On Thu, 22 Jul 2021 at 19:53, Valentin Schneider
<valentin.schneider@xxxxxxx> wrote:
>
> Hi folks,
>
> This stems from some more v5.13-rt1 breakage on arm64. This time per-CPU access
> safety isn't sufficient, we really need to keep preemption disabled.
>
> In a happy accident I stumbled on
>
> cba08c5dc6dc ("x86/fpu: Make kernel FPU protection RT friendly")
>
> so I packaged what was done there into some common helpers and plastered them
> over the problematic areas.
>
> Cheers,
> Valentin
>
> Valentin Schneider (3):
> sched/preempt: Introduce preempt_{enable, disable}_bh()
> x86/fpu: Make FPU protection reuse common helper
> arm64/fpsimd: Fix FPSIMD context handling vs PREEMPT_RT
>
Thanks for fixing this.
Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> arch/arm64/kernel/fpsimd.c | 6 ++++--
> arch/x86/include/asm/fpu/api.h | 19 ++-----------------
> include/linux/bottom_half.h | 26 ++++++++++++++++++++++++++
> 3 files changed, 32 insertions(+), 19 deletions(-)
>
> --
> 2.25.1
>
