[U-Boot] [PATCH v2 1/2] efi_loader: correctly call images

[Alexander Graf]

On 18.01.18 08:24, Heinrich Schuchardt wrote:
> Avoid a failed assertion when an EFI app calls an EFI app.
> 
> Avoid that the indent level increases when calling 'bootefi hello'
> repeatedly.
> 
> Avoid negative indent level when an EFI app calls an EFI app that
> calls an EFI app (e.g. iPXE loads grub which starts the kernel).
> 
> Return the status code of a loaded image that returns without
> calling the Exit boot service.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  lib/efi_loader/efi_boottime.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 2c5499e0c8..538cc55d20 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -1537,6 +1537,7 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
>  	asmlinkage ulong (*entry)(efi_handle_t image_handle,
>  				  struct efi_system_table *st);
>  	struct efi_loaded_image *info = image_handle;
> +	efi_status_t ret;
>  
>  	EFI_ENTRY("%p, %p, %p", image_handle, exit_data_size, exit_data);
>  	entry = info->reserved;
> @@ -1546,17 +1547,23 @@ static efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
>  	/* call the image! */
>  	if (setjmp(&info->exit_jmp)) {
>  		/* We returned from the child image */
> +#ifdef CONFIG_ARM
> +		/* efi_exit() called efi_restore_gd() */
> +		gd = app_gd;
> +#endif
> +		/* Execute the return part of EFI_CALL */
> +		assert(__efi_entry_check());
> +		debug("%sEFI: %lu returned by started image\n",
> +		      __efi_nesting_dec(),

I don't understand why you need to decrease the nesting level here after
the other rework. You're now calling EFI_ENTRY/EFI_EXIT in all normal
paths when going in/out of an application, no?


Alex

> +		      (unsigned long)((uintptr_t)info->exit_status &
> +				      ~EFI_ERROR_MASK));
>  		return EFI_EXIT(info->exit_status);
>  	}
>  
> -	__efi_nesting_dec();
> -	__efi_exit_check();
> -	entry(image_handle, &systab);
> -	__efi_entry_check();
> -	__efi_nesting_inc();
> +	ret = EFI_CALL(entry(image_handle, &systab));
>  
>  	/* Should usually never get here */
> -	return EFI_EXIT(EFI_SUCCESS);
> +	return EFI_EXIT(ret);
>  }
>  
>  /*
> @@ -1593,7 +1600,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
>  		  exit_data_size, exit_data);
>  
>  	/* Make sure entry/exit counts for EFI world cross-overs match */
> -	__efi_exit_check();
> +	EFI_EXIT(exit_status);
>  
>  	/*
>  	 * But longjmp out with the U-Boot gd, not the application's, as
>