[linux-dvb] Problems with kernel oops when installing HVR-1800.

Mark Jenks mjenks1968 at gmail.com
Thu Jan 1 23:53:48 CET 2009


On Thu, Jan 1, 2009 at 3:18 PM, Andy Walls <awalls at radix.net> wrote:

> On Thu, 2009-01-01 at 12:34 -0600, Mark Jenks wrote:
>
>
>
> > Well, I patched it, make clean, make, make install, and a reboot.
> >
> > BUG: unable to handle kernel NULL pointer dereference at 00000168
> > IP: [<f0e2571c>] :cx23885:mpeg_open+0x41/0xc0
> > *pde = 00000000
> > Oops: 0000 [#1] SMP
>
> Same failure mode, different place in the driver:
>
> linux/drivers/media/video/cx23885/cx23885-417.c:mpeg_open():
>
>        static int mpeg_open(struct file *file)
>        {
>                [...]
>                 lock_kernel();
>                list_for_each(list, &cx23885_devlist) {
>                        h = list_entry(list, struct cx23885_dev,
>        devlist);
>                         if (h->v4l_device->minor == minor) {
>                                dev = h;
>                [...]
>
> "h->v4l_device" is likely NULL here for one device due to one card
> having analog support in the driver and the other not having analog
> support in the driver.
>
> The fix for this is analogous to the previous fix.
>
> Those are the only two places in the driver the cx23885_devlist is
> iterated over, so hopefully every other instance of system will know
> what type of device it it dealing with and v4l_device and video_dev will
> only be used when well defined.
>
> Fix, Test, Repeat...
>
> Regards,
> Andy
>
>
>
>
> > Modules linked in: cpufreq_conservative cpufreq_userspace
> > cpufreq_powersave powernow_k8 xfs loop dm_mod cx25840 mt2131 s5h1409
> > cx23885 v4l2_compat_ioctl32 nvidia(P) snd_mpu401 cx2341x
> > videobuf_dma_sg videobuf_dvb dvb_core videobuf_core snd_usb_audio
> > snd_usb_lib snd_cs4232 snd_opl3_lib v4l2_common videodev agpgart
> > snd_hwdep lirc_mceusb2 snd_cs4231_lib snd_mpu401_uart snd_rawmidi
> > snd_hda_intel snd_pcm parport_pc ohci1394 snd_timer k8temp osst
> > v4l1_compat snd_seq_device hwmon snd button i2c_nforce2 lirc_dev
> > parport ieee1394 st forcedeth sr_mod cdrom rtc_cmos rtc_core btcx_risc
> > tveeprom i2c_core snd_page_alloc soundcore rtc_lib sg usbhid hid
> > ff_memless ohci_hcd ehci_hcd usbcore sd_mod edd ext3 mbcache jbd fan
> > aic7xxx scsi_transport_spi sata_nv pata_amd libata scsi_mod dock
> > thermal processor thermal_sys
> >
> > Pid: 2876, comm: X Tainted: P          (2.6.27.10-default #3)
> > EIP: 0060:[<f0e2571c>] EFLAGS: 00013287 CPU: 1
> > EIP is at mpeg_open+0x41/0xc0 [cx23885]
> > EAX: 00000000 EBX: ef1fd000 ECX: f0e308a8 EDX: ef3be000
> > ESI: 00000001 EDI: ef189980 EBP: efba1790 ESP: efe93e84
> >  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
> > Process X (pid: 2876, ti=efe92000 task=ef1e5070 task.ti=efe92000)
> > Stack: efbf5a00 efbf5a04 ef189980 f0d775b8 00000000 ef3876c0 00000000
> > efba1790
> >        c016bee5 ef189980 00000000 ef189980 efba1790 00000000 c016bdd9
> > c01683cd
> >        ef81ebc0 ef504c6c efe93f14 ef189980 efe93f14 00000003 c01684d8
> > ef189980
> > Call Trace:
> >  [<f0d775b8>] v4l2_open+0x62/0x76 [videodev]
> >  [<c016bee5>] chrdev_open+0x10c/0x122
> >  [<c016bdd9>] chrdev_open+0x0/0x122
> >  [<c01683cd>] __dentry_open+0x10d/0x1fc
> >  [<c01684d8>] nameidata_to_filp+0x1c/0x2c
> >  [<c0172986>] do_filp_open+0x33d/0x63e
> >  [<f1aad8ce>] _nv004117rm+0x9/0x12 [nvidia]
> >  [<c01582f8>] handle_mm_fault+0x2b3/0x5dd
> >  [<f0dcf391>] __videobuf_mmap_free+0x3e/0x7d [videobuf_core]
> >  [<c017ab2d>] alloc_fd+0x57/0xd3
> >  [<c01681e8>] do_sys_open+0x3f/0xb8
> >  [<c01682a5>] sys_open+0x1e/0x23
> >  [<c01037ad>] sysenter_do_call+0x12/0x21
> >  =======================
> > Code: 17 68 38 7a e2 f0 68 c8 0a 00 00 68 ee a2 e2 f0 e8 51 aa 2f cf
> > 83 c4 0c e8 88 66 49 cf 8b 1d a0 fd e2 f0 eb 10 8b 83 c4 0e 00 00 <39>
> > b0 68 01 00 00 74 1c 89 d3 8b 13 0f 18 02 90 81 fb a0 fd e2
> > EIP: [<f0e2571c>] mpeg_open+0x41/0xc0 [cx23885] SS:ESP 0068:efe93e84
> > ---[ end trace 1bdce38cbcdc8781 ]---
> >
> >
> >
>
>
So, now that I have it fixed.    I have no idea how to submit a patch for
what just happened.

-Mark
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