# FreeBSD9 Fatal trap 12 when trying to connect ppp, kernel built with pf vimage altq



## exz (Feb 8, 2012)

I build kernel with options 

```
device          pf
device          pflog
device          pfsync

options         VIMAGE
options         ALTQ
options         ALTQ_CBQ                
options         ALTQ_RED                
options         ALTQ_RIO                
options         ALTQ_HFSC               
options         ALTQ_PRIQ               
options         ALTQ_NOPCC
```
And *I* try connect to server through the ppp in resulting server going reboot

```
Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x18
fault code              = supervisor read, page not present
instruction pointer     = 0x20:0xc0b04dc6
stack pointer           = 0x28:0xd66b297c
frame pointer           = 0x28:0xd66b2994
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 7248 (ppp)
trap number             = 12
panic: page fault
cpuid = 0
KDB: stack backtrace:
#0 0xc0a8bda7 at kdb_backtrace+0x47
#1 0xc0a590d7 at panic+0x117
#2 0xc0d9ad93 at trap_fatal+0x323
#3 0xc0d9ae4d at trap_pfault+0xad
#4 0xc0d9bbd5 at trap+0x465
#5 0xc0d84b2c at calltrap+0x6
#6 0xc0b0a218 at if_alloc+0xb8
#7 0xc0b13f4c at tuncreate+0x11c
#8 0xc0b15d7a at tunopen+0x2a
#9 0xc09705d8 at devfs_open+0x128
#10 0xc0dbb182 at VOP_OPEN_APV+0x42
#11 0xc0af9ab1 at vn_open_cred+0x541
#12 0xc0af9c1b at vn_open+0x3b
#13 0xc0af108c at kern_openat+0x1ec
#14 0xc0af14b5 at kern_open+0x35
#15 0xc0af14f0 at sys_open+0x30
#16 0xc0d9b3b5 at syscall+0x355
#17 0xc0d84b91 at Xint0x80_syscall+0x21
```

I boot kernel.old with vimage only and try start ppp

```
# kldload pf
# ppp -ddial myconnect
```

And nothing happens, all works, ppp connect to servers.
I think maybe ALTQ initiator problem? Does anyone have ideas?


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## SirDice (Feb 9, 2012)

exz said:
			
		

> ```
> Fatal trap 12: page fault while in kernel mode
> cpuid = 0; apic id = 00
> fault virtual address   = 0x18
> ...


These are almost always caused by hardware issues, mainly memory.


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## exz (Feb 9, 2012)

SirDice said:
			
		

> These are almost always caused by hardware issues, mainly memory.



Hmm maybe. I had a problem with RAM. I will go check the memory


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## exz (Feb 15, 2012)

exz said:
			
		

> Hmm maybe. I had a problem with RAM. I will go check the memory


Finished checking the memory (memtest86) - no errors, but system go to Fatal trap 12. 
After that I decided to put the hard drive to another computer. In other PC - system go to Fatal trap 12. Maybe problem in HDD?
On other PC *I* make kernel and all work, start ppp did not result in system crashes.

```
options         VIMAGE
options         ALTQ
options         ALTQ_CBQ                # Class Bases Queuing (CBQ)
options         ALTQ_RED                # Random Early Detection (RED)
options         ALTQ_RIO                # RED In/Out
options         ALTQ_HFSC               # Hierarchical Packet Scheduler (HFSC)
options         ALTQ_PRIQ               # Priority Queuing (PRIQ)
options         ALTQ_NOPCC              # Required for SMP build
```

Now *I* insert HDD in old PC and make kernel and all works!


```
options         VIMAGE
device          pf
device          pflog
options         ALTQ
options         ALTQ_CBQ                # Class Bases Queuing (CBQ)
options         ALTQ_RED                # Random Early Detection (RED)
options         ALTQ_RIO                # RED In/Out
options         ALTQ_HFSC               # Hierarchical Packet Scheduler (HFSC)
options         ALTQ_PRIQ               # Priority Queuing (PRIQ)
options         ALTQ_NOPCC              # Required for SMP build
```

I*'m* happy but *I* don't understand how. What happened, why does it all work?


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## exz (Feb 25, 2012)

I installed FreeBSD on another computer and still have an error Fatal trap 12.
There are new symptoms at the start of the system without jails - ppp working. 
As soon as there is one running jail system goes to Fatal trap 12 at the start ppp.


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