> +static inline void fstate_off(struct task_struct *task,
> + struct pt_regs *regs)
> +{
> + regs->sstatus = (regs->sstatus & ~(SR_FS)) | SR_FS_OFF;
No need for the inner braces here.
> +}
> +
> static inline void fstate_save(struct task_struct *task,
> struct pt_regs *regs)
> {
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index f23794b..e3077ee 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -64,8 +64,16 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
> unsigned long sp)
> {
> regs->sstatus = SR_SPIE;
> - if (has_fpu)
> + if (has_fpu) {
> regs->sstatus |= SR_FS_INITIAL;
> +#ifdef CONFIG_FPU
> + /*
> + * Restore the initial value to the FP register
> + * before starting the user program.
> + */
> + fstate_restore(current, regs);
> +#endif
fstate_restore has a no-op stub for the !CONFIG_FPU case, so the ifdef
here is not needed.
Otherwise this looks good to me:
Reviewed-by: Christoph Hellwig <h...@lst.de>
