[PATCH 01/10] ima: implement function to allocate buffer at kexec load

[Mimi Zohar]

Hi Tushar,

On Mon, 2023-07-03 at 14:57 -0700, Tushar Sugandhi wrote:
> IMA does not provide a mechanism to allocate memory for IMA log storage
> during kexec operation.

The IMA measurement list is currently being carried across kexec, so
obviously a buffer is being allocated for it.  IMA not allocating
memory for the measurment list is not the problem statement.  Please
concisely provide the problem statement, explaining why IMA needs to
allocate the buffer.

> The function should handle the scenario where
> the kexec load is called multiple times.

Currently the buffer is being freed with the kexec 'unload'.  With this
patch IMA is allocating a buffer for the measurement list, which needs
to be freed independently of the kexec 'unload'.

> Implement a function to allocate buffer of size kexec_segment_size at
> kexec load.  If the buffer was already allocated, free that buffer and
> reallocate.  Finally, initialihze ima_khdr struct. 
> 
> The patch operates under the assumption that the segment size does not
> change between kexec load and execute.
> 
> Signed-off-by: Tushar Sugandhi <tusharsu at linux.microsoft.com>

-- 
thanks,

Mimib