[PATCH v7] x86/kexec: Carry forward IMA measurement log on kexec

[Mimi Zohar]

On Thu, 2022-06-30 at 08:36 +0000, Jonathan McDowell wrote:
> On kexec file load, the Integrity Measurement Architecture (IMA)
> subsystem may verify the IMA signature of the kernel and initramfs, and
> measure it. The command line parameters passed to the kernel in the
> kexec call may also be measured by IMA.
> 
> A remote attestation service can verify a TPM quote based on the TPM
> event log, the IMA measurement list and the TPM PCR data. This can
> be achieved only if the IMA measurement log is carried over from the
> current kernel to the next kernel across the kexec call.
> 
> PowerPC and ARM64 both achieve this using device tree with a
> "linux,ima-kexec-buffer" node. x86 platforms generally don't make use of
> device tree, so use the setup_data mechanism to pass the IMA buffer to
> the new kernel.
> 
> (Mimi, Baoquan, I haven't included your reviewed-bys because this has
>  changed the section annotations to __init and Boris reasonably enough
>  wants to make sure IMA folk are happy before taking this update.)

FYI, comments like this should be added before the patch changelog
(after the '---' separator).

> 
> Signed-off-by: Jonathan McDowell <noodles at fb.com>
> Link: https://lore.kernel.org/r/YmKyvlF3my1yWTvK@noodles-fedora-PC23Y6EG

Reviewed-by: Mimi Zohar <zohar at linux.ibm.com> # IMA function
definitions