[PATCH] efi_loader: capsule: detect possible ESP device path

[Heinrich Schuchardt]

On 5/8/24 13:24, Weizhao Ouyang wrote:
> When using CapsuleApp to execute on-disk update, it will choose the
> first boot option as BootNext entry to perform the capsule update after
> a reboot. But auto-generate boot option will ignore the logical
> partition which might be an ESP, thus it could not find the capsule
> file.
>
> Align with the EDK II, detect the possible ESP device path by expanding
> the media path.

Hello Wheizhoa,

 From the description I would not know how to reproduce the problem you
face.

Could you, please, provide an example (including disk image and capsule)
for QEMU and describe expected and observed behavior.

We should add a CI test case covering the observed bug.

>
> Fixes: f86fba8adbf3 ("efi_loader: auto-generate boot option for each blkio device")
> Signed-off-by: Weizhao Ouyang <o451686892 at gmail.com>
> ---
>   include/efi_loader.h          |   6 ++
>   lib/efi_loader/efi_boottime.c |  15 ++---
>   lib/efi_loader/efi_capsule.c  | 110 +++++++++++++++++++++++++++++++++-
>   3 files changed, 118 insertions(+), 13 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 9600941aa327..9d78fa936701 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -683,6 +683,12 @@ efi_status_t efi_protocol_open(struct efi_handler *handler,
>   			       void **protocol_interface, void *agent_handle,
>   			       void *controller_handle, uint32_t attributes);
>
> +/* Connect drivers to controller */
> +efi_status_t EFIAPI efi_connect_controller(efi_handle_t controller_handle,
> +					   efi_handle_t *driver_image_handle,
> +					   struct efi_device_path *remain_device_path,
> +					   bool recursive);
> +
>   /* Install multiple protocol interfaces */
>   efi_status_t EFIAPI
>   efi_install_multiple_protocol_interfaces(efi_handle_t *handle, ...);
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 1951291747cd..2c86d78208b2 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -103,12 +103,6 @@ static efi_status_t EFIAPI efi_disconnect_controller(
>   					efi_handle_t driver_image_handle,
>   					efi_handle_t child_handle);
>
> -static
> -efi_status_t EFIAPI efi_connect_controller(efi_handle_t controller_handle,
> -					   efi_handle_t *driver_image_handle,
> -					   struct efi_device_path *remain_device_path,
> -					   bool recursive);
> -
>   /* Called on every callback entry */
>   int __efi_entry_check(void)
>   {
> @@ -3670,11 +3664,10 @@ static efi_status_t efi_connect_single_controller(
>    *
>    * Return: status code
>    */
> -static efi_status_t EFIAPI efi_connect_controller(
> -			efi_handle_t controller_handle,
> -			efi_handle_t *driver_image_handle,
> -			struct efi_device_path *remain_device_path,
> -			bool recursive)
> +efi_status_t EFIAPI efi_connect_controller(efi_handle_t controller_handle,
> +					   efi_handle_t *driver_image_handle,
> +					   struct efi_device_path *remain_device_path,
> +					   bool recursive)
>   {
>   	efi_status_t r;
>   	efi_status_t ret = EFI_NOT_FOUND;
> diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
> index de0d49ebebda..919e3cba071b 100644
> --- a/lib/efi_loader/efi_capsule.c
> +++ b/lib/efi_loader/efi_capsule.c
> @@ -922,6 +922,105 @@ static bool device_is_present_and_system_part(struct efi_device_path *dp)
>   	return true;
>   }
>
> +/**
> + * get_esp_from_boot_option_file_path - get the expand device path
> + *
> + * Get a possible efi system partition by expanding a boot option
> + * file path.
> + *
> + * @boot_dev	The device path pointing to a boot option
> + * Return:	The full ESP device path or NULL if fail
> + */
> +static struct efi_device_path *get_esp_from_boot_option_file_path(struct efi_device_path *boot_dev)
> +{
> +	efi_status_t ret = EFI_SUCCESS;
> +	efi_handle_t handle;
> +	struct efi_device_path *dp = boot_dev;
> +	struct efi_device_path *full_path = NULL;
> +
> +	ret = EFI_CALL(efi_locate_device_path(&efi_simple_file_system_protocol_guid,
> +					      &dp,
> +					      &handle));
> +	if (ret != EFI_SUCCESS)
> +		ret = EFI_CALL(efi_locate_device_path(&efi_block_io_guid, &dp, &handle));
> +
> +	/* Expand Media Device Path */
> +	if (ret == EFI_SUCCESS && EFI_DP_TYPE(dp, END, END)) {
> +		struct efi_device_path *temp_dp;
> +		struct efi_block_io *block_io;
> +		void *buffer;
> +		efi_handle_t *simple_file_system_handle;
> +		efi_uintn_t number_handles, index;
> +		u32 size;
> +		u32 temp_size;
> +
> +		temp_dp = boot_dev;
> +		ret = EFI_CALL(efi_locate_device_path(&efi_simple_file_system_protocol_guid,
> +						      &temp_dp,
> +						      &handle));
> +		/*
> +		 * For device path pointing to simple file system, it only expands to one
> +		 * full path
> +		 */
> +		if (ret == EFI_SUCCESS && EFI_DP_TYPE(temp_dp, END, END)) {
> +			if (device_is_present_and_system_part(temp_dp))
> +				return temp_dp;
> +		}
> +
> +		/*
> +		 * For device path only pointing to the removable device handle, try to
> +		 * search all its children handles
> +		 */
> +		ret = EFI_CALL(efi_locate_device_path(&efi_block_io_guid, &temp_dp, &handle));
> +		EFI_CALL(efi_connect_controller(handle, NULL, NULL, true));

Which driver do you expect to connect here?

> +
> +		/* Align with edk2, issue a dummy read to the device to check the device change */
> +		ret = EFI_CALL(efi_handle_protocol(handle, &efi_block_io_guid, (void **)&block_io));
> +		if (ret == EFI_SUCCESS) {
> +			buffer = memalign(block_io->media->io_align, block_io->media->block_size);
> +			if (buffer) {
> +				ret = EFI_CALL(block_io->read_blocks(block_io,
> +								     block_io->media->media_id,
> +								     0,
> +								     block_io->media->block_size,
> +								     buffer));
> +				free(buffer);
> +			} else {
> +				return full_path;
> +			}
> +		} else {
> +			return full_path;
> +		}
> +
> +		/* detect the default boot file from removable media */
> +		size = efi_dp_size(boot_dev) - sizeof(struct efi_device_path);
> +		EFI_CALL(efi_locate_handle_buffer(BY_PROTOCOL,
> +						  &efi_simple_file_system_protocol_guid,

If you are looking for an ESP shouldn't you use the ESP GUID to find it?
It is installed on the ESP in efi_status_t efi_disk_add_dev().

Best regards

Heinrich

> +						  NULL,
> +						  &number_handles,
> +						  &simple_file_system_handle));
> +		for (index = 0; index < number_handles; index++) {
> +			EFI_CALL(efi_handle_protocol(simple_file_system_handle[index],
> +						     &efi_guid_device_path,
> +						     (void **)&temp_dp));
> +
> +			log_debug("Search ESP %pD\n", temp_dp);
> +			temp_size = efi_dp_size(temp_dp) - sizeof(struct efi_device_path);
> +			if (size <= temp_size && !memcmp(temp_dp, boot_dev, size)) {
> +				if (device_is_present_and_system_part(temp_dp)) {
> +					efi_free_pool(simple_file_system_handle);
> +					return temp_dp;
> +				}
> +			}
> +		}
> +
> +		if (simple_file_system_handle)
> +			efi_free_pool(simple_file_system_handle);
> +	}
> +
> +	return full_path;
> +}
> +
>   /**
>    * find_boot_device - identify the boot device
>    *
> @@ -938,6 +1037,7 @@ static efi_status_t find_boot_device(void)
>   	int i, num;
>   	struct efi_simple_file_system_protocol *volume;
>   	struct efi_device_path *boot_dev = NULL;
> +	struct efi_device_path *full_path = NULL;
>   	efi_status_t ret;
>
>   	/* find active boot device in BootNext */
> @@ -961,8 +1061,14 @@ static efi_status_t find_boot_device(void)
>   			if (device_is_present_and_system_part(boot_dev)) {
>   				goto found;
>   			} else {
> -				efi_free_pool(boot_dev);
> -				boot_dev = NULL;
> +				full_path = get_esp_from_boot_option_file_path(boot_dev);
> +				if (full_path) {
> +					boot_dev = full_path;
> +					goto found;
> +				} else {
> +					efi_free_pool(boot_dev);
> +					boot_dev = NULL;
> +				}
>   			}
>   		}
>   	}