linux-stable/drivers/firmware/efi/libstub
Cohen, Eugene 540f4c0e89 efi/libstub: Skip GOP with PIXEL_BLT_ONLY format
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@hp.com>
[ 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@linaro.org>
Cc: <stable@vger.kernel.org> # v4.7+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: leif.lindholm@linaro.org
Cc: linux-efi@vger.kernel.org
Cc: lorenzo.pieralisi@arm.com
Fixes: 9822504c1f ("efifb: Enable the efi-framebuffer platform driver ...")
Link: http://lkml.kernel.org/r/20170404152744.26687-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-05 09:20:18 +02:00
..
arm-stub.c efi: Get and store the secure boot status 2017-02-07 10:42:10 +01:00
arm32-stub.c efi/arm/libstub: Make screen_info accessible to the UEFI stub 2016-04-28 11:33:59 +02:00
arm64-stub.c arm64: kaslr: increase randomization granularity 2016-04-28 19:44:15 +01:00
efi-stub-helper.c efi/libstub: Make file I/O chunking x86-specific 2017-02-07 10:42:11 +01:00
efistub.h efi: Deduplicate efi_file_size() / _read() / _close() 2017-02-01 08:45:42 +01:00
fdt.c efi/fdt: Avoid FDT manipulation after ExitBootServices() 2017-02-01 21:17:49 +01:00
gop.c efi/libstub: Skip GOP with PIXEL_BLT_ONLY format 2017-04-05 09:20:18 +02:00
Makefile efi: Get and store the secure boot status 2017-02-07 10:42:10 +01:00
random.c efi/libstub: Make efi_random_alloc() allocate below 4 GB on 32-bit 2016-11-25 07:15:23 +01:00
secureboot.c efi/libstub: Treat missing SecureBoot variable as Secure Boot disabled 2017-03-02 08:11:18 +01:00
string.c arm64/efi: isolate EFI stub from the kernel proper 2015-10-12 16:20:12 +01:00