fix type of C.malloc in cgo

Author: cwangVT

perf/collector_libpfm.go

@@ -253,9 +253,9 @@ func (c *collector) createLeaderFileDescriptors(events []Event, cgroupFd int, gr
 }
 
 func readPerfEventAttr(name string, pfmGetOsEventEncoding func(string, unsafe.Pointer) error) (*unix.PerfEventAttr, error) {
-	perfEventAttrMemory := C.malloc(C.ulong(unsafe.Sizeof(unix.PerfEventAttr{})))
+	perfEventAttrMemory := C.malloc(C.size_t(unsafe.Sizeof(unix.PerfEventAttr{})))
 	// Fill memory with 0 values.
-	C.memset(perfEventAttrMemory, 0, C.ulong(unsafe.Sizeof(unix.PerfEventAttr{})))
+	C.memset(perfEventAttrMemory, 0, C.size_t(unsafe.Sizeof(unix.PerfEventAttr{})))
 	err := pfmGetOsEventEncoding(name, unsafe.Pointer(perfEventAttrMemory))
 	if err != nil {
 		return nil, err
@@ -269,7 +269,7 @@ func pfmGetOsEventEncoding(name string, perfEventAttrMemory unsafe.Pointer) erro
 	defer C.free(unsafe.Pointer(fstr))
 	event.fstr = unsafe.Pointer(fstr)
 	event.attr = perfEventAttrMemory
-	event.size = C.ulong(unsafe.Sizeof(event))
+	event.size = C.size_t(unsafe.Sizeof(event))
 	cSafeName := C.CString(name)
 	defer C.free(unsafe.Pointer(cSafeName))
 	pErr := C.pfm_get_os_event_encoding(cSafeName, C.PFM_PLM0|C.PFM_PLM3, C.PFM_OS_PERF_EVENT, unsafe.Pointer(&event))