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Android: Can i send a SIGUSR1/2 signal from the "system server" to one of my hardware daemon?

+1 vote
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I working on a project which needs adding a service with JNI to the system server and also a new daemon in init.rc script. I have successfully done this.
I might need the system service to periodically send SIGUSR1/2 signals to the daemon. Linux requires a sender of signals to be root. Do I have this privilege inside system server in Android?

posted Oct 18, 2013 by Bob Wise

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1 Answer

+1 vote

See frameworks/base/core/java/com/android/internal/os/ZygoteInit.java method startSystemServer()for a list of the capabilities of system server. Per man 2 kill, you'll need CAP_KILL:
"For a process to have permission to send a signal it must either be privileged (under Linux: have the CAP_KILL capability), or the real or effective user ID of the sending process must equal the real or saved set-user-ID of the target process."

answer Oct 18, 2013 by Jai Prakash
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