On Tue, Jun 18, 2024 at 11:27:27AM +0800, Miaohe Lin wrote: > When I did memory failure tests recently, below panic occurs: > > kernel BUG at include/linux/mm.h:1135! > invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14 > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > Call Trace: > <TASK> > do_shrink_slab+0x14f/0x6a0 > shrink_slab+0xca/0x8c0 > shrink_node+0x2d0/0x7d0 > balance_pgdat+0x33a/0x720 > kswapd+0x1f3/0x410 > kthread+0xd5/0x100 > ret_from_fork+0x2f/0x50 > ret_from_fork_asm+0x1a/0x30 > </TASK> > Modules linked in: mce_inject hwpoison_inject > ---[ end trace 0000000000000000 ]--- > RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0 > RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246 > RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0 > RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492 > R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00 > FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0 > > The root cause is that HWPoison flag will be set for huge_zero_folio > without increasing the folio refcnt. But then unpoison_memory() will > decrease the folio refcnt unexpectedly as it appears like a successfully > hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when > releasing huge_zero_folio. > > Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue. > We're not prepared to unpoison huge_zero_folio yet. > > Link: https://lkml.kernel.org/r/20240516122608.22610-1-linmiaohe@xxxxxxxxxx > Fixes: 478d134e9506 ("mm/huge_memory: do not overkill when splitting huge_zero_page") > Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> > Acked-by: David Hildenbrand <david@xxxxxxxxxx> > Reviewed-by: Yang Shi <shy828301@xxxxxxxxx> > Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> > Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> > Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx> > Cc: Xu Yu <xuyu@xxxxxxxxxxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > (cherry picked from commit fe6f86f4b40855a130a19aa589f9ba7f650423f4) > Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> > --- > mm/memory-failure.c | 7 +++++++ > 1 file changed, 7 insertions(+) > All now queued up, thanks! greg k-h
