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 <8b8c0b70-c7ab-33f3-b66c-9ea03388497b@linux.microsoft.com>
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From:   Thiago Jung Bauermann <bauerman@linux.ibm.com>
To:     Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Cc:     Mimi Zohar <zohar@linux.ibm.com>, robh@kernel.org,
        takahiro.akashi@linaro.org, gregkh@linuxfoundation.org,
        will@kernel.org, joe@perches.com, catalin.marinas@arm.com,
        mpe@ellerman.id.au, sfr@canb.auug.org.au, james.morse@arm.com,
        sashal@kernel.org, benh@kernel.crashing.org,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] of: error: 'const struct kimage' has no member named
 'arch'
In-reply-to: <8b8c0b70-c7ab-33f3-b66c-9ea03388497b@linux.microsoft.com>
Date:   Thu, 18 Feb 2021 22:13:23 -0300
Message-ID: <87k0r4yi4s.fsf@manicouagan.localdomain>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk


Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:

> On 2/18/21 4:07 PM, Mimi Zohar wrote:
>
> Hi Mimi,
>
>> On Thu, 2021-02-18 at 14:33 -0800, Lakshmi Ramasubramanian wrote:
>>> of_kexec_alloc_and_setup_fdt() defined in drivers/of/kexec.c builds
>>> a new device tree object that includes architecture specific data
>>> for kexec system call.  This should be defined only if the architecture
>>> being built defines kexec architecture structure "struct kimage_arch".
>>>
>>> Define a new boolean config OF_KEXEC that is enabled if
>>> CONFIG_KEXEC_FILE and CONFIG_OF_FLATTREE are enabled, and
>>> the architecture is arm64 or powerpc64.  Build drivers/of/kexec.c
>>> if CONFIG_OF_KEXEC is enabled.
>>>
>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>>> Fixes: 33488dc4d61f ("of: Add a common kexec FDT setup function")
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> ---
>>>   drivers/of/Kconfig  | 6 ++++++
>>>   drivers/of/Makefile | 7 +------
>>>   2 files changed, 7 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
>>> index 18450437d5d5..f2e8fa54862a 100644
>>> --- a/drivers/of/Kconfig
>>> +++ b/drivers/of/Kconfig
>>> @@ -100,4 +100,10 @@ config OF_DMA_DEFAULT_COHERENT
>>>   	# arches should select this if DMA is coherent by default for OF devices
>>>   	bool
>>>   +config OF_KEXEC
>>> +	bool
>>> +	depends on KEXEC_FILE
>>> +	depends on OF_FLATTREE
>>> +	default y if ARM64 || PPC64
>>> +
>>>   endif # OF
>>> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
>>> index c13b982084a3..287579dd1695 100644
>>> --- a/drivers/of/Makefile
>>> +++ b/drivers/of/Makefile
>>> @@ -13,11 +13,6 @@ obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
>>>   obj-$(CONFIG_OF_RESOLVE)  += resolver.o
>>>   obj-$(CONFIG_OF_OVERLAY) += overlay.o
>>>   obj-$(CONFIG_OF_NUMA) += of_numa.o
>>> -
>>> -ifdef CONFIG_KEXEC_FILE
>>> -ifdef CONFIG_OF_FLATTREE
>>> -obj-y	+= kexec.o
>>> -endif
>>> -endif
>>> +obj-$(CONFIG_OF_KEXEC) += kexec.o
>>>     obj-$(CONFIG_OF_UNITTEST) += unittest-data/
>> Is it possible to reuse CONFIG_HAVE_IMA_KEXEC here?
>> 
>
> For ppc64 CONFIG_HAVE_IMA_KEXEC is selected when CONFIG_KEXEC_FILE is enabled.
> So I don't see a problem in reusing CONFIG_HAVE_IMA_KEXEC for ppc.
>
> But for arm64, CONFIG_HAVE_IMA_KEXEC is enabled in the final patch in the patch
> set (the one for carrying forward IMA log across kexec for arm64). arm64 calls
> of_kexec_alloc_and_setup_fdt() prior to enabling CONFIG_HAVE_IMA_KEXEC and hence
> breaks the build for arm64.

One problem is that I believe that this patch won't placate the robot,
because IIUC it generates config files at random and this change still
allows hppa and s390 to enable CONFIG_OF_KEXEC.

Perhaps a new CONFIG_HAVE_KIMAGE_ARCH option? Not having that option
would still allow building kexec.o, but would be used inside kexec.c to
avoid accessing kimage.arch members.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center