Experimental Physics and
Industrial Control System

<greene%[email protected]> · Tue, 11 Jul 1995 14:40:32 -0600 (MDT)

I've encountered a bug while porting EPICS to the Hytec CAMAC controller.
The problem is in initDatabase() which is called by iocInit().  The
interesting part is how this function ever worked.

The problem is in the first call to ellFirst().  If there are no
records defined for a specific type, then the field precLoc->preclist
is null.  However, the call to ellFirst() does not check for this
condition and will return a garbage pointer.  This works fine with
the NI VXI cpu030 card because the data at 0x0 is also 0x0 which causes
the for-loop to continue with the next record type.  However, with
the Hytec card, 0x0 is the start of EPROM which contains non-zero
data.

Obviously I can easily fix this by checking for a null preclist value
but I'm curious how this works on other controllers.  I'm also concerned
with other areas in the EPICS code which might pass a null ELLLIST value
to ellFirst().

--
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                                Greg Greene
                                KineticSystems Corp.
                                ph:    303-220-7455 x13
                                fax:   303-220-7458
                                email: [email protected]
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System