try_module_get and friends

[Jon Masters <jonathan@jonmasters.org>]

Yo,

Ok...so I might just be missing something and you guys will set me right
if that is indeed the case, but...

What's protecting the -RT kernel from assumptions about atomicity of
module symbol references? Specifically, the kernel doesn't normally need
to protect against inter-module symbol references to EXPORT_SYMBOL(s),
however, it requires special protection when a function pointer is being
passed around - that's why we use things like try_module_get. But it is
assumed that it is ok not to do this in atomic contexts.

So, what's protecting the RT kernel from falling over if a CPU frequency
governor module is removed at the wrong moment?

Jon.