Re: Kernel Oops in 2.6.0-test2-mm4

[Matt Mackall <mpm@selenic.com>]

On Tue, Aug 05, 2003 at 05:05:58PM -0400, s0be wrote:
> here's the oops from dmesg and the surrounding messages.  I'm guessing it was caused by smb, but I can't confirm it.  trying to recreate it.
> 
> SMB connection re-established (-5)
> smb_errno: class ERRSRV, code 91 from command 0x80
> SMB connection re-established (-5)
> smb_errno: class ERRSRV, code 91 from command 0x80
> SMB connection re-established (-5)
> smb_errno: class ERRSRV, code 91 from command 0x80
> SMB connection re-established (-5)
> smb_errno: class ERRSRV, code 91 from command 0x80
> Debug: sleeping function called from invalid context at include/asm/uaccess.h:512Call Trace:
>  [<c011fd3c>] __might_sleep+0x5c/0x5e
>  [<c010da1a>] save_v86_state+0x6a/0x200
>  [<c010e565>] handle_vm86_fault+0xa5/0x8c0
>  [<c0170a23>] dput+0x23/0x200
>  [<c010c030>] do_general_protection+0x0/0xa0
>  [<c032519f>] error_code+0x2f/0x38
>  [<c0324733>] syscall_call+0x7/0xb
> 
> SMB connection re-established (-5)
> smb_errno: class ERRSRV, code 91 from command 0x80
> XFS mounting filesystem hda1

Actually, Samba seems unconnected.

This is not an oops, just a debug trace that says something tried to
do something unsafe (namely calling copy_from_user while in_atomic()
was true). 

Looks like we've got:

 do_general_protection
  handle_vm86_fault
   return_to_32bit
    save_v86_state
     copy_to_user   

and the destination of the copy is current->thread.vm86_info->regs,
which is labelled __user. Presuming this is actually in userspace,
this could be a problem.

-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon