diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 5fd421e48c04..a4297eb39887 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -504,17 +504,6 @@ static ssize_t read_zero(struct file *file, char __user *buf, return cleared; } -static int mmap_zero_private_success(const struct vm_area_struct *vma) -{ - /* - * This is a highly unique situation where we mark a MAP_PRIVATE mapping - * of /dev/zero anonymous, despite it not being. - */ - vma_set_anonymous((struct vm_area_struct *)vma); - - return 0; -} - static int mmap_zero_prepare(struct vm_area_desc *desc) { #ifndef CONFIG_MMU @@ -523,7 +512,11 @@ static int mmap_zero_prepare(struct vm_area_desc *desc) if (vma_desc_test(desc, VMA_SHARED_BIT)) return shmem_zero_setup_desc(desc); - desc->action.success_hook = mmap_zero_private_success; + /* + * This is a highly unique situation where we mark a MAP_PRIVATE mapping + * of /dev/zero anonymous, despite it not being. + */ + vma_desc_set_anonymous(desc); return 0; } diff --git a/include/linux/mm.h b/include/linux/mm.h index 11f440e9d7cd..0f2612a70fb1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1489,6 +1489,11 @@ static inline void vma_set_anonymous(struct vm_area_struct *vma) vma->vm_ops = NULL; } +static inline void vma_desc_set_anonymous(struct vm_area_desc *desc) +{ + desc->vm_ops = NULL; +} + static inline bool vma_is_anonymous(struct vm_area_struct *vma) { return !vma->vm_ops; diff --git a/mm/util.c b/mm/util.c index 3cc949a0b7ed..2b2a9df689d7 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1192,6 +1192,7 @@ void compat_set_desc_from_vma(struct vm_area_desc *desc, desc->vm_file = vma->vm_file; desc->vma_flags = vma->flags; desc->page_prot = vma->vm_page_prot; + desc->vm_ops = vma->vm_ops; /* Default. */ desc->action.type = MMAP_NOTHING; diff --git a/mm/vma.c b/mm/vma.c index d90791b00a7b..9eea2850818a 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -2697,6 +2697,8 @@ static void set_vma_user_defined_fields(struct vm_area_struct *vma, { if (map->vm_ops) vma->vm_ops = map->vm_ops; + else /* Only /dev/zero should do this. */ + vma_set_anonymous(vma); vma->vm_private_data = map->vm_private_data; } @@ -2744,6 +2746,7 @@ static unsigned long __mmap_region(struct file *file, unsigned long addr, .action = { .type = MMAP_NOTHING, /* Default to no further action. */ }, + .vm_ops = &vma_dummy_vm_ops, }; bool allocated_new = false; int error; diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h index 9e0dfd3a85b0..306171d061e7 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h @@ -1303,6 +1303,7 @@ static inline void compat_set_desc_from_vma(struct vm_area_desc *desc, desc->vm_file = vma->vm_file; desc->vma_flags = vma->flags; desc->page_prot = vma->vm_page_prot; + desc->vm_ops = vma->vm_ops; /* Default. */ desc->action.type = MMAP_NOTHING;