JDK 17: First Release Candidate

[Matthias Klose]

On 8/14/21 2:58 AM, David Holmes wrote:
> 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.

No, this change is intentional according to the glibc 2.34 release notes:

* Add _SC_MINSIGSTKSZ and _SC_SIGSTKSZ.  When _DYNAMIC_STACK_SIZE_SOURCE
  or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ are no longer
  constant on Linux.  MINSIGSTKSZ is redefined to sysconf(_SC_MINSIGSTKSZ)
  and SIGSTKSZ is redefined to sysconf (_SC_SIGSTKSZ).  This supports
  dynamic sized register sets for modern architectural features like
  Arm SVE.

Matthias