On 9/19/2023 2:25 PM, Matthew Wilcox wrote:
On Tue, Sep 19, 2023 at 08:24:02AM +0200, Mirsad Todorovac wrote:
Hi,
The usual setup: vanilla torvalds tree kernel 6.6-rc2, Ubuntu 22.04 LTS.
KCSAN had found a number of data-races in the btrfs implementation.
This isn't btrfs; it's the same as the race reported on August 18th.
https://lore.kernel.org/linux-mm/06645d2b-a964-1c4c-15cf-42ccc6c6e19b@xxxxxxxxxxxx/
Hi,
Thank you for your insight.
Yes, I see that it is the old report ... Mea culpa. But now I had more
instances and perhaps they can give more insight?
I must admit that I am a bit perplexed with the KCSAN reports data races
in hundreds.
Most of them were connected with the find_*_bit() family of functions
and ACPI. Eliminating those races might fix like 80% of the KCSAN
reported bugs.
Best regards,
Mirsad Todorovac
It is not clear whether this can lead to the corruption of data on the storage media.
Please find the complete KCSAN dmesg report attached.
Best regards,
Mirsad Todorovac
2149.512903] ==================================================================
[ 2149.512933] BUG: KCSAN: data-race in xas_clear_mark / xas_find_marked
[ 2149.512967] write to 0xffff8881ab9d2468 of 8 bytes by interrupt on cpu 27:
[ 2149.512984] xas_clear_mark (/home/marvin/linux/kernel/torvalds2/./arch/x86/include/asm/bitops.h:178 /home/marvin/linux/kernel/torvalds2/./include/asm-generic/bitops/instrumented-non-atomic.h:115 /home/marvin/linux/kernel/torvalds2/lib/xarray.c:102 /home/marvin/linux/kernel/torvalds2/lib/xarray.c:914)
[ 2149.513002] __xa_clear_mark (/home/marvin/linux/kernel/torvalds2/lib/xarray.c:1929)
[ 2149.513019] __folio_end_writeback (/home/marvin/linux/kernel/torvalds2/mm/page-writeback.c:2960)
[ 2149.513039] folio_end_writeback (/home/marvin/linux/kernel/torvalds2/mm/filemap.c:1613)
[ 2149.513053] end_page_writeback (/home/marvin/linux/kernel/torvalds2/mm/folio-compat.c:28)
[ 2149.513073] btrfs_page_clear_writeback (/home/marvin/linux/kernel/torvalds2/fs/btrfs/subpage.c:646) btrfs
[ 2149.513829] end_bio_extent_writepage (/home/marvin/linux/kernel/torvalds2/./include/linux/bio.h:84 /home/marvin/linux/kernel/torvalds2/fs/btrfs/extent_io.c:468) btrfs
[ 2149.514481] __btrfs_bio_end_io (/home/marvin/linux/kernel/torvalds2/fs/btrfs/bio.c:117 /home/marvin/linux/kernel/torvalds2/fs/btrfs/bio.c:112) btrfs
[ 2149.515130] btrfs_orig_bbio_end_io (/home/marvin/linux/kernel/torvalds2/fs/btrfs/bio.c:164) btrfs
[ 2149.515777] btrfs_simple_end_io (/home/marvin/linux/kernel/torvalds2/fs/btrfs/bio.c:380) btrfs
[ 2149.516425] bio_endio (/home/marvin/linux/kernel/torvalds2/block/bio.c:1603)
[ 2149.516436] blk_mq_end_request_batch (/home/marvin/linux/kernel/torvalds2/block/blk-mq.c:851 /home/marvin/linux/kernel/torvalds2/block/blk-mq.c:1089)
[ 2149.516449] nvme_pci_complete_batch (/home/marvin/linux/kernel/torvalds2/drivers/nvme/host/pci.c:986) nvme
[ 2149.516494] nvme_irq (/home/marvin/linux/kernel/torvalds2/drivers/nvme/host/pci.c:1086) nvme
[ 2149.516538] __handle_irq_event_percpu (/home/marvin/linux/kernel/torvalds2/kernel/irq/handle.c:158)
[ 2149.516553] handle_irq_event (/home/marvin/linux/kernel/torvalds2/kernel/irq/handle.c:195 /home/marvin/linux/kernel/torvalds2/kernel/irq/handle.c:210)
[ 2149.516566] handle_edge_irq (/home/marvin/linux/kernel/torvalds2/kernel/irq/chip.c:833)
[ 2149.516578] __common_interrupt (/home/marvin/linux/kernel/torvalds2/./include/linux/irqdesc.h:161 /home/marvin/linux/kernel/torvalds2/arch/x86/kernel/irq.c:238 /home/marvin/linux/kernel/torvalds2/arch/x86/kernel/irq.c:257)
[ 2149.516589] common_interrupt (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/irq.c:247 (discriminator 14))
[ 2149.516601] asm_common_interrupt (/home/marvin/linux/kernel/torvalds2/./arch/x86/include/asm/idtentry.h:636)
[ 2149.516612] cpuidle_enter_state (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:291)
[ 2149.516623] cpuidle_enter (/home/marvin/linux/kernel/torvalds2/drivers/cpuidle/cpuidle.c:390)
[ 2149.516633] call_cpuidle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:135)
[ 2149.516646] do_idle (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:219 /home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:282)
[ 2149.516655] cpu_startup_entry (/home/marvin/linux/kernel/torvalds2/kernel/sched/idle.c:378 (discriminator 1))
[ 2149.516664] start_secondary (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:210 /home/marvin/linux/kernel/torvalds2/arch/x86/kernel/smpboot.c:294)
[ 2149.516677] secondary_startup_64_no_verify (/home/marvin/linux/kernel/torvalds2/arch/x86/kernel/head_64.S:433)
[ 2149.516697] read to 0xffff8881ab9d2468 of 8 bytes by task 4603 on cpu 25:
[ 2149.516708] xas_find_marked (/home/marvin/linux/kernel/torvalds2/./include/linux/find.h:63 /home/marvin/linux/kernel/torvalds2/./include/linux/xarray.h:1722 /home/marvin/linux/kernel/torvalds2/lib/xarray.c:1354)
[ 2149.516719] filemap_get_folios_tag (/home/marvin/linux/kernel/torvalds2/mm/filemap.c:1978 /home/marvin/linux/kernel/torvalds2/mm/filemap.c:2266)
[ 2149.516729] __filemap_fdatawait_range (/home/marvin/linux/kernel/torvalds2/mm/filemap.c:516)
[ 2149.516739] filemap_fdatawait_range (/home/marvin/linux/kernel/torvalds2/mm/filemap.c:553)
[ 2149.516749] btrfs_wait_ordered_range (/home/marvin/linux/kernel/torvalds2/fs/btrfs/ordered-data.c:841) btrfs
[ 2149.517405] btrfs_sync_file (/home/marvin/linux/kernel/torvalds2/fs/btrfs/file.c:1844) btrfs
[ 2149.518059] vfs_fsync_range (/home/marvin/linux/kernel/torvalds2/fs/sync.c:188)
[ 2149.518071] __x64_sys_fsync (/home/marvin/linux/kernel/torvalds2/./include/linux/file.h:45 /home/marvin/linux/kernel/torvalds2/fs/sync.c:213 /home/marvin/linux/kernel/torvalds2/fs/sync.c:220 /home/marvin/linux/kernel/torvalds2/fs/sync.c:218 /home/marvin/linux/kernel/torvalds2/fs/sync.c:218)
[ 2149.518081] do_syscall_64 (/home/marvin/linux/kernel/torvalds2/arch/x86/entry/common.c:50 /home/marvin/linux/kernel/torvalds2/arch/x86/entry/common.c:80)
[ 2149.518095] entry_SYSCALL_64_after_hwframe (/home/marvin/linux/kernel/torvalds2/arch/x86/entry/entry_64.S:120)
[ 2149.518111] value changed: 0xffffff8000000000 -> 0x0000000000000000
[ 2149.518126] Reported by Kernel Concurrency Sanitizer on:
[ 2149.518133] CPU: 25 PID: 4603 Comm: mozStorage #1 Tainted: G L 6.6.0-rc2-kcsan-00003-g16819584c239-dirty #21
[ 2149.518146] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
[ 2149.518153] ==================================================================
