In kexec_file_load, kaslr-seed property of the current dtb will be deleted
any way before setting a new value if possible. It doesn't matter whether
it exists in the current dtb.

So "ret" should be reset to 0 here.

Fixes: commit 884143f6 ("arm64: kexec_file: add kaslr support")
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This is needed for compilation in some configurations that don't
include it implicitly:

arch/arm64/kernel/machine_kexec_file.c: In function 'arch_kimage_file_post_load_cleanup':
arch/arm64/kernel/machine_kexec_file.c:37:2: error: implicit declaration of function 'vfree'; did you mean 'kvfree'? [-Werror=implicit-function-declaration]

Fixes: 52b2a8af ("arm64: kexec_file: load initrd and device-tree")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

setup_dtb() is a little difficult to read. This is largely because it
duplicates the FDT -> Linux errno conversion for every intermediate
return value, but also because of silly cosmetic things like naming
and formatting.

Given that this is all brand new, refactor the function to get us off on
the right foot.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Adding "kaslr-seed" to dtb enables triggering kaslr, or kernel virtual
address randomization, at secondary kernel boot. We always do this as
it will have no harm on kaslr-incapable kernel.

We don't have any "switch" to turn off this feature directly, but still
can suppress it by passing "nokaslr" as a kernel boot argument.
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[will: Use rng_is_initialized()]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This patch provides kexec_file_ops for "Image"-format kernel. In this
implementation, a binary is always loaded with a fixed offset identified
in text_offset field of its header.

Regarding signature verification for trusted boot, this patch doesn't
contains CONFIG_KEXEC_VERIFY_SIG support, which is to be added later
in this series, but file-attribute-based verification is still a viable
option by enabling IMA security subsystem.

You can sign(label) a to-be-kexec'ed kernel image on target file system
with:
    $ evmctl ima_sign --key /path/to/private_key.pem Image

On live system, you must have IMA enforced with, at least, the following
security policy:
    "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig"

See more details about IMA here:
    https://sourceforge.net/p/linux-ima/wiki/Home/Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

load_other_segments() is expected to allocate and place all the necessary
memory segments other than kernel, including initrd and device-tree
blob (and elf core header for crash).
While most of the code was borrowed from kexec-tools' counterpart,
users may not be allowed to specify dtb explicitly, instead, the dtb
presented by the original boot loader is reused.

arch_kimage_kernel_post_load_cleanup() is responsible for freeing arm64-
specific data allocated in load_other_segments().
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Modify arm64/Kconfig to enable kexec_file_load support.
Signed-off-by: NAKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>