[asterisk-users] Kernel panic (asterisk 1.8.0-rc3, dahdi-linux-2.4)

[Alex]

Hello,

I'm having a very similar issue with dahdi 2.3.0.1 / 2.6.32 (and others
confirmed the occurence with same software revisions, same kind of old
hardware - P3, P4, different HFC hardware). You can look at my last
report on loosely related debian bug #598886.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=598886
(see messages #20 and #25)

My quick fix was to disable echo cancellation, which is a bit heavy
handed but also worked for others. A number of my crashes also pointed
out the math_state_restore function (see mess #25), but I didn't knew
what to do with this hint. I'll test if things are better off with MMX
disabled in dahdi during the week-end... it looks promising.

Also, have a look at kernel/Documentation/preempt-locking.txt...

  Alex

Karsten Wemheuer wrote:
> Hi,
> 
> I setup an asterisk system (asterisk 1.8-rc3, dahdi-linux-2.4.0 with
> dahdi-extra from Tzafrirs git, kernel 2.6.35.4). The hardware is an
> older pc system with Celeron CPU (2.5 GHz) with a Beronet BN4S0 ISDN
> card. The system starts without any errors.
> 
> I discovered a severe issue. The kernel panics on a very small load. The
> first call normally gets through. If I start the second or third call
> and sometimes when I terminate the first call, the system panics (Oops
> text on console).
> 
> After solving some difficulties (the relevant part of the Oops text
> scrolls out of the monitor, no serial interface), I get the text via
> netconsole. It seems to me, that the panic occurred in oslec (function
> "oslec_update"). But maybe I am wrong with this. In the oslec code there
> is a patch to enable MMX. After switching this off, the problem
> disappeared. AFAIK the cpu supports mmx.
> 
> Where should I address this issue to? Is it a known issue?
> 
> Here comes one example for the oops:
> 
> /-----
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<c0103dd6>] __math_state_restore+0x56/0x90
> *pde = 00000000 
> Oops: 0000 [#1] PREEMPT SMP 
> last sysfs file: /sys/module/configfs/initstate
> Modules linked in: netconsole configfs dahdi_echocan_oslec echo capifs
> loop wcb4xxp rtc_cmos i2c_i801 rtc_core dahdi 8250_pnp 8139too floppy
> 8250 rtc_lib mii serial_core i2c_core processor pcspkr rng_core button
> ide_pci_generic ide_core sd_mod crc_t10dif thermal [last unloaded:
> netconsole]
> 
> Pid: 1268, comm: clip.agi Not tainted 2.6.35.4 #1
> P4Dual-915GL/P4Dual-915GL
> EIP: 0060:[<c0103dd6>] EFLAGS: 00010046 CPU: 0
> EIP is at __math_state_restore+0x56/0x90
> EAX: 00000000 EBX: c5b20000 ECX: cd461960 EDX: ffffffff
> ESI: cd461960 EDI: c01045a0 EBP: 00000080 ESP: c5b21cb0
>  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
> Process clip.agi (pid: 1268, ti=c5b20000 task=cd461960 task.ti=c5b20000)
> Stack:
>  c5b21cd0 00000027 c01045a0 c01045e5 00000200 00000000 cfadd500 c0432273
> <0> cfadd500 cfadd200 00000008 00000027 00000080 00000080 cf33fa00
> 0000007b
> <0> 0000007b c02d00d8 000000e0 ffffffff d0ae2153 00000060 00010002
> 0000005a
> Call Trace:
>  [<c01045a0>] ? do_device_not_available+0x0/0x60
>  [<c01045e5>] ? do_device_not_available+0x45/0x60
>  [<c0432273>] ? error_code+0x73/0x80
>  [<c02d00d8>] ? DAC960_V1_ProcessCompletedCommand+0x1108/0x1510
>  [<d0ae2153>] ? oslec_update+0xe3/0x5c0 [echo]
>  [<d0aeb038>] ? echo_can_process+0x28/0x40 [dahdi_echocan_oslec]
>  [<d0aeb010>] ? echo_can_process+0x0/0x40 [dahdi_echocan_oslec]
>  [<d0a08a18>] ? dahdi_ec_span+0x268/0x2a0 [dahdi]
>  [<d0a9136c>] ? b4xxp_interrupt+0x11c/0x358 [wcb4xxp]
>  [<c0175ded>] ? handle_IRQ_event+0x2d/0xc0
>  [<c02dd71d>] ? scsi_decide_disposition+0x16d/0x180
>  [<c0177b85>] ? handle_fasteoi_irq+0x65/0xd0
>  [<c0105a55>] ? handle_irq+0x15/0x30
>  [<c01050a7>] ? do_IRQ+0x47/0xc0
>  [<c0103d30>] ? common_interrupt+0x30/0x40
>  [<c01300e0>] ? load_balance+0x550/0x7d0
>  [<c0431614>] ? _raw_spin_unlock_irq+0x4/0x20
>  [<c012d9ba>] ? finish_task_switch+0x3a/0x90
>  [<c042f5c9>] ? schedule+0x1c9/0x520
>  [<c0103d30>] ? common_interrupt+0x30/0x40
>  [<c042facf>] ? preempt_schedule+0x2f/0x50
>  [<c0198a60>] ? do_wp_page+0x160/0x960
>  [<c0199c02>] ? handle_mm_fault+0x5d2/0xaa0
>  [<c01244b0>] ? do_page_fault+0x0/0x370
>  [<c01245f0>] ? do_page_fault+0x140/0x370
>  [<c01b7b2f>] ? copy_strings+0x17f/0x1a0
>  [<c01b935e>] ? do_execve+0x2be/0x310
>  [<c01b935e>] ? do_execve+0x2be/0x310
>  [<c010aa80>] ? sys_execve+0x40/0x70
>  [<c01244b0>] ? do_page_fault+0x0/0x370
>  [<c0432273>] ? error_code+0x73/0x80
> Code: 89 c2 0f ae 2f 85 c9 75 27 83 4b 0c 01 80 86 98 00 00 00 01 8b 1c
> 24 8b 74 24 04 8b 7c 24 08 83 c4 0c c3 66 90 8b 86 50 02 00 00 <0f> ae
> 08 eb d9 e8 c0 ed 01 00 90 83 c8 08 e8 c7 ed 01 00 90 b8 
> EIP: [<c0103dd6>] __math_state_restore+0x56/0x90 SS:ESP 0068:c5b21cb0
> CR2: 0000000000000000
> ---[ end trace 65c27cd3a6b7bd8a ]---
> \-----
> 
> Thanks,
> 
> Karsten
> 
> 
>