[PATCHv3 1/3] mm: Introduce vma_init()

[Kirill A. Shutemov]

Not all VMAs allocated with vm_area_alloc(). Some of them allocated on
stack or in data segment.

The new helper can be use to initialize VMA properly regardless where
it was allocated.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
 include/linux/mm.h | 6 ++++++
 kernel/fork.c      | 6 ++----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d3a3842316b8..31540f166987 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -452,6 +452,12 @@ struct vm_operations_struct {
                                          unsigned long addr);
 };
 
+static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
+{
+       vma->vm_mm = mm;
+       INIT_LIST_HEAD(&vma->anon_vma_chain);
+}
+
 struct mmu_gather;
 struct inode;
 
diff --git a/kernel/fork.c b/kernel/fork.c
index a191c05e757d..1b27babc4c78 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -312,10 +312,8 @@ struct vm_area_struct *vm_area_alloc(struct mm_struct *mm)
 {
        struct vm_area_struct *vma = kmem_cache_zalloc(vm_area_cachep, 
GFP_KERNEL);
 
-       if (vma) {
-               vma->vm_mm = mm;
-               INIT_LIST_HEAD(&vma->anon_vma_chain);
-       }
+       if (vma)
+               vma_init(vma, mm);
        return vma;
 }
 
-- 
2.18.0