trace: Fix missing assignment in trace_ctxwake_*

The state char variable S should be reassigned, if S == 0.

We are missing the state of the task that is going to sleep for the
context switch events (in the raw mode).

Fortunately the problem arises with the sched_switch/wake_up
tracers, not the sched trace events.

The formers are legacy now. But still, that was buggy.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4AC43118.6050409@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index f572f44c6e1e..cda766f9f421 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -883,7 +883,7 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
         trace_assign_type(field, iter->ent);
 
         if (!S)
-                task_state_char(field->prev_state);
+                S = task_state_char(field->prev_state);
         T = task_state_char(field->next_state);
         if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
                               field->prev_pid,
@@ -918,7 +918,7 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
         trace_assign_type(field, iter->ent);
 
         if (!S)
-                task_state_char(field->prev_state);
+                S = task_state_char(field->prev_state);
         T = task_state_char(field->next_state);
 
         SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);