llvm dev - Apr 2010 - [LLVMdev] Bufer overrun in getValueTypeList()

Hello,

I've observed in some tests that getValueTypeList() is sometimes called with
type MVT::iPTR. There is a discrepancy between the size of the array VTs and the
use in getTypeValueList(). The array is allocated with space for elements up to
LAST_VALUE_TYPE  and iPTR is defined after it. The enumerator value of iPTR is
between LAST_VALUE_TYPE and LastSimpleValueType. For this reason the check
VT.isExtended() fails and the value is looked up in VTs triggering an out of
bounds access. In the version of LLVM we're using getValueTypeList even
tries  to write to that array element causing a memory corruption. Should iPTR
handled with the extended types, simple types or in a different way? Should this
function even be called with iPTR?

Other value types that could have the same problem are Metadata, iPTRAny, vAny,
fAny and iAny.

Thanks,
Javier
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Hi Javier,
> I’ve observed in some tests that getValueTypeList() is sometimes called
> with type MVT::iPTR.
I think this is a bug, and you would do best to open a bugreport with a
testcase.

Ciao,

Duncan.