When a Java program is run in a chroot environment on Linux,
InetAddress.getLocalHost() returns a broken InetAddress object (broken in the
same way as it was in bug 17069).
Test case:
import java.net.InetAddress;
import java.net.UnknownHostException;
public class TestAddr {
public static void main (String args []) throws UnknownHostException {
InetAddress.getLocalHost ().getAddress ();
}
} // end of class TestAddr
The test case prints this inside the chroot:
Exception in thread "main" java.lang.NullPointerException
at java.net.InetAddress.getAddress() (/usr/lib/libgcj.so.6.0.0)
at TestAddr.main(java.lang.String[]) (Unknown Source)
at gnu.java.lang.MainThread.call_main() (/usr/lib/libgcj.so.6.0.0)
at gnu.java.lang.MainThread.run() (/usr/lib/libgcj.so.6.0.0)
and nothing when not in a chroot.
By using LD_LIBRARY_PATH I have verified that the brokenness _is_ triggered by
the chroot, not by the different versions of libc and libgcj that are
dynamically linked against when inside the chroot:
bash-3.00$ LD_LIBRARY_PATH=/mnt/rawhide/usr/lib:/mnt/rawhide/lib ldd
/mnt/rawhide/home/greenrd/testaddr
linux-gate.so.1 => (0xffffe000)
libgcc_s.so.1 => /mnt/rawhide/lib/libgcc_s.so.1 (0x00db1000)
libgcj.so.6 => /mnt/rawhide/usr/lib/libgcj.so.6 (0x02000000)
libm.so.6 => /mnt/rawhide/lib/libm.so.6 (0x00354000)
libpthread.so.0 => /mnt/rawhide/lib/libpthread.so.0 (0x00390000)
libz.so.1 => /mnt/rawhide/usr/lib/libz.so.1 (0x0037b000)
libdl.so.2 => /mnt/rawhide/lib/libdl.so.2 (0x0034e000)
libc.so.6 => /mnt/rawhide/lib/libc.so.6 (0xf7ed1000)
/lib/ld-linux.so.2 (0x00248000)
bash-3.00$ LD_LIBRARY_PATH=/mnt/rawhide/usr/lib:/mnt/rawhide/lib
/mnt/rawhide/home/greenrd/testaddr
bash-3.00$
The real /dev, /proc and /sys are mounted inside the chroot, and /sbin/ifconfig
can see all the network interfaces and their IPs when run as the same user from
inside the chroot, so it is not the case that the kernel is hiding this
information.
--
Summary: InetAddress.getLocalHost() returns broken InetAddress
object when run in chroot
Product: gcc
Version: 4.0.2
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: libgcj
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: greenrd at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24583
