Re: [PATCH] riscv: force __cpu_up_ variables to put in data section

[Greentime Hu]

Zong Li <zong.li@xxxxxxxxxx> æ 2020å4æ30æ éå äå5:53åéï
>
> Put __cpu_up_stack_pointer and __cpu_up_task_pointer in data section.
> Currently, these two variables are put in bss section, there is a
> potential risk that secondary harts get the uninitialized value before
> main hart finishing the bss clearing. In this case, all secondary
> harts would go through the waiting loop and enable the MMU before
> main hart set up the page table.
>
> Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
> ---
>  arch/riscv/kernel/cpu_ops.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/cpu_ops.c b/arch/riscv/kernel/cpu_ops.c
> index c4c33bf02369..0ec22354018c 100644
> --- a/arch/riscv/kernel/cpu_ops.c
> +++ b/arch/riscv/kernel/cpu_ops.c
> @@ -15,8 +15,8 @@
>
>  const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
>
> -void *__cpu_up_stack_pointer[NR_CPUS];
> -void *__cpu_up_task_pointer[NR_CPUS];
> +void *__cpu_up_stack_pointer[NR_CPUS] __section(.data);
> +void *__cpu_up_task_pointer[NR_CPUS] __section(.data);
>
>  extern const struct cpu_operations cpu_ops_sbi;
>  extern const struct cpu_operations cpu_ops_spinwait;

Reviewed-by: Greentime Hu <greentime.hu@xxxxxxxxxx>