usb/125450: Removing USB flash card while being accessed causes
simsong at acm.org
Mon Jul 14 16:20:07 UTC 2008
> options USB_DEBUG
> sysctl hw.usb.umass.debug=-1
> sysctl hw.usb.debug=15
Strangely, it was considerably harder to make the machine panic once
USB_DEBUG was enabled and the usb debug messages were printing to the
kernel. It took me 6 tries of running the "dd" command on the raw USB
device and pulling the device before the machine actually panicked.
The panic is happened after the "dd" command finishes printing it's
statistics. but before the return to the command line.
page fault while in kernel mode. Fault virtual addr = 0
Is that a dereference through a null pointer?
The IP is 0x20:0xc0460c3b
Is there an easy way to get a link map of the kernel?
Unfortunately, I can't get the stack trace because the system is not
performing the crash dump. I've never done a FreeBSD crash dump. I
tried following the directions, but no luck.
I have also tried configuring a dumpdev in the /etc/rc.conf file:
03:27 PM copy:/home/simsong# cat /etc/rc.conf
03:28 PM copy:/home/simsong# cat /etc/fstab
# Device Mountpoint FStype Options Dump Pass#
/dev/ad0s1b none swap sw 0 0
/dev/ad0s1a / ufs rw 1 1
/dev/ad0s1e /tmp ufs rw 2 2
/dev/ad0s1f /usr ufs rw 2 2
/dev/ad0s1d /var ufs rw 2 2
/dev/acd0 /cdrom cd9660 ro,noauto 0 0
/dev/acd1 /cdrom1 cd9660 ro,noauto 0 0
/dev/ad8s1d /big ufs rw 3 3
03:29 PM copy:/home/simsong#
I can't figure out why it won't dump.
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