2.6.2-rc in BK: Oops loading parport_pc.

Loading the parport_pc modules crashes in 2.6.2-rc; I have recently done a "bk pull" and enabled some PNP options, among them ISA PNP.

Find attached the gzipped config and a decoded oops. Does ksymoops 2.4 (using 2.4.8) understand Kernel 2.6 kallsyms? Doesn't seem so. 2.4.9 segfaults for me, haven't yet figured why.

Matthias Andree

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ksymoops 2.4.8 on i686 2.6.2-rc1. Options used
-V (default)
-k /proc/ksyms (default)
-l /proc/modules (specified)
-o /lib/modules/2.6.2-rc1/ (default)
-m /boot/System.map-2.6.2-rc1 (specified)

Error (regular_file): read_ksyms stat /proc/ksyms failed No modules in ksyms, skipping objects
No ksyms, skipping lsmod

Unable to handle kernel paging request at virtual address d5bd0d48
c01e2c86
*pde = 12b6f067
Oops: 0002 [#1]
CPU:    0
EIP:    0060:[<c01e2c86>]    Not tainted

Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010296
eax: c03c1ac0 ebx: c03c1a64 ecx: d5bd0d48 edx: d5ca8c88
esi: c03c1aac edi: d5ca8c6c ebp: d16adee0 esp: d16adec8
ds: 007b es: 007b ss: 0068

Stack: c03c1ac8 00000042 c03c1ac8 d5ca8c6c ffffffea 00000000 d16adefc c01e2ce8 
       d5ca8c6c 00000000 d5ca8c6c d5ca8c6c c03c1a60 d16adf18 c0239e0c d5ca8c6c 
       d5ca5a64 d5ca8c40 d5ca8cc0 d5ca8d20 d16adf34 c023a2c1 d5ca8c54 d5c9b708 
Call Trace:
 [<c01e2ce8>] kobject_register+0x28/0x60
 [<c0239e0c>] bus_add_driver+0x4c/0xc0
 [<c023a2c1>] driver_register+0x31/0x40
 [<c0213a31>] pnp_register_driver+0x41/0x80
 [<d5bcd1ec>] parport_pc_init+0x2c/0xc4 [parport_pc]
 [<d5c6ffc7>] parport_parse_dmas+0x37/0x40 [parport]
 [<d5ca44c8>] init_module+0xa8/0x170 [parport_pc]
 [<c0137db0>] sys_init_module+0x110/0x210
 [<c010b1cf>] syscall_call+0x7/0xb
Code: 89 11 89 4a 04 8b 47 28 8b 18 8d 4b 48 89 c8 ba ff ff 00 00 

Trace; c01e2ce8 <kobject_register+28/60>
Trace; c0239e0c <bus_add_driver+4c/c0>
Trace; c023a2c1 <driver_register+31/40>
Trace; c0213a31 <pnp_register_driver+41/80>
Trace; d5bcd1ec <_end+1573b784/3fb6c598>
Trace; d5c6ffc7 <_end+157de55f/3fb6c598>
Trace; d5ca44c8 <_end+15812a60/3fb6c598>
Trace; c0137db0 <sys_init_module+110/210>
Trace; c010b1cf <syscall_call+7/b>

Code; c01e2c86 <kobject_add+d6/110>
00000000 <_EIP>:
Code; c01e2c86 <kobject_add+d6/110> <=====
0: 89 11 mov %edx,(%ecx) <=====
Code; c01e2c88 <kobject_add+d8/110>
2: 89 4a 04 mov %ecx,0x4(%edx)
Code; c01e2c8b <kobject_add+db/110>
5: 8b 47 28 mov 0x28(%edi),%eax
Code; c01e2c8e <kobject_add+de/110>
8: 8b 18 mov (%eax),%ebx
Code; c01e2c90 <kobject_add+e0/110>
a: 8d 4b 48 lea 0x48(%ebx),%ecx
Code; c01e2c93 <kobject_add+e3/110>
d: 89 c8 mov %ecx,%eax
Code; c01e2c95 <kobject_add+e5/110>
f: ba ff ff 00 00 mov $0xffff,%edx

1 error issued. Results may not be reliable.

Often this is because some other, unrelated module left things registered after it was removed. Or otherwise wrecked shared data structures.

So what you ned to do is to take careful note of what other modules were loaded and unloaded leading up to the crash, and suspect those.

There is one known problem in this area: unloading 8250_pnp will wreck the kobject tree. Try

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.2-rc1/2.6.2-rc1-mm3/broken-out/8250_pnp-cleanup.patch

The breakage is somehow related to CONFIG_PNP. I set that option to N, ran "make oldconfig ; make", installed the kernel, rebooted, problem gone.

Matthias Andree

Encrypt your mail: my GnuPG key ID is 0x052E7D95

In article <[email protected]>, Matthias Andree <[email protected]> wrote:

| On Sun, 25 Jan 2004, Andrew Morton wrote:
| 
| > Matthias Andree <[email protected]> wrote:
| > >
| > >  Loading the parport_pc modules crashes in 2.6.2-rc; I have recently done
| > >  a "bk pull" and enabled some PNP options, among them ISA PNP.
| > 
| > Often this is because some other, unrelated module left things registered
| > after it was removed.  Or otherwise wrecked shared data structures.
| 
| The breakage is somehow related to CONFIG_PNP. I set that option to N,
| ran "make oldconfig ; make", installed the kernel, rebooted, problem
| gone.

2.6.2-rc2:
root> grep PNP .config
CONFIG_PNP=y
CONFIG_PNP_DEBUG=y
CONFIG_ISAPNP=y
CONFIG_PNPBIOS=y
# CONFIG_BLK_DEV_IDEPNP is not set
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
CONFIG_IP_PNP_BOOTP=y
CONFIG_IP_PNP_RARP=y

Boots and loads parport_pc just fine, so it looks as if either it got fixed (likely) or other evildoers are at work.

bill davidsen <[email protected]>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

Are you using any modules other than parport_pc? Have you unloaded them before loading parport_pc?

Thanks,
Adam

Plenty I have, and no, I haven't tried unloading (or, for that matter, preferably not loading them in the first place) them. Will take a while before I can test again, I don't have PNP requirements at the moment, even my USB configuration is static.

Matthias Andree

Encrypt your mail: my GnuPG key ID is 0x052E7D95

Works for me. Thank you.

Matthias Andree

Encrypt your mail: my GnuPG key ID is 0x052E7D95