From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Adding support for a NULL vma means the init_vma_munmap() can be
initialized for a less error-prone process when calling
vms_complete_munmap_vmas() later on.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index a1544a68558e..722bcced0499 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -517,9 +517,14 @@ static inline void init_vma_munmap(struct vma_munmap_struct *vms,
{
vms->vmi = vmi;
vms->vma = vma;
- vms->mm = vma->vm_mm;
- vms->start = start;
- vms->end = end;
+ if (vma) {
+ vms->mm = vma->vm_mm;
+ vms->start = start;
+ vms->end = end;
+ } else {
+ vms->mm = NULL;
+ vms->start = vms->end = 0;
+ }
vms->unlock = unlock;
vms->uf = uf;
vms->vma_count = 0;
@@ -2950,11 +2955,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
/* Find the first overlapping VMA */
vma = vma_find(&vmi, end);
+ init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
if (vma) {
mt_init_flags(&mt_detach, vmi.mas.tree->ma_flags & MT_FLAGS_LOCK_MASK);
mt_on_stack(mt_detach);
mas_init(&mas_detach, &mt_detach, /* addr = */ 0);
- init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
/* Prepare to unmap any existing mapping in the area */
if (vms_gather_munmap_vmas(&vms, &mas_detach))
return -ENOMEM;
--
2.43.0
