java/nio/file/attribute/PosixFileAttributeView/Basic.java has started to fail recently on two Ubuntu 18.04 aarch64 systems at SAP.

An example failure is:

-- Lookup UserPrincipal Tests --
lookup: jvmtests
lookup group: kmem
lookup: scumbag99
----------System.err:(17/1126)----------
java.io.IOException: scumbag99: Operation not permitted
at java.base/sun.nio.fs.UnixUserPrincipals.lookupName(UnixUserPrincipals.java:148)
at java.base/sun.nio.fs.UnixUserPrincipals.lookupUser(UnixUserPrincipals.java:170)
at java.base/sun.nio.fs.UnixFileSystem$LookupService$1.lookupPrincipalByName(UnixFileSystem.java:328)
at Basic.lookupPrincipalTests(Basic.java:305)
at Basic.main(Basic.java:390)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:834)

JavaTest Message: Test threw exception: java.io.IOException: scumbag99: Operation not permitted

It appears that that getpwnam_r and getgrnam_r are failing with the error EPERM when these libc functions are called to lookup user or group names that do not exist.

As per man page of getpwnam_r, EPERM is a well defined error code that should indicate that "The given name or uid was not found."

https://linux.die.net/man/3/getpwnam_r

Errors
0 or ENOENT or ESRCH or EBADF or EPERM or ...

The given name or uid was not found.

I suggest to add EBADF and EPERM to the checked return codes in UnixNativeDispatcher.c