kernel.git/arch/arm64/kernel/efi-entry.S, branch linux-3.17.yHosts the 0x221E linux distro kernel.
https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-3.17.y2014-11-21T17:23:12Zarm64: efi: Fix stub cache maintenance2014-11-21T17:23:12ZMark Rutland2014-11-13T12:22:01Zurn:sha1:366b6d927d19a7f7e48543354ab1a812be2a11ce
commit 9b0b26580a753d4d6bdd2b8b4ca9a8f3f2d39065 upstream.
While efi-entry.S mentions that efi_entry() will have relocated the
kernel image, it actually means that efi_entry will have placed a copy
of the kernel in the appropriate location, and until this is branched to
at the end of efi_entry.S, all instructions are executed from the
original image.
Thus while the flush in efi_entry.S does ensure that the copy is visible
to noncacheable accesses, it does not guarantee that this is true for
the image instructions are being executed from. This could have
disasterous effects when the MMU and caches are disabled if the image
has not been naturally evicted to the PoC.
Additionally, due to a missing dsb following the ic ialluis, the new
kernel image is not necessarily clean in the I-cache when it is branched
to, with similar potentially disasterous effects.
This patch adds additional flushing to ensure that the currently
executing stub text is flushed to the PoC and is thus visible to
noncacheable accesses. As it is placed after the instructions cache
maintenance for the new image and __flush_dcache_area already contains a
dsb, we do not need to add a separate barrier to ensure completion of
the icache maintenance.
Comments are updated to clarify the situation with regard to the two
images and the maintenance required for both.
Fixes: 3c7f255039a2ad6ee1e3890505caf0d029b22e29
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Joel Schopp <joel.schopp@amd.com>
Reviewed-by: Roy Franz <roy.franz@linaro.org>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: fix el2_setup check of CurrentEL2014-07-04T15:16:52ZMarc Zyngier2014-06-06T13:16:21Zurn:sha1:974c8e450b9327a03453a4a450a2030b1bd42b5f
The CurrentEL system register reports the Current Exception Level
of the CPU. It doesn't say anything about the stack handling, and
yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h.
It works by chance because PSR_MODE_EL2t happens to match the right
bits, but that's otherwise a very bad idea. Just check for the EL
value instead.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: efi: add EFI stub2014-04-30T18:57:04ZMark Salter2014-04-16T02:47:52Zurn:sha1:3c7f255039a2ad6ee1e3890505caf0d029b22e29
This patch adds PE/COFF header fields to the start of the kernel
Image so that it appears as an EFI application to UEFI firmware.
An EFI stub is included to allow direct booting of the kernel
Image.
Signed-off-by: Mark Salter <msalter@redhat.com>
[Add support in PE/COFF header for signed images]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>