WARNING in tracepoint_probe_register_prio

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e6a95d88 Linux 4.14.124
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12611a46a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ab7251aa14ac721d
dashboard link: https://syzkaller.appspot.com/bug?extid=3d7758676b7a4e6f1cd4
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3d7758...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 28949 at kernel/tracepoint.c:210 tracepoint_add_func
kernel/tracepoint.c:210 [inline]
WARNING: CPU: 1 PID: 28949 at kernel/tracepoint.c:210
tracepoint_probe_register_prio+0x1e5/0x6d0 kernel/tracepoint.c:283
Kernel panic - not syncing: panic_on_warn set ...

kobject: 'loop0' (ffff888067b30e60): kobject_uevent_env
CPU: 1 PID: 28949 Comm: syz-executor.4 Not tainted 4.14.124 #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
panic+0x1f2/0x426 kernel/panic.c:182
kobject: 'loop0' (ffff888067b30e60): fill_kobj_path: path
= '/devices/virtual/block/loop0'
__warn.cold+0x2f/0x36 kernel/panic.c:546
kobject: 'loop2' (ffff8880a4a05220): kobject_uevent_env
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:960
RIP: 0010:tracepoint_add_func kernel/tracepoint.c:210 [inline]
RIP: 0010:tracepoint_probe_register_prio+0x1e5/0x6d0 kernel/tracepoint.c:283
kobject: 'loop2' (ffff8880a4a05220): fill_kobj_path: path
= '/devices/virtual/block/loop2'
RSP: 0018:ffff888066dbfb50 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffffffff8822a5c0 RCX: ffffc9000c460000
RDX: 0000000000000aac RSI: ffffffff815dcb45 RDI: ffff88809d818c30
RBP: ffff888066dbfba8 R08: dffffc0000000000 R09: ffffffff88cae9c8
R10: ffff888066dbfb40 R11: ffff888062176080 R12: ffff88809d818c10
R13: 00000000ffffffef R14: 00000000ffffffff R15: ffffffff82c48b90
tracepoint_probe_register+0x2b/0x40 kernel/tracepoint.c:304
trace_event_reg+0x277/0x330 kernel/trace/trace_events.c:305
perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
perf_trace_init+0x449/0xaa0 kernel/trace/trace_event_perf.c:221
perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:8106
perf_try_init_event+0x164/0x200 kernel/events/core.c:9342
perf_init_event kernel/events/core.c:9380 [inline]
perf_event_alloc.part.0+0xd48/0x2530 kernel/events/core.c:9640
kobject: 'loop2' (ffff8880a4a05220): kobject_uevent_env
perf_event_alloc kernel/events/core.c:9993 [inline]
SYSC_perf_event_open+0xa2d/0x24b0 kernel/events/core.c:10097
kobject: 'loop2' (ffff8880a4a05220): fill_kobj_path: path
= '/devices/virtual/block/loop2'
SyS_perf_event_open+0x34/0x40 kernel/events/core.c:9983
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459279
RSP: 002b:00007f35a9cafc78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f35a9cafc90 RCX: 0000000000459279
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f35a9cb06d4
kobject: 'loop5' (ffff8880a4af8ae0): kobject_uevent_env
R13: 00000000004c5ec2 R14: 00000000004da848 R15: 0000000000000003
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.