Re: general protection fault panic

On Mon, Mar 26, 2012 at 08:43:59AM -0700, Steve Kargl wrote:
> On Mon, Mar 26, 2012 at 10:59:35AM -0400, John Baldwin wrote:
> > On Friday, March 23, 2012 6:23:13 pm Steve Kargl wrote:
> > > Haven't seen one of these in a long time.
> > > 
> > > %uname -a
> > > FreeBSD troutmask.apl.washington.edu 10.0-CURRENT FreeBSD
> > > 10.0-CURRENT #0 r233282: Wed Mar 21 12:39:16 PDT 2012
> > > kargl_at_troutmask.apl.washington.edu:/usr/obj/usr/src/sys/SPEW  amd64
> > > 
> > > Hand transcribed
> > > 
> > > Fatal trap 9: general protection fault while in kernel mode
> > > cpuid = 1; apic id = 01
> > > instruction pointer = 0x20:0xffffffff80570b89
> > 
> > Can you run gdb on your kernel.debug and 'l *' this address?
> > 
> 
> Unfortunately, I don't have that kernel.debug anymore.  I saw
> that alc had committed a few changes, so updated the kernel.
> I do have the kernel and kernel.symbol files.  Loading 
> kernel.symbol into gdb shows
> 
> (gdb) l *0xffffffff80570b89
> 0xffffffff80570b89 is in strcmp (/usr/src/sys/libkern/strcmp.c:45).
> 40       */
> 41      int
> 42      strcmp(s1, s2)
> 43              register const char *s1, *s2;
> 44      {
> 45              while (*s1 == *s2++)
> 46                      if (*s1++ == 0)
> 47                              return (0);
> 48              return (*(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1));
> 49      }
> 
> Don't know if the above helps or is a red-herring.
> 
> I may be able to reproduce the crash.  I give it a try in a
> few moments.
> 

The above gdb is probably a red-herring.  I can 100%
reproduce the panic with 

1) Insert old MS-formatted floppy into drive.
2) mount_msdosfs /dev/fd0 /mnt

%kgdb /usr/obj/usr/src/sys/SPEW/kernel.debug vmcore.0

Unread portion of the kernel message buffer:
kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x33
fault code              = supervisor write data, page not present
instruction pointer     = 0x20:0xffffffff80751232
stack pointer           = 0x28:0xffffff8000229a50
frame pointer           = 0x28:0xffffff8000229b30
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = resume, IOPL = 0
current process         = 10 (idle: cpu0)
trap number             = 12
panic: page fault
cpuid = 0
Uptime: 2d16h49m51s
Dumping 1209 out of 8116 MB:..2%..11%..22%..31%..42%..51%..61%..71%..81%..92%

Reading symbols from /usr/local/libexec/linux_adobe/linux_adobe.ko...done.
Loaded symbols for /usr/local/libexec/linux_adobe/linux_adobe.ko
#0  doadump (textdump=1) at /usr/src/sys/kern/kern_shutdown.c:268
268             if (textdump && textdump_pending) {
(kgdb) bt
#0  doadump (textdump=1) at /usr/src/sys/kern/kern_shutdown.c:268
#1  0xffffffff804c8140 in kern_reboot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:454
#2  0xffffffff804c8617 in panic (fmt=0x0)
    at /usr/src/sys/kern/kern_shutdown.c:642
#3  0xffffffff806f6180 in trap_fatal (frame=0xc, eva=Variable "eva" is not available.
)
    at /usr/src/sys/amd64/amd64/trap.c:838
#4  0xffffffff806f64ff in trap_pfault (frame=0xffffff80002299a0, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:755
#5  0xffffffff806f69ee in trap (frame=0xffffff80002299a0)
    at /usr/src/sys/amd64/amd64/trap.c:454
#6  0xffffffff806e12bf in calltrap () at /usr/src/sys/amd64/amd64/exception.S:228
#7  0xffffffff80751232 in lapic_handle_intr (vector=51, frame=0xffffff8000229a70)
    at /usr/src/sys/x86/x86/local_apic.c:777
#8  0x0000000000001008 in ?? ()
#9  0xffffff8000229b54 in ?? ()
#9  0xffffff8000229b54 in ?? ()
#10 0x0000000000000000 in ?? ()
#11 0x000000000000100b in ?? ()
#12 0x0000000000000000 in ?? ()
#13 0x0000000000000000 in ?? ()
#14 0x0000000000000000 in ?? ()
#15 0x0000000000000000 in ?? ()
#16 0xffffff8000229b30 in ?? ()
#17 0x0000000000000000 in ?? ()
#18 0x0000000000000000 in ?? ()
#19 0xfffffe00032e3600 in ?? ()
#20 0xfffffe00032e3628 in ?? ()
#21 0xffffff8000229c40 in ?? ()
#22 0x0000000000000000 in ?? ()
#23 0x001b0013032e3628 in ?? ()
#24 0xffffff8000229c40 in ?? ()
#25 0x003b003b00000001 in ?? ()
#26 0xffffff8000229b30 in ?? ()
#27 0xffffffff806dc186 in acpi_cpu_c1 ()
    at /usr/src/sys/amd64/acpica/acpi_machdep.c:97

(kgdb) l *0xffffffff80751232
0xffffffff80751232 is in lapic_handle_intr (/usr/src/sys/x86/x86/local_apic.c:777).
772             lapic->eoi = 0;
773     }
774
775     void
776     lapic_handle_intr(int vector, struct trapframe *frame)
777     {
778             struct intsrc *isrc;
779
780             isrc = intr_lookup_source(apic_idt_to_irq(PCPU_GET(apic_id),
781                 vector));






-- 
Steve