x86/kasan: Map shadow for percpu pages on demand

mainline inclusion
from mainline-v6.2-rc1
commit 3f148f33
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6C6UC
CVE: CVE-2023-0597

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3f148f3318140035e87decc1214795ff0755757b



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

KASAN maps shadow for the entire CPU-entry-area:
  [CPU_ENTRY_AREA_BASE, CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_MAP_SIZE]

This will explode once the per-cpu entry areas are randomized since it
will increase CPU_ENTRY_AREA_MAP_SIZE to 512 GB and KASAN fails to
allocate shadow for such big area.

Fix this by allocating KASAN shadow only for really used cpu entry area
addresses mapped by cea_map_percpu_pages()

Thanks to the 0day folks for finding and reporting this to be an issue.

[ dhansen: tweak changelog since this will get committed before peterz's
	   actual cpu-entry-area randomization ]

Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Yujie Liu <yujie.liu@intel.com>
Cc: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202210241508.2e203c3d-yujie.liu@intel.com


Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>