mainline inclusion from mainline-v6.17-rc6 commit 397f6d14f9c370e4910e6885294c340f39dedbf5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICYCF4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- In do_migrate_range(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). I can reproduce this issue in qemu after adding delay in memory_failure() BUG: kernel NULL pointer dereference, address: 0000000000000000 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:try_to_unmap_one+0x16a/0xfc0 <TASK> rmap_walk_anon+0xda/0x1f0 try_to_unmap+0x78/0x80 ? __pfx_try_to_unmap_one+0x10/0x10 ? __pfx_folio_not_mapped+0x10/0x10 ? __pfx_folio_lock_anon_vma_read+0x10/0x10 unmap_poisoned_folio+0x60/0x140 do_migrate_range+0x4d1/0x600 ? slab_memory_callback+0x6a/0x190 ? notifier_call_chain+0x56/0xb0 offline_pages+0x3e6/0x460 memory_subsys_offline+0x130/0x1f0 device_offline+0xba/0x110 acpi_bus_offline+0xb7/0x130 acpi_scan_hot_remove+0x77/0x290 acpi_device_hotplug+0x1e0/0x240 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x186/0x340 Besides, do_migrate_range() may be called between memory_failure set hwpoison flag and isolate the folio from lru, so remove WARN_ON(). In other places, unmap_poisoned_folio() is called when the folio is isolated, obey it in do_migrate_range() too. [david@redhat.com: don't abort offlining, fixed typo, add comment] Link: https://lkml.kernel.org/r/3c214dff-9649-4015-840f-10de0e03ebe4@redhat.com Fixes: b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Raghav <kernel@pankajraghav.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: mm/memory_hotplug.c [Many conflicts, fix with same idea.] Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- mm/memory_hotplug.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 4812fb273de8..b464a3ba1d3c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1359,6 +1359,9 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) pfn = page_to_pfn(compound_head(page)) + hpage_nr_pages(page) - 1; + if (!get_page_unless_zero(page)) + continue; + /* * HWPoison pages have elevated reference counts so the migration would * fail on them. It also doesn't make any sense to migrate them in the @@ -1367,18 +1370,20 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * the unmap as the catch all safety net). */ if (PageHWPoison(page)) { - if (WARN_ON(PageLRU(page))) - isolate_lru_page(page); + if (PageTransHuge(page)) + goto page_put; + if (PageLRU(page) && isolate_lru_page(page)) + goto page_put; if (page_mapped(page)) { lock_page(page); try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); unlock_page(page); } +page_put: + put_page(page); continue; } - if (!get_page_unless_zero(page)) - continue; /* * We can skip free pages. And we can deal with pages on * LRU and non-lru movable pages. -- 2.43.0