kern/56525: panic from spdmem iic search

[Hauke Fath <hf%spg.tu-darmstadt.de@localhost>]

>Number:         56525
>Category:       kern
>Synopsis:       panic from spdmem iic search
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Nov 27 12:40:00 +0000 2021
>Originator:     Hauke Fath <hf%spg.tu-darmstadt.de@localhost>
>Release:        NetBSD 9.2_STABLE
>Organization:
Technische Universitaet Darmstadt
>Environment:
	
	
System: NetBSD Grossglockner 9.2_STABLE NetBSD 9.2_STABLE (RADMINDSRV) #1: Mon Nov 22 18:40:43 CET 2021 hf@Hochstuhl:/var/obj/netbsd-builds/9/amd64/sys/arch/amd64/compile/RADMINDSRV amd64
Architecture: x86_64
Machine: amd64
>Description:

	On an amd64 server (Supermicro H8DCL-iF board, AMD 4226 cpu,
	DDR3L-1600 ECC RAM), I enabled

spdmem* at iic? addr 0x50
spdmem* at iic? addr 0x51
spdmem* at iic? addr 0x52
spdmem* at iic? addr 0x53
spdmem* at iic? addr 0x54
spdmem* at iic? addr 0x55
spdmem* at iic? addr 0x56
spdmem* at iic? addr 0x57
sdtemp* at iic? addr 0x18
sdtemp* at iic? addr 0x19
sdtemp* at iic? addr 0x1a
sdtemp* at iic? addr 0x1b
sdtemp* at iic? addr 0x1c
sdtemp* at iic? addr 0x1d
sdtemp* at iic? addr 0x1e
sdtemp* at iic? addr 0x1f

which lead to a panic during startup:

[   1.0469023] piixpm0 at pci0 dev 20 function 0: vendor 1002 product 4385 (rev. 0x3d)
[   1.0469023] piixpm0: interrupting at SMI, 
[   1.0469023] iic0 at piixpm0 port 0: I2C bus
[   1.0469023] prevented execution of 0x0 (SMEP)
[   1.0469023] fatal page fault in supervisor mode
[   1.0469023] trap type 6 code 0x10 rip 0 cs 0x8 rflags 0x10202 cr2 0 ilevel 0x8 rsp 0xffffffff81adb368
[   1.0469023] curlwp 0xffffffff8165c4c0 pid 0.1 lowest kstack 0xffffffff81ad72c0
kernel: page fault trap, code=0
Stopped in pid 0.1 (system) at  0:      address 0x0 is invalid
push    %ds
db{0}> t
?() at 0
spdmem_i2c_match.part.0() at netbsd:spdmem_i2c_match.part.0+0x4d
spdmem_i2c_match() at netbsd:spdmem_i2c_match+0x4f
iic_search() at netbsd:iic_search+0x1eb
mapply() at netbsd:mapply+0x39
config_search_loc() at netbsd:config_search_loc+0xfe
iic_attach() at netbsd:iic_attach+0x409
config_attach_loc() at netbsd:config_attach_loc+0x1a5
config_found_sm_loc() at netbsd:config_found_sm_loc+0x48
piixpm_rescan() at netbsd:piixpm_rescan+0xf1
piixpm_attach() at netbsd:piixpm_attach+0x4ab
config_attach_loc() at netbsd:config_attach_loc+0x1a5
config_found_sm_loc() at netbsd:config_found_sm_loc+0x48
pci_probe_device() at netbsd:pci_probe_device+0x60c
pci_enumerate_bus() at netbsd:pci_enumerate_bus+0x1b7
pcirescan() at netbsd:pcirescan+0x4e
pciattach() at netbsd:pciattach+0x193
config_attach_loc() at netbsd:config_attach_loc+0x1a5
config_found_sm_loc() at netbsd:config_found_sm_loc+0x48
mp_pci_scan() at netbsd:mp_pci_scan+0xaa
amd64_mainbus_attach() at netbsd:amd64_mainbus_attach+0x22c
mainbus_attach() at netbsd:mainbus_attach+0x74
config_attach_loc() at netbsd:config_attach_loc+0x1a5
cpu_configure() at netbsd:cpu_configure+0x2b
main() at netbsd:main+0x351
db{0}> 

	
>How-To-Repeat:

	Attempt to configure spdmem/sdtemp devices on an older AMD
	Opteron server board.

	
>Fix:
	
	No idea.

>Unformatted: