USB Mass Storage Device with HPS Stack

[Xiaofan Chen]

On Tue, Apr 29, 2008 at 3:01 PM, Hans Petter Selasky <hselasky at c2i.net> wrote:
>  If umass is in the kernel you need to rebuild. Else you "kldunload umass".

I managed to crash the system again when playing with
 "kldload umass" and "kldunload umass". But maybe the
backtrace does not make much sense, to me anyway.

[root at freebsd7 /var/crash]# cat info.4
Dump header from device /dev/ad4s4b
  Architecture: i386
  Architecture Version: 2
  Dump Length: 152387584B (145 MB)
  Blocksize: 512
  Dumptime: Tue Apr 29 20:34:58 2008
  Hostname: freebsd7.MSHOME.net
  Magic: FreeBSD Kernel Dump
  Version String: FreeBSD 7.0-RELEASE #2: Tue Apr 29 19:47:40 SGT 2008
    root at freebsd7.MSHOME.net:/usr/obj/usr/src/sys/custom
  Panic String: page fault
  Dump Parity: 3612086858
  Bounds: 4
  Dump Status: good

[root at freebsd7 /usr/obj/usr/src/sys/custom]# kgdb kernel.debug
/var/crash/vmcore.4
[GDB will not be able to debug user-mode threads:
/usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
GNU gdb 6.1.1 [FreeBSD]
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welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
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This GDB was configured as "i386-marcel-freebsd".

Unread portion of the kernel message buffer:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x8
fault code              = supervisor write, page not present
instruction pointer     = 0x20:0xc4fcb2f5
stack pointer           = 0x28:0xe6fdfbf4
frame pointer           = 0x28:0xe6fdfc10
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         = 1376 (USB interrupt threa)
trap number             = 12
panic: page fault
cpuid = 0
Uptime: 44m1s
Physical memory: 1011 MB
Dumping 145 MB: 130 114 98 82 66 50 34 18 2

#0  doadump () at pcpu.h:195
195             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
(kgdb) list *0xc4fcb2f5
No source file for address 0xc4fcb2f5.
(kgdb) backtrace
#0  doadump () at pcpu.h:195
#1  0xc0739ac7 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:409
#2  0xc0739d89 in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:563
#3  0xc0a3fb4c in trap_fatal (frame=0xe6fdfbb4, eva=8)
    at /usr/src/sys/i386/i386/trap.c:899
#4  0xc0a3fdb0 in trap_pfault (frame=0xe6fdfbb4, usermode=0, eva=8)
    at /usr/src/sys/i386/i386/trap.c:812
#5  0xc0a40732 in trap (frame=0xe6fdfbb4) at /usr/src/sys/i386/i386/trap.c:490
#6  0xc0a270bb in calltrap () at /usr/src/sys/i386/i386/exception.s:139
#7  0xc4fcb2f5 in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb) quit

Xiaofan