modules oops in 2.5.52

modules oops in 2.5.52

[Jeremy Fitzhardinge]

Hi,

I just had an oops in the modules code:

Dec 18 16:58:59 ixodes kernel: Unable to handle kernel paging request at virtual address f8980924
Dec 18 16:58:59 ixodes kernel:  printing eip:
Dec 18 16:58:59 ixodes kernel: f896756d
Dec 18 16:58:59 ixodes kernel: *pde = 01bfc067
Dec 18 16:58:59 ixodes kernel: *pte = 00000000
Dec 18 16:58:59 ixodes kernel: Oops: 0000
Dec 18 16:58:59 ixodes kernel: CPU:    0
Dec 18 16:58:59 ixodes kernel: EIP:    0060:[<f896756d>]    Not tainted
Dec 18 16:58:59 ixodes kernel: EFLAGS: 00010282
Dec 18 16:58:59 ixodes kernel: EIP is at __exitfn+0xd/0x4c [parport_pc]
Dec 18 16:58:59 ixodes kernel: eax: d7b01c80   ebx: c0355bb8   ecx: c0355bb8   edx: c02f2b50
Dec 18 16:58:59 ixodes kernel: esi: f8964000   edi: 00000000   ebp: f4b9df5c   esp: f4b9df50
Dec 18 16:58:59 ixodes kernel: ds: 0068   es: 0068   ss: 0068
Dec 18 16:58:59 ixodes kernel: Process modprobe (pid: 1358, threadinfo=f4b9c000 task=eb929280)
Dec 18 16:58:59 ixodes kernel: Stack: f4b9c000 c0355bb8 f8964000 f4b9dfbc c0127d61 c02f2b50 00000077 0000003b
Dec 18 16:58:59 ixodes kernel:        70726170 5f74726f e1006370 f5025480 f5025380 40013000 40014000 f5025480
Dec 18 16:58:59 ixodes kernel:        f5025380 e1e4b200 e1e4b220 00000000 f4b9dfbc c0136839 00e4b200 40013000
Dec 18 16:58:59 ixodes kernel: Call Trace:
Dec 18 16:58:59 ixodes kernel:  [<c0127d61>] sys_delete_module+0x1bf/0x1e2
Dec 18 16:58:59 ixodes kernel:  [<c0136839>] sys_munmap+0x57/0x76
Dec 18 16:58:59 ixodes kernel:  [<c01090c3>] syscall_call+0x7/0xb
Dec 18 16:58:59 ixodes kernel:
Dec 18 16:58:59 ixodes kernel: Code: 8b 35 24 09 98 f8 85 f6 89 c3 74 24 85 db 74 0f f6 43 10 01
Dec 18 16:59:00 ixodes kernel:  end_request: I/O error, dev hdc, sector 0
Dec 18 16:59:00 ixodes kernel: end_request: I/O error, dev hdc, sector 0

I doubt parport_pc was being used.  I think this was caused by the
vmware-config script trying to unload modules.  Vmware was not loaded at
the time.

Now, any process which touches /proc/modules hangs, I guess because a
lock was being held.

I have module-init-tools 0.9.3 installed.

The only other patch in the kernel is AndrewM's buffer head tracing
code.

	J

Re: modules oops in 2.5.52

[Rusty Russell]

In message <1040260444.1316.4.camel@ixodes.goop.org> you write:
> Hi,
> 
> I just had an oops in the modules code:
> 
> Dec 18 16:58:59 ixodes kernel: Unable to handle kernel paging request at virt
ual address f8980924
> Dec 18 16:58:59 ixodes kernel:  printing eip:
> Dec 18 16:58:59 ixodes kernel: f896756d
> Dec 18 16:58:59 ixodes kernel: *pde = 01bfc067
> Dec 18 16:58:59 ixodes kernel: *pte = 00000000
> Dec 18 16:58:59 ixodes kernel: Oops: 0000
> Dec 18 16:58:59 ixodes kernel: CPU:    0
> Dec 18 16:58:59 ixodes kernel: EIP:    0060:[<f896756d>]    Not tainted
> Dec 18 16:58:59 ixodes kernel: EFLAGS: 00010282
> Dec 18 16:58:59 ixodes kernel: EIP is at __exitfn+0xd/0x4c [parport_pc]

Actually, you had an oops in the parport_pc code, in
cleanup_module().  Now, *why* that oopsed, I don't know...

> Now, any process which touches /proc/modules hangs, I guess because a
> lock was being held.

Yes.  Changing this would be particularly interesting, since you don't
want a simultaneous "modprobe" to fail.

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: modules oops in 2.5.52

[Jeremy Fitzhardinge]

On Wed, 2002-12-18 at 18:11, Rusty Russell wrote:
> In message <1040260444.1316.4.camel@ixodes.goop.org> you write:
> > Hi,
> > 
> > I just had an oops in the modules code:
> > 
> > Dec 18 16:58:59 ixodes kernel: Unable to handle kernel paging request at virt
> ual address f8980924
> > Dec 18 16:58:59 ixodes kernel:  printing eip:
> > Dec 18 16:58:59 ixodes kernel: f896756d
> > Dec 18 16:58:59 ixodes kernel: *pde = 01bfc067
> > Dec 18 16:58:59 ixodes kernel: *pte = 00000000
> > Dec 18 16:58:59 ixodes kernel: Oops: 0000
> > Dec 18 16:58:59 ixodes kernel: CPU:    0
> > Dec 18 16:58:59 ixodes kernel: EIP:    0060:[<f896756d>]    Not tainted
> > Dec 18 16:58:59 ixodes kernel: EFLAGS: 00010282
> > Dec 18 16:58:59 ixodes kernel: EIP is at __exitfn+0xd/0x4c [parport_pc]
> 
> Actually, you had an oops in the parport_pc code, in
> cleanup_module().  Now, *why* that oopsed, I don't know...

It looks like it might end up calling request_module() from within
cleanup_module(). Is that going to be a problem?
        
        J

Re: modules oops in 2.5.52

[Rusty Russell]

In message <1040271549.1317.12.camel@ixodes.goop.org> you write:
> On Wed, 2002-12-18 at 18:11, Rusty Russell wrote:
> > In message <1040260444.1316.4.camel@ixodes.goop.org> you write:
> > > Hi,
> > > 
> > > I just had an oops in the modules code:
> > > 
> > > Dec 18 16:58:59 ixodes kernel: Unable to handle kernel paging request at 
virt
> > ual address f8980924
> > > Dec 18 16:58:59 ixodes kernel:  printing eip:
> > > Dec 18 16:58:59 ixodes kernel: f896756d
> > > Dec 18 16:58:59 ixodes kernel: *pde = 01bfc067
> > > Dec 18 16:58:59 ixodes kernel: *pte = 00000000
> > > Dec 18 16:58:59 ixodes kernel: Oops: 0000
> > > Dec 18 16:58:59 ixodes kernel: CPU:    0
> > > Dec 18 16:58:59 ixodes kernel: EIP:    0060:[<f896756d>]    Not tainted
> > > Dec 18 16:58:59 ixodes kernel: EFLAGS: 00010282
> > > Dec 18 16:58:59 ixodes kernel: EIP is at __exitfn+0xd/0x4c [parport_pc]
> > 
> > Actually, you had an oops in the parport_pc code, in
> > cleanup_module().  Now, *why* that oopsed, I don't know...
> 
> It looks like it might end up calling request_module() from within
> cleanup_module(). Is that going to be a problem?

Yes, it would be a problem.  But I don't think that's the problem
here, and I don't think it can actually happen (it's a pretty insane
idea).

BTW, I can't reproduce your problem, maybe because I can't unload
parport_pc here:

Module parport cannot be unloaded due to unsafe usage in drivers/parport/init.c:234
Module parport_pc cannot be unloaded due to unsafe usage in drivers/parport/parport_pc.c:1239

A little confused,
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: modules oops in 2.5.52

[Jeremy Fitzhardinge]

On Wed, 2002-12-18 at 21:55, Rusty Russell wrote:
> Yes, it would be a problem.  But I don't think that's the problem
> here, and I don't think it can actually happen (it's a pretty insane
> idea).
> 
> BTW, I can't reproduce your problem, maybe because I can't unload
> parport_pc here:
> 
> Module parport cannot be unloaded due to unsafe usage in drivers/parport/init.c:234
> Module parport_pc cannot be unloaded due to unsafe usage in drivers/parport/parport_pc.c:1239

Well, I don't have any problem unloading it.  It doesn't show any
messages or other warnings.  It also doesn't crash any more, so I'm not
sure what's happening...

	J