On Tue, Apr 30, 2019 at 01:38:52PM +0200, Greg Kroah-Hartman wrote:
commit 12209993e98c5fa1855c467f22a24e3d5b8be205 upstream.
There is one user of __kernel_fpu_begin() and before invoking it, it invokes preempt_disable(). So it could invoke kernel_fpu_begin() right away. The 32bit version of arch_efi_call_virt_setup() and arch_efi_call_virt_teardown() does this already.
The comment above *kernel_fpu*() claims that before invoking __kernel_fpu_begin() preemption should be disabled and that KVM is a good example of doing it. Well, KVM doesn't do that since commit
f775b13eedee2 ("x86,kvm: move qemu/guest FPU switching out to vcpu_run")
so it is not an example anymore.
With EFI gone as the last user of __kernel_fpu_{begin|end}(), both can be made static and not exported anymore.
This is just a cleanup and therefore doesn't seem to satisfy the rules for stable patches per Documentation/process/stable-kernel-rules.rst ("It must fix a real bug that bothers people / fix a problem that causes a build error").
Why is it being queued up for stable and why are the rules disregarded here?
Thanks,
Lukas