So I do not believe our VM/370 supports ABMEXIT (If I am wrong please, please me, and let me know!)
I see no way to trap an ABEND (like divide by zero) nor a HX (which seems to be a pooling mechanism!?).
This means that an ABEND of a C program (well any program?!) will inevitably require an IPL as cleanups cannot be guaranteed :-(
Also HI is not supported.
It may not be the IBM way ... but a mod that fired SVC 13 (or 213 ... or whatever) on starting to process an abend would allow a SVC handler to be registered ...
Adrian
