Re: tty-related oops in latest kernel(s)?

["Pekka Enberg" <penberg@cs.helsinki.fi>]

Hi Tero,

(I am cc'ing Alan as he's been working on tty code recently.)

On 5/27/07, Tero Roponen <teanropo@jyu.fi> wrote:
> 2.6.22-rc3 (with Reiser4 patch) oopses when watching videos with
> mplayer using neofb console.

[snip]

> Ok, everything seems to work and I can watch the video.
> However, when the mplayer stops I get these warnings:
>
>   release_dev: driver.table[3] not tty for (tty4)
>   Warning: dev (tty4) tty->count(3) != #fd's(2) in release_dev
>   release_dev: driver.table[3] not tty for (tty4)

So sanity check for reference counting failed.

> When I try to repeat the previous step the kernel oopses:
>
>   neofb: no support for 32bpp
>   Mode (1024x768) larger than the LCD panel (800x600)
>   Mode (1152x864) larger than the LCD panel (800x600)
>   Mode (1024x1024) larger than the LCD panel (800x600)
>   Mode (1280x1024) larger than the LCD panel (800x600)
>   BUG: unable to handle kernel NULL pointer dereference at virtual address 00000731
>    printing eip:
>   c021e50e
>   *pde = 00000000
>   Oops: 0000 [#1]
>   Modules linked in: binfmt_misc floppy loop xirc2ps_cs pcmcia usb_storage parport_pc parport yenta_socket rsrc_nonstatic pcmcia_core evdev uhci_hcd usbcore
>   CPU:    0
>   EIP:    0060:[<c021e50e>]    Not tainted VLI
>   EFLAGS: 00010202   (2.6.22-rc3-atr #4)
>   EIP is at vt_ioctl+0xda8/0x1482
>   eax: 00000679   ebx: 00005600   ecx: c3d41200   edx: 00000000
>   esi: 0893159c   edi: c0386a2f   ebp: 00000003   esp: c26a5e28
>   ds: 007b   es: 007b   fs: 0000  gs: 0033  ss: 0068
>   Process mplayer (pid: 1502, ti=c26a5000 task=c3a22500 task.ti=c26a5000)
>   Stack: fffffffe c26a5f30 c0149fd9 c29fe400 c3d68600 00000001 4642f7b0 c3d0bcc0
>          c3c32464 00000101 00000001 00000000 4644793c 4642f7b0 00000002 00000005
>          0000001b 00000005 c34ad240 c3d0bcc0 c1386000 00000002 00000000 c021d766
>   Call Trace:
>    [<c0149fd9>] link_path_walk+0xa5/0xaf
>    [<c021d766>] vt_ioctl+0x0/0x1482
>    [<c021a395>] tty_ioctl+0xa01/0xa87
>    [<c0143c5a>] get_empty_filp+0x4f/0xc9
>    [<c01439bf>] put_filp+0x14/0x31
>    [<c014ab93>] __path_lookup_intent_open+0x6c/0x75
>    [<c014ac10>] path_lookup_open+0x20/0x25
>    [<c014acd9>] open_namei+0x6e/0x51d
>    [<c0141b0c>] do_filp_open+0x25/0x39
>    [<c0219994>] tty_ioctl+0x0/0xa87
>    [<c014ba8a>] do_ioctl+0x3e/0x4d
>    [<c014bc84>] vfs_ioctl+0x1eb/0x202
>    [<c014bcce>] sys_ioctl+0x33/0x4d
>    [<c01022c2>] sysenter_past_esp+0x5f/0x85
>    =======================
>   Code: 0f b7 c8 7f 04 85 c9 75 cd 8d 4e 04 89 d8 e8 aa 11 fd ff e9 20 f8 ff ff 8d 04 95 00 00 00 00 03 81 b8 00 00 00 8b 00 85 c0 74 16 <83> b8 b8 00 00 00 00 74 0d 42 83 fa 3f 75 de b0 ff e9 88 f7 ff
>   EIP: [<c021e50e>] vt_ioctl+0xda8/0x1482 SS:ESP 0068:c26a5e28

Can we have your .config please? Also, could you work out the file and
line number of vt_ioctl+0xda8/0x1482 like this:

gdb vmlinux
(gdb) l *0xc021e50e

                                  Pekka