diff --git a/drivers/char/mem.c b/drivers/char/mem.c index ffeb60d3434c51..f0a8b0b1768bb6 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -708,6 +708,7 @@ static int mmap_zero(struct file *file, struct vm_area_struct *vma) #endif if (vma->vm_flags & VM_SHARED) return shmem_zero_setup(vma); + vma->vm_ops = &anon_vm_ops; return 0; } diff --git a/fs/exec.c b/fs/exec.c index 2d4e0075bd2457..a1a2460625611a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -307,6 +307,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) * configured yet. */ BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); + vma->vm_ops = &anon_vm_ops; vma->vm_end = STACK_TOP_MAX; vma->vm_start = vma->vm_end - PAGE_SIZE; vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index d508c7844681fb..5ff73b1398ade3 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -597,6 +597,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, memset(&pseudo_vma, 0, sizeof(struct vm_area_struct)); pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); pseudo_vma.vm_file = file; + pseudo_vma.vm_ops = &dummy_vm_ops; for (index = start; index < end; index++) { /* diff --git a/include/linux/mm.h b/include/linux/mm.h index 3982c83fdcbfa3..176adbdc51b38d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1536,9 +1536,12 @@ int clear_page_dirty_for_io(struct page *page); int get_cmdline(struct task_struct *task, char *buffer, int buflen); +extern const struct vm_operations_struct anon_vm_ops; +extern const struct vm_operations_struct dummy_vm_ops; + static inline bool vma_is_anonymous(struct vm_area_struct *vma) { - return !vma->vm_ops; + return vma->vm_ops == &anon_vm_ops; } #ifdef CONFIG_SHMEM diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d7b2a4bf867164..5ae34097aed123 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -440,7 +440,7 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma, * page fault if needed. */ return 0; - if (vma->vm_ops || (vm_flags & VM_NO_KHUGEPAGED)) + if (!vma_is_anonymous(vma) || (vm_flags & VM_NO_KHUGEPAGED)) /* khugepaged not yet working on file or special mappings */ return 0; hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; @@ -831,7 +831,7 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff, HPAGE_PMD_NR); } - if (!vma->anon_vma || vma->vm_ops) + if (!vma->anon_vma || !vma_is_anonymous(vma)) return false; if (is_vma_temporary_stack(vma)) return false; diff --git a/mm/mmap.c b/mm/mmap.c index 5801b5f0a634b5..3dd845699e8cf9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -71,6 +71,9 @@ int mmap_rnd_compat_bits __read_mostly = CONFIG_ARCH_MMAP_RND_COMPAT_BITS; static bool ignore_rlimit_data; core_param(ignore_rlimit_data, ignore_rlimit_data, bool, 0644); +const struct vm_operations_struct anon_vm_ops = {}; +const struct vm_operations_struct dummy_vm_ops = {}; + static void unmap_region(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, unsigned long start, unsigned long end); @@ -561,6 +564,8 @@ static unsigned long count_vma_pages_range(struct mm_struct *mm, void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma, struct rb_node **rb_link, struct rb_node *rb_parent) { + WARN_ONCE(!vma->vm_ops, "missing vma->vm_ops"); + /* Update tracking information for the gap following the new vma. */ if (vma->vm_next) vma_gap_update(vma->vm_next); @@ -1774,12 +1779,19 @@ unsigned long mmap_region(struct file *file, unsigned long addr, */ WARN_ON_ONCE(addr != vma->vm_start); + /* All mappings must have ->vm_ops set */ + if (!vma->vm_ops) + vma->vm_ops = &dummy_vm_ops; + addr = vma->vm_start; vm_flags = vma->vm_flags; } else if (vm_flags & VM_SHARED) { error = shmem_zero_setup(vma); if (error) goto free_vma; + } else { + /* vma_is_anonymous() relies on this. */ + vma->vm_ops = &anon_vm_ops; } vma_link(mm, vma, prev, rb_link, rb_parent); @@ -2992,6 +3004,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla INIT_LIST_HEAD(&vma->anon_vma_chain); vma->vm_mm = mm; + vma->vm_ops = &anon_vm_ops; vma->vm_start = addr; vma->vm_end = addr + len; vma->vm_pgoff = pgoff; diff --git a/mm/shmem.c b/mm/shmem.c index 2cab8440305531..db5c319161ca76 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1424,6 +1424,7 @@ static void shmem_pseudo_vma_init(struct vm_area_struct *vma, /* Bias interleave by inode number to distribute better across nodes */ vma->vm_pgoff = index + info->vfs_inode.i_ino; vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index); + vma->vm_ops = &dummy_vm_ops; } static void shmem_pseudo_vma_destroy(struct vm_area_struct *vma)