RE: [PATCH] x86/fsgsbase/64: Fix the base write helper functions

From: Bae, Chang Seok
Date: Tue Oct 30 2018 - 13:54:56 EST

> Factor out the code to change index from x86_fsbase_write_cpu() and
> x86_gsbase_write_cpu_inactive(). Now the code is located in
> do_arch_prctl_64().
> The helper functions that purport to write the base register should just write the
> base register only. It shouldn't have magic optimizations to change the index.
> putreg() in ptrace does not write the current task, but a stopped task.

Wm, I just realized that the changelog should also clearly include this:
"While at here, subsequently factor out the read for the current task's base
from x86_fsbase_read_task() and x86_gsbase_read_task() to do_arch_prctl_64()."
Sorry for this. Let me know if you feel it should go as a separate patch.