crash while doing mkdir (system as of afternon today )

[Matthew Dillon]

:Hello!
:
:	Tried to build and install kde and got kernel crash:
:
:Fatal trap 12: page fault while in kernel mode
:fault virtual address	= 0x994
:fault code		= supervisor read, page not present
:instruction pointer	= 0x8:0xc038f0a4
:stack pointer		= 0x10:0xd79488fc
:frame pointer		= 0x10:0xd794895c
: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		= 4339 (mkdir)
:
:
:
:[ the rest is lost as my notebook decided to go into power-save world 
:from which it did not wake up properly... ]
:
:make.conf options:
:CFLAGS=-O2 -pipe -funroll-loops -fstack-protector
:COPTFLAGS=-O -pipe -funroll-loops -fstack-protector
:
:After reboot I had to use fsck manually...
:
:Hmm, similar crash... same spot basically while doing cvsup...
:ffs_dirpref+0x684:	cmpl	0x2c(%esi),%eax
:
:where shows something like this:
:ffs_dirpref(d78ab398,41ed,c051eac0,d7739bb4,c0ec6d38) at ffs_dirpref+0x684
:ffs_valloc(d75b5200,41ed,c0ec6d38,d77399b4,d7739bc4) at ffs_valloc+0x3d
:ufs_mkdir...
:
:Toma¾
:
:p.s.
:Any good way to write this into something that can be easily sent here 
:when in ddb?

    The best way is to get a kernel crash dump.  If your swap area
    (typically ad0s1b) is large enough to accomodoate main memory, then
    'dumpon /dev/ad0s1b' (and put 'dumpdev=/dev/ad0s1b' in your /etc/rc.conf),
    and then when it crashed and drops into DDB> type 'panic' and hit
    return twice and it should hopefully generate a crash dump.

    For the crash dump to be really useful having the kernel.debug for
    the kernel that you are running is important.  kernel.debug is built
    automatically when you buildkernel, but only the stripped 'kernel'
    version is actually installed.  kernel.debug should still be sitting
    in the kernel build object directory which is usually
    /usr/obj/usr/src/sys/<KERNELNAME> (if you used 'buildkernel' to build
    your kernel).

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>