# Fatal trap 12: page fault while in kernel mode



## Ulrar (Oct 5, 2013)

Hi,

I have FreeBSD 9.1 on a server since December, and it had crashed two times already so I enabled the crash dumps. Everything worked fine for months, and since yesterday it crashed 4 times already. Don't know why, might be the ftpfs I have mounted, it keeps "blinking" these days. When I try to list it, sometimes it's empty, sometimes it works fine, and it's not a server problem, others can use it just fine when I see it empty.


```
Fatal trap 12: page fault while in kernel mode
cpuid = 3; apic id = 06
fault virtual address   = 0x0
fault code              = supervisor write data, page not present
instruction pointer     = 0x20:0xffffffff809805a2
stack pointer           = 0x28:0xffffff845f91a290
frame pointer           = 0x28:0xffffff845f91a300
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 40860 (find)
trap number             = 12
panic: page fault
cpuid = 3
KDB: stack backtrace:
#0 0xffffffff809208a6 at kdb_backtrace+0x66
#1 0xffffffff808ea8be at panic+0x1ce
#2 0xffffffff80bd8240 at trap_fatal+0x290
#3 0xffffffff80bd857d at trap_pfault+0x1ed
#4 0xffffffff80bd8b9e at trap+0x3ce
#5 0xffffffff80bc315f at calltrap+0x8
#6 0xffffffff809844b6 at vnlru_free+0x366
#7 0xffffffff80984751 at getnewvnode+0x291
#8 0xffffffff80b1bf2f at ffs_vgetf+0xdf
#9 0xffffffff80b2939d at ufs_lookup_ino+0xbfd
#10 0xffffffff8096ceb8 at vfs_cache_lookup+0xf8
#11 0xffffffff80c68880 at VOP_LOOKUP_APV+0x40
#12 0xffffffff80974554 at lookup+0x464
#13 0xffffffff80975669 at namei+0x4e9
#14 0xffffffff80986993 at kern_statat_vnhook+0xb3
#15 0xffffffff80986b55 at kern_statat+0x15
#16 0xffffffff80986c1a at sys_lstat+0x2a
#17 0xffffffff80bd7ae6 at amd64_syscall+0x546
Uptime: 9h47m37s
Dumping 2134 out of 16271 MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%

Reading symbols from /boot/kernel/if_em.ko...Reading symbols from /boot/kernel/if_em.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/if_em.ko
Reading symbols from /boot/kernel/linprocfs.ko...Reading symbols from /boot/kernel/linprocfs.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linprocfs.ko
Reading symbols from /boot/kernel/linux.ko...Reading symbols from /boot/kernel/linux.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/linux.ko
Reading symbols from /boot/kernel/pflog.ko...Reading symbols from /boot/kernel/pflog.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/pflog.ko
Reading symbols from /boot/kernel/pf.ko...Reading symbols from /boot/kernel/pf.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/pf.ko
Reading symbols from /usr/local/modules/fuse.ko...done.
Loaded symbols for /usr/local/modules/fuse.ko
#0  doadump (textdump=Variable "textdump" is not available.
) at pcpu.h:224
224     pcpu.h: No such file or directory.
        in pcpu.h
```

Should I attach the coredump too?


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## wblock@ (Oct 5, 2013)

In the past, FUSE was not stable at all on FreeBSD.  There was some work on it recently, don't know the current status.  But I would recommend not using FUSE on anything that needs to be reliable.


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## Ulrar (Oct 6, 2013)

I use it for the ftpfs I mount. I tried lots of things, but nothing is really usable over internet. Every time I try NFSv4 the client end up completely frozen and I have to pull the plug to reboot it. Would there be a good network file system usable over internet that wouldn't freeze the client if the server crashes, not depending on FUSE?

And to get back on the subject, the problem seems to be triggered by the log mail thing. I haven't received my log mails for two days, and the last two reboots have been at 3 AM, time at which I usually receive the log emails. I will try to disable that tonight, see if that's really it.


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