[8u-dev] RFA: 8201509: Zero: S390 31bit atomic_copy64 inline assembler is wrong

[Severin Gehwolf]

Hi,

Please approve this Zero-only JDK 8u backport which fixes random SEGVs
on S390 (31 bit). We have been using this patch for months in Fedora
and would like to get this upstream. The patch is in JDK 10u and in JDK
11. The JDK 11 patch applies with minor patch context changes post
path-unshuffeling and after JDK-8185723[1] and JDK-8186461[2] have been
applied.

Bug: https://bugs.openjdk.java.net/browse/JDK-8201509
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8201509/webrev.01/
Original review-thread:
http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-April/031626.html

Thanks,
Severin

[1] http://mail.openjdk.java.net/pipermail/jdk8u-dev/2018-June/007579.html
[2] http://mail.openjdk.java.net/pipermail/jdk8u-dev/2018-June/007580.html