int trace_define_field(struct ftrace_event_call *call, char *type,
                       char *name, int offset, int size);
 extern void filter_free_pred(struct filter_pred *pred);
-extern int filter_print_preds(struct filter_pred **preds, char *buf);
+extern void filter_print_preds(struct filter_pred **preds,
+                              struct trace_seq *s);
 extern int filter_parse(char **pbuf, struct filter_pred *pred);
 extern int filter_add_pred(struct ftrace_event_call *call,
                           struct filter_pred *pred);
 
 
        trace_seq_init(s);
 
-       r = filter_print_preds(call->preds, s->buffer);
-       r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, r);
+       filter_print_preds(call->preds, s);
+       r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
        kfree(s);
 
 
        trace_seq_init(s);
 
-       r = filter_print_preds(system->preds, s->buffer);
-       r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, r);
+       filter_print_preds(system->preds, s);
+       r = simple_read_from_buffer(ubuf, cnt, ppos, s->buffer, s->len);
 
        kfree(s);
 
 
 #include <linux/ctype.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 static int filter_pred_64(struct filter_pred *pred, void *event)
 {
        return 1;
 }
 
-int filter_print_preds(struct filter_pred **preds, char *buf)
+void filter_print_preds(struct filter_pred **preds, struct trace_seq *s)
 {
-       ssize_t this_len = 0;
        char *field_name;
        struct filter_pred *pred;
        int i;
 
        if (!preds) {
-               this_len += sprintf(buf + this_len, "none\n");
-               return this_len;
+               trace_seq_printf(s, "none\n");
+               return;
        }
 
        for (i = 0; i < MAX_FILTER_PRED; i++) {
                        pred = preds[i];
                        field_name = pred->field_name;
                        if (i)
-                               this_len += sprintf(buf + this_len,
-                                           pred->or ? "|| " : "&& ");
-                       this_len += sprintf(buf + this_len,
-                                           "%s ", field_name);
-                       this_len += sprintf(buf + this_len,
-                                           pred->not ? "!= " : "== ");
+                               trace_seq_printf(s, pred->or ? "|| " : "&& ");
+                       trace_seq_printf(s, "%s ", field_name);
+                       trace_seq_printf(s, pred->not ? "!= " : "== ");
                        if (pred->str_val)
-                               this_len += sprintf(buf + this_len,
-                                                   "%s\n", pred->str_val);
+                               trace_seq_printf(s, "%s\n", pred->str_val);
                        else
-                               this_len += sprintf(buf + this_len,
-                                                   "%llu\n", pred->val);
+                               trace_seq_printf(s, "%llu\n", pred->val);
                } else
                        break;
        }
-
-       return this_len;
 }
 
 static struct ftrace_event_field *