RE: areaDetector problem

["Mark Rivers" <rivers@cars.uchicago.edu>]

John,
 
I'm willing to bet this problem is because you have not applied the patch to macLib in EPICS 3.14.11? 
 
This is from the areaDetector Release Notes:
 
Known problems. This release of areaDetector exposed two bugs in EPICS 3.14.11. Links to the required patches can be found on the EPICS 3.4.11 Known Problems page <http://www.aps.anl.gov/epics/base/R3-14/11-docs/KnownProblems.html> . 

*	The epicsThreadOnceOsd problem can cause crashes with an "assert" error on IOC initialization on Win32 systems. 
*	The macLib problem can cause crashes or memory corruption when the commonPlugins.cmd script expands lines with macros longer than 256 characters. 

The line that is crashing for you:

 dbLoadRecords("$(AREA_DETECTOR)/ADApp/Db/NDOverlayN.template", ...

generates a very long line when macro expansion is done.  This causes a buffer overflow in macLib, which Windows detects in the call to free().

Here is the note on the 3.14.11 Known Problems page:

2010-05-11: macLib has an off-by-one buffer overflow bug which only appears when using very long input lines. This patch <https://carsmail1.cars.aps.anl.gov/exchange/rivers/Drafts/RE:%20areaDetector%20problem.EML/macCore.patch>  modifies the src/libCom/macLib/macCore.c file to fix this issue. A more extensive patch can be found on the Launchpad bug #551909 page. 

Mark

 


________________________________

From: tech-talk-bounces@aps.anl.gov on behalf of John Dobbins
Sent: Thu 7/15/2010 3:44 PM
To: EPICS Techtalk
Subject: areaDetector problem



I am using areaDetector with Flea2 Firewire cameras on WindowsXP.

I can create a camera driver (WinFDC_Config) and pipe the output through a chain of plugins:

   camera_driver -> process-> overlay -> NDStdArray -> stats

and everything works.  I next tried to create an IOC with two cameras and found

   {camera_driver_1, camera_driver_2} -> process

works, where process can receive output from one camera or the other.  However

   {camera_driver_1, camera_driver_2} -> process -> overlay

crashes. In particular the IOC crashes on start up at the last of these lines:

   NDOverlayConfigure("OVER1", $(QSIZE), 0, "PROC1", 0, 8, -1, -1)
   dbLoadRecords("$(AREA_DETECTOR)/ADApp/Db/NDPluginBase.template",...
   dbLoadRecords("$(AREA_DETECTOR)/ADApp/Db/NDOverlay.template"
   dbLoadRecords("$(AREA_DETECTOR)/ADApp/Db/NDOverlayN.template", ...

I get an error message "myIOC.exe has encountered a problem and needs to close". If I omit the last line the IOC will start up. Note that these are the same db files that work in the single camera IOC.


I don't know how to proceed. Hoping someone can suggest a next step. Any wild guesses as to what might be a problem?


Regards,

John Dobbins
Lab for Elementary Particle Physics
Cornell University