Re: [syzbot] [block?] [trace?] INFO: task hung in blk_trace_remove (2)

[syzbot <syzbot+2373f6be3e6de4f92562@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: sleeping function called from invalid context in put_probe_ref

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 16, name: ksoftirqd/0
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by ksoftirqd/0/16:
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2184 [inline]
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_core+0x7bd/0x1680 kernel/rcu/tree.c:2465
Preemption disabled at:
[<ffffffff8a922753>] softirq_handle_begin kernel/softirq.c:394 [inline]
[<ffffffff8a922753>] __do_softirq+0x123/0x8de kernel/softirq.c:529
CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.8.0-rc2-syzkaller-g861c0981648f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
 __might_resched+0x3c3/0x5e0 kernel/sched/core.c:10176
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xe2/0x9d0 kernel/locking/mutex.c:752
 put_probe_ref+0x14/0x1b0 kernel/trace/blktrace.c:350
 blk_trace_rcu_free+0x71/0x90 kernel/trace/blktrace.c:394
 rcu_do_batch kernel/rcu/tree.c:2190 [inline]
 rcu_core+0x819/0x1680 kernel/rcu/tree.c:2465
 __do_softirq+0x21a/0x8de kernel/softirq.c:553
 run_ksoftirqd kernel/softirq.c:921 [inline]
 run_ksoftirqd+0x31/0x60 kernel/softirq.c:913
 smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>

=============================
[ BUG: Invalid wait context ]
6.8.0-rc2-syzkaller-g861c0981648f-dirty #0 Tainted: G        W         
-----------------------------
ksoftirqd/0/16 is trying to lock:
ffffffff8d22fa28 (blk_probe_mutex){+.+.}-{3:3}, at: put_probe_ref+0x14/0x1b0 kernel/trace/blktrace.c:350
other info that might help us debug this:
context-{2:2}
1 lock held by ksoftirqd/0/16:
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2184 [inline]
 #0: ffffffff8d1acac0 (rcu_callback){....}-{0:0}, at: rcu_core+0x7bd/0x1680 kernel/rcu/tree.c:2465
stack backtrace:
CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G        W          6.8.0-rc2-syzkaller-g861c0981648f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4751 [inline]
 check_wait_context kernel/locking/lockdep.c:4821 [inline]
 __lock_acquire+0x821/0x3b30 kernel/locking/lockdep.c:5087
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x175/0x9d0 kernel/locking/mutex.c:752
 put_probe_ref+0x14/0x1b0 kernel/trace/blktrace.c:350
 blk_trace_rcu_free+0x71/0x90 kernel/trace/blktrace.c:394
 rcu_do_batch kernel/rcu/tree.c:2190 [inline]
 rcu_core+0x819/0x1680 kernel/rcu/tree.c:2465
 __do_softirq+0x21a/0x8de kernel/softirq.c:553
 run_ksoftirqd kernel/softirq.c:921 [inline]
 run_ksoftirqd+0x31/0x60 kernel/softirq.c:913
 smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
BUG: scheduling while atomic: ksoftirqd/0/16/0x00000101
INFO: lockdep is turned off.
Modules linked in:
Preemption disabled at:
[<ffffffff8a922753>] softirq_handle_begin kernel/softirq.c:394 [inline]
[<ffffffff8a922753>] __do_softirq+0x123/0x8de kernel/softirq.c:529


Tested on:

commit:         861c0981 Merge tag 'jfs-6.8-rc3' of github.com:kleikam..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=121ea1fde80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b168fa511db3ca08
dashboard link: https://syzkaller.appspot.com/bug?extid=2373f6be3e6de4f92562
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13151c40180000