From: Ma Wupeng mawupeng1@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB8TSF
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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 page lock must be held before calling try_to_unmap. Add it to fix this problem.
Without page lock, kernel will BUG_ON with the following log:
------------[ cut here ]------------ kernel BUG at include/linux/swapops.h:326! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 55 PID: 59981 Comm: sh Kdump: loaded Tainted: G W OE 5.10.0 #1 pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--) pc : try_to_unmap_one+0xdfc/0x1380 lr : try_to_unmap_one+0x4f4/0x1380 Call trace: try_to_unmap_one+0xdfc/0x1380 rmap_walk_anon+0x150/0x45c rmap_walk+0x50/0xfc try_to_unmap+0x108/0x1b0 do_migrate_range+0x3bc/0x6d0 offline_pages+0x450/0x5b0 memory_subsys_offline+0x4c/0x9c device_offline+0xfc/0x14c state_store+0x98/0x110 dev_attr_store+0x1c/0x40 sysfs_kf_write+0x48/0x70 kernfs_fop_write_iter+0x128/0x1d0 new_sync_write+0xec/0x1a0 vfs_write+0x208/0x2b0 ksys_write+0x70/0x110 __arm64_sys_write+0x20/0x40 invoke_syscall+0x4c/0x124 el0_svc_common.constprop.0+0x140/0x15c do_el0_svc+0x30/0xd0 el0_svc+0x1c/0x2c el0_sync_handler+0xb0/0xb4 el0_sync+0x168/0x180 Code: 17ffffde d1000400 f9400000 3707a240 (d4210000) SMP: stopping secondary CPUs
Fixes: b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Ma Wupeng mawupeng1@huawei.com --- mm/memory_hotplug.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index e49bc4753eca..465100749d2d 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1160,8 +1160,11 @@ int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) if (PageHWPoison(page)) { if (WARN_ON(PageLRU(page))) isolate_lru_page(page); - if (page_mapped(page)) + if (page_mapped(page)) { + lock_page(page); try_to_unmap(page, TTU_IGNORE_MLOCK); + unlock_page(page); + } continue; }