Re: [PATCH v9 00/17] Enable FSGSBASE instructions

From: Thomas Gleixner
Date: Fri Nov 15 2019 - 13:29:26 EST


On Fri, 4 Oct 2019, Chang S. Bae wrote:
>
> Updates from v8 [10]:
> * Internalized the interrupt check in the helper functions (Andy L.)
> * Simplified GS base helper functions (Tony L.)
> * Changed the patch order to put the paranoid path changes before the
> context switch changes (Tony L.)
> * Fixed typos (Randy D.) and massaged a few sentences in the documentation
> * Massaged the FSGSBASE enablement message

That still lacks what Andy requested quite some time ago in the V8 thread:

https://lore.kernel.org/lkml/034aaf3a-a93d-ec03-0bbd-068e1905b774@xxxxxxxxxx/

"I also think that, before this series can have my ack, it needs an
actual gdb maintainer to chime in, publicly, and state that they have
thought about and tested the ABI changes and that gdb still works on
patched kernels with and without FSGSBASE enabled. I realize that there
were all kinds of discussions, but they were all quite theoretical, and
I think that the actual patches need to be considered by people who
understand the concerns. Specific test cases would be nice, too."

What's the state of this?

Thanks,

tglx