tracing: Add trace_seq_has_overflowed() and trace_handle_return()

Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.

Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.

Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.

This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.

Link: http://lkml.kernel.org/r/20141114011410.365183157@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 5 insertions, 11 deletions

diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 80b25b585a70..8ef2c40efb3c 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -35,17 +35,11 @@ trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry);
 extern int __unregister_ftrace_event(struct trace_event *event);
 extern struct rw_semaphore trace_event_sem;
 
-#define SEQ_PUT_FIELD_RET(s, x)                         \
-do {                                                    \
-        if (!trace_seq_putmem(s, &(x), sizeof(x)))      \
-                return TRACE_TYPE_PARTIAL_LINE;         \
-} while (0)
-
-#define SEQ_PUT_HEX_FIELD_RET(s, x)                     \
-do {                                                    \
-        if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))  \
-                return TRACE_TYPE_PARTIAL_LINE;         \
-} while (0)
+#define SEQ_PUT_FIELD(s, x)                             \
+        trace_seq_putmem(s, &(x), sizeof(x))
+
+#define SEQ_PUT_HEX_FIELD(s, x)                         \
+        trace_seq_putmem_hex(s, &(x), sizeof(x))
 
 #endif