Chief Delphi - OpenCV Crashing?!

We used GRIP to generate a vision pipeline (java), and then overlay the first two contours it sees onto a SmartDashboard camera feed. Last week, this was working great.

This week, we noticed sporadic and mysterious drops in comms with the RoboRio. When this happens, the driver station (and the computer) stops being able to ping the RoboRio until the robot is either rebooted or the Rio reset. The camera code has not changed from last week to now, but we have updated WPILib to 2017.2 and set up a PID loop on a CANTalon.

As to investigating the source of the error, we have USB'd into the Rio after a crash and looked at the FRC log, and there we found a java error with a message about further information at /tmp/hs_err_pid1429.log. The log at this location is as follows:

Code:

#

# A fatal error has been detected by the Java Runtime Environment:

#

#  SIGBUS (0x7) at pc=0xad323b9a, pid=1429, tid=2892047456

#

# JRE version: Java(TM) SE Embedded Runtime Environment (8.0_06-b23) (build 1.8.0_06-b23)

# Java VM: Java HotSpot(TM) Embedded Client VM (25.6-b23 mixed mode linux-arm )

# Problematic frame:

# C  [libopencv_core.so.3.1+0x14bb9a]  cv::_OutputArray::create(int, int const*, int, int, bool, int) const+0x8b1

#

# Core dump written. Default location: //core or core.1429 (max size 2048 kB). To ensure a full core dump, try "ulimit -c unlimited" before starting Java again

#

# If you would like to submit a bug report, please visit:

#   http://bugreport.sun.com/bugreport/crash.jsp

# The crash happened outside the Java Virtual Machine in native code.

# See problematic frame for where to report the bug.

#



---------------  T H R E A D  ---------------



Current thread (0xacd68000):  JavaThread "Thread-0" daemon [_thread_in_native, id=1468, stack(0xac5c3000,0xac613000)]



siginfo:si_signo=SIGBUS: si_errno=0, si_code=1 (BUS_ADRALN), si_addr=0x00000056



Registers:

  r0  = 0x00000000

  r1  = 0x00de0000

  r2  = 0xac6117d0

  r3  = 0x00000056

  r4  = 0x0000001c

  r5  = 0xffffffff

  r6  = 0xac611988

  r7  = 0x00000002

  r8  = 0x00000001

  r9  = 0x0000003c

  r10 = 0xab345ef0

  fp  = 0x00000001

  r12 = 0xad381a2c

  sp  = 0xac611570

  lr  = 0xad323edf

  pc  = 0xad323b9a

  cpsr = 0x00070030



Top of Stack: (sp=0xac611570)

0xac611570:   00000000 00000000 ac6117d0 0000001c

0xac611580:   fffffffe 00000000 00000000 00000000

0xac611590:   ae071130 ab3a78d8 00000000 00000000

0xac6115a0:   00000000 00000002 00000000 00000167

0xac6115b0:   0000a7d0 ad10dc84 ad10dc84 ad10dc84

0xac6115c0:   00000000 00000000 ac6115a8 ac6115d0

0xac6115d0:   000001e0 00000001 42ff4000 00000002

0xac6115e0:   00000000 00000000 00000000 00000000 



Instructions: (pc=0xad323b9a)

0xad323b7a:   f8cd4649 f6d2c000 4648ed02 ec9cf6d2

0xad323b8a:   3024f8da 330cb173 8f5ff3bf 2f00e853

0xad323b9a:   e8431e51 28001000 2a01d1f8 8f5ff3bf

0xad323baa:   85e1f000 2004f8da f8ca2300 429a3024 



Register to memory mapping:



  r0  = 0x00000000

0x00000000 is an unknown value



  r1  = 0x00de0000

0x00de0000 is an unknown value



  r2  = 0xac6117d0

0xac6117d0 is pointing into the stack for thread: 0xacd68000



  r3  = 0x00000056

0x00000056 is an unknown value



  r4  = 0x0000001c

0x0000001c is an unknown value



  r5  = 0xffffffff

0xffffffff is an unknown value



  r6  = 0xac611988

0xac611988 is pointing into the stack for thread: 0xacd68000



  r7  = 0x00000002

0x00000002 is an unknown value



  r8  = 0x00000001

0x00000001 is an unknown value



  r9  = 0x0000003c

0x0000003c is an unknown value



  r10 = 0xab345ef0

0xab345ef0 is an unknown value



  fp  = 0x00000001

0x00000001 is an unknown value



  r12 = 0xad381a2c

0xad381a2c: <offset 0x1a9a2c> in /usr/local/frc/lib/libopencv_core.so.3.1 at 0xad1d8000



  sp  = 0xac611570

0xac611570 is pointing into the stack for thread: 0xacd68000



  lr  = 0xad323edf

0xad323edf: _ZNK2cv12_OutputArray6createEiPKiiibi+0xbf6 in /usr/local/frc/lib/libopencv_core.so.3.1 at 0xad1d8000



  pc  = 0xad323b9a

0xad323b9a: _ZNK2cv12_OutputArray6createEiPKiiibi+0x8b1 in /usr/local/frc/lib/libopencv_core.so.3.1 at 0xad1d8000







Stack: [0xac5c3000,0xac613000],  sp=0xac611570,  free space=313k

Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)

C  [libopencv_core.so.3.1+0x14bb9a]  cv::_OutputArray::create(int, int const*, int, int, bool, int) const+0x8b1

I have never really had any experience with debugging this low level, and best I've been able to ascertain is that the library libopencv_core.so.3.1 is crashing. Any help would be greatly appreciated.