mm: fix the racy mm->locked_vm change in

"mm->locked_vm += grow" and vm_stat_account() in acct_stack_growth() are
not safe; multiple threads using the same ->mm can do this at the same
time trying to expans different vma's under down_read(mmap_sem).  This
means that one of the "locked_vm += grow" changes can be lost and we can
miss munlock_vma_pages_all() later.

Move this code into the caller(s) under mm->page_table_lock.  All other
updates to ->locked_vm hold mmap_sem for writing.

Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions