============================= WARNING: suspicious RCU usage 4.15.0-rc9+ #9 Not tainted ----------------------------- ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 3 locks held by syz-executor2/6024: #0: (&mm->mmap_sem){++++}, at: [<0000000078fdc07e>] __do_page_fault+0x32d/0xc90 arch/x86/mm/fault.c:1359 #1: (rcu_callback){....}, at: [<000000007753c18a>] __rcu_reclaim kernel/rcu/rcu.h:185 [inline] #1: (rcu_callback){....}, at: [<000000007753c18a>] rcu_do_batch kernel/rcu/tree.c:2758 [inline] #1: (rcu_callback){....}, at: [<000000007753c18a>] invoke_rcu_callbacks kernel/rcu/tree.c:3012 [inline] #1: (rcu_callback){....}, at: [<000000007753c18a>] __rcu_process_callbacks kernel/rcu/tree.c:2979 [inline] #1: (rcu_callback){....}, at: [<000000007753c18a>] rcu_process_callbacks+0xe57/0x17f0 kernel/rcu/tree.c:2996 #2: (rcu_read_lock){....}, at: [<00000000ae4620a9>] __is_insn_slot_addr+0x0/0x330 kernel/kprobes.c:207 stack backtrace: CPU: 0 PID: 6024 Comm: syz-executor2 Not tainted 4.15.0-rc9+ #9 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+0x194/0x257 lib/dump_stack.c:53 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585 rcu_preempt_sleep_check include/linux/rcupdate.h:301 [inline] ___might_sleep+0x385/0x470 kernel/sched/core.c:6025 clear_huge_page+0x24f/0x730 mm/memory.c:4601 __do_huge_pmd_anonymous_page mm/huge_memory.c:570 [inline] do_huge_pmd_anonymous_page+0x59c/0x1b00 mm/huge_memory.c:728 create_huge_pmd mm/memory.c:3834 [inline] __handle_mm_fault+0x1a0c/0x3ce0 mm/memory.c:4038 handle_mm_fault+0x334/0x8d0 mm/memory.c:4104 __do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1430 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1505 page_fault+0x4c/0x60 arch/x86/entry/entry_64.S:1260 RIP: 0033:0x405ad1 RSP: 002b:00007fffb86c8260 EFLAGS: 00010246 RAX: 00000000200ba000 RBX: 000000000071bea0 RCX: 000000000000000d RDX: 06f6a4b0adb37cc3 RSI: 0000000000000000 RDI: 0000000001fa6848 RBP: 0000000000000002 R08: 0000000000000000 R09: 000000000000007c R10: 00007fffb86c8260 R11: 0000000000000206 R12: 0000000000000003 R13: fffffffffffffffe R14: 000000000071ca20 R15: ffffffffffffffff ====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc9+ #9 Not tainted ------------------------------------------------------ syz-executor3/6032 is trying to acquire lock: (event_mutex){+.+.}, at: [<00000000ca81d0a4>] ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 but task is already holding lock: (&cpuctx_mutex){+.+.}, at: [<00000000764cab63>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&cpuctx_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0xb6/0x160 kernel/events/core.c:11076 perf_event_init+0x4e9/0x549 kernel/events/core.c:11123 start_kernel+0x4cc/0x819 init/main.c:627 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #3 (pmus_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0x2f/0x160 kernel/events/core.c:11070 cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182 cpuhp_up_callbacks kernel/cpu.c:477 [inline] _cpu_up+0x216/0x510 kernel/cpu.c:1036 do_cpu_up+0x73/0xa0 kernel/cpu.c:1066 cpu_up+0x18/0x20 kernel/cpu.c:1074 smp_init+0x13a/0x152 kernel/smp.c:578 kernel_init_freeable+0x2fe/0x521 init/main.c:1067 kernel_init+0x13/0x180 init/main.c:999 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 -> #2 (cpu_hotplug_lock.rw_sem){++++}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:293 static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123 tracepoint_add_func kernel/tracepoint.c:223 [inline] tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:283 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 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+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7959 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9192 perf_init_event kernel/events/core.c:9230 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9494 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9949 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9835 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #1 (tracepoints_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:279 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 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+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7959 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9192 perf_init_event kernel/events/core.c:9230 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9494 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9949 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9835 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #0 (event_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 perf_event_set_filter kernel/events/core.c:8545 [inline] _perf_ioctl kernel/events/core.c:4708 [inline] perf_ioctl+0x1092/0x1430 kernel/events/core.c:4748 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x273/0x920 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x75 other info that might help us debug this: Chain exists of: event_mutex --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(event_mutex); *** DEADLOCK *** 1 lock held by syz-executor3/6032: #0: (&cpuctx_mutex){+.+.}, at: [<00000000764cab63>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249 stack backtrace: CPU: 1 PID: 6032 Comm: syz-executor3 Not tainted 4.15.0-rc9+ #9 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+0x194/0x257 lib/dump_stack.c:53 print_circular_bug.isra.37+0x2cd/0x2dc kernel/locking/lockdep.c:1218 check_prev_add kernel/locking/lockdep.c:1858 [inline] check_prevs_add kernel/locking/lockdep.c:1971 [inline] validate_chain kernel/locking/lockdep.c:2412 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3426 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 perf_event_set_filter kernel/events/core.c:8545 [inline] _perf_ioctl kernel/events/core.c:4708 [inline] perf_ioctl+0x1092/0x1430 kernel/events/core.c:4748 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x273/0x920 arch/x86/entry/common.c:285 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x453299 RSP: 002b:00007f0b89208c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 RDX: 0000000020a1e000 RSI: 0000000040082406 RDI: 0000000000000012 RBP: 000000000000027a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2c10 R13: 00000000ffffffff R14: 00007f0b892096d4 R15: 0000000000000000 NFS: bad mount option value specified: v&)9S{Y[$sZ-R|0xNw\C;ξq{0řA NFS: bad mount option value specified: v&)9S{Y[$sZ-R|0xNw\C;ξq{0řA IPVS: ftp: loaded support on port[0] = 21 EXT4-fs (sda1): re-mounted. Opts: EXT4-fs (sda1): re-mounted. Opts: 9pnet_virtio: no channels available for device ./file0 IPVS: ftp: loaded support on port[0] = 21 xprt_adjust_timeout: rq_timeout = 0! autofs4:pid:6588:autofs4_fill_super: called with bogus options autofs4:pid:6600:autofs4_fill_super: called with bogus options xprt_adjust_timeout: rq_timeout = 0! IPVS: ftp: loaded support on port[0] = 21 EXT4-fs (sda1): re-mounted. Opts: EXT4-fs (sda1): re-mounted. Opts: xprt_adjust_timeout: rq_timeout = 0! xprt_adjust_timeout: rq_timeout = 0! IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21