Opened 10 years ago

Closed 10 years ago

#7003 closed defect (fixed)

Segmentation Fault on Full DVB-T scan on Homerun

Reported by: thomaslloyd@… Owned by: danielk
Priority: trivial Milestone: 0.22
Component: MythTV - Channel Scanner Version: head
Severity: low Keywords:
Cc: Ticket locked: no

Description

mythbackend --version

MythTV Version : 21682 MythTV Branch : trunk Network Protocol : 48 Library API : 0.22.20090905-1 QT Version : 4.5.0 Options compiled in:

linux debug using_oss using_alsa using_backend using_dvb using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_joystick_menu using_lirc using_mheg using_opengl_video using_opengl_vsync using_qtwebkit using_v4l using_x11 using_xrandr using_xv using_bindings_perl using_bindings_python using_opengl using_vdpau using_ffmpeg_threads using_live using_mheg

tail of gbd output...

2009-09-07 19:17:36.985 Current Schema Version: 1244 2009-09-07 19:18:12.253 Loading window theme from /usr/local/share/mythtv/themes/G.A.N.T/menu-ui.xml 2009-09-07 19:18:37.430 Loading menu theme from /usr/local/share/mythtv/setup.xml 2009-09-07 19:18:59.711 New DB connection, total: 2 2009-09-07 19:18:59.712 Connected to database 'mythconverg' at host: localhost 2009-09-07 19:18:59.716 New DB connection, total: 3 2009-09-07 19:18:59.717 Connected to database 'mythconverg' at host: localhost 2009-09-07 19:18:59.726 New DB connection, total: 4 2009-09-07 19:18:59.727 Connected to database 'mythconverg' at host: localhost [New Thread 0xac9ddb90 (LWP 30642)] [New Thread 0xabfffb90 (LWP 30643)] [Thread 0xabfffb90 (LWP 30643) exited] [New Thread 0xabfffb90 (LWP 30644)] [Thread 0xabfffb90 (LWP 30644) exited] [New Thread 0xabfffb90 (LWP 30645)] [New Thread 0xab7feb90 (LWP 30646)] [New Thread 0xaab38b90 (LWP 30647)]

Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xab7feb90 (LWP 30646)] 0xb7c22676 in DVBChannel::GetCardType? (this=0x0) at ./dvbchannel.h:55 55 DTVTunerType GetCardType?(void) const { return card_type; }

This seems to be happening as the program gets to the first frequency that it has digital channels in.

Attachments (6)

mythBT.log (185.6 KB) - added by thomaslloyd@… 10 years ago.
full BT for mythtv-setup
mythBT.2.log (227.9 KB) - added by thomaslloyd@… 10 years ago.
Full BT i think
gdb.log (13.5 KB) - added by Josh_ 10 years ago.
GDB trace of core dumpfile
7003-v1.patch (12.6 KB) - added by danielk 10 years ago.
7003-v2.patch (39.6 KB) - added by danielk 10 years ago.
7003-v3.patch (39.7 KB) - added by danielk 10 years ago.
Updated patch

Download all attachments as: .zip

Change History (17)

Changed 10 years ago by thomaslloyd@…

Attachment: mythBT.log added

full BT for mythtv-setup

comment:1 Changed 10 years ago by danielk

Priority: blockertrivial
Severity: mediumlow
Status: newinfoneeded_new

The segfault reported in the ticket description does not match the one in the provided log.

Note: If DVBChannel is being used that is a bug as this device should be using the HDHRChannel class. Please attach a full backtrace with the reported segfault.

Changed 10 years ago by thomaslloyd@…

Attachment: mythBT.2.log added

Full BT i think

comment:2 in reply to:  1 Changed 10 years ago by anonymous

307.113816] mythtv-setup[4253]: segfault at 68 ip b7ae4676 sp ab726a7c error 4 in libmythtv-0.22.so.0.22.0[b71ed000+cc6000]

This is the seg fault i am getting maybe i am dong something wrong but i might need some advise on how to do it correctly

comment:3 Changed 10 years ago by Josh_

Just adding my results as I appear to be having the same issue.

I'm using an ATSC HD Homerun, but in my situation, it's not the first frequency with digital channels. I've narrowed it to 3 specific channels so far that this happens in.

I don't have a backtrace, just a core dump that I analyzed with gdb.

Changed 10 years ago by Josh_

Attachment: gdb.log added

GDB trace of core dumpfile

comment:4 Changed 10 years ago by danielk

Milestone: unknown0.22
Status: infoneeded_newnew

Changed 10 years ago by danielk

Attachment: 7003-v1.patch added

comment:5 Changed 10 years ago by danielk

Status: newinfoneeded_new

This should fix the segfault... not sure if it is really a fix. Does the European HDHomeRun support QAM or just OFDM?

comment:6 in reply to:  5 Changed 10 years ago by Josh_

Replying to danielk:

This should fix the segfault... not sure if it is really a fix. Does the European HDHomeRun support QAM or just OFDM?

I've got the US version.

But per silicondust's website, the European version specs show: Specifications: ¶ DVB-T (QAM64/16/QPSK) DVB-C (QAM256/128/64 Annex A/C) 8/7/6 MHz channel bandwidth (multi-country operation). IR Receiver (signal PC with a standard remote control) 100baseTX high speed network 1 year warranty

comment:7 Changed 10 years ago by anonymous

I just realized that the OP for this bug was doing a DVB channel scan, I was doing an ATSC QAM scan.

Mabye this isn't the bug for me, but the trace on the core dumpfile shows the same error as the OP?

Changed 10 years ago by danielk

Attachment: 7003-v2.patch added

comment:8 Changed 10 years ago by danielk

(In [21852]) Refs #7003. Fixes the reported segfault. This does not fix the underlying problem, but the patch attached to #7003 should in theory fix that.

Changed 10 years ago by danielk

Attachment: 7003-v3.patch added

Updated patch

comment:9 Changed 10 years ago by danielk

I need someone who has a European HDHomeRun to test the patch. This should allow full DVB-T and DVB-C scans to be completed with this device as well as NIT add scans and all types of DVB-T scans.

Josh_, for you the segfault fix already committed to trunk should be sufficient to avoid problems. You are probably doing an QAM-256 scan on a cable system which is using DVB tables for some purpose, but a full scan will pick up everything on that system anyway. NIT tables are really most useful for DVB-S systems.

comment:10 Changed 10 years ago by thomaslloyd@…

Hi,

Just been compiling on my system. I have managed to do a DVB-T scan on my homerun now and can confirm no segfault and it now returns some channels. Have not got any further as i miss out pulseaudio support when i compiled. So just running through it again.

comment:11 Changed 10 years ago by danielk

Resolution: fixed
Status: infoneeded_newclosed

(In [21858]) Fixes #7003. Allow basic channel scanning with DVB version of HDHomeRun.

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