RFR(XS): 8193308: Disallow installing user signal handlers for SIGBUS on OSX

[Robin Westberg]

Hi Thomas,

Thanks for reviewing!

Best regards,
Robin

> On 6 Feb 2018, at 17:27, Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
> 
> Hi Robin,
> 
> this looks fine. 
> 
> Had some more looks:
> 
> - the secondary signal handler (vmError_posix.cpp) already unblocks SIGBUS correctly. 
> - CheckJNI on bsd already tests that SIGBUS handler does not get overwritten from outside.
> 
> So, looks like your patch is the last missing piece.
> 
> Best Regards, Thomas
> 
> On Tue, Feb 6, 2018 at 4:19 PM, Robin Westberg <robin.westberg at oracle.com <mailto:robin.westberg at oracle.com>> wrote:
> Hi all,
> 
> Please review the following change to disallow installing user signal handlers for SIGBUS on OSX. On OSX, SIGBUS is used internally by the VM (where most other platforms only use SIGSEGV), and installing a user handler can lead to a deadlock.
> 
> Issue: https://bugs.openjdk.java.net/browse/JDK-8193308 <https://bugs.openjdk.java.net/browse/JDK-8193308> <https://bugs.openjdk.java.net/browse/JDK-8193308 <https://bugs.openjdk.java.net/browse/JDK-8193308>>
> Webrev: http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/ <http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/> <http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/ <http://cr.openjdk.java.net/~rwestberg/8193308/webrev.00/>>
> Testing: hs-tier1, hs-tier2
> 
> Best regards,
> Robin
>