fsgsbase not properly re-enabled on wakeup

[smherwig]

I'm using an Intel NUC and running Ubuntu 16.04.

When I suspend and then resume the NUC, and then run Graphene-SGX's (commit 80030b1157da371251f632e325df71e9454b4e55) helloworld test, the application crashes. GDB indicates that the crash occurs from the illegal WRFSBASE instruction that occurs in the inline assembly of Graphene-SGX's (Pal/src/host/Linux-SGX/sgx_api.h) wrfsbase wrapper function.

To reproduce:

# suspend and resume machine

cd ~/src/graphene/LibOS/shim/test/native/
SGX=1 ./pal_loader ./helloworld`

The debug output is: helloworld-debug-log.txt

[yamahata]

Did you load graphene-sgx driver first, suspend/resume the machine, and then start graphene?
If yes, it's the issue of graphene-sgx driver. Currently it's not aware of power management and it enables fsgsbase in hacky way.
So g-sgx driver needs to be aware of power manager.
Probably notifier for PM_POST_SUSPEND needs to be installed in order to enable fsgsbase on wakeup.

[smherwig]

That's correct.