[tip:tracing/urgent] trace: Fix missing assignment in trace_ctxwake_*

From: tip-bot for Hiroshi Shimamoto
Date: Tue Oct 06 2009 - 08:51:00 EST


Commit-ID: b0f56f1a63b7b968e6feeeefeace24bc8e0a4a65
Gitweb: http://git.kernel.org/tip/b0f56f1a63b7b968e6feeeefeace24bc8e0a4a65
Author: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
AuthorDate: Thu, 1 Oct 2009 13:33:28 +0900
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 6 Oct 2009 14:28:24 +0200

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@xxxxxxxxxxxxx>
Cc: Steven Rostedt <srostedt@xxxxxxxxxx>
Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
LKML-Reference: <4AC43118.6050409@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/trace/trace_output.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index f572f44..cda766f 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);
--
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