4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Cohen, Eugene <eugene@xxxxxx>
commit 540f4c0e894f7e46a66dfa424b16424cbdc12c38 upstream.
The UEFI Specification permits Graphics Output Protocol (GOP) instances
without direct framebuffer access. This is indicated in the Mode structure
with a PixelFormat enumeration value of PIXEL_BLT_ONLY. Given that the
kernel does not know how to drive a Blt() only framebuffer (which is only
permitted before ExitBootServices() anyway), we should disregard such
framebuffers when looking for a GOP instance that is suitable for use as
the boot console.
So modify the EFI GOP initialization to not use a PIXEL_BLT_ONLY instance,
preventing attempts later in boot to use an invalid screen_info.lfb_base
address.
Signed-off-by: Eugene Cohen <eugene@xxxxxx>
[ Moved the Blt() only check into the loop and clarified that Blt() only GOPs are unusable by the kernel. ]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: leif.lindholm@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: lorenzo.pieralisi@xxxxxxx
Fixes: 9822504c1fa5 ("efifb: Enable the efi-framebuffer platform driver ...")
Link: http://lkml.kernel.org/r/20170404152744.26687-2-ard.biesheuvel@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/firmware/efi/libstub/gop.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -149,7 +149,8 @@ setup_gop32(efi_system_table_t *sys_tabl
status = __gop_query32(sys_table_arg, gop32, &info, &size,
¤t_fb_base);
- if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
+ if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+ info->pixel_format != PIXEL_BLT_ONLY) {
/*
* Systems that use the UEFI Console Splitter may
* provide multiple GOP devices, not all of which are
@@ -266,7 +267,8 @@ setup_gop64(efi_system_table_t *sys_tabl
status = __gop_query64(sys_table_arg, gop64, &info, &size,
¤t_fb_base);
- if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
+ if (status == EFI_SUCCESS && (!first_gop || conout_found) &&
+ info->pixel_format != PIXEL_BLT_ONLY) {
/*
* Systems that use the UEFI Console Splitter may
* provide multiple GOP devices, not all of which are
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