Debugging segmentation faults in the JVM on linux-powerpc

Mon Jun 12 13:29:40 UTC 2017

On Mon, Jun 12, 2017 at 03:15:44PM +0200, Thomas Stüfe wrote:
> I think there are several problems. The original problem, the bytebuffer
> OOM, happens in his release build. He then did a debug build. Slowdebug
> worked (?) but fastdebug crashed very early in SafeFetch initialization in
> tests which are omitted in release build.

To summarize:

On linux-ppc:

--with-debug-level=release => Segfault

> https://buildd.debian.org/status/fetch.php?pkg=openjdk-9&arch=powerpc&ver=9%7Eb170-2&stamp=1497029141&raw=0

Running the built jmod binary without arguments binary resulted in the out-of-memory error.

--with-debug-level=fastdebug => Segfault

> https://buildd.debian.org/status/fetch.php?pkg=openjdk-9&arch=powerpc&ver=9%7Eb170-2&stamp=1497076948&raw=0

Running the built jmod binary without arguments actually worked and printed the usage text.
Trying to run the full jmod command line from the build resulted in a segmentation fault.

--with-debug-level=slowdebug => Build succeeds

> https://buildd.debian.org/status/fetch.php?pkg=openjdk-9&arch=powerpc&ver=9%7Eb170-2&stamp=1497054989&raw=0

On linux-m68k (with patches to add m68k support):

--with-debug-level=release => JVM Exception

/<<PKGBUILDDIR>>/build/jdk/bin/java -Xms64M -Xmx1024M -XX:ThreadStackSize=768 -XX:+UseSerialGC -Xms32M -Xmx512M -XX:TieredStopAtLevel=1 -cp /<<PKGBUILDDIR>>/build/buildtool
s/tools_jigsaw_classes --add-exports java.base/jdk.internal.module=ALL-UNNAMED build.tools.jigsaw.AddPackagesAttribute /<<PKGBUILDDIR>>/build/jdk
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

> https://people.debian.org/~glaubitz/openjdk-9_9~b170-2_m68k-fail.build

--with-debug-level=slowdebug => Works

> https://people.debian.org/~glaubitz/openjdk-9_9~b170-2_m68k-success.build

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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