Re: [PATCH] x86: efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store

From: Ingo Molnar
Date: Tue Feb 13 2018 - 13:07:18 EST



* Jia-Ju Bai <baijiaju1990@xxxxxxxxx> wrote:

> The function kzalloc here is not called in atomic context.
> If nonblocking in efi_query_variable_store is true,
> namely it is in atomic context, efi_query_variable_store will return before
> this kzalloc is called.
> Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
>
> This is found by a static analysis tool named DCNS written by myself.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> ---
> arch/x86/platform/efi/quirks.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index 8a99a2e..b6dcb52 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -177,7 +177,7 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size,
> * that by attempting to use more space than is available.
> */
> unsigned long dummy_size = remaining_size + 1024;
> - void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
> + void *dummy = kzalloc(dummy_size, GFP_KERNEL);

Looks good to me!

Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks,

Ingo