tracing: Add a helper function for event print functions

Move duplicate code in event print functions to a helper function.

This shrinks the size of the kernel by ~13K.

   text    data     bss     dec     hex filename
6596137 1743966 10138672        18478775        119f6b7 vmlinux.o.old
6583002 1743849 10138672        18465523        119c2f3 vmlinux.o.new

Link: http://lkml.kernel.org/r/51258746.2060304@huawei.com

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 194d79602dc7..aa92ac322ba2 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -397,6 +397,32 @@ ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 }
 EXPORT_SYMBOL(ftrace_print_hex_seq);
 
+int ftrace_raw_output_prep(struct trace_iterator *iter,
+                           struct trace_event *trace_event)
+{
+        struct ftrace_event_call *event;
+        struct trace_seq *s = &iter->seq;
+        struct trace_seq *p = &iter->tmp_seq;
+        struct trace_entry *entry;
+        int ret;
+
+        event = container_of(trace_event, struct ftrace_event_call, event);
+        entry = iter->ent;
+
+        if (entry->type != event->event.type) {
+                WARN_ON_ONCE(1);
+                return TRACE_TYPE_UNHANDLED;
+        }
+
+        trace_seq_init(p);
+        ret = trace_seq_printf(s, "%s: ", event->name);
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+EXPORT_SYMBOL(ftrace_raw_output_prep);
+
 #ifdef CONFIG_KRETPROBES
 static inline const char *kretprobed(const char *name)
 {