[RFC V2 08/21] rv/monitor: Add the wip monitor skeleton created by dot2k

From: Daniel Bristot de Oliveira
Date: Mon Feb 14 2022 - 06:22:42 EST


This is the direct output this command line:
$ dot2k -d ~/wip.dot -t per_cpu

with wip.dot as:
----- %< -----
digraph state_automaton {
center = true;
size = "7,11";
rankdir = LR;
{node [shape = circle] "non_preemptive"};
{node [shape = plaintext, style=invis, label=""] "__init_preemptive"};
{node [shape = doublecircle] "preemptive"};
{node [shape = circle] "preemptive"};
"__init_preemptive" -> "preemptive";
"non_preemptive" [label = "non_preemptive"];
"non_preemptive" -> "non_preemptive" [ label = "sched_waking" ];
"non_preemptive" -> "preemptive" [ label = "preempt_enable" ];
"preemptive" [label = "preemptive"];
"preemptive" -> "non_preemptive" [ label = "preempt_disable" ];
{ rank = min ;
"__init_preemptive";
"preemptive";
}
}
----- >% -----

This model is broken because preempt_disable_notrace(). It is broken on
purpose to test the reactors.

It does not compile because it lacks the instrumentation, which will be
add next.

Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Gabriele Paoloni <gpaoloni@xxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-trace-devel@xxxxxxxxxxxxxxx
Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
---
kernel/trace/rv/monitor_wip/model.h | 38 +++++++++
kernel/trace/rv/monitor_wip/wip.c | 124 ++++++++++++++++++++++++++++
kernel/trace/rv/monitor_wip/wip.h | 64 ++++++++++++++
3 files changed, 226 insertions(+)
create mode 100644 kernel/trace/rv/monitor_wip/model.h
create mode 100644 kernel/trace/rv/monitor_wip/wip.c
create mode 100644 kernel/trace/rv/monitor_wip/wip.h

diff --git a/kernel/trace/rv/monitor_wip/model.h b/kernel/trace/rv/monitor_wip/model.h
new file mode 100644
index 000000000000..5212ba5b1dfb
--- /dev/null
+++ b/kernel/trace/rv/monitor_wip/model.h
@@ -0,0 +1,38 @@
+enum states_wip {
+ preemptive = 0,
+ non_preemptive,
+ state_max
+};
+
+enum events_wip {
+ preempt_disable = 0,
+ preempt_enable,
+ sched_waking,
+ event_max
+};
+
+struct automaton_wip {
+ char *state_names[state_max];
+ char *event_names[event_max];
+ char function[state_max][event_max];
+ char initial_state;
+ char final_states[state_max];
+};
+
+struct automaton_wip automaton_wip = {
+ .state_names = {
+ "preemptive",
+ "non_preemptive"
+ },
+ .event_names = {
+ "preempt_disable",
+ "preempt_enable",
+ "sched_waking"
+ },
+ .function = {
+ { non_preemptive, -1, -1 },
+ { -1, preemptive, non_preemptive },
+ },
+ .initial_state = preemptive,
+ .final_states = { 1, 0 },
+};
\ No newline at end of file
diff --git a/kernel/trace/rv/monitor_wip/wip.c b/kernel/trace/rv/monitor_wip/wip.c
new file mode 100644
index 000000000000..1aec75e683d2
--- /dev/null
+++ b/kernel/trace/rv/monitor_wip/wip.c
@@ -0,0 +1,124 @@
+#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/da_monitor.h>
+
+#define MODULE_NAME "wip"
+
+/*
+ * This is the self-generated part of the monitor. Generally, there is no need
+ * to touch this section.
+ */
+#include "model.h"
+
+/*
+ * Declare the deterministic automata monitor.
+ *
+ * The rv monitor reference is needed for the monitor declaration.
+ */
+struct rv_monitor rv_wip;
+DECLARE_DA_MON_PER_CPU(wip, char);
+
+#define CREATE_TRACE_POINTS
+#include "wip.h"
+
+/*
+ * This is the instrumentation part of the monitor.
+ *
+ * This is the section where manual work is required. Here the kernel events
+ * are translated into model's event.
+ *
+ */
+
+void handle_preempt_disable(void *data, /* XXX: fill header */)
+{
+ da_handle_event_wip(preempt_disable);
+}
+
+void handle_preempt_enable(void *data, /* XXX: fill header */)
+{
+ da_handle_event_wip(preempt_enable);
+}
+
+void handle_sched_waking(void *data, /* XXX: fill header */)
+{
+ da_handle_event_wip(sched_waking);
+}
+
+#define NR_TP 3
+static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+ {
+ .probe = handle_preempt_disable,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+ {
+ .probe = handle_preempt_enable,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+ {
+ .probe = handle_sched_waking,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+};
+
+static int start_wip(void)
+{
+ int retval;
+
+ da_monitor_init_wip();
+
+ retval = thh_hook_probes(tracepoints_to_hook, NR_TP);
+ if (retval)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ return -EINVAL;
+}
+
+static void stop_wip(void)
+{
+ rv_wip.enabled = 0;
+ thh_unhook_probes(tracepoints_to_hook, NR_TP);
+ return;
+}
+
+/*
+ * This is the monitor register section.
+ */
+struct rv_monitor rv_wip = {
+ .name = "wip",
+ .description = "auto-generated wip",
+ .start = start_wip,
+ .stop = stop_wip,
+ .reset = da_monitor_reset_all_wip,
+ .enabled = 0,
+};
+
+int register_wip(void)
+{
+ rv_register_monitor(&rv_wip);
+ return 0;
+}
+
+void unregister_wip(void)
+{
+ if (rv_wip.enabled)
+ stop_wip();
+
+ rv_unregister_monitor(&rv_wip);
+}
+
+module_init(register_wip);
+module_exit(unregister_wip);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("dot2k: auto-generated");
+MODULE_DESCRIPTION("wip");
diff --git a/kernel/trace/rv/monitor_wip/wip.h b/kernel/trace/rv/monitor_wip/wip.h
new file mode 100644
index 000000000000..7a751a8896e9
--- /dev/null
+++ b/kernel/trace/rv/monitor_wip/wip.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rv
+
+#if !defined(_WIP_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _WIP_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(event_wip,
+
+ TP_PROTO(char state, char event, char next_state, bool safe),
+
+ TP_ARGS(state, event, next_state, safe),
+
+ TP_STRUCT__entry(
+ __field( char, state )
+ __field( char, event )
+ __field( char, next_state )
+ __field( bool, safe )
+ ),
+
+ TP_fast_assign(
+ __entry->state = state;
+ __entry->event = event;
+ __entry->next_state = next_state;
+ __entry->safe = safe;
+ ),
+
+ TP_printk("%s x %s -> %s %s",
+ model_get_state_name_wip(__entry->state),
+ model_get_event_name_wip(__entry->event),
+ model_get_state_name_wip(__entry->next_state),
+ __entry->safe ? "(safe)" : "")
+);
+
+TRACE_EVENT(error_wip,
+
+ TP_PROTO(char state, char event),
+
+ TP_ARGS(state, event),
+
+ TP_STRUCT__entry(
+ __field( char, state )
+ __field( char, event )
+ ),
+
+ TP_fast_assign(
+ __entry->state = state;
+ __entry->event = event;
+ ),
+
+ TP_printk("event %s not expected in the state %s",
+ model_get_event_name_wip(__entry->event),
+ model_get_state_name_wip(__entry->state))
+);
+
+#endif /* _WIP_H */
+
+/* This part ust be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE wip
+#include <trace/define_trace.h>
--
2.33.1