While booting x86_64 with Linux next 20200908 tag kernel this warning was noticed. metadata: git branch: master git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git commit: dff9f829e5b0181d4ed9d35aa62d695292399b54 git describe: next-20200908 kernel-config: http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/intel-corei7-64/lkft/linux-next/853/config warning logs: --------------------- [ 18.874329] Freeing unused kernel image (rodata/data gap) memory: 2012K [ 18.881107] Run /sbin/init as init process [ 18.905611] [ 18.907190] ============================= [ 18.911194] WARNING: suspicious RCU usage [ 18.915199] 5.9.0-rc4-next-20200908 #1 Not tainted [ 18.919982] ----------------------------- [ 18.923984] /usr/src/kernel/include/trace/events/tlb.h:57 suspicious rcu_dereference_check() usage! [ 18.933016] [ 18.933016] other info that might help us debug this: [ 18.933016] [ 18.941006] [ 18.941006] rcu_scheduler_active = 2, debug_locks = 1 [ 18.947523] RCU used illegally from extended quiescent state! [ 18.953261] no locks held by swapper/2/0. [ 18.957264] [ 18.957264] stack backtrace: [ 18.961619] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 18.969007] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 18.976392] Call Trace: [ 18.978844] dump_stack+0x7d/0x9f [ 18.982158] lockdep_rcu_suspicious+0xce/0xf0 [ 18.986517] switch_mm_irqs_off+0x441/0x450 [ 18.990702] switch_mm+0x1b/0x50 [ 18.993936] leave_mm+0x34/0x40 [ 18.997082] acpi_idle_enter_bm+0x23/0x120 [ 19.001180] acpi_idle_enter+0x189/0x2a0 [ 19.005104] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.010072] cpuidle_enter_state+0xa5/0x4b0 [ 19.015265] cpuidle_enter+0x2e/0x40 [ 19.015268] do_idle+0x226/0x2b0 [ 19.015273] cpu_startup_entry+0x1d/0x20 [ 19.015275] start_secondary+0x114/0x150 [ 19.029943] secondary_startup_64+0xb6/0xc0 [ 19.034141] [ 19.034142] ============================= [ 19.034142] WARNING: suspicious RCU usage [ 19.034142] 5.9.0-rc4-next-20200908 #1 Not tainted [ 19.034143] ----------------------------- [ 19.034143] /usr/src/kernel/include/trace/events/lock.h:37 suspicious rcu_dereference_check() usage! [ 19.034143] [ 19.034144] other info that might help us debug this: [ 19.034144] [ 19.034144] [ 19.034145] rcu_scheduler_active = 2, debug_locks = 1 [ 19.034145] RCU used illegally from extended quiescent state! [ 19.034146] no locks held by swapper/2/0. [ 19.034146] [ 19.034146] stack backtrace: [ 19.034147] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 19.034147] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 19.034147] Call Trace: [ 19.034148] dump_stack+0x7d/0x9f [ 19.034148] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034148] lock_acquire+0x327/0x390 [ 19.034149] _raw_spin_lock+0x2f/0x40 [ 19.034149] ? vprintk_emit+0x78/0x2f0 [ 19.034149] vprintk_emit+0x78/0x2f0 [ 19.034149] vprintk_default+0x1f/0x30 [ 19.034150] vprintk_func+0x51/0xf0 [ 19.034150] printk+0x52/0x6e [ 19.034150] ? __lock_acquire+0x32a/0x19f0 [ 19.034151] lockdep_rcu_suspicious+0x20/0xf0 [ 19.034151] switch_mm_irqs_off+0x441/0x450 [ 19.034151] switch_mm+0x1b/0x50 [ 19.034152] leave_mm+0x34/0x40 [ 19.034152] acpi_idle_enter_bm+0x23/0x120 [ 19.034152] acpi_idle_enter+0x189/0x2a0 [ 19.034153] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.034153] cpuidle_enter_state+0xa5/0x4b0 [ 19.034153] cpuidle_enter+0x2e/0x40 [ 19.034154] do_idle+0x226/0x2b0 [ 19.034154] cpu_startup_entry+0x1d/0x20 [ 19.034154] start_secondary+0x114/0x150 [ 19.034155] secondary_startup_64+0xb6/0xc0 [ 19.034155] [ 19.034155] ============================= [ 19.034156] WARNING: suspicious RCU usage [ 19.034156] 5.9.0-rc4-next-20200908 #1 Not tainted [ 19.034156] ----------------------------- [ 19.034157] /usr/src/kernel/include/trace/events/lock.h:63 suspicious rcu_dereference_check() usage! [ 19.034157] [ 19.034157] other info that might help us debug this: [ 19.034158] [ 19.034158] [ 19.034158] rcu_scheduler_active = 2, debug_locks = 1 [ 19.034159] RCU used illegally from extended quiescent state! [ 19.034159] 1 lock held by swapper/2/0: [ 19.034159] #0: ffffffffbed25f58 (logbuf_lock){-...}-{2:2}, at: vprintk_emit+0x78/0x2f0 [ 19.034161] [ 19.034161] stack backtrace: [ 19.034162] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 19.034162] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 19.034162] Call Trace: [ 19.034163] dump_stack+0x7d/0x9f [ 19.034163] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034163] ? vprintk_emit+0x9e/0x2f0 [ 19.034164] lock_release+0x246/0x270 [ 19.034164] _raw_spin_unlock+0x1a/0x30 [ 19.034164] vprintk_emit+0x9e/0x2f0 [ 19.034165] vprintk_default+0x1f/0x30 [ 19.034165] vprintk_func+0x51/0xf0 [ 19.034165] printk+0x52/0x6e [ 19.034166] ? __lock_acquire+0x32a/0x19f0 [ 19.034166] lockdep_rcu_suspicious+0x20/0xf0 [ 19.034166] switch_mm_irqs_off+0x441/0x450 [ 19.034167] switch_mm+0x1b/0x50 [ 19.034167] leave_mm+0x34/0x40 [ 19.034167] acpi_idle_enter_bm+0x23/0x120 [ 19.034167] acpi_idle_enter+0x189/0x2a0 [ 19.034168] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.034168] cpuidle_enter_state+0xa5/0x4b0 [ 19.034168] cpuidle_enter+0x2e/0x40 [ 19.034169] do_idle+0x226/0x2b0 [ 19.034169] cpu_startup_entry+0x1d/0x20 [ 19.034169] start_secondary+0x114/0x150 [ 19.034170] secondary_startup_64+0xb6/0xc0 [ 19.034170] [ 19.034170] ============================= [ 19.034171] WARNING: suspicious RCU usage [ 19.034171] 5.9.0-rc4-next-20200908 #1 Not tainted [ 19.034171] ----------------------------- [ 19.034172] /usr/src/kernel/include/trace/events/sched.h:90 suspicious rcu_dereference_check() usage! [ 19.034172] [ 19.034172] other info that might help us debug this: [ 19.034173] [ 19.034173] [ 19.034173] rcu_scheduler_active = 2, debug_locks = 1 [ 19.034174] RCU used illegally from extended quiescent state! [ 19.034174] 2 locks held by swapper/2/0: [ 19.034174] #0: ffffffffbed25ff8 ((console_sem).lock){-...}-{2:2}, at: up+0x16/0x50 [ 19.034176] #1: ffff90dbeea90800 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x52/0x7a0 [ 19.034178] [ 19.034178] stack backtrace: [ 19.034178] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 19.034179] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 19.034179] Call Trace: [ 19.034179] dump_stack+0x7d/0x9f [ 19.034180] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034180] try_to_wake_up+0x6a4/0x7a0 [ 19.034180] ? find_held_lock+0x35/0xa0 [ 19.034181] wake_up_process+0x15/0x20 [ 19.034181] __up.isra.4+0x39/0x40 [ 19.034181] up+0x46/0x50 [ 19.034182] __up_console_sem+0x32/0x60 [ 19.034182] console_unlock+0x346/0x5c0 [ 19.034182] vprintk_emit+0x1d1/0x2f0 [ 19.034183] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034183] vprintk_default+0x1f/0x30 [ 19.034183] vprintk_func+0x51/0xf0 [ 19.034184] ? rcu_nmi_exit+0x12a/0x260 [ 19.034184] printk+0x52/0x6e [ 19.034184] ? kernel_text_address+0x96/0xf0 [ 19.034185] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034185] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034185] show_trace_log_lvl+0x32f/0x3b0 [ 19.034186] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034186] show_stack+0x30/0x40 [ 19.034186] dump_stack+0x7d/0x9f [ 19.034186] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034187] switch_mm_irqs_off+0x441/0x450 [ 19.034187] switch_mm+0x1b/0x50 [ 19.034187] leave_mm+0x34/0x40 [ 19.034188] acpi_idle_enter_bm+0x23/0x120 [ 19.034188] acpi_idle_enter+0x189/0x2a0 [ 19.034188] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.034189] cpuidle_enter_state+0xa5/0x4b0 [ 19.034189] cpuidle_enter+0x2e/0x40 [ 19.034189] do_idle+0x226/0x2b0 [ 19.034190] cpu_startup_entry+0x1d/0x20 [ 19.034190] start_secondary+0x114/0x150 [ 19.034190] secondary_startup_64+0xb6/0xc0 [ 19.034191] [ 19.034191] ============================= [ 19.034191] WARNING: suspicious RCU usage [ 19.034192] 5.9.0-rc4-next-20200908 #1 Not tainted [ 19.034192] ----------------------------- [ 19.034192] /usr/src/kernel/include/linux/rcupdate.h:643 rcu_read_lock() used illegally while idle! [ 19.034193] [ 19.034193] other info that might help us debug this: [ 19.034193] [ 19.034194] [ 19.034194] rcu_scheduler_active = 2, debug_locks = 1 [ 19.034194] RCU used illegally from extended quiescent state! [ 19.034195] 3 locks held by swapper/2/0: [ 19.034195] #0: ffffffffbed25ff8 ((console_sem).lock){-...}-{2:2}, at: up+0x16/0x50 [ 19.034196] #1: ffff90dbeea90800 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x52/0x7a0 [ 19.034198] #2: ffffffffbed28580 (rcu_read_lock){....}-{1:2}, at: select_task_rq_fair+0xd0/0x10a0 [ 19.034199] [ 19.034200] stack backtrace: [ 19.034200] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 19.034201] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 19.034201] Call Trace: [ 19.034201] dump_stack+0x7d/0x9f [ 19.034202] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034202] select_task_rq_fair+0x4aa/0x10a0 [ 19.034202] ? show_stack+0x30/0x40 [ 19.034203] try_to_wake_up+0x181/0x7a0 [ 19.034203] ? find_held_lock+0x35/0xa0 [ 19.034203] wake_up_process+0x15/0x20 [ 19.034203] __up.isra.4+0x39/0x40 [ 19.034204] up+0x46/0x50 [ 19.034204] __up_console_sem+0x32/0x60 [ 19.034204] console_unlock+0x346/0x5c0 [ 19.034205] vprintk_emit+0x1d1/0x2f0 [ 19.034205] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034205] vprintk_default+0x1f/0x30 [ 19.034206] vprintk_func+0x51/0xf0 [ 19.034206] ? rcu_nmi_exit+0x12a/0x260 [ 19.034206] printk+0x52/0x6e [ 19.034207] ? kernel_text_address+0x96/0xf0 [ 19.034207] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034207] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034208] show_trace_log_lvl+0x32f/0x3b0 [ 19.034208] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034208] show_stack+0x30/0x40 [ 19.034209] dump_stack+0x7d/0x9f [ 19.034209] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034209] switch_mm_irqs_off+0x441/0x450 [ 19.034210] switch_mm+0x1b/0x50 [ 19.034210] leave_mm+0x34/0x40 [ 19.034210] acpi_idle_enter_bm+0x23/0x120 [ 19.034211] acpi_idle_enter+0x189/0x2a0 [ 19.034211] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.034211] cpuidle_enter_state+0xa5/0x4b0 [ 19.034212] cpuidle_enter+0x2e/0x40 [ 19.034212] do_idle+0x226/0x2b0 [ 19.034212] cpu_startup_entry+0x1d/0x20 [ 19.034213] start_secondary+0x114/0x150 [ 19.034213] secondary_startup_64+0xb6/0xc0 [ 19.034213] [ 19.034214] ============================= [ 19.034214] WARNING: suspicious RCU usage [ 19.034214] 5.9.0-rc4-next-20200908 #1 Not tainted [ 19.034215] ----------------------------- [ 19.034215] /usr/src/kernel/kernel/sched/fair.c:6694 suspicious rcu_dereference_check() usage! [ 19.034215] [ 19.034216] other info that might help us debug this: [ 19.034216] [ 19.034216] [ 19.034217] rcu_scheduler_active = 2, debug_locks = 1 [ 19.034217] RCU used illegally from extended quiescent state! [ 19.034217] 3 locks held by swapper/2/0: [ 19.034217] #0: ffffffffbed25ff8 ((console_sem).lock){-...}-{2:2}, at: up+0x16/0x50 [ 19.034219] #1: ffff90dbeea90800 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x52/0x7a0 [ 19.034220] #2: ffffffffbed28580 (rcu_read_lock){....}-{1:2}, at: select_task_rq_fair+0xd0/0x10a0 [ 19.034222] [ 19.034222] stack backtrace: [ 19.034223] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 5.9.0-rc4-next-20200908 #1 [ 19.034223] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 19.034223] Call Trace: [ 19.034224] dump_stack+0x7d/0x9f [ 19.034224] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034224] select_task_rq_fair+0x448/0x10a0 [ 19.034225] ? show_stack+0x30/0x40 [ 19.034225] try_to_wake_up+0x181/0x7a0 [ 19.034225] ? find_held_lock+0x35/0xa0 [ 19.034226] wake_up_process+0x15/0x20 [ 19.034226] __up.isra.4+0x39/0x40 [ 19.034226] up+0x46/0x50 [ 19.034227] __up_console_sem+0x32/0x60 [ 19.034227] console_unlock+0x346/0x5c0 [ 19.034227] vprintk_emit+0x1d1/0x2f0 [ 19.034228] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034228] vprintk_default+0x1f/0x30 [ 19.034228] vprintk_func+0x51/0xf0 [ 19.034228] ? rcu_nmi_exit+0x12a/0x260 [ 19.034229] printk+0x52/0x6e [ 19.034229] ? kernel_text_address+0x96/0xf0 [ 19.034229] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034230] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034230] show_trace_log_lvl+0x32f/0x3b0 [ 19.034230] ? cpuidle_enter_state+0xa5/0x4b0 [ 19.034231] show_stack+0x30/0x40 [ 19.034231] dump_stack+0x7d/0x9f [ 19.034231] lockdep_rcu_suspicious+0xce/0xf0 [ 19.034232] switch_mm_irqs_off+0x441/0x450 [ 19.034232] switch_mm+0x1b/0x50 [ 19.034232] leave_mm+0x34/0x40 [ 19.034233] acpi_idle_enter_bm+0x23/0x120 [ 19.034233] acpi_idle_enter+0x189/0x2a0 [ 19.034233] ? rcu_eqs_enter.constprop.85+0xb2/0x180 [ 19.034234] cpuidle_enter_state+0xa5/0x4b0 [ 19.034234] cpuidle_enter+0x2e/0x40 [ 19.034234] do_idle+0x226/0x2b0 [ 19.034235] cpu_startup_entry+0x1d/0x20 [ 19.034235] start_secondary+0x114/0x150 [ 19.034235] secondary_startup_64+0xb6/0xc0 Full test log, https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20200908/testrun/3171064/suite/linux-log-parser/test/check-kernel-bug-1743477/log -- Linaro LKFT https://lkft.linaro.org
