Re: Fatal trap 12: .. cpu_idle_acpi .. callout_process

From: Bjoern A. Zeeb <bzeeb-lists_at_lists.zabbadoz.net>
Date: Wed, 03 Jun 2026 04:20:14 UTC
On Wed, 27 May 2026, Bjoern A. Zeeb wrote:

> On Tue, 26 May 2026, Bjoern A. Zeeb wrote:
>
>> Hi,
>> 
>> I got some LinuxKPI problems sorted and can finally shutdown a system w/o
>> a driver panicing but now I see on a recent main (pxe booted in bhyve);
>> this seems reproducible and typing reset I get the next panic and the next
>> and the next and ... until bhyve stops after scrolling for a few seconds.
>> 
>> Anyone seen this or any ideas?  I'll try to build a plain main kernel 
>> otherwise
>> to check that it's not anything else...
>
> I have already found the next LinuxKPI bug.
>
> If I just boot a kernel and do a shutdown -r I do not run into it
> so unless it rings a bell for someone else as well, please ignore this for 
> now.

It just happened again;  no known LinuxKPI bugs in the way this time.

So maybe it's real after all...


>> Syncing disks, vnodes remaining... 0 done
>> All buffers synced.
>> Uptime: 46s
>> kernel trap 12 with interrupts disabled
>> 
>> 
>> Fatal trap 12: page fault while in kernel mode
>> cpuid = 0; apic id = 00
>> fault virtual address   = 0xfffffe00a58a0630
>> fault code              = supervisor read data, page not present
>> instruction pointer     = 0x20:0xffffffff80c0ebe8
>> stack pointer           = 0x28:0xfffffe008bc49bb0
>> frame pointer           = 0x28:0xfffffe008bc49c20
>> code segment            = base 0x0, limit 0xfffff, type 0x1b
>>                        = DPL 0, pres 1, long 1, def32 0, gran 1
>> processor eflags        = resume, IOPL = 0
>> current process         = 11 (idle: cpu0)
>> rdi: 0000000000002f2c rsi: 0000000000008000 rdx: 0000000000002e2d
>> rcx: 0000000000002e2c  r8: fffffe00a58a0630  r9: 000000007fff2744
>> rax: fffffe000ef4e000 rbx: 0000000000002e2c rbp: fffffe008bc49c20
>> r10: 00000000000003e7 r11: 000000000000044c r12: 0000002f2d000000
>> r13: 0000002f2d000000 r14: 0000002e2dd1597a r15: ffffffff82b28300
>> trap number             = 12
>> panic: page fault
>> cpuid = 0
>> time = 1779819492
>> KDB: stack backtrace:
>> db_trace_self_wrapper() at db_trace_self_wrapper+0x36/frame 
>> 0xfffffe008bc498e0
>> vpanic() at vpanic+0x149/frame 0xfffffe008bc49a10
>> panic() at panic+0x43/frame 0xfffffe008bc49a70
>> trap_pfault() at trap_pfault+0x449/frame 0xfffffe008bc49ae0
>> calltrap() at calltrap+0x8/frame 0xfffffe008bc49ae0
>> --- trap 0xc, rip = 0xffffffff80c0ebe8, rsp = 0xfffffe008bc49bb0, rbp = 
>> 0xfffffe008bc49c20 ---
>> callout_process() at callout_process+0x138/frame 0xfffffe008bc49c20
>> handleevents() at handleevents+0x19a/frame 0xfffffe008bc49c60
>> timercb() at timercb+0x19e/frame 0xfffffe008bc49cc0
>> lapic_handle_timer() at lapic_handle_timer+0xa4/frame 0xfffffe008bc49cf0
>> Xtimerint() at Xtimerint+0xb1/frame 0xfffffe008bc49cf0
>> --- interrupt, rip = 0xffffffff810b1104, rsp = 0xfffffe008bc49dc0, rbp = 
>> 0xfffffe008bc49dd0 ---
>> cpu_idle_acpi() at cpu_idle_acpi+0x54/frame 0xfffffe008bc49dd0
>> cpu_idle() at cpu_idle+0xa6/frame 0xfffffe008bc49df0
>> sched_ule_idletd() at sched_ule_idletd+0x524/frame 0xfffffe008bc49ef0
>> fork_exit() at fork_exit+0x82/frame 0xfffffe008bc49f30
>> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe008bc49f30
>> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
>> KDB: enter: panic
>> [ thread pid 11 tid 100003 ]
>> Stopped at      kdb_enter+0x33: movq    $0,0x15be0c2(%rip)
>> db> reset
>> panic: mtx_lock_spin: recursed on non-recursive mutex callout @ 
>> /usr/src/sys/kern/kern_timeout.c:576
>> 
>> cpuid = 0
>> time = 1779819492
>> KDB: stack backtrace:
>> db_trace_self_wrapper() at db_trace_self_wrapper+0x36/frame 
>> 0xfffffe008bc49160
>> vpanic() at vpanic+0x149/frame 0xfffffe008bc49290
>> panic() at panic+0x43/frame 0xfffffe008bc492f0
>> __mtx_lock_spin_flags() at __mtx_lock_spin_flags+0x11b/frame 
>> 0xfffffe008bc49330
>> _callout_stop_safe() at _callout_stop_safe+0x106/frame 0xfffffe008bc493a0
>> shutdown_resettodr() at shutdown_resettodr+0x15/frame 0xfffffe008bc493b0
>> kern_reboot() at kern_reboot+0x2a3/frame 0xfffffe008bc493f0
>> db_reset() at db_reset+0x108/frame 0xfffffe008bc49420
>> db_command() at db_command+0x3aa/frame 0xfffffe008bc494e0
>> db_command_loop() at db_command_loop+0x4d/frame 0xfffffe008bc494f0
>> db_trap() at db_trap+0x100/frame 0xfffffe008bc49590
>> kdb_trap() at kdb_trap+0x25f/frame 0xfffffe008bc496e0
>> trap() at trap+0x888/frame 0xfffffe008bc49810
>> calltrap() at calltrap+0x8/frame 0xfffffe008bc49810
>> --- trap 0x3, rip = 0xffffffff80c44f43, rsp = 0xfffffe008bc498e8, rbp = 
>> 0xfffffe008bc49a10 ---
>> kdb_enter() at kdb_enter+0x33/frame 0xfffffe008bc49a10
>> panic() at panic+0x43/frame 0xfffffe008bc49a70
>> trap_pfault() at trap_pfault+0x449/frame 0xfffffe008bc49ae0
>> calltrap() at calltrap+0x8/frame 0xfffffe008bc49ae0
>> --- trap 0xc, rip = 0xffffffff80c0ebe8, rsp = 0xfffffe008bc49bb0, rbp = 
>> 0xfffffe008bc49c20 ---
>> callout_process() at callout_process+0x138/frame 0xfffffe008bc49c20
>> handleevents() at handleevents+0x19a/frame 0xfffffe008bc49c60
>> timercb() at timercb+0x19e/frame 0xfffffe008bc49cc0
>> lapic_handle_timer() at lapic_handle_timer+0xa4/frame 0xfffffe008bc49cf0
>> Xtimerint() at Xtimerint+0xb1/frame 0xfffffe008bc49cf0
>> --- interrupt, rip = 0xffffffff810b1104, rsp = 0xfffffe008bc49dc0, rbp = 
>> 0xfffffe008bc49dd0 ---
>> cpu_idle_acpi() at cpu_idle_acpi+0x54/frame 0xfffffe008bc49dd0
>> cpu_idle() at cpu_idle+0xa6/frame 0xfffffe008bc49df0
>> sched_ule_idletd() at sched_ule_idletd+0x524/frame 0xfffffe008bc49ef0
>> fork_exit() at fork_exit+0x82/frame 0xfffffe008bc49f30
>> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe008bc49f30
>> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
>> panic: mtx_lock_spin: recursed on non-recursive mutex callout @ 
>> /usr/src/sys/kern/kern_timeout.c:576
>> 
>> cpuid = 0
>> time = 1779819492
>> ..
>> ..
>> ..
>> 
>> 
>> 
>
>

-- 
Bjoern A. Zeeb                                                     r15:7