mm: mark VMA as being written when changing vm_flags

Updates to vm_flags have to be done with VMA marked as being written for
preventing concurrent page faults or other modifications.

Link: https://lkml.kernel.org/r/20230227173632.3292573-14-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mm.h

@@ -727,28 +727,28 @@ static inline void vm_flags_init(struct vm_area_struct *vma,
 static inline void vm_flags_reset(struct vm_area_struct *vma,
 				  vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	vm_flags_init(vma, flags);
 }
 
 static inline void vm_flags_reset_once(struct vm_area_struct *vma,
 				       vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	WRITE_ONCE(ACCESS_PRIVATE(vma, __vm_flags), flags);
 }
 
 static inline void vm_flags_set(struct vm_area_struct *vma,
 				vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	ACCESS_PRIVATE(vma, __vm_flags) |= flags;
 }
 
 static inline void vm_flags_clear(struct vm_area_struct *vma,
 				  vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	ACCESS_PRIVATE(vma, __vm_flags) &= ~flags;
 }
 
@@ -769,7 +769,7 @@ static inline void __vm_flags_mod(struct vm_area_struct *vma,
 static inline void vm_flags_mod(struct vm_area_struct *vma,
 				vm_flags_t set, vm_flags_t clear)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	__vm_flags_mod(vma, set, clear);
 }