Re: [PATCH v10 6/8] powerpc: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to ima

Lakshmi Ramasubramanian
2020-12-07T01:59:33Z

On 12/5/20 1:02 PM, Thiago Jung Bauermann wrote:
>
> Lakshmi Ramasubramanian <nramas@linux.microsoft.com> writes:
>
>> ima_get_kexec_buffer() retrieves the address and size of the buffer
>> used for carrying forward the IMA measurement logs on kexec from
>> the device tree.
>>
>> ima_free_kexec_buffer() removes the chosen node
>> "linux,ima-kexec-buffer" from the device tree, and frees the buffer
>> used for carrying forward the IMA measurement logs on kexec.
>>
>> These functions do not have architecture specific code, but are
>> currently limited to powerpc. Move ima_get_kexec_buffer() and
>> ima_free_kexec_buffer() to ima_kexec.c in IMA so that they are
>> accessible for other architectures as well.
>>
>> With the above change the functions in arch/powerpc/kexec/ima.c are
>> defined only when the kernel config CONFIG_IMA_KEXEC is enabled.
>> Update the Makefile to build arch/powerpc/kexec/ima.c only when
>> CONFIG_IMA_KEXEC is enabled and remove "#ifdef CONFIG_IMA_KEXEC"
>> in arch/powerpc/kexec/ima.c.
>
> Nice.
>
>> Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
>> Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
>> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
>
> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
>
> Just a small nit below:
>
>> ---
>> arch/powerpc/include/asm/ima.h | 3 --
>> arch/powerpc/kexec/Makefile | 7 +---
>> arch/powerpc/kexec/ima.c | 50 -----------------------------
>> security/integrity/ima/ima_kexec.c | 51 ++++++++++++++++++++++++++++++
>> 4 files changed, 52 insertions(+), 59 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/ima.h b/arch/powerpc/include/asm/ima.h
>> index a2fc71bc3b23..d8444d27f0d8 100644
>> --- a/arch/powerpc/include/asm/ima.h
>> +++ b/arch/powerpc/include/asm/ima.h
>> @@ -6,9 +6,6 @@
>>
>> struct kimage;
>>
>> -int ima_get_kexec_buffer(void **addr, size_t *size);
>> -int ima_free_kexec_buffer(void);
>> -
>> #ifdef CONFIG_IMA_KEXEC
>> int arch_ima_add_kexec_buffer(struct kimage *image, unsigned long load_addr,
>> size_t size);
>> diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
>> index 4aff6846c772..f54a9dbff4c8 100644
>> --- a/arch/powerpc/kexec/Makefile
>> +++ b/arch/powerpc/kexec/Makefile
>> @@ -9,12 +9,7 @@ obj-$(CONFIG_PPC32) += relocate_32.o
>>
>> obj-$(CONFIG_KEXEC_FILE) += file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
>>
>> -ifdef CONFIG_HAVE_IMA_KEXEC
>> -ifdef CONFIG_IMA
>> -obj-y += ima.o
>> -endif
>> -endif
>> -
>> +obj-$(CONFIG_IMA_KEXEC) += ima.o
>>
>> # Disable GCOV, KCOV & sanitizers in odd or sensitive code
>> GCOV_PROFILE_core_$(BITS).o := n
>> diff --git a/arch/powerpc/kexec/ima.c b/arch/powerpc/kexec/ima.c
>> index 68017123b07d..bf7084c0c4da 100644
>> --- a/arch/powerpc/kexec/ima.c
>> +++ b/arch/powerpc/kexec/ima.c
>> @@ -13,55 +13,6 @@
>> #include <linux/libfdt.h>
>> #include <asm/ima.h>
>
> With this patch, the following includes become unnecessary and can be
> removed from this file:
>
> #include <linux/of.h>
> #include <linux/memblock.h>
>

Sure - will make this change.

thanks,
-lakshmi

>> -/**
>> - * ima_get_kexec_buffer - get IMA buffer from the previous kernel
>> - * @addr: On successful return, set to point to the buffer contents.
>> - * @size: On successful return, set to the buffer size.
>> - *
>> - * Return: 0 on success, negative errno on error.
>> - */
>> -int ima_get_kexec_buffer(void **addr, size_t *size)
>> -{
>> - int ret;
>> - unsigned long tmp_addr;
>> - size_t tmp_size;
>> -
>> - ret = get_ima_kexec_buffer(NULL, 0, &tmp_addr, &tmp_size);
>> - if (ret)
>> - return ret;
>> -
>> - *addr = __va(tmp_addr);
>> - *size = tmp_size;
>> -
>> - return 0;
>> -}
>> -
>> -/**
>> - * ima_free_kexec_buffer - free memory used by the IMA buffer
>> - */
>> -int ima_free_kexec_buffer(void)
>> -{
>> - int ret;
>> - unsigned long addr;
>> - size_t size;
>> - struct property *prop;
>> -
>> - prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
>> - if (!prop)
>> - return -ENOENT;
>> -
>> - ret = get_ima_kexec_buffer(NULL, 0, &addr, &size);
>> - if (ret)
>> - return ret;
>> -
>> - ret = of_remove_property(of_chosen, prop);
>> - if (ret)
>> - return ret;
>> -
>> - return memblock_free(addr, size);
>> -}
>> -
>> -#ifdef CONFIG_IMA_KEXEC
>> /**
>> * arch_ima_add_kexec_buffer - do arch-specific steps to add the IMA buffer
>> *
>> @@ -154,4 +105,3 @@ int setup_ima_buffer(const struct kimage *image, void *fdt, int chosen_node)
>>
>> return 0;
>> }
>> -#endif /* CONFIG_IMA_KEXEC */
>