Commit 2e9f46ee authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Borislav Petkov (AMD)
Browse files

efi/x86: Get full memory map in allocate_e820() 



Currently allocate_e820() is only interested in the size of map and size
of memory descriptor to determine how many e820 entries the kernel
needs.

UEFI Specification version 2.9 introduces a new memory type --
unaccepted memory. To track unaccepted memory, the kernel needs to
allocate a bitmap. The size of the bitmap is dependent on the maximum
physical address present in the system. A full memory map is required to
find the maximum address.

Modify allocate_e820() to get a full memory map.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230606142637.5171-3-kirill.shutemov@linux.intel.com
parent dcdfdd40

drivers/firmware/efi/libstub/x86-stub.c

+11 −15
Original line number Diff line number Diff line
@@ -681,28 +681,24 @@ static efi_status_t allocate_e820(struct boot_params *params, 
				  struct setup_data **e820ext,

				  u32 *e820ext_size)

{

	unsigned long map_size, desc_size, map_key;

	struct efi_boot_memmap *map;

	efi_status_t status;

	__u32 nr_desc, desc_version;

	__u32 nr_desc;



	/* Only need the size of the mem map and size of each mem descriptor */

	map_size = 0;

	status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,

			     &desc_size, &desc_version);

	if (status != EFI_BUFFER_TOO_SMALL)

		return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;



	nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;

	status = efi_get_memory_map(&map, false);

	if (status != EFI_SUCCESS)

		return status;



	if (nr_desc > ARRAY_SIZE(params->e820_table)) {

		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);

	nr_desc = map->map_size / map->desc_size;

	if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {

		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +

				 EFI_MMAP_NR_SLACK_SLOTS;



		status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);

		if (status != EFI_SUCCESS)

			return status;

	}



	return EFI_SUCCESS;

	efi_bs_call(free_pool, map);

	return status;

}



struct exit_boot_struct {