Hello,
kernel test robot noticed "WARNING:possible_irq_lock_inversion_dependency_detected" on:
commit: e3bfecb7310ade68457392f0e7d4c4ec22d0a401 ("pidfs: keep pidfs dentry stashed once created")
https://git.kernel.org/cgit/linux/kernel/git/vfs/vfs.git work.pidfs.xattr
in testcase: boot
config: x86_64-randconfig-078-20250618
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
(please refer to attached dmesg/kmsg for entire log/backtrace)
+---------------------------------------------------------+-----------+------------+
| | v6.16-rc1 | e3bfecb731 |
+---------------------------------------------------------+-----------+------------+
| WARNING:possible_irq_lock_inversion_dependency_detected | 0 | 12 |
+---------------------------------------------------------+-----------+------------+
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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-lkp/202506191555.448b188b-lkp@xxxxxxxxx
[ 48.631814][ C0] WARNING: possible irq lock inversion dependency detected
[ 48.632323][ C0] 6.16.0-rc1-00001-ge3bfecb7310a #1 Tainted: G T
[ 48.632866][ C0] --------------------------------------------------------
[ 48.633351][ C0] sed/223 just changed the state of lock:
[ 48.633739][ C0] ffff8881123ae5d8 (&sighand->siglock){-...}-{3:3}, at: __lock_task_sighand (kernel/signal.c:1380)
[ 48.634422][ C0] but this lock took another, HARDIRQ-unsafe lock in the past:
[ 48.634933][ C0] (&lockref->lock){+.+.}-{3:3}
[ 48.634939][ C0]
[ 48.634939][ C0] and interrupts could create inverse lock ordering between them.
[ 48.634939][ C0]
[ 48.636229][ C0]
[ 48.636229][ C0] other info that might help us debug this:
[ 48.636782][ C0] Chain exists of:
[ 48.636782][ C0] &sighand->siglock --> &(&sig->stats_lock)->lock --> &lockref->lock
[ 48.636782][ C0]
[ 48.637722][ C0] Possible interrupt unsafe locking scenario:
[ 48.637722][ C0]
[ 48.638283][ C0] CPU0 CPU1
[ 48.638649][ C0] ---- ----
[ 48.639015][ C0] lock(&lockref->lock);
[ 48.639315][ C0] local_irq_disable();
[ 48.639774][ C0] lock(&sighand->siglock);
[ 48.640257][ C0] lock(&(&sig->stats_lock)->lock);
[ 48.640796][ C0] <Interrupt>
[ 48.641036][ C0] lock(&sighand->siglock);
[ 48.641365][ C0]
[ 48.641365][ C0] *** DEADLOCK ***
[ 48.641365][ C0]
[ 48.641932][ C0] 2 locks held by sed/223:
[ 48.642237][ C0] #0: ffffffff87307760 (rcu_read_lock){....}-{1:3}, at: kill_pid_info_type (kernel/signal.c:1451)
[ 48.642895][ C0] #1: ffffffff87307760 (rcu_read_lock){....}-{1:3}, at: __lock_task_sighand (include/linux/rcupdate.h:331 include/linux/rcupdate.h:841 kernel/signal.c:1363)
[ 48.643557][ C0]
[ 48.643557][ C0] the shortest dependencies between 2nd lock and 1st lock:
[ 48.644192][ C0] -> (&lockref->lock){+.+.}-{3:3} {
[ 48.644575][ C0] HARDIRQ-ON-W at:
[ 48.644885][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
[ 48.645364][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.645824][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
[ 48.646290][ C0] __d_instantiate (fs/dcache.c:1915 (discriminator 3))
[ 48.646767][ C0] d_instantiate (include/linux/spinlock.h:391 fs/dcache.c:1948)
[ 48.647225][ C0] d_make_root (fs/dcache.c:1992)
[ 48.647672][ C0] shmem_fill_super (mm/shmem.c:5106)
[ 48.648170][ C0] get_tree_nodev (fs/super.c:1324 fs/super.c:1342)
[ 48.648648][ C0] vfs_get_tree (fs/super.c:1803)
[ 48.649107][ C0] vfs_kern_mount (fs/namespace.c:6278)
[ 48.649620][ C0] kern_mount (fs/namespace.c:6273)
[ 48.650062][ C0] shmem_init (mm/shmem.c:5413)
[ 48.650512][ C0] mnt_init (fs/namespace.c:6257)
[ 48.650954][ C0] vfs_caches_init (fs/dcache.c:3243)
[ 48.651430][ C0] start_kernel (init/main.c:1084)
[ 48.651894][ C0] x86_64_start_reservations (arch/x86/kernel/head64.c:295)
[ 48.652443][ C0] x86_64_start_kernel (arch/x86/kernel/head64.c:231 (discriminator 17))
[ 48.652952][ C0] common_startup_64 (arch/x86/kernel/head_64.S:419)
[ 48.653433][ C0] SOFTIRQ-ON-W at:
[ 48.653737][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
[ 48.654213][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.654670][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
[ 48.655132][ C0] __d_instantiate (fs/dcache.c:1915 (discriminator 3))
[ 48.655605][ C0] d_instantiate (include/linux/spinlock.h:391 fs/dcache.c:1948)
[ 48.656062][ C0] d_make_root (fs/dcache.c:1992)
[ 48.656507][ C0] shmem_fill_super (mm/shmem.c:5106)
[ 48.657010][ C0] get_tree_nodev (fs/super.c:1324 fs/super.c:1342)
[ 48.657480][ C0] vfs_get_tree (fs/super.c:1803)
[ 48.657939][ C0] vfs_kern_mount (fs/namespace.c:6278)
[ 48.658452][ C0] kern_mount (fs/namespace.c:6273)
[ 48.658896][ C0] shmem_init (mm/shmem.c:5413)
[ 48.659345][ C0] mnt_init (fs/namespace.c:6257)
[ 48.659788][ C0] vfs_caches_init (fs/dcache.c:3243)
[ 48.660264][ C0] start_kernel (init/main.c:1084)
[ 48.660738][ C0] x86_64_start_reservations (arch/x86/kernel/head64.c:295)
[ 48.661266][ C0] x86_64_start_kernel (arch/x86/kernel/head64.c:231 (discriminator 17))
[ 48.661766][ C0] common_startup_64 (arch/x86/kernel/head_64.S:419)
[ 48.662264][ C0] INITIAL USE at:
[ 48.662555][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
[ 48.663026][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.663479][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
[ 48.663937][ C0] __d_instantiate (fs/dcache.c:1915 (discriminator 3))
[ 48.664406][ C0] d_instantiate (include/linux/spinlock.h:391 fs/dcache.c:1948)
[ 48.664866][ C0] d_make_root (fs/dcache.c:1992)
[ 48.665307][ C0] shmem_fill_super (mm/shmem.c:5106)
[ 48.665796][ C0] get_tree_nodev (fs/super.c:1324 fs/super.c:1342)
[ 48.666259][ C0] vfs_get_tree (fs/super.c:1803)
[ 48.666711][ C0] vfs_kern_mount (fs/namespace.c:6278)
[ 48.667216][ C0] kern_mount (fs/namespace.c:6273)
[ 48.667651][ C0] shmem_init (mm/shmem.c:5413)
[ 48.668092][ C0] mnt_init (fs/namespace.c:6257)
[ 48.668527][ C0] vfs_caches_init (fs/dcache.c:3243)
[ 48.669004][ C0] start_kernel (init/main.c:1084)
[ 48.669461][ C0] x86_64_start_reservations (arch/x86/kernel/head64.c:295)
[ 48.669982][ C0] x86_64_start_kernel (arch/x86/kernel/head64.c:231 (discriminator 17))
[ 48.670476][ C0] common_startup_64 (arch/x86/kernel/head_64.S:419)
[ 48.670950][ C0] }
[ 48.671147][ C0] ... key at: __key.4+0x0/0x40
[ 48.671654][ C0] ... acquired at:
[ 48.671958][ C0] __lock_acquire (kernel/locking/lockdep.c:5240)
[ 48.672295][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.672616][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
[ 48.672945][ C0] lockref_get (lib/lockref.c:51)
[ 48.673244][ C0] pidfs_stash_dentry (fs/pidfs.c:973)
[ 48.673603][ C0] path_from_stashed (fs/libfs.c:2243)
[ 48.673956][ C0] pidfs_register_pid (fs/pidfs.c:1067)
[ 48.674308][ C0] unix_socketpair (net/unix/af_unix.c:754 net/unix/af_unix.c:1782)
[ 48.674650][ C0] __sys_socketpair (net/socket.c:1764)
[ 48.674998][ C0] __do_compat_sys_socketcall (net/compat.c:470)
[ 48.675405][ C0] __do_fast_syscall_32 (arch/x86/entry/syscall_32.c:83 arch/x86/entry/syscall_32.c:306)
[ 48.675769][ C0] do_fast_syscall_32 (arch/x86/entry/syscall_32.c:331)
[ 48.676116][ C0] entry_SYSENTER_compat_after_hwframe (arch/x86/entry/entry_64_compat.S:127)
[ 48.676561][ C0]
[ 48.676737][ C0] -> (&pid->wait_pidfd){....}-{3:3} {
[ 48.677128][ C0] INITIAL USE at:
[ 48.677415][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
[ 48.677877][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.678321][ C0] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[ 48.678820][ C0] __wake_up (kernel/sched/wait.c:106 kernel/sched/wait.c:127)
[ 48.679243][ C0] do_notify_parent (kernel/signal.c:2187 (discriminator 11))
[ 48.679715][ C0] exit_notify (kernel/exit.c:762)
[ 48.680160][ C0] do_exit (kernel/exit.c:979)
[ 48.680582][ C0] kthread_exit (kernel/kthread.c:326)
[ 48.681042][ C0] kthread (arch/x86/include/asm/current.h:25 include/linux/cgroup.h:649 kernel/kthread.c:462)
[ 48.681464][ C0] ret_from_fork (arch/x86/kernel/process.c:154)
[ 48.681920][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
[ 48.682410][ C0] }
[ 48.682603][ C0] ... key at: __key.4+0x0/0x40
[ 48.683107][ C0] ... acquired at:
[ 48.683386][ C0] __lock_acquire (kernel/locking/lockdep.c:5240)
[ 48.683720][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.684037][ C0] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[ 48.684404][ C0] __wake_up (kernel/sched/wait.c:106 kernel/sched/wait.c:127)
[ 48.684704][ C0] __exit_signal (kernel/exit.c:143 kernel/exit.c:211)
[ 48.685144][ C0] release_task (kernel/exit.c:274 (discriminator 11))
[ 48.685647][ C0] exit_notify (kernel/exit.c:780)
[ 48.686160][ C0] do_exit (kernel/exit.c:979)
[ 48.686618][ C0] kthread_exit (kernel/kthread.c:326)
[ 48.687126][ C0] kthread (arch/x86/include/asm/current.h:25 include/linux/cgroup.h:649 kernel/kthread.c:462)
[ 48.687588][ C0] ret_from_fork (arch/x86/kernel/process.c:154)
[ 48.688085][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
[ 48.688603][ C0]
[ 48.688848][ C0] -> (&____s->seqcount#4){....}-{0:0} {
[ 48.689419][ C0] INITIAL USE at:
[ 48.689832][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
[ 48.690480][ C0] lock_acquire (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873 kernel/locking/lockdep.c:5828)
[ 48.691106][ C0] __exit_signal (include/linux/seqlock.h:431 include/linux/seqlock.h:478 include/linux/seqlock.h:503 include/linux/seqlock.h:877 kernel/exit.c:198)
[ 48.691740][ C0] release_task (kernel/exit.c:274 (discriminator 11))
[ 48.692403][ C0] exit_notify (kernel/exit.c:780)
[ 48.693050][ C0] do_exit (kernel/exit.c:979)
[ 48.693684][ C0] kthread_exit (kernel/kthread.c:326)
[ 48.694360][ C0] kthread (arch/x86/include/asm/current.h:25 include/linux/cgroup.h:649 kernel/kthread.c:462)
[ 48.694973][ C0] ret_from_fork (arch/x86/kernel/process.c:154)
[ 48.695646][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
[ 48.696356][ C0] INITIAL READ USE at:
[ 48.696860][ C0] __lock_acquire (kernel/locking/lockdep.c:5194)
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250619/202506191555.448b188b-lkp@xxxxxxxxx
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
