RE: [Update][PATCH] ACPI / hotplug: Fix concurrency issues andmemory leaks
From: Moore, Robert
Date: Wed Feb 13 2013 - 21:31:30 EST
> > > I thought about that, but actually there's no guarantee that the
> > > handle will be valid after _EJ0 as far as I can say. So the race
> > > condition is going to be there anyway and using struct acpi_device
> > > just makes it easier to avoid it.
> > In theory, yes, a stale handle could be a problem, if _EJ0 performs
> > unload table and if ACPICA frees up its internal data structure
> > pointed by the handle as a result. But we should not see such issue
> > now since we do not support dynamic ACPI namespace yet.
> I'm waiting for information from Bob about that. If we can assume ACPI
> handles to be always valid, that will simplify things quite a bit.
If a table is unloaded, all the namespace nodes for that table are removed from the namespace, and thus any ACPI_HANDLE pointers go stale and invalid.