_count++; batch->next = NULL; @@ -228,7 +229,7 @@ static int tlb_next_batch(struct mmu_gather *tlb) tlb->active->next = batch; tlb->active = batch; - return 1; + return true; } /* tlb_gather_mmu @@ -2720,6 +2721,12 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, page_table = pte_offset_map_lock(mm, pmd, address, &ptl); if (!pte_none(*page_table)) goto unlock; + /* Deliver the page fault to userland, check inside PT lock */ + if (userfaultfd_missing(vma)) { + pte_unmap_unlock(page_table, ptl); + return handle_userfault(vma, address, flags, + VM_UFFD_MISSING); + } goto setpte; } @@ -2748,6 +2755,15 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (!pte_none(*page_table)) goto release; + /* Deliver the page fault to userland, check inside PT lock */ + if (userfaultfd_missing(vma)) { + pte_unmap_unlock(page_table, ptl); + mem_cgroup_cancel_charge(page, memcg); + page_cache_release(page); + return handle_userfault(vma, address, flags, + VM_UFFD_MISSING); + } + inc_mm_counter_fast(mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); mem_cgroup_commit_charge(page, memcg, false); @@ -3034,9 +3050,9 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma, } else { /* * The fault handler has no page to lock, so it holds - * i_mmap_lock for read to protect against truncate. + * i_mmap_lock for write to protect against truncate. */ - i_mmap_unlock_read(vma->vm_file->f_mapping); + i_mmap_unlock_write(vma->vm_file->f_mapping); } goto uncharge_out; } @@ -3050,9 +3066,9 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma, } else { /* * The fault handler has no page to lock, so it holds - * i_mmap_lock for read to protect against truncate. + * i_mmap_lock for write to protect against truncate. */ - i_mmap_unlock_read(vma->vm_file->f_mapping); + i_mmap_unlock_write(vma->vm_file->f_mapping); } return ret; uncharge_out: @@ -3251,6 +3267,27 @@ out: return 0; } +static int create_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, unsigned int flags) +{ + if (vma_is_anonymous(vma)) + return do_huge_pmd_anonymous_page(mm, vma, address, pmd, flags); + if (vma->vm_ops->pmd_fault) + return vma->vm_ops->pmd_fault(vma, address, pmd, flags); + return VM_FAULT_FALLBACK; +} + +static int wp_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, pmd_t orig_pmd, + unsigned int flags) +{ + if (vma_is_anonymous(vma)) + return do_huge_pmd_wp_page(mm, vma, address, pmd, orig_pmd); + if (vma->vm_ops->pmd_fault) + return vma->vm_ops->pmd_fault(vma, address, pmd, flags); + return VM_FAULT_FALLBACK; +} + /* * These routines also need to handle stuff like marking pages dirty * and/or accessed for architectures that don't do it in hardware (most @@ -3286,12 +3323,12 @@ static int handle_pte_fault(struct mm_struct *mm, barrier(); if (!pte_present(entry)) { if (pte_none(entry)) { - if (vma->vm_ops) + if (vma_is_anonymous(vma)) + return do_anonymous_page(mm, vma, address, + pte, pmd, flags); + else return do_fault(mm, vma, address, pte, pmd, flags, entry); - - return do_anonymous_page(mm, vma, address, pte, pmd, - flags); } return do_swap_page(mm, vma, address, pte, pmd, flags, entry); @@ -3353,10 +3390,7 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (!pmd) return VM_FAULT_OOM; if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { - int ret = VM_FAULT_FALLBACK; - if (!vma->vm_ops) - ret = do_huge_pmd_anonymous_page(mm, vma, address, - pmd, flags); + int ret = create_huge_pmd(mm, vma, address, pmd, flags); if (!(ret & VM_FAULT_FALLBACK)) return ret; } else { @@ -3380,8 +3414,8 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, orig_pmd, pmd); if (dirty && !pmd_write(orig_pmd)) { - ret = do_huge_pmd_wp_page(mm, vma, address, pmd, - orig_pmd); + ret = wp_huge_pmd(mm, vma, address, pmd, + orig_pmd, flags); if (!(ret & VM_FAULT_FALLBACK)) return ret; } else { |