[Devel] [PATCH rh7] mm: mmap_region: uncharge UB_LOCKEDPAGES if vma cannot be locked

[Vladimir Davydov]

mmap_region workflow regarding locked pages was changed during rebase
from RH6 to RH7. The patch porting locked pages accounting did not allow
for that.

Presumably, this should fix UB_LOCKEDPAGES leak on CT stop:

  Ub 101 helds 8 in lockedpages on put
  UB: leaked beancounter 101 (ffff880404e95000)
  Tainting kernel with flag 0xa

https://jira.sw.ru/browse/PSBM-39435

Signed-off-by: Vladimir Davydov <vdavydov at virtuozzo.com>
---
 mm/mmap.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 8796ed643a6f..b981d80ab100 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1654,8 +1654,10 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 		if (!((vm_flags & VM_SPECIAL) || is_vm_hugetlb_page(vma) ||
 					vma == get_gate_vma(current->mm)))
 			mm->locked_vm += (len >> PAGE_SHIFT);
-		else
+		else {
 			vma->vm_flags &= ~VM_LOCKED;
+			ub_locked_uncharge(mm, len);
+		}
 	}
 
 	if (file)
-- 
2.1.4