[PATCH 2/3] tpm/kexec: Duplicate TPM measurement log in of-tree for kexec

[Nageswara R Sastry]

> The memory area of the TPM measurement log is currently not properly
> duplicated for carrying it across kexec when an Open Firmware
> Devicetree is used. Therefore, the contents of the log get corrupted.
> Fix this for the kexec_file_load() syscall by allocating a buffer and
> copying the contents of the existing log into it. The new buffer is
> preserved across the kexec and a pointer to it is available when the new
> kernel is started. To achieve this, store the allocated buffer's address
> in the flattened device tree (fdt) under the name linux,tpm-kexec-buffer
> and search for this entry early in the kernel startup before the TPM
> subsystem starts up. Adjust the pointer in the of-tree stored under
> linux,sml-base to point to this buffer holding the preserved log. The
> TPM driver can then read the base address from this entry when making
> the log available.

> Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>

Tested-by: Nageswara R Sastry <rnsastry at linux.ibm.com>
...
> -- 
> 2.35.1