Re: [PATCH v12 4/4] arm64: Add IMA log information in kimage used for kexec

From: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
To: zohar@linux.ibm.com, bauerman@linux.ibm.com, robh@kernel.org,
	takahiro.akashi@linaro.org, gregkh@linuxfoundation.org,
	will@kernel.org, catalin.marinas@arm.com, mpe@ellerman.id.au
Cc: james.morse@arm.com, sashal@kernel.org, benh@kernel.crashing.org,
	paulus@samba.org, frowand.list@gmail.com,
	vincenzo.frascino@arm.com, mark.rutland@arm.com,
	dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com,
	pasha.tatashin@soleen.com, allison@lohutok.net,
	masahiroy@kernel.org, bhsharma@redhat.com, mbrugger@suse.com,
	hsinyi@chromium.org, tao.li@vivo.com, christophe.leroy@c-s.fr,
	prsriva@linux.microsoft.com, balajib@linux.microsoft.com,
	linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v12 4/4] arm64: Add IMA log information in kimage used for kexec
Date: Thu, 17 Dec 2020 10:31:13 -0800	[thread overview]
Message-ID: <01514c44-5cac-e2b8-6392-1cc31adb276c@linux.microsoft.com> (raw)
In-Reply-To: <20201217173708.6940-5-nramas@linux.microsoft.com>

On 12/17/20 9:37 AM, Lakshmi Ramasubramanian wrote:
> Address and size of the buffer containing the IMA measurement log need
> to be passed from the current kernel to the next kernel on kexec.
> 

Typo in the email address of James Morse (ARM.com). Sorry about that.
Adding the correct email address.

  -lakshmi

> Any existing "linux,ima-kexec-buffer" property in the device tree
> needs to be removed and its corresponding memory reservation in
> the currently running kernel needs to be freed. The address and
> size of the current kernel's IMA measurement log need to be added
> to the device tree's IMA kexec buffer node and memory for the buffer
> needs to be reserved for the log to be carried over to the next kernel
> on the kexec call.
> 
> Add address and size fields to "struct kimage_arch" for ARM64 platform
> to hold the address and size of the IMA measurement log buffer. Remove
> any existing "linux,ima-kexec-buffer" property in the device tree and
> free the corresponding memory reservation in the currently running
> kernel. Add "linux,ima-kexec-buffer" property to the device tree and
> reserve the memory for storing the IMA log that needs to be passed from
> the current kernel to the next one.
> 
> Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC to indicate
> that the IMA measurement log information is present in the device tree
> for ARM64.
> 
> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
> ---
>   arch/arm64/Kconfig             | 1 +
>   arch/arm64/include/asm/kexec.h | 5 +++++
>   2 files changed, 6 insertions(+)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 1d466addb078..c85d18b1f2fd 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1094,6 +1094,7 @@ config KEXEC
>   config KEXEC_FILE
>   	bool "kexec file based system call"
>   	select KEXEC_CORE
> +	select HAVE_IMA_KEXEC
>   	help
>   	  This is new version of kexec system call. This system call is
>   	  file based and takes file descriptors as system call argument
> diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> index d24b527e8c00..2bd19ccb6c43 100644
> --- a/arch/arm64/include/asm/kexec.h
> +++ b/arch/arm64/include/asm/kexec.h
> @@ -100,6 +100,11 @@ struct kimage_arch {
>   	void *elf_headers;
>   	unsigned long elf_headers_mem;
>   	unsigned long elf_headers_sz;
> +
> +#ifdef CONFIG_IMA_KEXEC
> +	phys_addr_t ima_buffer_addr;
> +	size_t ima_buffer_size;
> +#endif
>   };
>   
>   extern const struct kexec_file_ops kexec_image_ops;
> 