tracing: fix multiple use of __print_flags and __print_symbolic

Here is an updated patch to include the extra call to
trace_seq_init() as requested. This is vs. the latest
-tip tree and fixes the use of multiple __print_flags
and __print_symbolic in a single tracer. Also tested
to ensure its working now:

mount.gfs2-2534  [000]   235.850587: gfs2_glock_queue: 8.7 glock 1:2 dequeue PR
mount.gfs2-2534  [000]   235.850591: gfs2_demote_rq: 8.7 glock 1:0 demote EX to NL flags:DI
mount.gfs2-2534  [000]   235.850591: gfs2_glock_queue: 8.7 glock 1:0 dequeue EX
glock_workqueue-2529  [000]   235.850666: gfs2_glock_state_change: 8.7 glock 1:0 state EX => NL tgt:NL dmt:NL flags:lDpI
glock_workqueue-2529  [000]   235.850672: gfs2_glock_put: 8.7 glock 1:0 state NL => IV flags:I

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
LKML-Reference: <1244037123.29604.603.camel@localhost.localdomain>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 6 insertions, 6 deletions

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index b5478dab579b..40ede4db4d88 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -104,6 +104,7 @@
  *      field = (typeof(field))entry;
  *
  *      p = get_cpu_var(ftrace_event_seq);
+ *      trace_seq_init(p);
  *      ret = trace_seq_printf(s, <TP_printk> "\n");
  *      put_cpu();
  *      if (!ret)
@@ -167,6 +168,7 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
         field = (typeof(field))entry;                                   \
                                                                         \
         p = &get_cpu_var(ftrace_event_seq);                             \
+        trace_seq_init(p);                                              \
         ret = trace_seq_printf(s, #call ": " print);                    \
         put_cpu();                                                      \
         if (!ret)                                                       \
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 8dadbbbd2d5c..8afeea412e77 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -223,10 +223,9 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 {
         unsigned long mask;
         const char *str;
+        const char *ret = p->buffer + p->len;
         int i;
 
-        trace_seq_init(p);
-
         for (i = 0;  flag_array[i].name && flags; i++) {
 
                 mask = flag_array[i].mask;
@@ -249,7 +248,7 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 
         trace_seq_putc(p, 0);
 
-        return p->buffer;
+        return ret;
 }
 EXPORT_SYMBOL(ftrace_print_flags_seq);
 
@@ -258,8 +257,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
                          const struct trace_print_flags *symbol_array)
 {
         int i;
-
-        trace_seq_init(p);
+        const char *ret = p->buffer + p->len;
 
         for (i = 0;  symbol_array[i].name; i++) {
 
@@ -275,7 +273,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
                 
         trace_seq_putc(p, 0);
 
-        return p->buffer;
+        return ret;
 }
 EXPORT_SYMBOL(ftrace_print_symbols_seq);