OpenJDK6 20.0-b12 intermittent crash

[Kurt Miller]

On Saturday 02 February 2013 12:30:53 pm Kurt Miller wrote:
> Hi,
> 
> I recently finished porting OpenJDK6 to OpenBSD. For the most part everything is working well, however on x86-32 using the client vm I am experiencing an intermittent crash when using OpenJDK6 to bootstrap the OpenJDK7 build. I have rebuilt OpenJDK6 using the fastdebug target and reproduced the problem. I don't know the internals of hotstop well enough to find the root cause. Could someone take a look at the following crash report and provide some feedback. In particular I'd like to know if this crash is related to os specific porting issues or a general hotspot problem. If os specific what areas should I focus my attention on. I also have the core file for this crash and can provide additional information from the core upon request.

Further investigation into this problem revealed the segfaults were due to protection faults from trying to execute a non-executable page. OpenBSD uses the code segment on i386 to split the vm space into executable and non-executable areas. Looking at the kernels handling of the protection fault closely revealed a case where the code segment was set to a value that was unexpected. This lead to the kernel passing the execution protection fault through to userland when it shouldn't have.

Regards,
-Kurt