signal 10 in malloc call???

[Tom Armistead]

I've been having an *interesting* thing happen under System 5, release 3.1
Unix, on a 3b2/310 and was wondering if I could get any insight from
any one as to the problem (or cause of)???

I am getting signal 10 (buss error) in the middle of a malloc call.
It doesn't happen under any regular set of circumstances as far as I can
tell. From sdb I can tell that that everything was set up ok, (but how can
you mess up on a malloc call?) One case in mind was:

	structptr = (struct st *)malloc( sizeof( struct st ) );

structptr was NULL before the call and was still after the crash.
The size of the struct is 230 bytes. We don't have kernel source so I am
not able to go into malloc except for dissasembly. The instruction
the thing dies on is a BITW (I think?) maybe something like:
	BITW	0(%r7),1

The system has 2meg of memory and at the time of the crash is
running 20 process and very heavily loaded. This has happend
in about half of those 20 processes at random times in random
places in the code (C of cource). All the processes use malloc,
realloc and free a WHOLE lot.

Call me crazy, but shouldn't malloc just return me an error if there 
are problems???

Any ideas??? This this is about to drive me to COBOL!!!

Any help would be GREATLY appreciated!

Thanks,
Tom
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UUCP: ...!ihnp4!killer!toma

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Tom Armistead
UUCP:  ...!ihnp4!killer!toma