[U-Boot] efi_loader: Allow width smaller than buffer stride in efi_gop Blt()

[Heinrich Schuchardt]

On 03/14/2018 04:31 AM, Ivan Gorinov wrote:
> Current implementation of Blt() in EFI_GRAPHICS_OUTPUT_PROTOCOL
> assumes the memory buffer stride (number of bytes in a row)
> always matches the rectangle Width, ignoring non-zero Delta.
> 
> Signed-off-by: Ivan Gorinov <ivan.gorinov at intel.com>
> ---
>  lib/efi_loader/efi_gop.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/efi_loader/efi_gop.c b/lib/efi_loader/efi_gop.c
> index 3caddd5..362065b 100644
> --- a/lib/efi_loader/efi_gop.c
> +++ b/lib/efi_loader/efi_gop.c
> @@ -64,6 +64,7 @@ efi_status_t EFIAPI gop_blt(struct efi_gop *this, void *buffer,
>  {
>  	struct efi_gop_obj *gopobj = container_of(this, struct efi_gop_obj, ops);
>  	int i, j, line_len16, line_len32;
> +	int buffer_stride;
>  	void *fb;
>  
>  	EFI_ENTRY("%p, %p, %u, %zu, %zu, %zu, %zu, %zu, %zu, %zu", this,
> @@ -72,6 +73,11 @@ efi_status_t EFIAPI gop_blt(struct efi_gop *this, void *buffer,
>  	if (operation != EFI_BLT_BUFFER_TO_VIDEO)
>  		return EFI_EXIT(EFI_INVALID_PARAMETER);
>  
> +	if (delta == 0)
> +		buffer_stride = width * sizeof(u32);
> +	else
> +		buffer_stride = delta;
> +
>  	fb = gopobj->fb;
>  	line_len16 = gopobj->info.width * sizeof(u16);
>  	line_len32 = gopobj->info.width * sizeof(u32);
> @@ -87,7 +93,7 @@ efi_status_t EFIAPI gop_blt(struct efi_gop *this, void *buffer,
>  		for (i = 0; i < height; i++) {
>  			u32 *dest = fb + ((i + dy)  * line_len32) +
>  					 (dx * sizeof(u32));
> -			u32 *src = buffer + ((i + sy)  * line_len32) +
> +			u32 *src = buffer + ((i + sy) * buffer_stride) +
>  					 (sx * sizeof(u32));
>  
>  			/* Same color format, just memcpy */
> @@ -102,7 +108,7 @@ efi_status_t EFIAPI gop_blt(struct efi_gop *this, void *buffer,
>  		for (i = 0; i < height; i++) {
>  			u16 *dest = fb + ((i + dy)  * line_len16) +
>  					 (dx * sizeof(u16));
> -			u32 *src = buffer + ((i + sy)  * line_len32) +
> +			u32 *src = buffer + ((i + sy) * buffer_stride) +

If delta cannot be divided by 4 a misaligned access error will occur on
arm64.

Best regards

Heinrich

>  					 (sx * sizeof(u32));
>  
>  			/* Convert from rgb888 to rgb565 */
>