trying to mount a write prptected zip disk panics the machine (unless the -r flag is used)

John Baldwin jhb at freebsd.org
Tue Aug 19 22:05:01 UTC 2008


On Monday 18 August 2008 01:44:00 pm Torfinn Ingolfsen wrote:
> On Mon, 18 Aug 2008 10:33:05 -0400
> John Baldwin <jhb at freebsd.org> wrote:
> 
> > 
> > Can you get the stack trace?
> 
> Like this?
> root at music1# kgdb kernel.debug /var/crash/vmcore.0
> GNU gdb 6.1.1 [FreeBSD]
> Copyright 2004 Free Software Foundation, Inc.
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> details. 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   = 0x0
> fault code              = supervisor read, page not present
> instruction pointer     = 0x20:0xc0737b19
> stack pointer           = 0x28:0xceb9cbcc
> frame pointer           = 0x28:0xceb9cbf8
> 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         = 42 (syncer)
> trap number             = 12
> panic: page fault
> cpuid = 0
> Uptime: 24m34s
> Physical memory: 307 MB
> Dumping 58 MB: 43 27 11
> 
> Reading symbols from /boot/kernel/acpi.ko...Reading symbols
> from /boot/kernel/acpi.ko.symbols...done. done.
> Loaded symbols for /boot/kernel/acpi.ko
> #0  doadump () at pcpu.h:195
> 195             __asm __volatile("movl %%fs:0,%0" : "=r" (td));
> (kgdb) 
> (kgdb) backtrace
> #0  doadump () at pcpu.h:195
> #1  0xc078eed7 in boot (howto=260)
> #at /usr/src/sys/kern/kern_shutdown.c:418 2  0xc078f199 in panic
> #(fmt=Variable "fmt" is not available.
> ) at /usr/src/sys/kern/kern_shutdown.c:572
> #3  0xc0a9efbc in trap_fatal (frame=0xceb9cb8c, eva=0)
> #at /usr/src/sys/i386/i386/trap.c:899 4  0xc0a9f240 in trap_pfault
> #(frame=0xceb9cb8c, usermode=0, eva=0)
> #at /usr/src/sys/i386/i386/trap.c:812 5  0xc0a9fbec in trap
> #(frame=0xceb9cb8c) at /usr/src/sys/i386/i386/trap.c:490 6  0xc0a859ab
> #in calltrap () at /usr/src/sys/i386/i386/exception.s:139 7  0xc0737b19
> #in g_io_request (bp=0xc299ba50, cp=0xc29b2e00)
> #at /usr/src/sys/geom/geom_io.c:364 8  0xc073c116 in g_vfs_strategy
> #(bo=0xc29881d4, bp=0xc88efc24) at /usr/src/sys/geom/geom_vfs.c:107 9
> #0xc07f97b0 in bufwrite (bp=0xc88efc24) at buf.h:429 10 0xc07f2618 in
> #bawrite (bp=0xc88efc24) at buf.h:417 11 0xc07fddaa in vop_stdfsync
> #(ap=0xceb9ccd4) at /usr/src/sys/kern/vfs_default.c:479 12 0xc071cbbe
> #in devfs_fsync (ap=0xceb9ccd4)
> #at /usr/src/sys/fs/devfs/devfs_vnops.c:395 13 0xc0ab3ce2 in
> #VOP_FSYNC_APV (vop=0xc0bcf040, a=0xceb9ccd4) at vnode_if.c:1007 14
> #0xc080dff8 in sched_sync () at vnode_if.h:538 15 0xc076bc59 in
> #fork_exit (callout=0xc080d8f0 <sched_sync>, arg=0x0, frame=0xceb9cd38)
>     at /usr/src/sys/kern/kern_fork.c:781
> #16 0xc0a85a20 in fork_trampoline ()
> #at /usr/src/sys/i386/i386/exception.s:205
> 
> Let me know if it was wrong, or if you need something else.

That's right, but not the specific bug I am familiar with. :(

-- 
John Baldwin


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