[OOPS] 2.4.13+preemptive lp0/devfs

[The Doctor What <docwhat@gerf.org>]

Good day!

Hit this oops and thought you all might like to look at it:
Kernel version 2.4.13 vanilla with Robert Love's Premptive Patch.

ksymoops 2.4.3 on i686 2.4.13-p1.  Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.13-p1/ (default)
     -m /boot/System.map-2.4.13-p1 (default)

Warning: You did not tell me where to find symbol information.  I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc.  ksymoops -h explains the options.

Unable to handle kernel NULL pointer dereference at virtual address 00000000
c013effa
*pde = 00000000
Oops: 0000
CPU:    0
EIP:    0010:[<c013effa>]    Tainted: P 
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010217
eax: c2e6ffa4   ebx: c2e6ffa4   ecx: c2a20240   edx: c0221188
esi: 00000000   edi: 00000000   ebp: c2e6ffa4   esp: c2e6ff1c
ds: 0018   es: 0018   ss: 0018
Process checkpc (pid: 410, stackpage=c2e6f000)
Stack: c0221188 c2e6e000 c25f9c00 c2e6ffa4 c015bb85 c2e6ffa4 00000000 c25f80c0 
       c013c344 c25f80c0 c2e6ffa4 c25f9c00 c7f89000 00000000 c2e6ffa4 00000009 
       00000001 00000009 c2e6ffa8 00000009 c7f89008 c25f80c0 c7f89005 00000003 
Call Trace: [<c015bb85>] [<c013c344>] [<c013c46a>] [<c013c8d1>] [<c0139415>] 
   [<c0106d5b>] 
Code: 80 3e 2f 0f 85 d5 00 00 00 53 e8 af c8 ff ff 83 c4 04 ba 00 

>>EIP; c013effa <vfs_follow_link+1a/164>   <=====
Trace; c015bb84 <devfs_follow_link+44/6c>
Trace; c013c344 <link_path_walk+7b4/8c0>
Trace; c013c46a <path_walk+1a/1c>
Trace; c013c8d0 <__user_walk+34/50>
Trace; c0139414 <sys_stat64+18/74>
Trace; c0106d5a <system_call+32/38>
Code;  c013effa <vfs_follow_link+1a/164>
00000000 <_EIP>:
Code;  c013effa <vfs_follow_link+1a/164>   <=====
   0:   80 3e 2f                  cmpb   $0x2f,(%esi)   <=====
Code;  c013effc <vfs_follow_link+1c/164>
   3:   0f 85 d5 00 00 00         jne    de <_EIP+0xde> c013f0d8 <vfs_follow_link+f8/164>
Code;  c013f002 <vfs_follow_link+22/164>
   9:   53                        push   %ebx
Code;  c013f004 <vfs_follow_link+24/164>
   a:   e8 af c8 ff ff            call   ffffc8be <_EIP+0xffffc8be> c013b8b8 <path_release+0/2c>
Code;  c013f008 <vfs_follow_link+28/164>
   f:   83 c4 04                  add    $0x4,%esp
Code;  c013f00c <vfs_follow_link+2c/164>
  12:   ba 00 00 00 00            mov    $0x0,%edx


1 warning issued.  Results may not be reliable.

The above happened after doing a checkpc -f in my startup scripts.

lp, parport_pc and parport were all modules that weren't loaded till
the checkpc ran.

I had just turned on devfs, and this happened.

Also: /dev/lp0 had incorrect (unwritable) permissions after being
created.

Hope this is helpful.

Ciao!

-- 
"So. let me get this straight. You want to fly on a magic carpet to see the
King of the Potato People and plead with him for your freedom, and you're
telling me you're completely sane?!"
		--Rimmer (Red Dwarf episode: Quarantine)

The Doctor What: Kaboom!                         http://docwhat.gerf.org/
docwhat@gerf.org                                                   KF6VNC