[PATCH v2] riscv: cacheinfo: Fix using smp_processor_id() in preemptible

[Palmer Dabbelt]

On Tue, 22 Dec 2020 08:01:52 PST (-0800), wangkefeng.wang at huawei.com wrote:
> Use raw_smp_processor_id instead of smp_processor_id() to fix warning,
>
> BUG: using smp_processor_id() in preemptible [00000000] code: init/1
> caller is debug_smp_processor_id+0x1c/0x26
> CPU: 0 PID: 1 Comm: init Not tainted 5.10.0-rc4 #211
> Call Trace:
>   walk_stackframe+0x0/0xaa
>   show_stack+0x32/0x3e
>   dump_stack+0x76/0x90
>   check_preemption_disabled+0xaa/0xac
>   debug_smp_processor_id+0x1c/0x26
>   get_cache_size+0x18/0x68
>   load_elf_binary+0x868/0xece
>   bprm_execve+0x224/0x498
>   kernel_execve+0xdc/0x142
>   run_init_process+0x90/0x9e
>   try_to_run_init_process+0x12/0x3c
>   kernel_init+0xb4/0xf8
>   ret_from_exception+0x0/0xc
>
> The issue is found when CONFIG_DEBUG_PREEMPT enabled.
>
> Reviewed-by: Atish Patra <atish.patra at wdc.com>
> Tested-by: Atish Patra <atish.patra at wdc.com>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
> ---
>  arch/riscv/kernel/cacheinfo.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
> index de59dd457b41..9b5a8a347434 100644
> --- a/arch/riscv/kernel/cacheinfo.c
> +++ b/arch/riscv/kernel/cacheinfo.c
> @@ -26,7 +26,7 @@ cache_get_priv_group(struct cacheinfo *this_leaf)
>
>  static struct cacheinfo *get_cacheinfo(u32 level, enum cache_type type)
>  {
> -	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(smp_processor_id());
> +	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(raw_smp_processor_id());
>  	struct cacheinfo *this_leaf;
>  	int index;

Thanks, this is on fixes with a comment about why we need the raw_.