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SubjectRe: [PATCH v9 6/8] powerpc: Move ima_get_kexec_buffer() and ima_free_kexec_buffer() to ima
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On 12/1/20 3:38 AM, Mimi Zohar wrote:
> Hi Lakshmi,
>
> On Fri, 2020-11-13 at 11:22 -0800, Lakshmi Ramasubramanian wrote:
>> 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 namely
>> "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.
>
> This sentence flows from the previous line. No need for separate
> paragraphs here.

Sure - will update Mimi.

>>
>> 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.
>>
>> 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>
>
> After making the two changes,
>
> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
>
>
>> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
>> index 121de3e04af2..3f0fa2673dd3 100644
>> --- a/security/integrity/ima/ima_kexec.c
>> +++ b/security/integrity/ima/ima_kexec.c
>> @@ -9,9 +9,60 @@
>>
>> #include <linux/seq_file.h>
>> #include <linux/vmalloc.h>
>> +#include <linux/memblock.h>
>> +#include <linux/of.h>
>> #include <linux/kexec.h>
>> +#include <linux/ima.h>
>> #include "ima.h"
>>
>> +/**
>> + * 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.
>> + */
>> +static 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
>> + */
>> +static 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);
>> +}
>> +
>
> Please move these functions, after the ifdef below, before the function
> where they're used.

Will make the above change.

thanks,
-lakshmi

>
>> #ifdef CONFIG_IMA_KEXEC
>> static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
>> unsigned long segment_size)
>

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