Created attachment 296893 [details]
dmesg (kernel 5.13-rc2, Shuttle XPC FS51, Pentium 4)

Happens reproducibly at boot on this machine when DEBUG_HIGHMEM=y is set.

[...]
BUG: unable to handle page fault for address: fffbb000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
*pde = 128f0067 *pte = 00000000 
Oops: 0002 [#1] SMP
CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.13.0-rc2-Pentium4 #3
Hardware name:  /FS51, BIOS 6.00 PG 12/02/2003
Workqueue: ata_sff ata_sff_pio_task
EIP: ioread16_rep+0x25/0x37
Code: ff ff 5f 5d c3 55 89 e5 57 89 d7 3d ff ff 03 00 76 0e 49 78 24 66 8b 10 66 89 17 83 c7 02 eb f2 3d 00 00 01 00 76 08 0f b7 d0 <f3> 66 6d eb 0a ba ef f3 72 d2 e8 7a fd ff ff 5f 5d c3 55 89 e5 57
EAX: 000101f0 EBX: 00000100 ECX: 00000080 EDX: 000001f0
ESI: 00000200 EDI: fffbb000 EBP: c11a5e7c ESP: c11a5e78
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010006
CR0: 80050033 CR2: fffbb000 CR3: 128ed000 CR4: 000006d0
Call Trace:
 ata_sff_data_xfer+0x2b/0x7e
 ? ata_qc_from_tag+0x44/0x44
 ata_pio_sector+0x93/0xff
 ata_pio_sectors+0x2d/0x69
 ata_sff_hsm_move+0x49f/0x543
 ? __delay+0x10/0x12
 ? ata_sff_check_status+0xb/0xd
 ata_sff_pio_task+0x67/0xc6
 process_one_work+0x24f/0x3ba
 worker_thread+0x164/0x1f7
 kthread+0xe5/0xe7
 ? drain_workqueue+0xf5/0xf5
 ? cpu_online+0xb/0xb
 ret_from_fork+0x1c/0x28
Modules linked in:
CR2: 00000000fffbb000
---[ end trace f36e9c8f14912bb4 ]---
EIP: ioread16_rep+0x25/0x37
Code: ff ff 5f 5d c3 55 89 e5 57 89 d7 3d ff ff 03 00 76 0e 49 78 24 66 8b 10 66 89 17 83 c7 02 eb f2 3d 00 00 01 00 76 08 0f b7 d0 <f3> 66 6d eb 0a ba ef f3 72 d2 e8 7a fd ff ff 5f 5d c3 55 89 e5 57
EAX: 000101f0 EBX: 00000100 ECX: 00000080 EDX: 000001f0
ESI: 00000200 EDI: fffbb000 EBP: c11a5e7c ESP: c11a5e78
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010006
CR0: 80050033 CR2: fffbb000 CR3: 128ed000 CR4: 000006d0
note: kworker/0:1[7] exited with preempt_count 2
random: fast init done
printk: console [netcon0] enabled
netconsole: network logging started
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 56s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: vmstat_shepherd, tsc_refine_calibration_work
workqueue events_unbound: flags=0x2
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=2/512 refcnt=4
    in-flight: 8:async_run_entry_fn, 49:async_run_entry_fn
workqueue events_power_efficient: flags=0x80
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: toggle_allocation_gate
workqueue mm_percpu_wq: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
workqueue ata_sff: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/512 refcnt=3
    in-flight: 1802201963:ata_sff_pio_task BAR(52)
workqueue mld: flags=0x40008
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=2
    pending: mld_ifc_work
workqueue ipv6_addrconf: flags=0x40008
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=2
    pending: addrconf_dad_work
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=56s workers=3 idle: 32 5
pool 4: cpus=0-1 flags=0x4 nice=0 hung=56s workers=4 idle: 56 64


 # lspci 
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 651 Host (rev 02)
00:01.0 PCI bridge: Silicon Integrated Systems [SiS] AGP Port (virtual PCI-to-PCI bridge)
00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS962 [MuTIOL Media IO] LPC Controller (rev 14)
00:02.1 SMBus: Silicon Integrated Systems [SiS] SiS961/2/3 SMBus controller
00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 IDE Controller
00:02.7 Multimedia audio controller: Silicon Integrated Systems [SiS] SiS7012 AC'97 Sound Controller (rev a0)
00:03.0 USB controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f)
00:03.1 USB controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f)
00:03.2 USB controller: Silicon Integrated Systems [SiS] USB 1.1 Controller (rev 0f)
00:03.3 USB controller: Silicon Integrated Systems [SiS] USB 2.0 Controller
00:0a.0 Network controller: Ralink corp. RT2500 Wireless 802.11bg (rev 01)
00:0f.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8100/8101L/8139 PCI Fast Ethernet Adapter (rev 10)
00:10.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6306/7/8 [Fire II(M)] IEEE 1394 OHCI Controller (rev 46)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series]
01:00.1 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series] (Secondary)

 # inxi -bZ
System:    Host: hakla04 Kernel: 5.12.5-gentoo-Pentium4 i686 bits: 32 Desktop: MATE 1.24.0 
           Distro: Gentoo Base System release 2.7 
Machine:   Type: Desktop Mobo: Shuttle model: FS51 serial: N/A BIOS: Phoenix v: 6.00 PG date: 12/02/2003 
CPU:       Info: Single Core Intel Pentium 4 [MT] speed: 3063 MHz 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series] driver: radeon v: kernel 
           Display: server: X.Org 1.20.0 driver: ati,radeon unloaded: fbdev,modesetting resolution: 1600x900~60Hz 
           OpenGL: renderer: llvmpipe (LLVM 11.1.0 128 bits) v: 4.5 Mesa 20.3.5 
Network:   Device-1: Ralink RT2500 Wireless 802.11bg driver: rt2500pci 
           Device-2: Realtek RTL-8100/8101L/8139 PCI Fast Ethernet Adapter driver: 8139too