How can I access ULONG_MAX constant without using -g option?

[David Smith]

On 05/06/2014 01:02 AM, Tetsuo Handa wrote:
> Hello.
> 
> I'm using systemtap-2.3-4.el6_5.i686 and I need to mask a value with ULONG_MAX
> constant because task_current() returns 64bits value on 32bits architecture.
> 
>   # uname -m
>   i686
>   # stap -e 'probe begin { printf("current=%lx\n", task_current()); exit(); }'
>   current=ffffffffc1681aa0
> 
> In the example output above, current=c1681aa0 is the expected value on i686.
> 
> I know I can wrap like
> 
>   function get_current:long() {
>     return task_current() & %{ ULONG_MAX %};
>   }
> 
> and use get_current() instead of task_current(), but this needs -g option.
> Is there a way to do it without using -g option?
> 
> Regards.

I think fixing this in task_current() is the right way to go here, but
there is a way around this without using '-g'. Also note that it is
gross (and untested):

====
function get_current:long()
{
%( arch == "i386" || arch == "arm" %?
	return task_current() & 0xffffffff
%:
	return task_current() & 0xffffffffffffffff
%)
}
====

-- 
David Smith
dsmith@redhat.com
Red Hat
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