[U-Boot] [PATCH v2 1/1] efi_loader: unload applications upon Exit()

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

On Tue, May 07, 2019 at 09:13:24PM +0200, Heinrich Schuchardt wrote:
> Implement unloading of images in the Exit() boot services:
> 
> * unload images that are not yet started,
> * unload started applications,
> * unload drivers returning an error.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> v2
> 	Images that are no yet started can be unloaded by calling Exit().
> 	In this case they are not the current image. Move the test for
> 	current down in the code.
> 
> 	A started driver that called Exit() should still be considered a
> 	started image. Exit cannot be called by another image afterwards,
> 	cf. UEFI SCT 2.6 (2017), 3.5.1 Exit(), 5.1.4.5.8 - 5.1.4.5.10.
> ---
>  include/efi_loader.h              |  1 +
>  lib/efi_loader/efi_boottime.c     | 36 +++++++++++++++++++++++++------
>  lib/efi_loader/efi_image_loader.c |  2 ++
>  3 files changed, 33 insertions(+), 6 deletions(-)
> 
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 3b50cd28ef..4e4cffa799 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -234,6 +234,7 @@ struct efi_loaded_image_obj {
>  	struct jmp_buf_data exit_jmp;
>  	EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
>  				     struct efi_system_table *st);
> +	u16 image_type;
>  };
> 
>  /**
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 0385883ded..1ea96dab6c 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -13,6 +13,7 @@
>  #include <linux/libfdt_env.h>
>  #include <u-boot/crc.h>
>  #include <bootm.h>
> +#include <pe.h>
>  #include <watchdog.h>
> 
>  DECLARE_GLOBAL_DATA_PTR;
> @@ -2798,7 +2799,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
>  	 *	 image protocol.
>  	 */
>  	efi_status_t ret;
> -	void *info;
> +	struct efi_loaded_image *loaded_image_protocol;
>  	struct efi_loaded_image_obj *image_obj =
>  		(struct efi_loaded_image_obj *)image_handle;
> 
> @@ -2806,13 +2807,33 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
>  		  exit_data_size, exit_data);
> 
>  	/* Check parameters */
> -	if (image_handle != current_image)
> -		goto out;
>  	ret = EFI_CALL(efi_open_protocol(image_handle, &efi_guid_loaded_image,
> -					 &info, NULL, NULL,
> +					 (void **)&loaded_image_protocol,
> +					 NULL, NULL,
>  					 EFI_OPEN_PROTOCOL_GET_PROTOCOL));
> -	if (ret != EFI_SUCCESS)
> +	if (ret != EFI_SUCCESS) {
> +		ret = EFI_INVALID_PARAMETER;
>  		goto out;
> +	}
> +
> +	/* Unloading of unstarted images */
> +	switch (image_obj->header.type) {
> +	case EFI_OBJECT_TYPE_STARTED_IMAGE:
> +		break;
> +	case EFI_OBJECT_TYPE_LOADED_IMAGE:
> +		efi_delete_image(image_obj, loaded_image_protocol);
> +		ret = EFI_SUCCESS;
> +		goto out;
> +	default:
> +		/* Handle does not refer to loaded image */
> +		ret = EFI_INVALID_PARAMETER;
> +		goto out;
> +	}
> +	/* A started image can only be unloaded it is the last one started. */
> +	if (image_handle != current_image) {
> +		ret = EFI_INVALID_PARAMETER;
> +		goto out;
> +	}
> 
>  	/* Exit data is only foreseen in case of failure. */
>  	if (exit_status != EFI_SUCCESS) {
> @@ -2822,6 +2843,9 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
>  		if (ret != EFI_SUCCESS)
>  			EFI_PRINT("%s: out of memory\n", __func__);
>  	}
> +	if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION ||
> +	    exit_status != EFI_SUCCESS)
> +		efi_delete_image(image_obj, loaded_image_protocol);

No change around efi_delete_image() and "goto" above?

-Takahiro Akashi

>  	/* Make sure entry/exit counts for EFI world cross-overs match */
>  	EFI_EXIT(exit_status);
> @@ -2837,7 +2861,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
> 
>  	panic("EFI application exited");
>  out:
> -	return EFI_EXIT(EFI_INVALID_PARAMETER);
> +	return EFI_EXIT(ret);
>  }
> 
>  /**
> diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
> index f8092b6202..13541cfa7a 100644
> --- a/lib/efi_loader/efi_image_loader.c
> +++ b/lib/efi_loader/efi_image_loader.c
> @@ -273,6 +273,7 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>  		IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
>  		image_base = opt->ImageBase;
>  		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
> +		handle->image_type = opt->Subsystem;
>  		efi_reloc = efi_alloc(virt_size,
>  				      loaded_image_info->image_code_type);
>  		if (!efi_reloc) {
> @@ -288,6 +289,7 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
>  		IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
>  		image_base = opt->ImageBase;
>  		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
> +		handle->image_type = opt->Subsystem;
>  		efi_reloc = efi_alloc(virt_size,
>  				      loaded_image_info->image_code_type);
>  		if (!efi_reloc) {
> --
> 2.20.1
>