kern/122331: panic's on KDE-launches (but only in WPA Wifi area)

[John Baldwin]

The following reply was made to PR kern/122331; it has been noted by GNATS.

From: John Baldwin <jhb at freebsd.org>
To: Matthias Apitz <guru at unixarea.de>
Cc: freebsd-hackers at freebsd.org, freebsd-net at freebsd.org,
        bug-followup at freebsd.org
Subject: Re: kern/122331: panic's on KDE-launches (but only in WPA Wifi area)
Date: Tue, 16 Sep 2008 11:25:44 -0400

 On Monday 15 September 2008 06:24:14 pm Matthias Apitz wrote:
 > El d=EDa Monday, September 15, 2008 a las 04:08:06PM -0400, John Baldwin=
 =20
 escribi=F3:
 >=20
 > > > > Can you go to frame 7 in kgdb and 'p *fdp'?
 > > >=20
 > > > (kgdb) frame 7
 > > > #7  0xc0788b98 in kern_select (td=3D0xc49d5630, nd=3D9, fd_in=3D0x298=
 ad840,=20
 > > >     fd_ou=3D0x298ad9c4, fd_ex=3D0x298adb48, tvp=3D0x0) at filedesc.h:=
 136
 > > > 		return (fd < 0 || fd >=3D fdp->fd_nfiles ? NULL : fdp->fd_ofiles[fd=
 ]);
 > > > (kgdb) p *fdp
 > > > Variable "fdp" is not available.
 > > > (kgdb)=20
 > >=20
 > > If 'td' is available then you can do 'p *td->td_proc->p_fd'
 >=20
 > (kgdb) frame 7
 > #7  0xc0788b98 in kern_select (td=3D0xc49d5630, nd=3D9, fd_in=3D0x298ad84=
 0,=20
 >     fd_ou=3D0x298ad9c4, fd_ex=3D0x298adb48, tvp=3D0x0) at filedesc.h:136
 > 136             return (fd < 0 || fd >=3D fdp->fd_nfiles ? NULL :
 > fdp->fd_ofiles[fd]);
 > (kgdb) p td
 > $7 =3D (struct thread *) 0xc49d5630
 > (kgdb) p *td->td_proc->p_fd
 > $8 =3D {fd_ofiles =3D 0x0, fd_ofileflags =3D 0x0, fd_cdir =3D 0x0,=20
 
 Well, fd_ofiles being NULL here is really odd.  It's also odd that you have=
  no=20
 current directory.  Because fd_nfiles is 20, fd_ofiles should be pointing t=
 o=20
 the static file descriptor array.  Off the top of my head I don't see how=20
 this is happening.  It might help if you can narrow down exactly what WPA=20
 operation you are doing that causes the panic.
 
 =2D-=20
 John Baldwin