tracing/filters: use trace_seq_printf() to print filters

Impact: cleanup

Instead of just using the trace_seq buffer to print the filters, use
trace_seq_printf() as it was intended to be used.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237878871.8339.59.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 15 insertions, 21 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 54fd9bcd0a65..90a848debcba 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -840,7 +840,8 @@ struct filter_pred {
 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);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index a9381384aa9e..d132997ab756 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -481,8 +481,8 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 
         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);
 
@@ -547,8 +547,8 @@ subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 
         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);
 
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 3f0b79f8a4bc..9fca8bb1c06b 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -24,6 +24,7 @@
 #include <linux/ctype.h>
 
 #include "trace.h"
+#include "trace_output.h"
 
 static int filter_pred_64(struct filter_pred *pred, void *event)
 {
@@ -108,16 +109,15 @@ int filter_match_preds(struct ftrace_event_call *call, void *rec)
         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++) {
@@ -125,23 +125,16 @@ int filter_print_preds(struct filter_pred **preds, char *buf)
                         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 *