Opened 13 years ago

Closed 13 years ago

#1444 closed defect (fixed)

Backend SEGV under TVRec::TuningSignalCheck

Reported by: martin@… Owned by: danielk
Priority: minor Milestone: 0.20
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

Backend is normally completely stable, but r9247 has crashed 6 times in the last 24 hours. Backend is idle at the time (apart from processing EIT from UK DVB).

Backtrace attached, and last few minutes of log from one crash (log was record,channel,siparser).

Attachments (7)

gdb.txt (20.8 KB) - added by martin@… 13 years ago.
mythbackend backtrace
backend.log (17.0 KB) - added by martin@… 13 years ago.
Last few minutes of log
gdb-ex2.txt (21.0 KB) - added by martin@… 13 years ago.
This is another of the backtraces. Looks quite different though. End of log was full of lines with "SIParser: NIT Present on this transport on PID 0x0"
mbe-valgrind.log (54.0 KB) - added by Martin Ebourne <martin@…> 13 years ago.
first run of valgrind
mythbackend.log.bz2 (11.2 KB) - added by Martin Ebourne <martin@…> 13 years ago.
record,channel,siparser from first run of valgrind
mbe-valgrind.log.2.bz2 (10.3 KB) - added by Martin Ebourne <martin@…> 13 years ago.
Valgrind output from second run
mythbackend.log.2.bz2 (35.2 KB) - added by Martin Ebourne <martin@…> 13 years ago.
Backend log from second valgrind run

Download all attachments as: .zip

Change History (13)

Changed 13 years ago by martin@…

Attachment: gdb.txt added

mythbackend backtrace

Changed 13 years ago by martin@…

Attachment: backend.log added

Last few minutes of log

Changed 13 years ago by martin@…

Attachment: gdb-ex2.txt added

This is another of the backtraces. Looks quite different though. End of log was full of lines with "SIParser: NIT Present on this transport on PID 0x0"

comment:1 Changed 13 years ago by martin@…

Added trace from another of the crashes (gdb-ex2.txt), though looks different. This died with:

Program terminated with signal 11, Segmentation fault.
#0  0x00002aaaab327c74 in ProgramAssociationTable::ProgramNumber (this=0x4aa0e8f0, i=4756403) at mpeg/mpegtables.h:421
421             { return (psipdata()[(i<<2)] << 8) | psipdata()[(i<<2) + 1]; }

comment:2 Changed 13 years ago by danielk

Milestone: 0.20
Resolution: invalid
Status: newclosed

[invalid]

The first backtrace is for a memory error, I need you do run valgrind to find where the error actually occurs.

The second backtrace is for a completely different problem and should have it's own ticket. Before you create another ticket though, I will need a matching "mythbackend -v siparser,channel,record" log with the backtrace. This looks like it is having problems with the reported length of the pes packet being inaccurate.

Changed 13 years ago by Martin Ebourne <martin@…>

Attachment: mbe-valgrind.log added

first run of valgrind

comment:3 Changed 13 years ago by Martin Ebourne <martin@…>

Added a run with valgrind. It stopped after 7 mins due to a pure virtual method call. I'll run it again, see if it has anything else.

Changed 13 years ago by Martin Ebourne <martin@…>

Attachment: mythbackend.log.bz2 added

record,channel,siparser from first run of valgrind

Changed 13 years ago by Martin Ebourne <martin@…>

Attachment: mbe-valgrind.log.2.bz2 added

Valgrind output from second run

Changed 13 years ago by Martin Ebourne <martin@…>

Attachment: mythbackend.log.2.bz2 added

Backend log from second valgrind run

comment:4 Changed 13 years ago by Martin Ebourne <martin@…>

Resolution: invalid
Status: closedreopened

I've added a second valgrind run. Doesn't look too helpful though, and eventually valgrind fails on an assert. Also it's not clear if the pure virtual call from the first run was in myth or valgrind itself. I'm on x86_64 which is relatively new to valgrind, so it may have bugs.

comment:5 Changed 13 years ago by Janne <janne-mythtv@…>

please test current svn with fixes from #1459 and #1493 if the tickets are open or the pathes aren't applied to svn.

comment:6 Changed 13 years ago by danielk

Resolution: fixed
Status: reopenedclosed

no reply from reporter about whether the fixes in SVN worked, assuming they did.

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