RFR(S): 8148696: Race loading hsdis may cause SIGSEGV

[Vladimir Ivanov]

Nils,

Is the webrev you posted complete? I don't see any LoadDisassembler_lock 
usages and all the changed paths have ttyLocker.

Best regards,
Vladimir Ivanov

On 2/5/16 6:22 PM, Nils Eliasson wrote:
> Hi all,
>
> Please review this fix to loading hsdis library.
>
> Summary:
> We have had two crashes on Sparc where two C2 thread simultaneously
> tries to load the hsdis library. Three of four code paths are locked by
> the ttyLocker, but the fourth is open to races.
>
> Solution:
> I chose to add another lock (mutex) for this purpose and adapted the
> code so that library_load code works as intented.
> - The old can_decode() method was removed and resued as an wrapper for
> the load_library().
> - Fixed a typo
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8148696
> Webrev: http://cr.openjdk.java.net/~neliasso/8148696/webrev.01/
>
> Regards,
> Nils Eliasson