Subject: Re: [PATCH v8 3/8] powerpc: detect the trusted boot state of the system

From: Mimi Zohar <[email-masked]>
Date: Sun, 20 Oct 2019 08:48:58 -0400

On Sat, 2019-10-19 at 14:06 -0400, Nayna Jain wrote:
> While secure boot permits only properly verified signed kernels to be
> booted, trusted boot takes a measurement of the kernel image prior to
> boot that can be subsequently compared against good known values via
> attestation services.
> 

Instead of "takes a measurement", either "stores a measurement" or
"calculates the file hash of the kernel image and stores the
measurement prior to boot, that".

> This patch reads the trusted boot state of a PowerNV system. The state
> is used to conditionally enable additional measurement rules in the IMA
> arch-specific policies.
> 
> Signed-off-by: Nayna Jain <[email-masked]>
> ---
>  arch/powerpc/include/asm/secure_boot.h |  6 ++++++
>  arch/powerpc/kernel/secure_boot.c      | 24 ++++++++++++++++++++++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/secure_boot.h b/arch/powerpc/include/asm/secure_boot.h
> index 07d0fe0ca81f..a2ff556916c6 100644
> --- a/arch/powerpc/include/asm/secure_boot.h
> +++ b/arch/powerpc/include/asm/secure_boot.h
> 
> diff --git a/arch/powerpc/kernel/secure_boot.c b/arch/powerpc/kernel/secure_boot.c
> index 99bba7915629..9753470ab08a 100644
> --- a/arch/powerpc/kernel/secure_boot.c
> +++ b/arch/powerpc/kernel/secure_boot.c
> @@ -7,6 +7,17 @@
>  #include <linux/of.h>
>  #include <asm/secure_boot.h>
>  
> +static struct device_node *get_ppc_fw_sb_node(void)
> +{
> +	static const struct of_device_id ids[] = {
> +		{ .compatible = "ibm,secureboot-v1", },
> +		{ .compatible = "ibm,secureboot-v2", },
> +		{},
> +	};
> +

scripts/checkpatch.pl is complaining that secureboot-v1, secureboot-v2 
are not documented in the device tree bindings.

Mimi