Using xarray in kprobes cause RCU error

gistfile1.txt

[381] Probing on seq_hlist_start    7 sec
[382] Probing on __x64_sys_finit_module    7 sec
[383] Probing on vgacon_set_palette    7 sec
[384] Probing on cp_compat_stat    7 sec
[385] Probing on smp_call_function_single_interrupt    [   37.669723] 
[   37.672350] =============================
[   37.675551] WARNING: suspicious RCU usage
[   37.678733] 4.20.0-rc7+ #29 Not tainted
[   37.681849] -----------------------------
[   37.685034] /home/mhiramat/ksrc/linux/include/linux/rcupdate.h:609 rcu_read_lock() used illegally while idle!
[   37.720599] 
[   37.720599] other info that might help us debug this:
[   37.720599] 
[   37.726645] 
[   37.726645] RCU used illegally from idle CPU!
[   37.726645] rcu_scheduler_active = 2, debug_locks = 1
[   37.734121] RCU used illegally from extended quiescent state!
[   37.737104] 1 lock held by swapper/5/0:
[   37.739572]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   37.744176] 
[   37.744176] stack backtrace:
[   37.747887] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   37.751171] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   37.756894] Call Trace:
[   37.759138]  <IRQ>
[   37.761259]  dump_stack+0x67/0x9b
[   37.763952]  xa_load+0x10a/0x160
[   37.766343]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.769335]  get_kprobe_cached+0x94/0xf0
[   37.771900]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.775280]  kprobe_ftrace_handler+0x18/0x120
[   37.778312]  ftrace_ops_assist_func+0x5e/0x120
[   37.781300]  0xffffffffa00000bf
[   37.783839]  ? call_function_single_interrupt+0xa/0x20
[   37.787021]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   37.790270]  smp_call_function_single_interrupt+0x5/0x1e0
[   37.793304]  call_function_single_interrupt+0xf/0x20
[   37.797153]  </IRQ>
[   37.799496] RIP: 0010:default_idle+0x1c/0x150
[   37.802810] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   37.815278] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   37.821290] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   37.825914] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   37.830791] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   37.835480] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   37.840144] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   37.844844]  ? default_idle+0x1a/0x150
[   37.847876]  default_idle_call+0x24/0x30
[   37.850999]  do_idle+0x1fe/0x230
[   37.853797]  ? trace_hardirqs_on+0x2c/0xe0
[   37.856988]  cpu_startup_entry+0x19/0x20
[   37.860804]  start_secondary+0x190/0x1c0
[   37.864028]  secondary_startup_64+0xa4/0xb0
[   37.867362] 
[   37.869318] =============================
[   37.872552] WARNING: suspicious RCU usage
[   37.875804] 4.20.0-rc7+ #29 Not tainted
[   37.878878] -----------------------------
[   37.882042] /home/mhiramat/ksrc/linux/include/linux/xarray.h:887 suspicious rcu_dereference_check() usage!
[   37.889057] 
[   37.889057] other info that might help us debug this:
[   37.889057] 
[   37.897300] 
[   37.897300] RCU used illegally from idle CPU!
[   37.897300] rcu_scheduler_active = 2, debug_locks = 1
[   37.905939] RCU used illegally from extended quiescent state!
[   37.909941] 1 lock held by swapper/5/0:
[   37.913015]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   37.918832] 
[   37.918832] stack backtrace:
[   37.923385] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   37.927204] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   37.932968] Call Trace:
[   37.935280]  <IRQ>
[   37.937240]  dump_stack+0x67/0x9b
[   37.939907]  xas_start+0x134/0x1c0
[   37.942264]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.945059]  xas_load+0x12/0xf0
[   37.947318]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.950184]  xa_load+0x80/0x160
[   37.952630]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.955797]  get_kprobe_cached+0x94/0xf0
[   37.958388]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   37.961698]  kprobe_ftrace_handler+0x18/0x120
[   37.964278]  ftrace_ops_assist_func+0x5e/0x120
[   37.966932]  0xffffffffa00000bf
[   37.969132]  ? call_function_single_interrupt+0xa/0x20
[   37.971995]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   37.974996]  smp_call_function_single_interrupt+0x5/0x1e0
[   37.977966]  call_function_single_interrupt+0xf/0x20
[   37.980704]  </IRQ>
[   37.982644] RIP: 0010:default_idle+0x1c/0x150
[   37.985284] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   37.995221] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   37.999865] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   38.003264] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   38.006650] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   38.010060] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   38.013450] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   38.016841]  ? default_idle+0x1a/0x150
[   38.019609]  default_idle_call+0x24/0x30
[   38.022485]  do_idle+0x1fe/0x230
[   38.024776]  ? trace_hardirqs_on+0x2c/0xe0
[   38.027303]  cpu_startup_entry+0x19/0x20
[   38.029736]  start_secondary+0x190/0x1c0
[   38.032175]  secondary_startup_64+0xa4/0xb0
[   38.034680] 
[   38.036362] =============================
[   38.038800] WARNING: suspicious RCU usage
[   38.041256] 4.20.0-rc7+ #29 Not tainted
[   38.043659] -----------------------------
[   38.046190] /home/mhiramat/ksrc/linux/include/linux/xarray.h:903 suspicious rcu_dereference_check() usage!
[   38.052286] 
[   38.052286] other info that might help us debug this:
[   38.052286] 
[   38.058381] 
[   38.058381] RCU used illegally from idle CPU!
[   38.058381] rcu_scheduler_active = 2, debug_locks = 1
[   38.065499] RCU used illegally from extended quiescent state!
[   38.068548] 1 lock held by swapper/5/0:
[   38.070997]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   38.075644] 
[   38.075644] stack backtrace:
[   38.079373] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   38.082628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   38.087735] Call Trace:
[   38.089765]  <IRQ>
[   38.091677]  dump_stack+0x67/0x9b
[   38.093972]  xas_load+0xe9/0xf0
[   38.096222]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.099089]  xa_load+0x80/0x160
[   38.101334]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.104203]  get_kprobe_cached+0x94/0xf0
[   38.106701]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.109563]  kprobe_ftrace_handler+0x18/0x120
[   38.112158]  ftrace_ops_assist_func+0x5e/0x120
[   38.114953]  0xffffffffa00000bf
[   38.117203]  ? call_function_single_interrupt+0xa/0x20
[   38.120522]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   38.124561]  smp_call_function_single_interrupt+0x5/0x1e0
[   38.127798]  call_function_single_interrupt+0xf/0x20
[   38.130584]  </IRQ>
[   38.132471] RIP: 0010:default_idle+0x1c/0x150
[   38.135042] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   38.144174] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   38.148876] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   38.152551] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   38.156487] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   38.159903] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   38.163439] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   38.166849]  ? default_idle+0x1a/0x150
[   38.169268]  default_idle_call+0x24/0x30
[   38.171929]  do_idle+0x1fe/0x230
[   38.174500]  ? trace_hardirqs_on+0x2c/0xe0
[   38.176983]  cpu_startup_entry+0x19/0x20
[   38.179538]  start_secondary+0x190/0x1c0
[   38.182145]  secondary_startup_64+0xa4/0xb0
[   38.184865] 
[   38.186569] =============================
[   38.190637] WARNING: suspicious RCU usage
[   38.193122] 4.20.0-rc7+ #29 Not tainted
[   38.196089] -----------------------------
[   38.199047] /home/mhiramat/ksrc/linux/include/linux/rcupdate.h:658 rcu_read_unlock() used illegally while idle!
[   38.205188] 
[   38.205188] other info that might help us debug this:
[   38.205188] 
[   38.211224] 
[   38.211224] RCU used illegally from idle CPU!
[   38.211224] rcu_scheduler_active = 2, debug_locks = 1
[   38.218208] RCU used illegally from extended quiescent state!
[   38.221200] 1 lock held by swapper/5/0:
[   38.248335]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   38.252923] 
[   38.252923] stack backtrace:
[   38.256827] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   38.260495] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   38.265623] Call Trace:
[   38.267650]  <IRQ>
[   38.269552]  dump_stack+0x67/0x9b
[   38.271838]  xa_load+0x137/0x160
[   38.274284]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.277225]  get_kprobe_cached+0x94/0xf0
[   38.279725]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.282637]  kprobe_ftrace_handler+0x18/0x120
[   38.285573]  ftrace_ops_assist_func+0x5e/0x120
[   38.288547]  0xffffffffa00000bf
[   38.290807]  ? call_function_single_interrupt+0xa/0x20
[   38.294090]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   38.297242]  smp_call_function_single_interrupt+0x5/0x1e0
[   38.300116]  call_function_single_interrupt+0xf/0x20
[   38.302901]  </IRQ>
[   38.304769] RIP: 0010:default_idle+0x1c/0x150
[   38.307451] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   38.317664] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   38.322354] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   38.325898] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   38.329427] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   38.332903] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   38.336412] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   38.340153]  ? default_idle+0x1a/0x150
[   38.342543]  default_idle_call+0x24/0x30
[   38.344986]  do_idle+0x1fe/0x230
[   38.347227]  ? trace_hardirqs_on+0x2c/0xe0
[   38.349698]  cpu_startup_entry+0x19/0x20
[   38.352215]  start_secondary+0x190/0x1c0
[   38.354837]  secondary_startup_64+0xa4/0xb0
[   38.357799] 
8 sec
[   38.357800] =============================
[386] Probing on __uncore_umask_show    [   38.357800] WARNING: suspicious RCU usage
[   38.357800] 4.20.0-rc7+ #29 Not tainted
[   38.357801] -----------------------------
[   38.357801] /home/mhiramat/ksrc/linux/include/linux/rcupdate.h:609 rcu_read_lock() used illegally while idle!
[   38.357802] 
[   38.357802] other info that might help us debug this:
[   38.357803] 
[   38.357803] 
[   38.357803] RCU used illegally from idle CPU!
[   38.357804] rcu_scheduler_active = 2, debug_locks = 1
[   38.357804] RCU used illegally from extended quiescent state!
[   38.357805] 5 locks held by swapper/5/0:
[   38.357805]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   38.357807]  #1: 00000000ffadd4fd (console_lock){+.+.}, at: vprintk_emit+0xdf/0x280
[   38.357809]  #2: 00000000bae6bdc1 (console_owner){-...}, at: console_unlock+0x13c/0x5c0
[   38.357811]  #3: 00000000df0b409b (printing_lock){....}, at: vt_console_print+0x78/0x3f0
[   38.357813]  #4: 00000000732d2139 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x5/0x100
[   38.357815] 
[   38.357815] stack backtrace:
[   38.357816] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   38.357816] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   38.357817] Call Trace:
[   38.357817]  <IRQ>
[   38.357827]  dump_stack+0x67/0x9b
[   38.357828]  atomic_notifier_call_chain+0xcc/0x100
[   38.357828]  vt_console_print+0x171/0x3f0
[   38.357829]  ? console_unlock+0x13c/0x5c0
[   38.357829]  console_unlock+0x47e/0x5c0
[   38.357830]  ? __down_trylock_console_sem+0x76/0x80
[   38.357830]  vprintk_emit+0xe8/0x280
[   38.357830]  printk+0x52/0x6e
[   38.357831]  ? xa_clear_mark+0x30/0x30
[   38.357831]  lockdep_rcu_suspicious+0x1b/0xf0
[   38.357832]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357832]  xa_load+0x10a/0x160
[   38.357832]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357833]  get_kprobe_cached+0x94/0xf0
[   38.357833]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357834]  kprobe_ftrace_handler+0x18/0x120
[   38.357834]  ftrace_ops_assist_func+0x5e/0x120
[   38.357834]  0xffffffffa00000bf
[   38.357835]  ? call_function_single_interrupt+0xa/0x20
[   38.357835]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   38.357836]  smp_call_function_single_interrupt+0x5/0x1e0
[   38.357836]  call_function_single_interrupt+0xf/0x20
[   38.357836]  </IRQ>
[   38.357837] RIP: 0010:default_idle+0x1c/0x150
[   38.357838] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   38.357838] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   38.357839] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   38.357840] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   38.357840] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   38.357841] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   38.357841] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   38.357842]  ? default_idle+0x1a/0x150
[   38.357842]  default_idle_call+0x24/0x30
[   38.357842]  do_idle+0x1fe/0x230
[   38.357843]  ? trace_hardirqs_on+0x2c/0xe0
[   38.357843]  cpu_startup_entry+0x19/0x20
[   38.357843]  start_secondary+0x190/0x1c0
[   38.357844]  secondary_startup_64+0xa4/0xb0
[   38.357844] 
[   38.357845] =============================
[   38.357845] WARNING: suspicious RCU usage
[   38.357845] 4.20.0-rc7+ #29 Not tainted
[   38.357846] -----------------------------
[   38.357846] /home/mhiramat/ksrc/linux/include/linux/rcupdate.h:658 rcu_read_unlock() used illegally while idle!
[   38.357847] 
[   38.357847] other info that might help us debug this:
[   38.357847] 
[   38.357848] 
[   38.357848] RCU used illegally from idle CPU!
[   38.357849] rcu_scheduler_active = 2, debug_locks = 1
[   38.357849] RCU used illegally from extended quiescent state!
[   38.357849] 5 locks held by swapper/5/0:
[   38.357850]  #0: 00000000732d2139 (rcu_read_lock){....}, at: xa_load+0x0/0x160
[   38.357852]  #1: 00000000ffadd4fd (console_lock){+.+.}, at: vprintk_emit+0xdf/0x280
[   38.357853]  #2: 00000000bae6bdc1 (console_owner){-...}, at: console_unlock+0x13c/0x5c0
[   38.357855]  #3: 00000000df0b409b (printing_lock){....}, at: vt_console_print+0x78/0x3f0
[   38.357857]  #4: 00000000732d2139 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x5/0x100
[   38.357859] 
[   38.357859] stack backtrace:
[   38.357860] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc7+ #29
[   38.357860] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
[   38.357861] Call Trace:
[   38.357861]  <IRQ>
[   38.357861]  dump_stack+0x67/0x9b
[   38.357862]  atomic_notifier_call_chain+0xf6/0x100
[   38.357862]  vt_console_print+0x171/0x3f0
[   38.357863]  ? console_unlock+0x13c/0x5c0
[   38.357863]  console_unlock+0x47e/0x5c0
[   38.357863]  ? __down_trylock_console_sem+0x76/0x80
[   38.357864]  vprintk_emit+0xe8/0x280
[   38.357864]  printk+0x52/0x6e
[   38.357865]  ? xa_clear_mark+0x30/0x30
[   38.357865]  lockdep_rcu_suspicious+0x1b/0xf0
[   38.357865]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357870]  xa_load+0x10a/0x160
[   38.357871]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357871]  get_kprobe_cached+0x94/0xf0
[   38.357872]  ? smp_call_function_interrupt+0x1e0/0x1e0
[   38.357874]  kprobe_ftrace_handler+0x18/0x120
[   38.357876]  ftrace_ops_assist_func+0x5e/0x120
[   38.357876]  0xffffffffa00000bf
[   38.357877]  ? call_function_single_interrupt+0xa/0x20
[   38.357878]  ? smp_call_function_single_interrupt+0x5/0x1e0
[   38.357879]  smp_call_function_single_interrupt+0x5/0x1e0
[   38.357879]  call_function_single_interrupt+0xf/0x20
[   38.357880]  </IRQ>
[   38.357881] RIP: 0010:default_idle+0x1c/0x150
[   38.357882] Code: 44 00 00 48 89 f2 31 f6 e9 41 61 d9 ff 90 0f 1f 44 00 00 41 55 41 54 55 53 e8 b0 2a cc ff 0f 1f 44 00 00 e8 66 7b 9e ff fb f4 <e8> 9f 2a cc ff 89 c5 0f 1f 44 00 00 5b 5d 41 5c 41 5d c3 65 8b 05
[   38.357882] RSP: 0018:ffffc9000014beb8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff04
[   38.357884] RAX: ffff88801ee90000 RBX: 0000000000000005 RCX: 0000000000000000
[   38.357885] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88801ee90000
[   38.357886] RBP: ffffffff82119818 R08: 0000000000000000 R09: 0000000000000000
[   38.357887] R10: 0000000000000001 R11: 4f5b7acdfb6fba6f R12: 0000000000000000
[   38.357887] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   38.357888]  ? default_idle+0x1a/0x150
[   38.357888]  default_idle_call+0x24/0x30
[   38.357889]  do_idle+0x1fe/0x230
[   38.357889]  ? trace_hardirqs_on+0x2c/0xe0
[   38.357890]  cpu_startup_entry+0x19/0x20
[   38.357890]  start_secondary+0x190/0x1c0
[   38.357891]  secondary_startup_64+0xa4/0xb0
8 sec

smp_call_function_single_interrupt() is rcu-safe, but not rcu-"assert"-safe, since a kind of assert check flag is set in it.
generic_smp_call_function_single_interrupt() is safe for both.