Robert Lougher wrote:
> On 12/6/05, Gary Benson <[EMAIL PROTECTED]> wrote:
> > ...I was just looking at an some code in an
> > AccessController.doPrivileged() that was doing security checks.
> > Perhaps JamVM's AccessController.doPrivileged() is not in fact
> > doing anything.
>
> What version of JamVM are you using?
I'm using cvs HEAD, with Classpath HEAD.
> As far as I'm aware, JamVMs implementation of VMAccessController is
> complete (it was provided by Casey Marshall, if I remember
> correctly). I've made some recent changes to the native method that
> obtains the stack, so it _could_ have broken in 1.4.1.
>
> Do you have a testcase?
If you build and run the attached testcase you ought to see only one
checkPermission() between "Calling checkRead()" and "Done". GCJ (for
example) makes this of it:
$ gij Test
Calling checkRead()
checkPermission((java.io.FilePermission / read))
Done
checkPermission((java.lang.RuntimePermission exitVM ))
checkPermission((java.lang.RuntimePermission exitVM ))
Based on what I'm seeing in Mauve you _should_ see a load of extra
stuff before the actual checkPermission you're interested in if you
run the testcase with JamVM:
$ jamvm Test
Calling checkRead()
checkPermission((java.io.FilePermission /path/to/JamVM.security read))
checkPermission((java.io.FilePermission /path/to/JamVM.security read))
checkPermission((java.io.FilePermission /path/to/classpath.security read))
checkPermission((java.io.FilePermission /path/to/classpath.security read))
checkPermission((java.io.FilePermission /path/to/classpath.security read))
checkPermission((java.util.PropertyPermission java.util.logging.manager
read))
checkPermission(null)
checkPermission(null)
checkPermission(null)
checkPermission(null)
checkPermission((java.util.PropertyPermission
java.util.logging.config.class read))
checkPermission((java.util.PropertyPermission java.util.logging.config.file
read))
checkPermission((java.util.PropertyPermission gnu.classpath.home.url read))
checkPermission((java.io.FilePermission /path/to/logging.properties read))
checkPermission((java.io.FilePermission /path/to/logging.properties read))
checkPermission((java.util.logging.LoggingPermission control ))
checkPermission((java.util.logging.LoggingPermission control ))
checkPermission((java.security.SecurityPermission
getProperty.package.access ))
checkPermission((java.io.FilePermission / read))
Done
...
In reality, JamVM chokes on it pretty hard. I _think_ what is
happening is that the System.out.println in checkPermission() is
itself doing some initialisation which causes security checks,
causing an infinite loop. It's hard to say, though, not knowing
JamVM or Classpath particularly well.
Cheers,
Gary
import java.security.Permission;
class Test
{
static class TestSecurityManager extends SecurityManager
{
public void checkPermission(Permission perm) {
System.out.println(" checkPermission(" + perm + ")");
}
}
public static void main(String[] args) {
try {
SecurityManager sm = new TestSecurityManager();
System.setSecurityManager(sm);
System.out.println("Calling checkRead()");
sm.checkRead("/");
System.out.println("Done");
}
catch (Throwable t) {
t.printStackTrace();
}
}
}
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