Subject: [PATCH V9 14/16] rv/monitor: Add the wwnr monitor

Per task wakeup while not running (wwnr) monitor.

This model is broken, the reason is that a task can be running in the
processor without being set as RUNNABLE. Think about a task about to
sleep:

1: set_current_state(TASK_UNINTERRUPTIBLE);
2: schedule();

And then imagine an IRQ happening in between the lines one and two,
waking the task up. BOOM, the wakeup will happen while the task is
running.

Q: Why do we need this model, so?
A: To test the reactors.

Cc: Wim Van Sebroeck <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Tao Zhou <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
---
Documentation/trace/rv/index.rst | 1 +
Documentation/trace/rv/monitor_wwnr.rst | 45 +++++++++++++
include/trace/events/rv.h | 12 ++++
kernel/trace/rv/Kconfig | 12 ++++
kernel/trace/rv/Makefile | 1 +
kernel/trace/rv/monitors/wwnr/wwnr.c | 87 +++++++++++++++++++++++++
kernel/trace/rv/monitors/wwnr/wwnr.h | 46 +++++++++++++
tools/verification/models/wwnr.dot | 16 +++++
8 files changed, 220 insertions(+)
create mode 100644 Documentation/trace/rv/monitor_wwnr.rst
create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.c
create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.h
create mode 100644 tools/verification/models/wwnr.dot

diff --git a/Documentation/trace/rv/index.rst b/Documentation/trace/rv/index.rst
index 4cb71ed628b8..15fa966102c0 100644
--- a/Documentation/trace/rv/index.rst
+++ b/Documentation/trace/rv/index.rst
@@ -11,3 +11,4 @@ Runtime Verification
da_monitor_synthesis.rst
da_monitor_instrumentation.rst
monitor_wip.rst
+ monitor_wwnr.rst
diff --git a/Documentation/trace/rv/monitor_wwnr.rst b/Documentation/trace/rv/monitor_wwnr.rst
new file mode 100644
index 000000000000..80f1777b85aa
--- /dev/null
+++ b/Documentation/trace/rv/monitor_wwnr.rst
@@ -0,0 +1,45 @@
+Monitor wwnr
+============
+
+- Name: wwrn - wakeup while not running
+- Type: per-task deterministic automaton
+- Author: Daniel Bristot de Oliveira <[email protected]>
+
+Description
+-----------
+
+This is a per-task sample monitor, with the following
+definition::
+
+ |
+ |
+ v
+ wakeup +-------------+
+ +--------- | |
+ | | not_running |
+ +--------> | | <+
+ +-------------+ |
+ | |
+ | switch_in | switch_out
+ v |
+ +-------------+ |
+ | running | -+
+ +-------------+
+
+This model is borken, the reason is that a task can be running
+in the processor without being set as RUNNABLE. Think about a
+task about to sleep::
+
+ 1: set_current_state(TASK_UNINTERRUPTIBLE);
+ 2: schedule();
+
+And then imagine an IRQ happening in between the lines one and two,
+waking the task up. BOOM, the wakeup will happen while the task is
+running.
+
+- Why do we need this model, so?
+- To test the reactors.
+
+Specification
+-------------
+Grapviz Dot file in tools/verification/models/wwnr.dot
diff --git a/include/trace/events/rv.h b/include/trace/events/rv.h
index e972f27d8df3..56592da9301c 100644
--- a/include/trace/events/rv.h
+++ b/include/trace/events/rv.h
@@ -122,6 +122,18 @@ DECLARE_EVENT_CLASS(error_da_monitor_id,
__entry->event,
__entry->state)
);
+
+#ifdef CONFIG_RV_MON_WWNR
+/* id is the pid of the task */
+DEFINE_EVENT(event_da_monitor_id, event_wwnr,
+ TP_PROTO(int id, char *state, char *event, char *next_state, bool final_state),
+ TP_ARGS(id, state, event, next_state, final_state));
+
+DEFINE_EVENT(error_da_monitor_id, error_wwnr,
+ TP_PROTO(int id, char *state, char *event),
+ TP_ARGS(id, state, event));
+#endif /* CONFIG_RV_MON_WWNR */
+
#endif /* CONFIG_DA_MON_EVENTS_ID */
#endif /* _TRACE_RV_H */

diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index e50f3346164a..b259d6e8dc7c 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -38,6 +38,18 @@ config RV_MON_WIP
For further information, see:
Documentation/trace/rv/monitor_wip.rst

+config RV_MON_WWNR
+ depends on RV
+ select DA_MON_EVENTS_ID
+ bool "wwnr monitor"
+ help
+ Enable wwnr (wakeup while not running) sample monitor, this is a
+ sample monitor that illustrates the usage of per-task monitor.
+ The model is borken on purpose: it serves to test reactors.
+
+ For further information, see:
+ Documentation/trace/rv/monitor_wwnr.rst
+
config RV_REACTORS
bool "Runtime verification reactors"
default y
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index b41109d2750a..af0ff9a46418 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -3,3 +3,4 @@
obj-$(CONFIG_RV) += rv.o
obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
+obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o
diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.c b/kernel/trace/rv/monitors/wwnr/wwnr.c
new file mode 100644
index 000000000000..599225d9cf38
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ftrace.h>
+#include <linux/tracepoint.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/rv.h>
+#include <rv/instrumentation.h>
+#include <rv/da_monitor.h>
+
+#define MODULE_NAME "wwnr"
+
+#include <trace/events/rv.h>
+#include <trace/events/sched.h>
+
+#include "wwnr.h"
+
+struct rv_monitor rv_wwnr;
+DECLARE_DA_MON_PER_TASK(wwnr, unsigned char);
+
+static void handle_switch(void *data, bool preempt, struct task_struct *p,
+ struct task_struct *n, unsigned int prev_state)
+{
+ /* start monitoring only after the first suspension */
+ if (prev_state == TASK_INTERRUPTIBLE)
+ da_handle_start_event_wwnr(p, switch_out_wwnr);
+ else
+ da_handle_event_wwnr(p, switch_out_wwnr);
+
+ da_handle_event_wwnr(n, switch_in_wwnr);
+}
+
+static void handle_wakeup(void *data, struct task_struct *p)
+{
+ da_handle_event_wwnr(p, wakeup_wwnr);
+}
+
+static int enable_wwnr(void)
+{
+ int retval;
+
+ retval = da_monitor_init_wwnr();
+ if (retval)
+ return retval;
+
+ rv_attach_trace_probe("wwnr", sched_switch, handle_switch);
+ rv_attach_trace_probe("wwnr", sched_wakeup, handle_wakeup);
+
+ return 0;
+}
+
+static void disable_wwnr(void)
+{
+ rv_wwnr.enabled = 0;
+
+ rv_detach_trace_probe("wwnr", sched_switch, handle_switch);
+ rv_detach_trace_probe("wwnr", sched_wakeup, handle_wakeup);
+
+ da_monitor_destroy_wwnr();
+}
+
+struct rv_monitor rv_wwnr = {
+ .name = "wwnr",
+ .description = "wakeup while not running per-task testing model.",
+ .enable = enable_wwnr,
+ .disable = disable_wwnr,
+ .reset = da_monitor_reset_all_wwnr,
+ .enabled = 0,
+};
+
+static int register_wwnr(void)
+{
+ rv_register_monitor(&rv_wwnr);
+ return 0;
+}
+
+static void unregister_wwnr(void)
+{
+ rv_unregister_monitor(&rv_wwnr);
+}
+
+module_init(register_wwnr);
+module_exit(unregister_wwnr);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Bristot de Oliveira <[email protected]>");
+MODULE_DESCRIPTION("wwnr: wakeup while not running monitor");
diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.h b/kernel/trace/rv/monitors/wwnr/wwnr.h
new file mode 100644
index 000000000000..d1afe55cdd4c
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.h
@@ -0,0 +1,46 @@
+/*
+ * Automatically generated C representation of wwnr automaton
+ * For further information about this format, see kernel documentation:
+ * Documentation/trace/rv/deterministic_automata.rst
+ */
+
+enum states_wwnr {
+ not_running_wwnr = 0,
+ running_wwnr,
+ state_max_wwnr
+};
+
+#define INVALID_STATE state_max_wwnr
+
+enum events_wwnr {
+ switch_in_wwnr = 0,
+ switch_out_wwnr,
+ wakeup_wwnr,
+ event_max_wwnr
+};
+
+struct automaton_wwnr {
+ char *state_names[state_max_wwnr];
+ char *event_names[event_max_wwnr];
+ unsigned char function[state_max_wwnr][event_max_wwnr];
+ unsigned char initial_state;
+ bool final_states[state_max_wwnr];
+};
+
+struct automaton_wwnr automaton_wwnr = {
+ .state_names = {
+ "not_running",
+ "running"
+ },
+ .event_names = {
+ "switch_in",
+ "switch_out",
+ "wakeup"
+ },
+ .function = {
+ { running_wwnr, INVALID_STATE, not_running_wwnr },
+ { INVALID_STATE, not_running_wwnr, INVALID_STATE },
+ },
+ .initial_state = not_running_wwnr,
+ .final_states = { 1, 0 },
+};
diff --git a/tools/verification/models/wwnr.dot b/tools/verification/models/wwnr.dot
new file mode 100644
index 000000000000..1b206e83129c
--- /dev/null
+++ b/tools/verification/models/wwnr.dot
@@ -0,0 +1,16 @@
+digraph state_automaton {
+ {node [shape = plaintext, style=invis, label=""] "__init_not_running"};
+ {node [shape = ellipse] "not_running"};
+ {node [shape = plaintext] "not_running"};
+ {node [shape = plaintext] "running"};
+ "__init_not_running" -> "not_running";
+ "not_running" [label = "not_running", color = green3];
+ "not_running" -> "not_running" [ label = "wakeup" ];
+ "not_running" -> "running" [ label = "switch_in" ];
+ "running" [label = "running"];
+ "running" -> "not_running" [ label = "switch_out" ];
+ { rank = min ;
+ "__init_not_running";
+ "not_running";
+ }
+}
--
2.35.1