Re: 2.6.18-rc1 bttv modprobe null pointer dereference

[Andrew Morton <akpm@osdl.org>]

On Thu, 6 Jul 2006 20:51:27 -0700
"Bret Towe" <magnade@gmail.com> wrote:

> when upgrading to 2.6.18-rc1 i got the below error
> when doing modprobe bttv card=78
> tho the card option didnt seem to matter much
> i did see a email on the list on what looked to me the same issue
> but was for a -mm kernel only 3 message in the thread i have
> and no follow up was done from what i see
> 
> 
> bttv0: registered device video0
> Unable to handle kernel NULL pointer dereference at 0000000000000149 RIP:
>  [<ffffffff802f1f9b>] sysfs_add_file+0x2b/0xb0
> PGD 27755067 PUD 27754067 PMD 0
> Oops: 0000 [1] PREEMPT
> CPU 0
> Modules linked in: bttv video_buf firmware_class ir_common
> compat_ioctl32 i2c_algo_bit btcx_risc tveeprom videodev v4l2_common
> radeon drm snd_seq_midi snd_emu10k1_synth snd_emux_synth
> snd_seq_virmidi snd_seq_midi_emul snd_pcm_oss snd_mixer_oss
> snd_seq_oss snd_seq_midi_event snd_seq snd_emu10k1 snd_rawmidi
> snd_ac97_codec snd_ac97_bus snd_pcm snd_seq_device snd_timer
> snd_page_alloc snd_util_mem snd_hwdep snd vfat fat w83627hf hwmon_vid
> i2c_isa i2c_core r8169 dm_snapshot dm_mirror dm_mod sbp2 ohci1394
> ieee1394 usb_storage
> Pid: 9330, comm: modprobe Tainted: G   M  2.6.18-rc1 #1

That's claiming there was a machine check exception.  Can you check the
full dmesg, see if anything else odd happened?

Is this repeatable?  It sounds like it is.

> RIP: 0010:[<ffffffff802f1f9b>]  [<ffffffff802f1f9b>] sysfs_add_file+0x2b/0xb0
> RSP: 0018:ffff81002ac71c28  EFLAGS: 00010286
> RAX: 00000000ffffff00 RBX: ffffffff88207460 RCX: 00000000ffffffff
> RDX: 0000000000000004 RSI: ffffffff881fd6c0 RDI: 0000000000000001
> RBP: ffff81002ac71c58 R08: 0000000000000000 R09: 0000000000000001
> R10: ffffffff80218b42 R11: 0000000000000000 R12: ffffffff881fd6c0
> R13: 0000000000000001 R14: 00000000ffffffef R15: 0000000000000000
> FS:  00002b58f0e16d50(0000) GS:ffffffff809f2000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: 0000000000000149 CR3: 0000000027740000 CR4: 00000000000006e0
> Process modprobe (pid: 9330, threadinfo ffff81002ac70000, task ffff8100284ea040)
> Stack:  000000042ac71c38 ffffffff88207460 0000000000000000 ffff81003ff5f000
>  ffffffff88208160 0000000000000000 ffff81002ac71c68 ffffffff802f205e
>  ffff81002ac71c78 ffffffff8040c307 ffff81002ac71cb8 ffffffff881e6b9d
> Call Trace:
>  [<ffffffff802f205e>] sysfs_create_file+0x3e/0x40
>  [<ffffffff8040c307>] class_device_create_file+0x17/0x20
>  [<ffffffff881e6b9d>] :bttv:bttv_probe+0x64d/0x840
>  [<ffffffff8039f4cd>] pci_device_probe+0x5d/0xa0
>  [<ffffffff8040b327>] driver_probe_device+0x67/0xe0
>  [<ffffffff8040b4cd>] __driver_attach+0x8d/0xf0
>  [<ffffffff8040abdf>] bus_for_each_dev+0x4f/0x80
>  [<ffffffff8040b22c>] driver_attach+0x1c/0x20
>  [<ffffffff8040a75e>] bus_add_driver+0x8e/0x160
>  [<ffffffff8040b80d>] driver_register+0xcd/0xe0
>  [<ffffffff8039f713>] __pci_register_driver+0x63/0x90
>  [<ffffffff881e3414>] :bttv:bttv_init_module+0xb4/0xc0
>  [<ffffffff802ad7ab>] sys_init_module+0x155b/0x1760
>  [<ffffffff80267b92>] system_call+0x7e/0x83
>  [<00002b58f0ca66cc>]
> 
> Code: 4c 8b bf 48 01 00 00 48 8b bf c0 00 00 00 8b 5e 10 48 81 c7
> RIP  [<ffffffff802f1f9b>] sysfs_add_file+0x2b/0xb0
>  RSP <ffff81002ac71c28>
> CR2: 0000000000000149

There don't seem to have been significant changes in bttv-driver.c for some
time, and we're seeing a few reports like this.  I'm suspecting that either
a sysfs/driver-core change was wrong, or previously wrong driver behaviour
is now causing oopses.

And Mauro is offline until July 12.

Can you send the .config please?