[oe] OpenJDK 8 Segfault on i.MX6

[Attie Grande]

Hi all,

I've been trying to get OpenJDK 8 162-b12 running on Linux on an ARM
platform (i.MX6), using the Yocto Sumo recipes from meta-java [1].

Unfortunately, the result is a java executable that cannot startup
without hitting a SIGSEGV. Even running "simple" things like `java` or
`java -help` result in a segmentation fault.

I've tried to investigate it, but I don't have the insight into the
project to really be able to debug the issue properly myself.

I've been in contact with jdk-dev [2], who have been helpful so far,
but we're starting to wonder about the patches applied as part of the
Yocto build.

After enabling fastdebug, I still get a segfault with little insight
into the issue - a fatal error log is available here [3].

Investigating with GDB shows that the segfault is in libjvm.so, but
there are no symbols in this region of memory, and the stack has been
destroyed (I suspect as part of the VM's operation).

We've confirmed that another build of OpenJDK 8 runs on this platform
[4] (currently jdk8u191-b12).

I've spent some time trying to update to 191-b12, but a number of the
patches appear to be necessary for Yocto's build environment, while
others require major rework to apply cleanly.

I see that Thud is using 172b11 [5] which is somewhere in between...
so I could give those recipes a try - though there is a Sumo / Thud
dependency issue with xorg-proto.

Has anyone seen this before, or have any insight into the patches / Yocto build?

Aleksey (from jdk-dev) mentioned [6] a user on IRC called hitendra had
a similar sounding issue with Yocto Sumo / i.MX6 / OpenJDK 8 162-b12,
and I've also come across a brief / frutiless IRC log in #yocto [7].

Regards,
Attie

[1]: https://git.yoctoproject.org/cgit/cgit.cgi/meta-java/tree/recipes-core/openjdk?h=sumo
[2]: http://mail.openjdk.java.net/pipermail/jdk-dev/2018-November/002246.html
[3]: https://pastebin.com/raw/iXTz8v9z
[4]: https://builds.shipilev.net/openjdk-jdk8-redhat/openjdk-jdk8-redhat-latest-linux-arm32-hflt-zero-fastdebug.tar.xz
[5]: https://git.yoctoproject.org/cgit/cgit.cgi/meta-java/tree/recipes-core/openjdk?h=master-next
[6]: http://mail.openjdk.java.net/pipermail/jdk-dev/2018-November/002251.html
[7]: https://www.yoctoproject.org/irc/%23yocto.2018-10-23.log.html#t2018-10-23T09:46:21