.return probes now have $return target variable

[David Smith]

Yesterday I checked in a fix for BZ 1132
(<http://sourceware.org/bugzilla/show_bug.cgi?id=1132>).

Using a new elfutils interface provided by Roland McGrath, we now use
the dwarf debugging information to find the return value.

So, you can do the following now:

=====================================================
probe kernel.function("sys_read").return
{
    printf("return value is %d\n", $return)
}
=====================================================

As a result of adding the "$return" functionality, the old retval()
function is now deprecated.  If you have any existing scripts that use
the retval() function, please update them to use the new "$return"
target variable.

In a few weeks the retval() function will be removed.

-- 
David Smith
dsmith@redhat.com
Red Hat, Inc.
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)