bisecting fixing commit since 811218eceeaa7618652e1b8d11caeff67ab42072 building syzkaller on a52ee10ae11c1342cfca60cf3957619bcf92bd1a testing commit 811218eceeaa7618652e1b8d11caeff67ab42072 with gcc (GCC) 8.4.1 20210217 kernel signature: 7f92f079da579ec9f075a55f925b470f61a2ab24b19da5ea9c9cc65f7675c7a2 all runs: crashed: INFO: task hung in acct testing current HEAD 030194a5b292bb7613407668d85af0b987bb9839 testing commit 030194a5b292bb7613407668d85af0b987bb9839 with gcc (GCC) 8.4.1 20210217 kernel signature: 277137b10edf3c9297b14590307c9a892454c98efb97854907593615a2af33f0 all runs: crashed: INFO: task hung in acct revisions tested: 2, total time: 35m3.817133287s (build: 15m39.981341238s, test: 19m4.863014087s) the crash still happens on HEAD commit msg: Linux 4.19.180 crash: INFO: task hung in acct autofs4:pid:12859:autofs_fill_super: called with bogus options Bluetooth: hci3: command 0x0406 tx timeout Bluetooth: hci4: command 0x0406 tx timeout Bluetooth: hci2: command 0x0406 tx timeout Bluetooth: hci5: command 0x0406 tx timeout INFO: task syz-executor.0:11971 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29784 11971 10094 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: Bad RIP value. RSP: 002b:00007f65477fd188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffdd7fdfdff R14: 00007f65477fd300 R15: 0000000000022000 INFO: task syz-executor.4:11978 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29784 11978 10093 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: Bad RIP value. RSP: 002b:00007fd5e97e5188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd7d20047f R14: 00007fd5e97e5300 R15: 0000000000022000 INFO: task syz-executor.5:11981 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29448 11981 11253 0x00000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: Bad RIP value. RSP: 002b:00007f3f0713d188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcf7f3a7cf R14: 00007f3f0713d300 R15: 0000000000022000 INFO: task syz-executor.4:11991 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28904 11991 10093 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: Bad RIP value. RSP: 002b:00007fd5e97e5188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd7d20047f R14: 00007fd5e97e5300 R15: 0000000000022000 INFO: task syz-executor.0:11992 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29784 11992 10094 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: 00 e9 30 ff ff ff 83 f9 77 75 26 48 83 b8 d8 00 00 00 00 7c e2 83 f9 72 75 10 80 78 19 00 74 0a b9 03 00 00 00 e9 0c ff ff ff <31> c9 e9 05 ff ff ff 83 f9 72 eb e2 e8 c6 35 00 00 e9 c1 fe ff ff RSP: 002b:00007f65477fd188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffdd7fdfdff R14: 00007f65477fd300 R15: 0000000000022000 INFO: task syz-executor.5:11995 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29784 11995 11253 0x00000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: 00 e9 30 ff ff ff 83 f9 77 75 26 48 83 b8 d8 00 00 00 00 7c e2 83 f9 72 75 10 80 78 19 00 74 0a b9 03 00 00 00 e9 0c ff ff ff <31> c9 e9 05 ff ff ff 83 f9 72 eb e2 e8 c6 35 00 00 e9 c1 fe ff ff RSP: 002b:00007f3f0713d188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcf7f3a7cf R14: 00007f3f0713d300 R15: 0000000000022000 INFO: task syz-executor.0:12011 blocked for more than 140 seconds. Not tainted 4.19.180-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29448 12011 10094 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_acct kernel/acct.c:285 [inline] __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 __x64_sys_acct+0x2c/0x40 kernel/acct.c:273 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: 00 e9 30 ff ff ff 83 f9 77 75 26 48 83 b8 d8 00 00 00 00 7c e2 83 f9 72 75 10 80 78 19 00 74 0a b9 03 00 00 00 e9 0c ff ff ff <31> c9 e9 05 ff ff ff 83 f9 72 eb e2 e8 c6 35 00 00 e9 c1 fe ff ff RSP: 002b:00007f65477fd188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a3 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffdd7fdfdff R14: 00007f65477fd300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1567: #0: 000000009ad5bcd8 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 3 locks held by kworker/u4:4/2884: #0: 00000000b8da07a7 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1824 [inline] #0: 00000000b8da07a7 (&rq->lock){-.-.}, at: __schedule+0x1f6/0x1f70 kernel/sched/core.c:3455 #1: 000000009ad5bcd8 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000009ad5bcd8 (rcu_read_lock){....}, at: update_curr+0x2cf/0x870 kernel/sched/fair.c:857 #2: 00000000ba002616 (&wdev->mtx){+.+.}, at: sdata_lock net/mac80211/ieee80211_i.h:990 [inline] #2: 00000000ba002616 (&wdev->mtx){+.+.}, at: ieee80211_ibss_work+0x8b/0xdb0 net/mac80211/ibss.c:1675 1 lock held by syz-executor.0/11971: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.5/11976: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.4/11978: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.5/11981: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.4/11991: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.0/11992: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.5/11995: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.0/12011: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.3/12731: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.3/12742: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.2/12795: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.1/12812: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.1/12815: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.2/12826: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.0/12825: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.1/12831: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.5/12832: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.3/12833: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.3/12847: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 1 lock held by syz-executor.1/12848: #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __do_sys_acct kernel/acct.c:285 [inline] #0: 00000000401c6010 (acct_on_mutex){+.+.}, at: __se_sys_acct+0x65/0x7d0 kernel/acct.c:273 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1567 Comm: khungtaskd Not tainted 4.19.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf6/0x120 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tsc_verify_tsc_adjust+0x2a9/0x380 arch/x86/kernel/tsc_sync.c:61 Code: c1 ea 03 80 3c 02 00 75 6f 4d 8d 74 24 10 4c 8b 3d 9c 1a 5d 08 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 <75> 42 4d 3b 7c 24 10 0f 89 2f fe ff ff e9 ce fd ff ff 0f 0b 0f 0b RSP: 0018:ffff8880b59efcd8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffffffff12b85e1 RDX: 1ffff11017463c4e RSI: 0000000000000000 RDI: ffffffff895c2f08 RBP: ffff8880b59efd10 R08: 1ffffffff1572b01 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ba31e260 R13: ffffffff8980d980 R14: ffff8880ba31e270 R15: 0000000100001614 FS: 0000000000000000(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8264291000 CR3: 00000000b359d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_cpu_idle_enter+0xb/0x20 arch/x86/kernel/process.c:534 do_idle+0x17b/0x570 kernel/sched/idle.c:251 cpu_startup_entry+0xc8/0xe0 kernel/sched/idle.c:369 start_secondary+0x459/0x5d0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243