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>

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index b5478dab579b77906ec29e51b04876092c14831f..40ede4db4d8853725c4ef307b5ad3fe70fd0fb15 100644 (file)
--- 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 8dadbbbd2d5c36be0399e69a417b069b5f05d965..8afeea412e77b2ad0ff9c1ac55f85f098114e8ca 100644 (file)
--- 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);