Re: [PATCH V2] LoongArch: Ensure FP/SIMD registers in the core dump file is up to date

[Huacai Chen]

On Sat, Aug 26, 2023 at 11:22 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, Aug 26, 2023 at 10:23:41PM +0800, Huacai Chen wrote:
> > This is a port of commit 379eb01c21795edb4c ("riscv: Ensure the value
> > of FP registers in the core dump file is up to date").
> >
> > The values of FP/SIMD registers in the core dump file come from the
> > thread.fpu. However, kernel saves the FP/SIMD registers only before
> > scheduling out the process. If no process switch happens during the
> > exception handling, kernel will not have a chance to save the latest
> > values of FP/SIMD registers. So it may cause their values in the core
> > dump file incorrect. To solve this problem, force fpr_get()/simd_get()
> > to save the FP/SIMD registers into the thread.fpu if the target task
> > equals the current task.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> > V2: Rename get_fpu_regs() to save_fpu_regs().
>
> What stable tree(s) is this for?
For 5.19+, but before 6.4 we should remove the call site in simd_get()
because that function doesn't exist.

Huacai

>
> thanks,
>
> greg k-h