On Tue, Aug 30, 2016 at 06:59:39PM +0800, wei.guo.simon@xxxxxxxxx wrote: > From: Simon Guo <wei.guo.simon@xxxxxxxxx> > > When one vma was with flag VM_LOCKED|VM_LOCKONFAULT (by invoking > mlock2(,MLOCK_ONFAULT)), it can again be populated with mlock() with > VM_LOCKED flag only. > > There is a hole in mlock_fixup() which increase mm->locked_vm twice even > the two operations are on the same vma and both with VM_LOCKED flags. > > The issue can be reproduced by following code: > mlock2(p, 1024 * 64, MLOCK_ONFAULT); //VM_LOCKED|VM_LOCKONFAULT > mlock(p, 1024 * 64); //VM_LOCKED > Then check the increase VmLck field in /proc/pid/status(to 128k). > > When vma is set with different vm_flags, and the new vm_flags is with > VM_LOCKED, it is not necessarily be a "new locked" vma. This patch > corrects this bug by prevent mm->locked_vm from increment when old > vm_flags is already VM_LOCKED. > > Signed-off-by: Simon Guo <wei.guo.simon@xxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>