fe48ba7dae
KCSAN has discovered a data race in kernel/workqueue.c:2598:
[ 1863.554079] ==================================================================
[ 1863.554118] BUG: KCSAN: data-race in process_one_work / process_one_work
[ 1863.554142] write to 0xffff963d99d79998 of 8 bytes by task 5394 on cpu 27:
[ 1863.554154] process_one_work (kernel/workqueue.c:2598)
[ 1863.554166] worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2752)
[ 1863.554177] kthread (kernel/kthread.c:389)
[ 1863.554186] ret_from_fork (arch/x86/kernel/process.c:145)
[ 1863.554197] ret_from_fork_asm (arch/x86/entry/entry_64.S:312)
[ 1863.554213] read to 0xffff963d99d79998 of 8 bytes by task 5450 on cpu 12:
[ 1863.554224] process_one_work (kernel/workqueue.c:2598)
[ 1863.554235] worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2752)
[ 1863.554247] kthread (kernel/kthread.c:389)
[ 1863.554255] ret_from_fork (arch/x86/kernel/process.c:145)
[ 1863.554266] ret_from_fork_asm (arch/x86/entry/entry_64.S:312)
[ 1863.554280] value changed: 0x0000000000001766 -> 0x000000000000176a
[ 1863.554295] Reported by Kernel Concurrency Sanitizer on:
[ 1863.554303] CPU: 12 PID: 5450 Comm: kworker/u64:1 Tainted: G L 6.5.0-rc6+ #44
[ 1863.554314] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
[ 1863.554322] Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
[ 1863.554941] ==================================================================
lockdep_invariant_state(true);
→ pwq->stats[PWQ_STAT_STARTED]++;
trace_workqueue_execute_start(work);
worker->current_func(work);
Moving pwq->stats[PWQ_STAT_STARTED]++; before the line
raw_spin_unlock_irq(&pool->lock);
resolves the data race without performance penalty.
KCSAN detected at least one additional data race:
[ 157.834751] ==================================================================
[ 157.834770] BUG: KCSAN: data-race in process_one_work / process_one_work
[ 157.834793] write to 0xffff9934453f77a0 of 8 bytes by task 468 on cpu 29:
[ 157.834804] process_one_work (/home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2606)
[ 157.834815] worker_thread (/home/marvin/linux/kernel/linux_torvalds/./include/linux/list.h:292 /home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2752)
[ 157.834826] kthread (/home/marvin/linux/kernel/linux_torvalds/kernel/kthread.c:389)
[ 157.834834] ret_from_fork (/home/marvin/linux/kernel/linux_torvalds/arch/x86/kernel/process.c:145)
[ 157.834845] ret_from_fork_asm (/home/marvin/linux/kernel/linux_torvalds/arch/x86/entry/entry_64.S:312)
[ 157.834859] read to 0xffff9934453f77a0 of 8 bytes by task 214 on cpu 7:
[ 157.834868] process_one_work (/home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2606)
[ 157.834879] worker_thread (/home/marvin/linux/kernel/linux_torvalds/./include/linux/list.h:292 /home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2752)
[ 157.834890] kthread (/home/marvin/linux/kernel/linux_torvalds/kernel/kthread.c:389)
[ 157.834897] ret_from_fork (/home/marvin/linux/kernel/linux_torvalds/arch/x86/kernel/process.c:145)
[ 157.834907] ret_from_fork_asm (/home/marvin/linux/kernel/linux_torvalds/arch/x86/entry/entry_64.S:312)
[ 157.834920] value changed: 0x000000000000052a -> 0x0000000000000532
[ 157.834933] Reported by Kernel Concurrency Sanitizer on:
[ 157.834941] CPU: 7 PID: 214 Comm: kworker/u64:2 Tainted: G L 6.5.0-rc7-kcsan-00169-g81eaf55a60fc #4
[ 157.834951] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
[ 157.834958] Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
[ 157.835567] ==================================================================
in code:
trace_workqueue_execute_end(work, worker->current_func);
→ pwq->stats[PWQ_STAT_COMPLETED]++;
lock_map_release(&lockdep_map);
lock_map_release(&pwq->wq->lockdep_map);
which needs to be resolved separately.
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.