From: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Date: Mon, 28 Aug 2023 21:50:09 +0000 (+0200)
Subject: video/efi_gop: Require shadow if PixelBltOnly
X-Git-Tag: grub-2.12~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=34a3adff822a6d136430e631d0a93448b27fac4e;p=thirdparty%2Fgrub.git

video/efi_gop: Require shadow if PixelBltOnly

If the EFI graphics pixel format is PixelBltOnly, we cannot write directly
to the frame buffer. We need the shadow frame buffer which we copy via
the BitBlt operation to the hardware.

If the pixel format is PixelBltOnly and allocation of the shadow frame
buffer fails, we must raise an error to signal that the EFI GOP protocol
is not usable.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/video/efi_gop.c b/grub-core/video/efi_gop.c
index 7247aeea7..9452f5e58 100644
--- a/grub-core/video/efi_gop.c
+++ b/grub-core/video/efi_gop.c
@@ -480,6 +480,10 @@ grub_video_gop_setup (unsigned int width, unsigned int height,
   if (!buffer)
     {
       grub_dprintf ("video", "GOP: couldn't allocate shadow\n");
+
+      if (info->pixel_format == GRUB_EFI_GOT_BLT_ONLY)
+        return grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));
+
       grub_errno = 0;
       grub_video_gop_fill_mode_info (gop->mode->mode, info,
 				     &framebuffer.mode_info);