The patch titled
Subject: page-flags: fix a crash at SetPageError(THP_SWAP)
has been added to the -mm tree. Its filename is
page-flags-fix-a-crash-at-setpageerrorthp_swap.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/page-flags-fix-a-crash-at-setpageerrorthp_swap.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/page-flags-fix-a-crash-at-setpageerrorthp_swap.patch
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------------------------------------------------------
From: Qian Cai <cai@xxxxxx>
Subject: page-flags: fix a crash at SetPageError(THP_SWAP)
The commit bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped
out") supported writing THP to a swap device but forgot to upgrade an
older commit df8c94d13c7e ("page-flags: define behavior of FS/IO-related
flags on compound pages") which could trigger a crash during THP swapping
out with DEBUG_VM_PGFLAGS=y,
kernel BUG at include/linux/page-flags.h:317!
page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page))
page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c
index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0
compound_pincount:0
anon flags:
0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked)
end_swap_bio_write()
SetPageError(page)
VM_BUG_ON_PAGE(1 && PageCompound(page))
<IRQ>
bio_endio+0x297/0x560
dec_pending+0x218/0x430 [dm_mod]
clone_endio+0xe4/0x2c0 [dm_mod]
bio_endio+0x297/0x560
blk_update_request+0x201/0x920
scsi_end_request+0x6b/0x4b0
scsi_io_completion+0x509/0x7e0
scsi_finish_command+0x1ed/0x2a0
scsi_softirq_done+0x1c9/0x1d0
__blk_mqnterrupt+0xf/0x20
</IRQ>
Fix by checking PF_NO_TAIL in those places instead.
Link: http://lkml.kernel.org/r/20200310235846.1319-1-cai@xxxxxx
Fixes: bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: Qian Cai <cai@xxxxxx>
Acked-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/page-flags.h~page-flags-fix-a-crash-at-setpageerrorthp_swap
+++ a/include/linux/page-flags.h
@@ -311,7 +311,7 @@ static inline int TestClearPage##uname(s
__PAGEFLAG(Locked, locked, PF_NO_TAIL)
PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD)
-PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
+PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL)
PAGEFLAG(Referenced, referenced, PF_HEAD)
TESTCLEARFLAG(Referenced, referenced, PF_HEAD)
__SETPAGEFLAG(Referenced, referenced, PF_HEAD)
_
Patches currently in -mm which might be from cai@xxxxxx are
page-flags-fix-a-crash-at-setpageerrorthp_swap.patch
mm-disable-kcsan-for-kmemleak.patch
mm-swapfile-fix-data-races-in-try_to_unuse.patch
kasan-detect-negative-size-in-memory-operation-function-fix.patch
mm-vmscan-fix-data-races-at-kswapd_classzone_idx.patch
percpu_counter-fix-a-data-race-at-vm_committed_as.patch
mm-frontswap-mark-various-intentional-data-races.patch
mm-page_io-mark-various-intentional-data-races.patch
mm-page_io-mark-various-intentional-data-races-v2.patch
mm-swap_state-mark-various-intentional-data-races.patch
mm-swapfile-fix-and-annotate-various-data-races.patch
mm-swapfile-fix-and-annotate-various-data-races-v2.patch
mm-page_counter-fix-various-data-races-at-memsw.patch
mm-memcontrol-fix-a-data-race-in-scan-count.patch
mm-list_lru-fix-a-data-race-in-list_lru_count_one.patch
mm-mempool-fix-a-data-race-in-mempool_free.patch
mm-util-annotate-an-data-race-at-vm_committed_as.patch
mm-rmap-annotate-a-data-race-at-tlb_flush_batched.patch
mm-annotate-a-data-race-in-page_zonenum.patch
mm-swap-annotate-data-races-for-lru_rotate_pvecs.patch
