RR(S) 8049684: pstack crashes on java core dump

[serguei.spitsyn at oracle.com]

Hi Kevin,

It looks good.
Thank you fixing it!

Thanks,
Serguei

On 7/18/14 5:02 AM, Kevin Walls wrote:
> Hi,
>
> May I get a review of this little change:
>
> pstack can crash on a Java core, where the core is transported from 
> one machine to another, and they have different JDKs but in the same 
> directory location.  So pstack does find libjvm etc, and does find 
> libjvm_db.so (but clearly symbols are not going to be good). 
> libjvm_db.c's parse_vmstructs fails early, after the call to libproc's 
> ps_pglobal_lookup(), which is before it has cleared its VMStructEntry, 
> which it will then test for non-null pointers in a few fields, and 
> free them (bad).
>
> Seen on Solaris, though the same problem is in the bsd code.
>
> bug
> https://bugs.openjdk.java.net/browse/JDK-8049684
>
> webrev
> http://cr.openjdk.java.net/~kevinw/8049684/webrev.01/
>
> I can reproduce this with a script, but it is time-consuming to 
> copy/unpack different JDKs in place, generate a core, replace the JDK, 
> run pstack.  Does not seem appropriate to add as a regression test 
> given the simple change.
>
> Thanks
> Kevin
>