Java crashes using musl-1.2.5

[Severin Gehwolf]

Hi,

On Thu, 2025-09-11 at 10:59 +1000, David Holmes wrote:
> Hi,
> 
> At present we don't really expect statx to work on Musl-C IIUC the code 
> correctly, but Musl-C 1.2.5 has added it:
> 
>  > This release adds extension functions statx
> 
> so likely our code needs adjusting to match what is now provided.

This is likely an incompatibility of the statx support that was added
for Linux with https://bugs.openjdk.org/browse/JDK-8316304 and musl
1.2.5. Is there a bug for this? If not I can open one.

Thanks,
Severin

> On 10/09/2025 10:54 pm, Konstantin Kletschke wrote:
> > Hello,
> > 
> > I am used to crosscompile openjdk for cortex-a[7|8|9] manually or using
> > buildroot framework without severe Problems.
> > ARM EABIhf 32Bit.
> > 
> > However recently I got in contact with a customer's rootfs using
> > musl-1.2.5 instead of musl-1.2.4 which I was used to and had no problems with.
> > 
> > Severe debugging resulted in the crash whenever musl-1.2.5 was used in
> > the target (regardeless what musl version was used to crosscompile and
> > regardeless with java I tried, correto-24, openjdk-21, openjdk-24).
> > 
> > I tested with a helloworld downloaded from github somewhere.
> > "java -jar helloworld.jar" crashes. Unzippping the jar and using
> > "java -cp . HelloWorld" works!
> > 
> > Crashes looks something like those:
> > 
> > #  SIGSEGV (0xb) at pc=0x7693e018, pid=8026, tid=8027
> > #
> > # JRE version: OpenJDK Runtime Environment (21.0+21) (build 21+21)
> > # Java VM: OpenJDK Server VM (21+21, mixed mode, serial gc, linux-arm)
> > # Problematic frame:
> > # V  [libjvm.so+0x61e018]
> > 
> > FATAL ERROR in native method: Null object passed to JNI
> >    at sun.nio.fs.UnixNativeDispatcher.stat0(java.base at 21/Native Method)
> >    at sun.nio.fs.UnixNativeDispatcher.stat(java.base at 21/Unknown Source)
> >    at sun.nio.fs.UnixFileAttributes.get(java.base at 21/Unknown Source)
> >    at sun.nio.fs.UnixFileAttributeViews$Basic.readAttributes(java.base at 21/Unknown Source)
> >    at sun.nio.fs.UnixFileSystemProvider.readAttributes(java.base at 21/Unknown Source)
> >    at sun.nio.fs.LinuxFileSystemProvider.readAttributes(java.base at 21/Unknown Source)
> >    at java.nio.file.Files.readAttributes(java.base at 21/Unknown Source)
> >    at java.util.zip.ZipFile$Source.get(java.base at 21/Unknown Source)
> >    at java.util.zip.ZipFile$CleanableResource.<init>(java.base at 21/Unknown Source)
> >    at java.util.zip.ZipFile.<init>(java.base at 21/Unknown Source)
> >    at java.util.zip.ZipFile.<init>(java.base at 21/Unknown Source)
> >    at java.util.jar.JarFile.<init>(java.base at 21/Unknown Source)
> >    at java.util.jar.JarFile.<init>(java.base at 21/Unknown Source)
> >    at java.util.jar.JarFile.<init>(java.base at 21/Unknown Source)
> >    at sun.launcher.LauncherHelper.getMainClassFromJar(java.base at 21/Unknown Source)
> >    at sun.launcher.LauncherHelper.loadMainClass(java.base at 21/Unknown Source)
> >    at sun.launcher.LauncherHelper.checkAndLoadMain(java.base at 21/Unknown Source)
> > Aborted
> > 
> > 
> > With 1.2.4 everything works fine.
> > 
> > 
> > Farther debugging revealed that following fix in Java allowed to run it
> > with 1.2.5:
> > 
> > Index: openjdk-21.0.9+6/src/java.base/unix/native/libnio/fs/UnixNativeDispatcher.c
> > ===================================================================
> > --- openjdk-21.0.9+6.orig/src/java.base/unix/native/libnio/fs/UnixNativeDispatcher.c
> > +++ openjdk-21.0.9+6/src/java.base/unix/native/libnio/fs/UnixNativeDispatcher.c
> > @@ -430,7 +430,7 @@ Java_sun_nio_fs_UnixNativeDispatcher_ini
> >       capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_BIRTHTIME;
> > #endif
> > #if defined(__linux__)
> > -    my_statx_func = (statx_func*) dlsym(RTLD_DEFAULT, "statx");
> > +    my_statx_func = NULL;
> >       if (my_statx_func != NULL) {
> >           capabilities |= sun_nio_fs_UnixNativeDispatcher_SUPPORTS_BIRTHTIME;
> >       }
> > 
> > 
> > May be this has something to do with the stat ./. stat64 stuff changed
> > in musl from 1.2.4 to 1.2.5 or so.
> > I already headed to the musl people but I am not shure if its placed
> > better over there or here. I also already showed up at client-libs-dev
> > but was told to be come over here.
> > 
> > Kind Regards
> > Konstantin
> >