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<== Date ==> <== Thread ==>

Subject: Re: dbGet() problem and exception vector table question
From: [email protected] (Marty Kraimer)
To: [email protected]
Date: Thu, 14 Sep 1995 14:50:28 -0500
> From [email protected] Wed Sep 13 20:51 CDT 1995
> Date: Wed, 13 Sep 95 15:48:25 HST
> From: [email protected] (William Lupton)
> To: [email protected]
> Subject: dbGet() problem and exception vector table question
> Content-Type> : > text> 
> Content-Length: 1134
> 
> Dear all,
> 
>   We ran into a problem with dbGet() today. It's probably been there for
> ages and is pretty benign _unless_ you happen (by mistake) to have an
> interrupt vector at address zero (in which case your IOC may hang in the
> same way as ours did)!
> 
>   The problem is that long *perr_status is initialized to NULL and then
> the statement *perr_status = 0 is executed, which overwrites the first
> four bytes of memory with zeroes. All other accesses to *perr_status are
> protected with checks on whether perr_status is NULL (actually I think
> that it can be removed since it always _is_ NULL).


I was shocked when I looked.  William is completely correct.
I looked and this bug has been in epics since 3.11.
It will be fixed in the next release. 

Marty Kraimer


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