WARNING: at drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()

[Michał Piotrowski]

2010/10/21 Kyle McMartin <kyle at mcmartin.ca>:
> On Thu, Oct 21, 2010 at 08:38:10PM +0200, Micha? Piotrowski wrote:
>> I hit this bug after upgrade from testing systemd repo
>>
>> [   15.630389] WARNING: at drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
>> [   15.630393] Hardware name: HP 550
>> [   15.630396] Modules linked in: snd_hda_codec_analog iwlagn
>> snd_hda_intel iwlcore snd_hda_codec snd_hwdep snd_seq uinput
>> snd_seq_device hp_wmi btusb mac80211 snd_pcm cfg80211 bluetooth rfkill
>> snd_timer joydev serio_raw wmi shpchp snd soundcore e1000e iTCO_wdt
>> snd_page_alloc iTCO_vendor_support ipv6 i915 drm_kms_helper drm
>> i2c_algo_bit i2c_core video output [last unloaded: scsi_wait_scan]
>> [   15.630460] Pid: 123, comm: plymouthd Not tainted 2.6.36-1.fc15.x86_64 #1
>
> Do you remember if this turned up when systemd was enabled in fc14?

No, I did not seen this bug before.

I noticed it today after systemd update - I grepped /var/log/messages
grep drivers/char/tty_io.c messages
Oct 21 20:28:53 dio kernel: [   15.630389] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:28:53 dio kernel: [   16.410427] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:45:05 dio kernel: [   14.682062] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:45:05 dio kernel: [   16.568228] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:57:21 dio kernel: [   14.515496] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:57:21 dio kernel: [   15.976412] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 20:57:21 dio kernel: [   16.781814] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 21:01:56 dio kernel: [   14.792913] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 21:01:56 dio kernel: [   15.902248] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()
Oct 21 21:01:56 dio kernel: [   16.629255] WARNING: at
drivers/char/tty_io.c:1325 tty_open+0x29c/0x49b()


> I
> have a feeling this is going to be a nasty race as a result of the BKL
> removal from the TTY code...

It's not nasty - it's repeatable on my system :)

(and I bet that on the others too, after systemd upgrade - systemd 11
somehow triggers this bug)

>
> --Kyle
>
>

Regards,
Michal