[dtrace-discuss] Question about 'long long' and USDT probes

[Keith McGuigan]

Hello,

Someone provided me with an example of USDT usage that doesn't appear to work 
right.  Namely, 'long long' arguments get truncated when read into the DTrace 
script.

Here is a quick example and the output:

 > cat probetest.c
#include <stdio.h>
#include <sys/time.h>
#include <sys/sdt.h>

int main() {
   long long v = 0x0FFFFFFF00000001LL;

   printf("In the user process value = %llx\n",v);
   DTRACE_PROBE1(testprov,getvalue,v);
   return 0;
}

 > cc -c probetest.c
 > cat testprov.d
provider testprov {
         probe getvalue(long long);
};

#pragma D attributes Evolving/Evolving/Common provider testprov provider
#pragma D attributes Private/Private/Unknown provider testprov module
#pragma D attributes Private/Private/Unknown provider testprov function
#pragma D attributes Evolving/Evolving/Common provider testprov name
#pragma D attributes Evolving/Evolving/Common provider testprov args
 > dtrace -G -32 -s testprov.d probetest.o
 > cc -o probetest testprov.o probetest.o
 > cat test.d
testprov$target:::getvalue
{
         printf("In the D script value = %llx\n",arg0);
}
 > dtrace -s test.d -c ./probetest
dtrace: script 'test.d' matched 1 probe
In the user process value = fffffff00000001
dtrace: pid 22849 has exited
CPU     ID                    FUNCTION:NAME
  20  46997                    main:getvalue In the D script value = 1


Anyone have any idea what I'm doing wrong here (if anything)?

--
- Keith