[aarch64-port-dev ] Simple HTTP server app crashes on JDK 11 and 8 on OSv AArch64

[Andrew Dinn]

On 06/03/2022 10:11, Andrew Haley wrote:
>> This might be a good time for us to resurrect the 64-bit address patch,
>> but that might not help you much, because I guess you'll want older Java
>> versions to work.
> 
> Or, easier, fix the patching sequence always to put ffff into the top
> nybble. That would be easy enough, but I guess I'd need to be able to
> test on OSv.
Note that Waldemar said in his initial post that this is a *unikernel*.

> I am one of the committers to the OSv project (http://osv.io/). OSv is is a
> Linux-compatible unikernel.

I believe that means everything is compiled into kernel space. If so, 
then I believe that implies that malloced addresses that are usually 
mapped in the user space range will actually reside in the kernel 
address space range,-- including addresses for JITted code. Perhaps 
Waldemar can confirm?

That would suggest that patching ffff into the top 16 bits is indeed the 
required fix.

regards,


Andrew Dinn
-----------
Red Hat Distinguished Engineer
Red Hat UK Ltd
Registered in England and Wales under Company Registration No. 03798903
Directors: Michael Cunningham, Michael ("Mike") O'Neill