[PATCH 12/16] efi_loader: optional pointer for ConvertPointer

[AKASHI Takahiro]

On Fri, Mar 27, 2020 at 06:27:56AM +0100, Heinrich Schuchardt wrote:
> If the EFI_OPTIONAL_PTR is set in DebugDisposition, a NULL pointer does not
> constitute an invalid parameter.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  include/efi_api.h            | 2 ++
>  lib/efi_loader/efi_runtime.c | 6 ++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/include/efi_api.h b/include/efi_api.h
> index 1c40ffc4f5..c56703fc5e 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -250,6 +250,8 @@ struct efi_rt_properties_table {
>  	u32 runtime_services_supported;
>  };
> 
> +#define EFI_OPTIONAL_PTR	0x00000001
> +
>  struct efi_runtime_services {
>  	struct efi_table_hdr hdr;
>  	efi_status_t (EFIAPI *get_time)(struct efi_time *time,
> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> index 67fa693e41..664a0422e2 100644
> --- a/lib/efi_loader/efi_runtime.c
> +++ b/lib/efi_loader/efi_runtime.c
> @@ -511,6 +511,12 @@ efi_convert_pointer(efi_uintn_t debug_disposition, void **address)
>  		ret = EFI_INVALID_PARAMETER;
>  		goto out;
>  	}
> +	if (!*address) {
> +		if (debug_disposition & EFI_OPTIONAL_PTR)
> +			return EFI_SUCCESS;
> +		else
> +			return EFI_INVALID_PARAMETER;
> +	}

In either case, NULL won't be converted.
Is this a behavior UEFI specification expects?
(I haven't found any description there.)

-Takahiro Akashi


>  	for (i = 0; i < efi_descriptor_count; i++) {
>  		struct efi_mem_desc *map = (void *)efi_virtmap +
> --
> 2.25.1
>