Elevating lvuser permissions in Labview RT Linux

[bkopietz]

Hi everyone, 

I am attempting a integrate an external library into a Labview RT Linux application.   I can compile and run an application using the library in C++ but the same application fails to run when called through Labview.  What I found is the compiled C++ application also fails to run from the command line when using the user lvuser.  The application fails with the following response:

ERROR - cannot change scheduling policy!
root privilege is required or realtime group has to be joined!

I attempted to add the lvuser to the administrators group using the command usermod -a -G administrators lvuser.  This had not effect.  I cannot call su admin from the application as the actual interface to the library is through the call library function.  Is there another way to elevated the user permissions of the lvuser? 

[bkopietz]

I still need an answer.   Is anyone able to help? 

[bkopietz · Accepted solution]

I was able to solve this using setcap in the command shell.  I used the command:

setcap cap_net_bind_service,cap_net_admin,cap_ipc_lock,cap_sys_rawio,cap_sys_admin,cap_sys_boot,cap_sys_nice,
cap_sys_time+ep /usr/local/natinst/labview/lvrt  

Reboot the system for 

Inside of the Labview application you must call setuid(0) using call library function from the library libc.so.6.  Make sure to set run in any thread as this is per thread.  

[tony0924]

My driver install in NI LINUX RT and put so to "/home/lvuser/natinst/bin"

Client of window Labview call so but has error : open dev failed ! Permission denied !

How to do ?