This data is used by smm_region_overlaps_handler(). Callers use this
helper to determine if it's safe to read/write to memory buffers taken
from untrusted input.
coreboot SMI handlers must not be confused into writing over any SMRAM
subregion, which includes the TSEG_STAGE_CACHE and chipset-specific area
(sometimes, IED), not just the handlers.
If stage cache writes were permitted, this could compromise the
integrity of the S3 resume path.
The consequences to overwriting the chipset-specific area are undefined.
Change-Id: Ibd9ed34fcfd77a4236b5cf122747a6718ce9c91f
Signed-off-by: Benjamin Doron <benjamin.doron@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80703
Reviewed-by: Shuo Liu <shuo.liu@intel.com>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
bb1f81271b