hwpoison, memory_hotplug: lock folio before unmap hwpoisoned folio

In the Linux kernel, the following vulnerability has been resolved:

hwpoison, memory_hotplug: lock folio before unmap hwpoisoned folio

Commit b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to

be offlined) add page poison checks in do_migrate_range in order to make

offline hwpoisoned page possible by introducing isolate_lru_page and

try_to_unmap for hwpoisoned page. However folio lock must be held before

calling try_to_unmap. Add it to fix this problem.

Warning will be produced if folio is not locked during unmap:

------------[ cut here ]------------

kernel BUG at ./include/linux/swapops.h:400!

Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP

Modules linked in:

CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41

Tainted: [W]=WARN

Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015

pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : try_to_unmap_one+0xb08/0xd3c

lr : try_to_unmap_one+0x3dc/0xd3c

Call trace:

try_to_unmap_one+0xb08/0xd3c (P)

try_to_unmap_one+0x3dc/0xd3c (L)

rmap_walk_anon+0xdc/0x1f8

rmap_walk+0x3c/0x58

try_to_unmap+0x88/0x90

unmap_poisoned_folio+0x30/0xa8

do_migrate_range+0x4a0/0x568

offline_pages+0x5a4/0x670

memory_block_action+0x17c/0x374

memory_subsys_offline+0x3c/0x78

device_offline+0xa4/0xd0

state_store+0x8c/0xf0

dev_attr_store+0x18/0x2c

sysfs_kf_write+0x44/0x54

kernfs_fop_write_iter+0x118/0x1a8

vfs_write+0x3a8/0x4bc

ksys_write+0x6c/0xf8

__arm64_sys_write+0x1c/0x28

invoke_syscall+0x44/0x100

el0_svc_common.constprop.0+0x40/0xe0

do_el0_svc+0x1c/0x28

el0_svc+0x30/0xd0

el0t_64_sync_handler+0xc8/0xcc

el0t_64_sync+0x198/0x19c

Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000)

---[ end trace 0000000000000000 ]---