RFR: 8073688: Infinite loop reading types during jmap attach.

[Mikael Gerdin]

Kevin,

On 2015-03-03 14:15, Kevin Walls wrote:
> Hi,
>
> This is a review request for a way to make the SA tools protect
> themselves from infinite loops during initialisation.
>
> Attaching jmap (for example) to a JVM can fail, infinitely writing an
> error - and filling a disk if being logged to a file.  This reproduces
> on a Solaris package based install, but not with other distribution
> bundles.  In those packages, there's a link JDK/jre/lib/sparc/libjvm ->
> client/libjvm.so.  If a server/libjvm.so is loaded and running, we see
> libverify.so pull in client/libjvm.so, as it finds the symlink in its
> $ORIGIN, in preference to finding the already loaded libjvm.so.

There is only server/libjvm.so on Solaris since JDK 8, so I assume that 
this RFR is for JDK 7u only. The late stage of the JDK 7u updates 
project should perhaps be considered when looking at this change.

/Mikael

>
> Symbol lookup in the SA is fooled by having multiple libjvm.so loaded.
> There are various things wrong with that.  Protection against zero
> strides through the type arrays and a maximum count for duplicated types
> will protect us from a few possible problems.
>
> I'll also work a bug for the "install" repo where we create that
> symlink, but the tools need to protect themselves from this kind of
> problem.
>
> Testing was manual.
>
> bug
> https://bugs.openjdk.java.net/browse/JDK-8073688
>
> webrev
> http://cr.openjdk.java.net/~kevinw/8073688/webrev.00/
>
> Thanks
> Kevin