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Subject: Re: [PATCH v2 1/2] Add support for arm64 to carry ima measurement log
 in kexec_file_load
To:     Sasha Levin <sashal@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-integrity@vger.kernel.org, kexec@lists.infradead.org,
        arnd@arndb.de, jean-philippe@linaro.org, allison@lohutok.net,
        kristina.martsenko@arm.org, yamada.masahiro@socionext.com,
        duwe@lst.de, mark.rutland@arm.com, tglx@linutronix.de,
        takahiro.akashi@linaro.org, james.morse@arm.org,
        catalin.marinas@arm.com, sboyd@kernel.org, bauerman@linux.ibm.com,
        zohar@linux.ibm.com
References: <20191007185943.1828-1-prsriva@linux.microsoft.com>
 <20191007185943.1828-2-prsriva@linux.microsoft.com>
 <20191008212224.GC1396@sasha-vm>
From:   prsriva <prsriva@linux.microsoft.com>
Message-ID: <b4ca20f8-dc8c-7266-de54-8062cf6ac8e3@linux.microsoft.com>
Date:   Wed, 9 Oct 2019 13:49:09 -0700
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On 10/8/19 2:22 PM, Sasha Levin wrote:
> On Mon, Oct 07, 2019 at 11:59:42AM -0700, Prakhar Srivastava wrote:
>> During kexec_file_load, carrying forward the ima measurement log allows
>> a verifying party to get the entire runtime event log since the last
>> full reboot since that is when PCRs were last reset.
>>
>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> ---
>> arch/Kconfig                           |   6 +-
>> arch/arm64/include/asm/ima.h           |  24 +++
>> arch/arm64/include/asm/kexec.h         |   5 +
>> arch/arm64/kernel/Makefile             |   3 +-
>> arch/arm64/kernel/ima_kexec.c          |  78 ++++++++++
>> arch/arm64/kernel/machine_kexec_file.c |   6 +
>> drivers/of/Kconfig                     |   6 +
>> drivers/of/Makefile                    |   1 +
>> drivers/of/of_ima.c                    | 204 +++++++++++++++++++++++++
>> include/linux/of.h                     |  31 ++++
>> 10 files changed, 362 insertions(+), 2 deletions(-)
>> create mode 100644 arch/arm64/include/asm/ima.h
>> create mode 100644 arch/arm64/kernel/ima_kexec.c
>> create mode 100644 drivers/of/of_ima.c
>>
>> diff --git a/arch/Kconfig b/arch/Kconfig
>> index a7b57dd42c26..d53e1596c5b1 100644
>> --- a/arch/Kconfig
>> +++ b/arch/Kconfig
>> @@ -19,7 +19,11 @@ config KEXEC_CORE
>>     bool
>>
>> config HAVE_IMA_KEXEC
>> -    bool
>> +    bool "Carry over IMA measurement log during kexec_file_load() 
>> syscall"
>> +    depends on KEXEC_FILE
>> +    help
>> +      Select this option to carry over IMA measurement log during
>> +      kexec_file_load.
> 
> This change looks very wrong: HAVE_* config symbols are used to indicate
> the availability of certain arch specific capability, rather than act as
> a config option. How does this work with CONFIG_IMA_KEXEC ?
> 
Thanks for pointing this out. My attempt was to move this out of arch 
dependent config. I will fix the CONFIG.

> Also, please, at the very least verify that basic functionality works on
> the architectures we have access to. Trying it on x86:
> 

Let me fix the build issues for other archs.
I have tested these changes for arm64.

> $ make allmodconfig
> scripts/kconfig/conf  --allmodconfig Kconfig
> #
> # No change to .config
> #
> $ make
>   CALL    scripts/checksyscalls.sh
>   CALL    scripts/atomic/check-atomics.sh
>   DESCEND  objtool
>   CC      security/integrity/ima/ima_fs.o
> In file included from security/integrity/ima/ima_fs.c:26:
> security/integrity/ima/ima.h:28:10: fatal error: asm/ima.h: No such file 
> or directory
> #include <asm/ima.h>
>           ^~~~~~~~~~~
> compilation terminated.
> make[3]: *** [scripts/Makefile.build:266: 
> security/integrity/ima/ima_fs.o] Error 1
> make[2]: *** [scripts/Makefile.build:509: security/integrity/ima] Error 2
> make[1]: *** [scripts/Makefile.build:509: security/integrity] Error 2
> make: *** [Makefile:1649: security] Error 2
> 
> -- 
> Thanks,
> Sasha