[RFC PATCH v2 07/12] rv: Adapt the sco monitor to the new set_state

[Gabriele Monaco <gmonaco@redhat.com>]

The sched_set_state tracepoint changed prototype adding a new argument,
this argument can differentiate between an explicit set_state called by
a task and a set state to runnable by the scheduler due to a pending
signal.

Adapt the handlers prototypes for the sco monitor.
Expand the model to handle the new set_state flavour, the monitor was
making sure set state happens only outside of the scheduler, if the
event occurs with the new argument (from_signal) set to true, we instead
expect it to be inside the scheduler.

Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
 Documentation/trace/rv/monitor_sched.rst | 35 +++++++++++++-----------
 kernel/trace/rv/monitors/sco/sco.c       |  8 ++++--
 kernel/trace/rv/monitors/sco/sco.h       |  6 ++--
 tools/verification/models/sched/sco.dot  |  1 +
 4 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/Documentation/trace/rv/monitor_sched.rst b/Documentation/trace/rv/monitor_sched.rst
index 24b2c62a3bc2..6f76bba94d9f 100644
--- a/Documentation/trace/rv/monitor_sched.rst
+++ b/Documentation/trace/rv/monitor_sched.rst
@@ -64,22 +64,25 @@ Monitor sco
 ~~~~~~~~~~~
 
 The scheduling context operations (sco) monitor ensures changes in a task state
-happen only in thread context::
-
-
-                        |
-                        |
-                        v
-    sched_set_state   +------------------+
-  +------------------ |                  |
-  |                   |  thread_context  |
-  +-----------------> |                  | <+
-                      +------------------+  |
-                        |                   |
-                        | schedule_entry    | schedule_exit
-                        v                   |
-                                            |
-                       scheduling_context  -+
+happen only in thread context, the only exception is a special kind of set
+state that occurs if a task about to sleep has a pending signal. This set state
+is not called by the thread but by the scheduler itself::
+
+                                        |
+                                        |
+                                        v
+    sched_set_state                   +------------------+
+  +---------------------------------- |                  |
+  |                                   |  thread_context  |
+  +---------------------------------> |                  | <+
+                                      +------------------+  |
+                                        |                   |
+                                        | schedule_entry    | schedule_exit
+                                        v                   |
+    sched_set_state_runnable_signal                         |
+  +----------------------------------                       |
+  |                                    scheduling_context   |
+  +--------------------------------->                      -+
 
 Monitor snroc
 ~~~~~~~~~~~~~
diff --git a/kernel/trace/rv/monitors/sco/sco.c b/kernel/trace/rv/monitors/sco/sco.c
index 66f4639d46ac..6457ff2469d0 100644
--- a/kernel/trace/rv/monitors/sco/sco.c
+++ b/kernel/trace/rv/monitors/sco/sco.c
@@ -19,9 +19,13 @@
 static struct rv_monitor rv_sco;
 DECLARE_DA_MON_PER_CPU(sco, unsigned char);
 
-static void handle_sched_set_state(void *data, struct task_struct *tsk, int state)
+static void handle_sched_set_state(void *data, struct task_struct *tsk,
+				   int state, bool from_signal)
 {
-	da_handle_start_event_sco(sched_set_state_sco);
+	if (from_signal)
+		da_handle_event_sco(sched_set_state_runnable_signal_sco);
+	else
+		da_handle_start_event_sco(sched_set_state_sco);
 }
 
 static void handle_schedule_entry(void *data, bool preempt, unsigned long ip)
diff --git a/kernel/trace/rv/monitors/sco/sco.h b/kernel/trace/rv/monitors/sco/sco.h
index 7a4c1f2d5ca1..302750687f9c 100644
--- a/kernel/trace/rv/monitors/sco/sco.h
+++ b/kernel/trace/rv/monitors/sco/sco.h
@@ -15,6 +15,7 @@ enum states_sco {
 
 enum events_sco {
 	sched_set_state_sco = 0,
+	sched_set_state_runnable_signal_sco,
 	schedule_entry_sco,
 	schedule_exit_sco,
 	event_max_sco
@@ -35,12 +36,13 @@ static const struct automaton_sco automaton_sco = {
 	},
 	.event_names = {
 		"sched_set_state",
+		"sched_set_state_runnable_signal",
 		"schedule_entry",
 		"schedule_exit"
 	},
 	.function = {
-		{     thread_context_sco, scheduling_context_sco,          INVALID_STATE },
-		{          INVALID_STATE,          INVALID_STATE,     thread_context_sco },
+		{     thread_context_sco,          INVALID_STATE, scheduling_context_sco,          INVALID_STATE },
+		{          INVALID_STATE, scheduling_context_sco,          INVALID_STATE,     thread_context_sco },
 	},
 	.initial_state = thread_context_sco,
 	.final_states = { 1, 0 },
diff --git a/tools/verification/models/sched/sco.dot b/tools/verification/models/sched/sco.dot
index 20b0e3b449a6..4e44ed58c62a 100644
--- a/tools/verification/models/sched/sco.dot
+++ b/tools/verification/models/sched/sco.dot
@@ -7,6 +7,7 @@ digraph state_automaton {
 	{node [shape = plaintext] "thread_context"};
 	"__init_thread_context" -> "thread_context";
 	"scheduling_context" [label = "scheduling_context"];
+	"scheduling_context" -> "scheduling_context" [ label = "sched_set_state_runnable_signal" ];
 	"scheduling_context" -> "thread_context" [ label = "schedule_exit" ];
 	"thread_context" [label = "thread_context", color = green3];
 	"thread_context" -> "scheduling_context" [ label = "schedule_entry" ];
-- 
2.49.0