Re: [PATCH 1/1] efi_loader: remove efi_disk_is_system_part()

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

Heinrich,

On Sat, Mar 05, 2022 at 12:51:00AM +0100, Heinrich Schuchardt wrote:
> The block IO protocol may be installed on any handle. We should make
> no assumption about the structure the handle points to.
> 
> efi_disk_is_system_part() makes an illegal widening cast from a handle
> to a struct efi_disk_obj. Remove the function.

NAK.
If this is a problem, please fix the function rather than remove it.

> As side effect capsules might be read from non-ESP partitions.

UEFI specification requires that capsules be loaded from ESP.

-Takahiro Akashi

> 
> Fixes: Fixes: 41fd506842c2 ("efi_loader: disk: add efi_disk_is_system_part()")
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
>  include/efi_loader.h         |  2 --
>  lib/efi_loader/efi_capsule.c |  4 +++-
>  lib/efi_loader/efi_disk.c    | 29 -----------------------------
>  3 files changed, 3 insertions(+), 32 deletions(-)
> 
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index e390d323a9..5ac736ebce 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -539,8 +539,6 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
>  int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
>  			       const char *if_typename, int diskid,
>  			       const char *pdevname);
> -/* Check if it is EFI system partition */
> -bool efi_disk_is_system_part(efi_handle_t handle);
>  /* Called by bootefi to make GOP (graphical) interface available */
>  efi_status_t efi_gop_register(void);
>  /* Called by bootefi to make the network interface available */
> diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
> index 613b531b82..2e7474a5d0 100644
> --- a/lib/efi_loader/efi_capsule.c
> +++ b/lib/efi_loader/efi_capsule.c
> @@ -684,7 +684,9 @@ static bool device_is_present_and_system_part(struct efi_device_path *dp)
>  	if (!handle)
>  		return false;
>  
> -	return efi_disk_is_system_part(handle);
> +	/* TODO: add system partition check */
> +
> +	return true;
>  }
>  
>  /**
> diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
> index 45127d1768..97223537a1 100644
> --- a/lib/efi_loader/efi_disk.c
> +++ b/lib/efi_loader/efi_disk.c
> @@ -587,32 +587,3 @@ efi_status_t efi_disk_register(void)
>  
>  	return EFI_SUCCESS;
>  }
> -
> -/**
> - * efi_disk_is_system_part() - check if handle refers to an EFI system partition
> - *
> - * @handle:	handle of partition
> - *
> - * Return:	true if handle refers to an EFI system partition
> - */
> -bool efi_disk_is_system_part(efi_handle_t handle)
> -{
> -	struct efi_handler *handler;
> -	struct efi_disk_obj *diskobj;
> -	struct disk_partition info;
> -	efi_status_t ret;
> -	int r;
> -
> -	/* check if this is a block device */
> -	ret = efi_search_protocol(handle, &efi_block_io_guid, &handler);
> -	if (ret != EFI_SUCCESS)
> -		return false;
> -
> -	diskobj = container_of(handle, struct efi_disk_obj, header);
> -
> -	r = part_get_info(diskobj->desc, diskobj->part, &info);
> -	if (r)
> -		return false;
> -
> -	return !!(info.bootable & PART_EFI_SYSTEM_PARTITION);
> -}
> -- 
> 2.34.1
>