Commit d1f92782 authored by Peng Liu's avatar Peng Liu Committed by Zheng Zengkai
Browse files

arm64: Add memmap reserve range check to avoid conflict 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I59AN8


CVE: NA
backport: openEuler-22.03-LTS

--------------------------------

The user specificed memmap-reserve range may overlap in-use memory
region, and users are hard to avoid this due to KASLR. Thus, the
reduplicative memmap-reserve range should be ignored. Furthermore,
to be consistent with INITRD, the range that not in a memory region
will also be ignored.

Fixes: d05cfbd9 ("arm64: Add support for memmap kernel parameters")
Signed-off-by: default avatarPeng Liu <liupeng256@huawei.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 8d3549b9

Documentation/admin-guide/kernel-parameters.txt

+2 −1
Original line number Diff line number Diff line
@@ -2848,7 +2848,8 @@ 
			[KNL,ACPI] Mark specific memory as reserved.

			Region of memory to be reserved is from ss to ss+nn.

			For ARM64, reserved memory must be in the range of

			existed memory.

			existed memory and do not overlap in-use memory region,

			otherwise request will be ignored.

			Example: Exclude memory from 0x18690000-0x1869ffff

			         memmap=64K$0x18690000

			         or

arch/arm64/mm/init.c

+21 −1
Original line number Diff line number Diff line
@@ -298,7 +298,27 @@ static void __init reserve_memmap_regions(void) 
	for (i = 0; i < mbk_memmap_cnt; i++) {

		base = mbk_memmap_regions[i].base;

		size = mbk_memmap_regions[i].size;

		memblock_reserve(base, size);



		if (!memblock_is_region_memory(base, size)) {

			pr_warn("memmap reserve: 0x%08llx - 0x%08llx is not a memory region - ignore\n",

				base, base + size);

			continue;

		}



		if (memblock_is_region_reserved(base, size)) {

			pr_warn("memmap reserve: 0x%08llx - 0x%08llx overlaps in-use memory region - ignore\n",

				base, base + size);

			continue;

		}



		if (memblock_reserve(base, size)) {

			pr_warn("memmap reserve: 0x%08llx - 0x%08llx failed\n",

				base, base + size);

			continue;

		}



		pr_info("memmap reserved: 0x%08llx - 0x%08llx (%lld MB)",

			base, base + size, size >> 20);

		memblock_mark_memmap(base, size);

	}

}