+#undef LEN_OR_ZERO
+
+ /* return the length of print_fmt */
+ return pos;
+}
+
+static int set_syscall_print_fmt(struct ftrace_event_call *call)
+{
+ char *print_fmt;
+ int len;
+ struct syscall_metadata *entry = call->data;
+
+ if (entry->enter_event != call) {
+ call->print_fmt = "\"0x%lx\", REC->ret";
+ return 0;
+ }
+
+ /* First: called with 0 length to calculate the needed length */
+ len = __set_enter_print_fmt(entry, NULL, 0);
+
+ print_fmt = kmalloc(len + 1, GFP_KERNEL);
+ if (!print_fmt)
+ return -ENOMEM;
+
+ /* Second: actually write the @print_fmt */
+ __set_enter_print_fmt(entry, print_fmt, len + 1);
+ call->print_fmt = print_fmt;
+
+ return 0;
+}
+
+static void free_syscall_print_fmt(struct ftrace_event_call *call)
+{
+ struct syscall_metadata *entry = call->data;
+
+ if (entry->enter_event == call)
+ kfree(call->print_fmt);
+}
+
+int syscall_enter_define_fields(struct ftrace_event_call *call)
+{
+ struct syscall_trace_enter trace;
+ struct syscall_metadata *meta = call->data;
+ int ret;
+ int i;
+ int offset = offsetof(typeof(trace), args);
+
+ ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < meta->nb_args; i++) {
+ ret = trace_define_field(call, meta->types[i],
+ meta->args[i], offset,
+ sizeof(unsigned long), 0,
+ FILTER_OTHER);
+ offset += sizeof(unsigned long);