diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b2d56b1c3276..f7c63bd6506e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -823,7 +823,6 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, spinlock_t *ptl; pgtable_t pgtable; struct page *zero_page; - bool set; int ret; pgtable = pte_alloc_one(mm, haddr); if (unlikely(!pgtable)) @@ -836,10 +835,11 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, } ptl = pmd_lock(mm, pmd); ret = 0; - set = false; if (pmd_none(*pmd)) { if (userfaultfd_missing(vma)) { spin_unlock(ptl); + pte_free(mm, pgtable); + put_huge_zero_page(); ret = handle_userfault(vma, address, flags, VM_UFFD_MISSING); VM_BUG_ON(ret & VM_FAULT_FALLBACK); @@ -848,11 +848,9 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, haddr, pmd, zero_page); spin_unlock(ptl); - set = true; } - } else + } else { spin_unlock(ptl); - if (!set) { pte_free(mm, pgtable); put_huge_zero_page(); } @@ -1269,13 +1267,12 @@ out_unlock: } /* - * FOLL_FORCE can write to even unwritable pmd's, but only - * after we've gone through a COW cycle and they are dirty. + * FOLL_FORCE or a forced COW break can write even to unwritable pmd's, + * but only after we've gone through a COW cycle and they are dirty. */ static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags) { - return pmd_write(pmd) || - ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd)); + return pmd_write(pmd) || ((flags & FOLL_COW) && pmd_dirty(pmd)); } struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, @@ -1342,9 +1339,6 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, bool was_writable; int flags = 0; - /* A PROT_NONE fault should not end up here */ - BUG_ON(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))); - ptl = pmd_lock(mm, pmdp); if (unlikely(!pmd_same(pmd, *pmdp))) goto out_unlock; @@ -2135,7 +2129,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, static inline int khugepaged_test_exit(struct mm_struct *mm) { - return atomic_read(&mm->mm_users) == 0; + return atomic_read(&mm->mm_users) == 0 || !mmget_still_valid(mm); } int __khugepaged_enter(struct mm_struct *mm) @@ -2148,7 +2142,7 @@ int __khugepaged_enter(struct mm_struct *mm) return -ENOMEM; /* __khugepaged_exit() must not run from under us */ - VM_BUG_ON_MM(khugepaged_test_exit(mm), mm); + VM_BUG_ON_MM(atomic_read(&mm->mm_users) == 0, mm); if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) { free_mm_slot(mm_slot); return 0; |