Still panicing...

[Robin P. Blanchard]

> Unfortunately this is missing the rest of the page fault 
> panic messages including the 'trap 12' etc.  Those messages 
> include a line that says 'cs:eip = 0x8:0xblah', and we need 
> the 0xblah part to work out where the page fault happened.  
> Usually these bugs are a NULL pointer deref that can often be 
> easily fixed if we can find out where it happened.  Actually, 
> though, the ip can be found from the tf_eip member of struct 
> trapframe, which is 0xc05d1e69.  
> Can you send the output of 'l *0xc05d1e69' from gdb on the 
> same kernel.debug?
> 
> --
> John Baldwin <jhb at FreeBSD.org>  <><  
> http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to 
> Serve"  =  http://www.FreeBSD.org
> 
>

Sure...here we go:

# gdb -k /usr/obj/usr/src/sys/fbsd5.vpn/kernel.debug ./vmcore.11 
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This GDB was configured as "i386-undermydesk-freebsd"...
panic: page fault
panic messages:
---
---
#0  doadump () at /usr/src/sys/kern/kern_shutdown.c:236
236             dumping++;
(kgdb) bt full
#0  doadump () at /usr/src/sys/kern/kern_shutdown.c:236
No locals.
#1  0xc04cdb26 in boot (howto=256) at /usr/src/sys/kern/kern_shutdown.c:370
No locals.
#2  0xc04cdf5c in __panic () at /usr/src/sys/kern/kern_shutdown.c:548
        td = (struct thread *) 0xc1cef6e0
        bootopt = 256
        newpanic = 0
        ap = 0xd1022b8c "\f?fÀ\001"
        buf = "page fault", '\0' <repeats 245 times>
#3  0xc061e24c in trap_fatal (frame=0xd1022c30, eva=0) at
/usr/src/sys/i386/i386/trap.c:815
        code = 16
        type = 12
        ss = 16
        esp = 0
        softseg = {ssd_base = 0, ssd_limit = 1048575, ssd_type = 27, ssd_dpl
= 0, ssd_p = 1, ssd_xx = 13, 
  ssd_xx1 = 2, ssd_def32 = 1, ssd_gran = 1}
#4  0xc061ded2 in trap_pfault (frame=0xd1022c30, usermode=0, eva=3522064088)
    at /usr/src/sys/i386/i386/trap.c:733
        va = 3522060288
        vm = (struct vmspace *) 0x0
        map = 0x1
        rv = 1
        ftype = 1 '\001'
        td = (struct thread *) 0xc1cef6e0
        p = (struct proc *) 0xc1e5a528
#5  0xc061da8d in trap (frame=
      {tf_fs = -1066860520, tf_es = -788398064, tf_ds = -1068630000, tf_edi =
-788386540, tf_esi = 4098, tf_ebp = -788386588, tf_isp = -788386724, tf_ebx =
-1041914584, tf_edx = 0, tf_ecx = -772903432, tf_eax = 536870912, tf_trapno =
12, tf_err = 0, tf_eip = -1067639191, tf_cs = 8, tf_eflags = 66066, tf_esp =
-1041914584, tf_ss = 2}) at /usr/src/sys/i386/i386/trap.c:420
        td = (struct thread *) 0xc1cef6e0
        p = (struct proc *) 0xc1e5a528
        sticks = 2405433344
        i = 0
        ucode = 0
        type = 12
        code = 0
        eva = 3522064088
#6  0xc05d1e69 in mmap (td=0xc1cef6e0, uap=0xd1022d14) at
/usr/src/sys/vm/vm_mmap.c:280
        fp = (struct file *) 0x0
        vp = (struct vnode *) 0x0
        addr = 0
        size = 69632
        pageoff = 3163
        prot = 54 '6'
        maxprot = 0 '\0'
        handle = (void *) 0xd1022d14
        flags = 4098
        error = -1041914584
        pos = -4481373134027661312
        vms = (struct vmspace *) 0xd1022cf8
#7  0xc061e630 in syscall (frame=
      {tf_fs = 47, tf_es = 47, tf_ds = 47, tf_edi = 0, tf_esi = 4096, tf_ebp
= -1077943656, tf_isp = -788386444, tf_ebx = 65536, tf_edx = 0, tf_ecx =
137734528, tf_eax = 198, tf_trapno = 12, tf_err = 2, tf_eip = 137101951,
tf_cs = 31, tf_eflags = 642, tf_esp = -1077943700, tf_ss = 47}) at
/usr/src/sys/i386/i386/trap.c:1004
        params = 0xbfbfe278---Can't read userspace from dump, or kernel
process---

(kgdb) l *0xc05d1e69
0xc05d1e69 is in mmap (/usr/src/sys/vm/vm_mmap.c:280).
275                     PROC_LOCK(td->td_proc);
276                     if (addr == 0 ||
277                         (addr >= round_page((vm_offset_t)vms->vm_taddr)
&&
278                         addr < round_page((vm_offset_t)vms->vm_daddr +
279                         lim_max(td->td_proc, RLIMIT_DATA))))
280                             addr = round_page((vm_offset_t)vms->vm_daddr
+
281                                 lim_max(td->td_proc, RLIMIT_DATA));
282                     PROC_UNLOCK(td->td_proc);
283             }
284             if (flags & MAP_ANON) {
(kgdb)