# Fatal trap 12: page fault while in kernel mode when trying to start or install FreeBSD 12.2-RELEASE



## melancholy (Mar 23, 2021)

Hi,

I get the above errormessage when trying to start FreeBSD 12.2 on an old Dell Poweredge R230.
Have tried it on 3 different R230 with pretty much identical HW configurations so shouldn´t be a hardware issue.
Previous FreeBSD versions work, also FreeBSD 13.0 and 13.0-RC2 got installed without a hitch.

I have updated BIOS and the RAID controller to the latest versions, 2.11.0 and ´Dell PERC H330 Mini/Adapter RAID Controllers firmware version 25.5.8.0001´ respectively.
Very grateful for any help I can get on this



```
Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x0
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff806d040b
stack pointer           = 0x28:0xfffffe003f3e0840
frame pointer           = 0x28:0xfffffe003fe0870
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, uhub0: <0x8086 XHCI root
B, class9/0, rev 3.00/1.00, addr 1> on usbus0
IOPL = 0
current process         = 13 (g_down)
trap number             = 12
panic: page fault
cpuid = 3
time = 1
KDB: stack backtrace:
#0 0xffffffff80c0a8f5 at kbd_backtrace+0x65
#1 0xffffffff80bbe01b at vpanic+0x17b
#2 0xffffffff80bbe993 at panic+00x43
#3 0xffffffff8108f911 at trap_fatal+0x391
#4 0xffffffff8108f96f at trap_pfault+0x4f
#5 0xffffffff8108efb6 at trap+0x286
#6 0xffffffff81066f38 at calltrap+0x8
#7 0xffffffff806c92b8 at mfi_send_frame+0x28
#8 0xffffffff806c91a9 at mfi_data_cb+0x359
#9 0xffffffff80c00382 at bus_dmamap_load_bio+0xb2
#10 0xffffffff806c8cce at mfi_mapcmd+0xae
#11 0xffffffff806c802b at mfi_startio+0xdb
#12 0xffffffff806ce3d9 at mfi_syspd_strategy+0x99
#13 0xffffffff80b07d85 at g_disk_start+0x325
#14 0xffffffff80b0bd49 at g_io_schedule_down+0x169
#15 0xffffffff80b0c57c at g_down_procbody+0x6c
#16 0xffffffff80b8044e at fork_exit+0x7e
#17 0xffffffff81067f6e at fork_trampoline+0xe
Uptime: 1s
```


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## zirias@ (Mar 23, 2021)

Pragmatic solution: Just use 13 – it's only a few days from official RELEASE. 

But then, what you describe ist most probably indeed a bug, so I'd suggest you open a PR with your findings on https://bugs.freebsd.org/


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## SirDice (Mar 23, 2021)

The crash seems to be related to mfi(4), you probably want to enable mrsas(4) for this system. You can get crashes with certain cards if it tries to attach the mfi(4) driver. Switch to mrsas(4) and it'll work.


```
Using /boot/device.hints (as mentioned below), the	user can provide a
     preference	for the	mrsas driver to	detect a MR-Fusion card	instead	of the
     mfi(4) driver.

	   hw.mfi.mrsas_enable="1"

     At	boot time, the mfi(4) driver will get priority to detect MR-Fusion
     controllers by default.  Before changing this default driver selection
     policy, LSI advises users to understand how the driver selection policy
     works.  LSI's policy is to	provide	priority to the	mfi(4) driver to de-
     tect MR-Fusion cards, but allow for the ability to	choose the mrsas
     driver to detect MR-Fusion	cards.
```


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## melancholy (Mar 29, 2021)

SirDice said:


> The crash seems to be related to mfi(4), you probably want to enable mrsas(4) for this system. You can get crashes with certain cards if it tries to attach the mfi(4) driver. Switch to mrsas(4) and it'll work.
> 
> 
> ```
> ...


Above + also adding `mrsas_load="YES"` to loader.conf(5) (not 100% sure if that was necessary) solved it, thank you very much!


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## SirDice (Mar 29, 2021)

melancholy said:


> not 100% sure if that was necessary


It's not, as I said earlier mrsas(4) is included with the GENERIC kernel, so it's already loaded.


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