From: kernel test robot <oliver.sang@intel.com>
To: Julian Anastasov <ja@ssi.bg>
Cc: <oe-lkp@lists.linux.dev>, <lkp@intel.com>,
<linux-kernel@vger.kernel.org>, Florian Westphal <fw@strlen.de>,
<rcu@vger.kernel.org>, <oliver.sang@intel.com>
Subject: [linus:master] [rculist_bl] 1ac252ad03: BUG:KCSAN:data-race_in__d_lookup_rcu/print_report
Date: Sun, 12 Jul 2026 17:21:11 +0800 [thread overview]
Message-ID: <202607101627.2909550e-lkp@intel.com> (raw)
Hello,
as we understand, this commit is not the root cause of the issue, it just
changes the stats of the (random) issue:
=========================================================================================
tbox_group/testcase/rootfs/kconfig/compiler/sleep:
vm-snb/boot/debian-11.1-i386-20220923.cgz/x86_64-randconfig-074-20260622/gcc-14/1
34a6a003d4e49313 1ac252ad036cdb18f5fb7f76bb6
---------------- ---------------------------
fail:runs %reproduction fail:runs
| | |
:200 32% 65:200 dmesg.BUG:KCSAN:data-race_in__d_lookup_rcu/print_report
69:200 -34% :200 dmesg.BUG:KCSAN:data-race_in_hlist_bl_first_rcu/print_report
we still make out this report FYI in case it could supply any useful information
to solve any potential code problems. thanks
kernel test robot noticed "BUG:KCSAN:data-race_in__d_lookup_rcu/print_report" on:
commit: 1ac252ad036cdb18f5fb7f76bb6061adfed9cedf ("rculist_bl: add hlist_bl_for_each_entry_continue_rcu")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
[tail failed on linus/master d2c9a99135da931377240942d44f3dea104cedb8]
[test failed on linux-next/master 6eb8711ece2ce27e52e327a5b7a628ed39b97f45]
in testcase: boot
config: x86_64-randconfig-074-20260622
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202607101627.2909550e-lkp@intel.com
[ 94.613216][ T178] BUG: KCSAN: data-race in __d_lookup_rcu / print_report
[ 94.616584][ T178]
[ 94.617709][ T178] read (marked) to 0xffff88881e358348 of 8 bytes by task 170 on cpu 0:
[ 94.621462][ T178] __d_lookup_rcu (dcache.c:2332 (discriminator 2))
[ 94.623009][ T178] lookup_fast (namei.c:1850)
[ 94.624382][ T178] link_path_walk (namei.c:2275 namei.c:2647)
[ 94.625855][ T178] path_openat (namei.c:4826 (discriminator 2))
[ 94.627207][ T178] do_file_open (namei.c:4859)
[ 94.628575][ T178] do_sys_openat2 (open.c:1366 (discriminator 1))
[ 94.630019][ T178] do_sys_open (open.c:1372)
[ 94.631330][ T178] __ia32_compat_sys_openat (open.c:1434 open.c:1432 open.c:1432)
[ 94.632980][ T178] ia32_sys_call (kbuild/obj/consumer/x86_64-randconfig-074-20260622/./arch/x86/include/generated/asm/syscalls_32.h:296)
[ 94.634453][ T178] __do_fast_syscall_32 (x86/entry/syscall_32.c:83 x86/entry/syscall_32.c:307)
[ 94.636053][ T178] do_fast_syscall_32 (x86/entry/syscall_32.c:332)
[ 94.637566][ T178] do_SYSENTER_32 (x86/entry/syscall_32.c:370)
[ 94.638930][ T178] entry_SYSENTER_compat_after_hwframe (x86/entry/entry_64_compat.S:126)
[ 94.640851][ T178]
[ 94.641599][ T178] write to 0xffff88881e358348 of 8 bytes by task 178 on cpu 1:
[ 94.643871][ T178] print_report (kcsan/report.c:399)
[ 94.645239][ T178] kcsan_report_known_origin (kcsan/report.c:697)
[ 94.646960][ T178] kcsan_setup_watchpoint (kcsan/core.c:678)
[ 94.648580][ T178] hlist_bl_unlock (linux/instrumented.h:42 asm-generic/bitops/instrumented-lock.h:42 linux/bit_spinlock.h:96 linux/list_bl.h:155)
[ 94.650030][ T178] ___d_drop (dcache.c:569)
[ 94.651274][ T178] __d_drop (dcache.c:575)
[ 94.652486][ T178] __dentry_kill (dcache.c:668)
[ 94.653876][ T178] finish_dput (dcache.c:879)
[ 94.655196][ T178] dput (dcache.c:928)
[ 94.656362][ T178] step_into_slowpath (namei.c:1748 namei.c:2101)
[ 94.657897][ T178] link_path_walk (namei.c:2149 namei.c:2285 namei.c:2647)
[ 94.659316][ T178] path_parentat (namei.c:2851)
[ 94.660680][ T178] __filename_parentat (namei.c:2875)
[ 94.662217][ T178] filename_parentat (namei.c:2893)
[ 94.663649][ T178] filename_unlinkat (namei.c:5509)
[ 94.665114][ T178] __do_sys_unlink (namei.c:5575)
[ 94.666511][ T178] __ia32_sys_unlink (namei.c:5572 namei.c:5572)
[ 94.667941][ T178] ia32_sys_call (kbuild/obj/consumer/x86_64-randconfig-074-20260622/./arch/x86/include/generated/asm/syscalls_32.h:11)
[ 94.669382][ T178] __do_fast_syscall_32 (x86/entry/syscall_32.c:83 x86/entry/syscall_32.c:307)
[ 94.670950][ T178] do_fast_syscall_32 (x86/entry/syscall_32.c:332)
[ 94.672430][ T178] do_SYSENTER_32 (x86/entry/syscall_32.c:370)
[ 94.673797][ T178] entry_SYSENTER_compat_after_hwframe (x86/entry/entry_64_compat.S:126)
[ 94.675698][ T178]
[ 94.676432][ T178] Reported by Kernel Concurrency Sanitizer on:
[ 94.678270][ T178] CPU: 1 UID: 0 PID: 178 Comm: systemd-udevd Not tainted 7.0.0-rc1-00328-g1ac252ad036c #1 PREEMPT(lazy)
[ 94.682170][ T178] ==================================================================
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260710/202607101627.2909550e-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-07-12 9:21 UTC|newest]
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