Re: 9.1 panic in ccb/iscsi

[mlelstv%serpens.de@localhost (Michael van Elst)]

joel.bertrand%systella.fr@localhost (=?UTF-8?Q?BERTRAND_Jo=c3=abl?=) writes:

>	Hello,

>	I can see some panics on a server that exports iSCSI volumes (istgt on
>a CCB device) to some workstations. dmesg always contains this kind of
>backtrace :

That would be on the workstation that uses the volumes unless your
server would also be a client.


>[ 308324,087343] S-1C-1: ccb_timeout: num=1 total=1 disp=0
>[ 308324,087343] uvm_fault(0xffffffff81585e20, 0x0, 2) -> e
>[ 308324,087343] fatal page fault in supervisor mode
>[ 308324,087343] trap type 6 code 0x2 rip 0xffffffff802280cc cs 0x8
>rflags 0x10246 cr2 0x10 ilevel 0 rsp 0xffff97813fa16f48

A NULL pointer dereference...

>[ 308324,087343] curlwp 0xffffc947d4f304c0 pid 0.201 lowest kstack
>0xffff97813fa142c0
>[ 308324,087343] panic: trap
>[ 308324,087343] cpu1: Begin traceback...
>[ 308324,087343] vpanic() at netbsd:vpanic+0x160
>[ 308324,087343] snprintf() at netbsd:snprintf
>[ 308324,087343] startlwp() at netbsd:startlwp
>[ 308324,087343] alltraps() at netbsd:alltraps+0xbb
>[ 308324,087343] ccb_timeout() at iscsi:ccb_timeout+0xf0
>[ 308324,087343] iscsi_cleanup_thread() at iscsi:iscsi_cleanup_thread+0x2b6

in something called by ccb_timeout().

If you have a version of the kernel with debug symbols, you could
use addr2line to identify the instruction that caused the uvm_fault
at address 0xffffffff802280cc. Without debug symbols it is not
that easy.