Matthew Wilcox willy@infradead.org writes:

On Thu, Apr 06, 2023 at 09:53:37AM -0700, Stefan Roesch wrote:

...

• case PR_SET_MEMORY_MERGE:

• if (mmap_write_lock_killable(me->mm))
  

• 	return -EINTR;
  

• if (arg2) {
  

• 	int err = ksm_add_mm(me->mm);
  

• 	if (err)
  

• 		return err;
  

You'll return to userspace with the mutex held, no?

Thanks for catching this, I'll fix it in the next version.