Crash in at_gprs_context_remove()

[Zhang, Zhenhua]

Hi,

Zhang, Zhenhua wrote:
> Hi Kalle,
> 
> Kalle Valo wrote:
>> Hi,
>> 
>> (gdb) bt
>> #0  0x00007ffff790b642 in IA__g_atomic_int_exchange_and_add   
>> (atomic=0x0, val=-1) at
>> /build/buildd/glib2.0-2.25.8/glib/gatomic-gcc.c:30 #1
>>    0x00000000004325a3 in g_at_ppp_unref (ppp=0x0) at
>> gatchat/gatppp.c:448 #2  0x0000000000448e12 in
>> at_gprs_context_remove (gc=0x6e2f50) at
>> drivers/atmodem/gprs-context.c:260 #3  0x00000000004923c9 in 
> 
> As Denis has pointed out, we can add a check for gcd->ppp in
> at_gprs_context_remove() to avoid this crash.
> 
> When I tried to activate & deactivate context on my Huawei
> EM770W modem, I see kernel module usb_serial warning.
> 
> ------------[ cut here ]------------
> WARNING: at
> /build/buildd/linux-2.6.31/drivers/usb/serial/usb-serial.c:460
> serial_ioctl+0x99/0xa0 [usbserial]()
> Hardware name: 7661BL4
> Modules linked in: tun option usbserial usb_storage hidp
> aes_i586 aes_generic ppdev binfmt_misc bridge stp bnep btusb
> joydev snd_hda_codec_analog pcmcia snd_hda_intel snd_hda_codec
> snd_hwdep snd_pcm_oss snd_mixer_oss arc4 snd_pcm ecb
> snd_seq_dummy uvcvideo videodev v4l1_compat snd_seq_oss
> yenta_socket rsrc_nonstatic ricoh_mmc pcmcia_core iwlagn
> iwlcore mac80211 sdhci_pci sdhci psmouse serio_raw
> snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer
> snd_seq_device cfg80211 thinkpad_acpi led_class nvram snd
> soundcore snd_page_alloc heci(C) lp parport usbhid dm_raid45
> xor fbcon tileblit font bitblit softcursor ohci1394 e1000e
> ieee1394 i915 drm i2c_algo_bit video output intel_agp agpgart
> Pid: 5180, comm: ofonod Tainted: G         C 2.6.31-16-generic
> #53-Ubuntu Call Trace:
> [<c014518d>] warn_slowpath_common+0x6d/0xa0
> [<fa3ab689>] ? serial_ioctl+0x99/0xa0 [usbserial]
> [<fa3ab689>] ? serial_ioctl+0x99/0xa0 [usbserial]
> [<c01451d5>] warn_slowpath_null+0x15/0x20
> [<fa3ab689>] serial_ioctl+0x99/0xa0 [usbserial]
> [<c0386414>] ? tty_buffer_flush+0x54/0xe0
> [<fa3ab5f0>] ? serial_ioctl+0x0/0xa0 [usbserial]
> [<c03801b7>] tty_ioctl+0x77/0x620
> [<c0380140>] ? tty_ioctl+0x0/0x620
> [<c01f518c>] vfs_ioctl+0x1c/0x90
> [<c01f0726>] ? putname+0x26/0x40
> [<c01f54b1>] do_vfs_ioctl+0x71/0x310
> [<c01f57af>] sys_ioctl+0x5f/0x80
> [<c01e5939>] ? sys_open+0x29/0x40
> [<c010336c>] syscall_call+0x7/0xb
> ---[ end trace ac231b55ebb1fdca ]---
> 
> When I shutdown the oFono, kernel reports:
> 	tty_port_close_start: tty->count = 1 port count = 0.
> 
> Any ideas?

I observed the warning shows up when /dev/ttyUSB2 send us any intermediate result. If I remove gprs atom and recreate it in huawei_disconnect, the kernel warning is gone. Does anyone see the same problem in other Huawei modem? If not, I assume it's a problem only for EM770 modem. (I don't have other Huawei modem at hand)

Thanks,
Zhenhua

>> 
>> --
>> Kalle Valo
>> _______________________________________________
>> ofono mailing list
>> ofono at ofono.org
>> http://lists.ofono.org/listinfo/ofono
> 
> 
> 
> Regards,
> Zhenhua



Regards,
Zhenhua