Re: [PATCH v7 4/5] efi: Load efi_secret module if EFI secret area is populated

From: Gerd Hoffmann
Date: Wed Feb 02 2022 - 03:47:43 EST


On Tue, Feb 01, 2022 at 12:44:12PM +0000, Dov Murik wrote:
> If the efi_secret module is built, register a late_initcall in the EFI
> driver which checks whether the EFI secret area is available and
> populated, and then requests to load the efi_secret module.

> + area = memremap(efi.coco_secret, sizeof(*area), MEMREMAP_WB);
> + if (!area) {
> + pr_err("Failed to map confidential computing secret area descriptor\n");
> + return -ENOMEM;
> + }
> + if (!area->base_pa || area->size < sizeof(*header_guid))
> + goto unmap_desc;
> +
> + header_guid = (void __force *)ioremap_encrypted(area->base_pa, sizeof(*header_guid));
> + if (!header_guid) {
> + pr_err("Failed to map secret area\n");
> + ret = -ENOMEM;
> + goto unmap_desc;
> + }
> + if (efi_guidcmp(*header_guid, EFI_SECRET_TABLE_HEADER_GUID))
> + goto unmap_encrypted;

Why these sanity checks are here and not in the efi_secret module?

take care,
Gerd