This is a note to let you know that I've just added the patch titled
mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-mmap.c-fix-missing-call-to-vm_unacct_memory-in-mm.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit af76088513f0705ff3fe9284babe2c6a0c5772de
Author: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Date: Sat Jun 18 16:20:27 2022 +0800
mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region
[ Upstream commit 7f82f922319ede486540e8746769865b9508d2c2 ]
Since the beginning, charged is set to 0 to avoid calling vm_unacct_memory
twice because vm_unacct_memory will be called by above unmap_region. But
since commit 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from
the unmap_vmas() interfaces"), unmap_region doesn't call vm_unacct_memory
anymore. So charged shouldn't be set to 0 now otherwise the calling to
paired vm_unacct_memory will be missed and leads to imbalanced account.
Link: https://lkml.kernel.org/r/20220618082027.43391-1-linmiaohe@xxxxxxxxxx
Fixes: 4f74d2c8e827 ("vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/mm/mmap.c b/mm/mmap.c
index bb8ba3258945..590840c3a3b5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1821,7 +1821,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
/* Undo any partial mapping done by a device driver. */
unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
- charged = 0;
if (vm_flags & VM_SHARED)
mapping_unmap_writable(file->f_mapping);
allow_write_and_free_vma:
