JDK 17: First Release Candidate

[Florian Weimer]

* David Holmes:

> Hi Matthias,
>
> On 14/08/2021 2:00 am, Matthias Klose wrote:
>> On 8/6/21 7:09 PM, mark.reinhold at oracle.com wrote:
>>> There are no unresolved P1 bugs in build 35, so that is our
>>> first JDK 17 Release Candidate.
>>>
>>> Binaries available here, as usual: https://jdk.java.net/17
>> this fails to build with glibc 2.34, i.e. on recent Fedora and
>> Ubuntu
>> development versions:
>> /<<PKGBUILDDIR>>/test/hotspot/jtreg/runtime/StackGuardPages/exeinvoke.c:
>> In
>> function 'set_signal_handler':
>> /<<PKGBUILDDIR>>/test/hotspot/jtreg/runtime/StackGuardPages/exeinvoke.c:72:15:
>> error: storage size of 'altstack' isn't constant
>>     72 |   static char altstack[SIGSTKSZ];
>>        |               ^~~~~~~~
>> gmake[4]: *** [test/JtregNativeHotspot.gmk:1525:
>> /<<PKGBUILDDIR>>/build/support/test/hotspot/jtreg/native/support/exeinvoke/exeinvoke.o]
>> Error 1
>
> That seems like a glibc bug to me as SIGSTKSZ is supposed to be a constant.

It is still a constant in glibc's POSIX mode, but OpenJDK does not use
POSIX mode (with good reason).  8192 bytes is really tight on AVX-512
capability CPUs, so the code could still be buggy if it compiled.

Thanks,
Florian