Bug fixes for IcedTea 1.6 (ARM interpreter)

[Gary Benson]

Edward Nevill wrote:
> However, I have 4 bug fixes which I had not checked in because I did
> not realise it was going into the release.
> 
> Attached below is a diff file for the 4 bug fixes.

Please commit.  I suggest that for things like this you should be
allowed to commit without approval since I doubt anyone else really
knows how this stuff works!  Does anybody object to that?

> ...if for some reason an exception is thrown by SafepointSynchronize...

As an aside, anything that safepoints can _always_ throw exceptions.
When a thread is stopped by another thread, for example, a ThreadDeath
exception is stored in the thread as a pending asynchronous exception.
The next safepoint will convert the pending asynchronous exception
into a normal pending exception.  I got caught out by this once and it
was a pig to figure out.

> Note: There is at least one more known bug in the ARM interpreter
> which causes it to segfault approx every 4th or 5th run of the
> JCK. I am currently investigating this but it is proving very
> elusive.

Check you aren't storing oops in registers across safepoints.  Most of
the "odd segfaults" I had in the PPC interpreter and then Zero were
down to this.

Cheers,
Gary

-- 
http://gbenson.net/