ima: define a canonical binary_runtime_measurements list format

ima: define a canonical binary_runtime_measurements list format

The IMA binary_runtime_measurements list is currently in platform native
format.

To allow restoring a measurement list carried across kexec with a
different endianness than the targeted kernel, this patch defines
little-endian as the canonical format.  For big endian systems wanting
to save/restore the measurement list from a system with a different
endianness, a new boot command line parameter named "ima_canonical_fmt"
is defined.

Considerations: use of the "ima_canonical_fmt" boot command line option
will break existing userspace applications on big endian systems
expecting the binary_runtime_measurements list to be in platform native
format.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mimi Zohar <[email protected]>
Acked-by: Dmitry Kasatkin <[email protected]>
Cc: Thiago Jung Bauermann <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Andreas Steffen <[email protected]>
Cc: Josh Sklar <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Stewart Smith <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>