Re: [PATCH v2 1/2] Add support for arm64 to carry ima measurement log in kexec_file_load

[Sasha Levin]

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@xxxxxxxxxxxxxxxxxxx>
> ---
> 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 ?

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

$ 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