* [RFC PATCH 01/16] rv: Add Runtime Verification (RV) interface
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 18:10 ` Randy Dunlap
2021-05-19 11:36 ` [RFC PATCH 02/16] rv: Add runtime reactors interface Daniel Bristot de Oliveira
` (14 subsequent siblings)
15 siblings, 1 reply; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
RV is a lightweight (yet rigorous) method that complements classical
exhaustive verification techniques (such as model checking and
theorem proving) with a more practical approach to complex systems.
RV works by analyzing the trace of the system's actual execution,
comparing it against a formal specification of the system behavior.
RV can give precise information on the runtime behavior of the
monitored system while enabling the reaction for unexpected
events, avoiding, for example, the propagation of a failure on
safety-critical systems.
The development of this interface roots in the development of the
paper:
DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.
And:
DE OLIVEIRA, Daniel Bristot, et al. Automata-based formal analysis
and verification of the real-time Linux kernel. PhD Thesis, 2020.
The RV interface resembles the tracing/ interface on purpose. The current
path for the RV interface is /sys/kernel/tracing/rv/.
It presents these files:
"available_monitors"
- List the available monitors, one per line.
For example:
[root@f32 rv]# cat available_monitors
wip
wwnr
"enabled_monitors"
- Lists the enabled monitors, one per line;
- Writing to it enables a given monitor;
- Writing a monitor name with a '-' prefix disables it;
- Truncating the file disables all enabled monitors.
For example:
[root@f32 rv]# cat enabled_monitors
[root@f32 rv]# echo wip > enabled_monitors
[root@f32 rv]# echo wwnr >> enabled_monitors
[root@f32 rv]# cat enabled_monitors
wip
wwnr
[root@f32 rv]# echo -wip >> enabled_monitors
[root@f32 rv]# cat enabled_monitors
wwnr
[root@f32 rv]# echo > enabled_monitors
[root@f32 rv]# cat enabled_monitors
[root@f32 rv]#
Note that more than one monitor can be enabled concurrently.
"monitoring_on"
- It is an on/off general switcher for monitoring. Note
that it does not disable enabled monitors, but stop the per-entity
monitors of monitoring the events received from the system.
It resambles the "tracing_on" switcher.
"monitors/"
Each monitor will have its one directory inside "monitors/". There
the monitor specific files will be presented.
The "monitors/" directory resambles the "events" directory on
tracefs.
For example:
[root@f32 rv]# cd monitors/wip/
[root@f32 wip]# ls
desc enable
[root@f32 wip]# cat desc
auto-generated wakeup in preemptive monitor.
[root@f32 wip]# cat enable
0
For further information, see the comments in the header of
kernel/trace/rv/rv.c from this patch.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
include/linux/rv.h | 21 ++
kernel/trace/Kconfig | 2 +
kernel/trace/Makefile | 2 +
kernel/trace/rv/Kconfig | 13 +
kernel/trace/rv/Makefile | 3 +
kernel/trace/rv/rv.c | 687 +++++++++++++++++++++++++++++++++++++++
kernel/trace/rv/rv.h | 31 ++
kernel/trace/trace.c | 4 +
kernel/trace/trace.h | 2 +
9 files changed, 765 insertions(+)
create mode 100644 include/linux/rv.h
create mode 100644 kernel/trace/rv/Kconfig
create mode 100644 kernel/trace/rv/Makefile
create mode 100644 kernel/trace/rv/rv.c
create mode 100644 kernel/trace/rv/rv.h
diff --git a/include/linux/rv.h b/include/linux/rv.h
new file mode 100644
index 000000000000..04f94919ebb0
--- /dev/null
+++ b/include/linux/rv.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Runtime Verification.
+ *
+ * For futher information, see: kernel/trace/rv/rv.c.
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+struct rv_monitor {
+ const char *name;
+ const char *description;
+ bool enabled;
+ int (*start)(void);
+ void (*stop)(void);
+ void (*reset)(void);
+};
+
+extern bool monitoring_on;
+int rv_unregister_monitor(struct rv_monitor *monitor);
+int rv_register_monitor(struct rv_monitor *monitor);
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 7fa82778c3e6..870ecd8a023f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -969,6 +969,8 @@ config HIST_TRIGGERS_DEBUG
If unsure, say N.
+source "kernel/trace/rv/Kconfig"
+
endif # FTRACE
endif # TRACING_SUPPORT
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index b28d3e5013cd..70788f15912c 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -98,3 +98,5 @@ obj-$(CONFIG_FTRACE_RECORD_RECURSION) += trace_recursion_record.o
obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o
libftrace-y := ftrace.o
+
+obj-$(CONFIG_RV) += rv/
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
new file mode 100644
index 000000000000..e8e65cfc7959
--- /dev/null
+++ b/kernel/trace/rv/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+menuconfig RV
+ bool "Runtime Verification"
+ depends on TRACING
+ default y if DEBUG_KERNEL
+ help
+ Enable the kernel runtime verification infrastructure. RV is a
+ lightweight (yet rigorous) method that complements classical
+ exhaustive verification techniques (such as model checking and
+ theorem proving). RV works by analyzing the trace of the system's
+ actual execution, comparing it against a formal specification of
+ the system behavior.
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
new file mode 100644
index 000000000000..fd995379df67
--- /dev/null
+++ b/kernel/trace/rv/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_RV) += rv.o
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
new file mode 100644
index 000000000000..e6e1acfc8666
--- /dev/null
+++ b/kernel/trace/rv/rv.c
@@ -0,0 +1,687 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This is the online Runtime Verification (RV) interface.
+ *
+ * RV is a lightweight (yet rigorous) method that complements classical
+ * exhaustive verification techniques (such as model checking and
+ * theorem proving) with a more practical approach to complex systems.
+ *
+ * RV works by analyzing the trace of the system's actual execution,
+ * comparing it against a formal specification of the system behavior.
+ * RV can give precise information on the runtime behavior of the
+ * monitored system while enabling the reaction for unexpected
+ * events, avoiding, for example, the propagation of a failure on
+ * safety-critical systems.
+ *
+ * The development of this interface roots in the development of the
+ * paper:
+ *
+ * DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Romulo
+ * Silva. Efficient formal verification for the Linux kernel. In:
+ * International Conference on Software Engineering and Formal Methods.
+ * Springer, Cham, 2019. p. 315-332.
+ *
+ * And:
+ *
+ * DE OLIVEIRA, Daniel Bristot, et al. Automata-based formal analysis
+ * and verification of the real-time Linux kernel. PhD Thesis, 2020.
+ *
+ * == Runtime monitor interface ==
+ *
+ * A monitor is the central part of the runtime verification of a system.
+ *
+ * The monitor stands in between the formal specification of the desired
+ * (or undesired) behavior, and the trace of the actual system system.
+ *
+ * In Linux terms, the runtime verification monitors are encapsulated
+ * inside the "RV monitor" abstraction. A RV monitor includes a reference
+ * model of the system, a set of instances of the monitor (per-cpu monitor,
+ * per-task monitor, and so on), and the helper functions that glue the
+ * monitor to the system via trace. Generally, a monitor includes some form
+ * of trace output as a reaction for event parsing and exceptions,
+ * as depicted bellow:
+ *
+ * Linux +----- RV Monitor ----------------------------------+ Formal
+ * Realm | | Realm
+ * +-------------------+ +----------------+ +-----------------+
+ * | Linux kernel | | Monitor | | Reference |
+ * | Tracing | -> | Instance(s) | <- | Model |
+ * | (instrumentation) | | (verification) | | (specification) |
+ * +-------------------+ +----------------+ +-----------------+
+ * | | |
+ * | V |
+ * | +----------+ |
+ * | | Reaction | |
+ * | +--+--+--+-+ |
+ * | | | | |
+ * | | | +-> trace output ? |
+ * +------------------------|--|----------------------+
+ * | +----> panic ?
+ * +-------> <user-specified>
+ *
+ * This file implements the interface for loading RV monitors, and
+ * to control the verification session.
+ *
+ * == Registering monitors ==
+ *
+ * The struct rv_monitor defines a set of callback functions to control
+ * a verification session. For instance, when a given monitor is enabled,
+ * the "start" callback function is called to hook the instrumentation
+ * functions to the kernel trace events. The "stop" function is called
+ * when disabling the verification session.
+ *
+ * A RV monitor is registered via:
+ * int rv_register_monitor(struct rv_monitor *monitor);
+ * And unregistered via:
+ * int rv_unregister_monitor(struct rv_monitor *monitor);
+ *
+ * These functions are exported to modules, enabling verification monitors
+ * to be dynamically loaded.
+ *
+ * == User interface ==
+ *
+ * The user interface resembles kernel tracing interface. It presents
+ * these files:
+ *
+ * "available_monitors"
+ * - List the available monitors, one per line.
+ *
+ * For example:
+ * [root@f32 rv]# cat available_monitors
+ * wip
+ * wwnr
+ *
+ * "enabled_monitors"
+ * - Lists the enabled monitors, one per line;
+ * - Writing to it enables a given monitor;
+ * - Writing a monitor name with a '-' prefix disables it;
+ * - Truncating the file disables all enabled monitors.
+ *
+ * For example:
+ * [root@f32 rv]# cat enabled_monitors
+ * [root@f32 rv]# echo wip > enabled_monitors
+ * [root@f32 rv]# echo wwnr >> enabled_monitors
+ * [root@f32 rv]# cat enabled_monitors
+ * wip
+ * wwnr
+ * [root@f32 rv]# echo -wip >> enabled_monitors
+ * [root@f32 rv]# cat enabled_monitors
+ * wwnr
+ * [root@f32 rv]# echo > enabled_monitors
+ * [root@f32 rv]# cat enabled_monitors
+ * [root@f32 rv]#
+ *
+ * Note that more than one monitor can be enabled concurrently.
+ *
+ * "monitoring_on"
+ * - It is an on/off general switcher for monitoring. Note
+ * that it does not disable enabled monitors, but stop the per-entity
+ * monitors of monitoring the events received from the system.
+ * It resambles the "tracing_on" switcher.
+ *
+ * "monitors/"
+ * Each monitor will have its one directory inside "monitors/". There
+ * the monitor specific files will be presented.
+ * The "monitors/" directory resambles the "events" directory on
+ * tracefs.
+ *
+ * For example:
+ * [root@f32 rv]# cd monitors/wip/
+ * [root@f32 wip]# ls
+ * desc enable
+ * [root@f32 wip]# cat desc
+ * auto-generated wakeup in preemptive monitor.
+ * [root@f32 wip]# cat enable
+ * 0
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+#include "rv.h"
+
+DEFINE_MUTEX(interface_lock);
+struct rv_interface rv_root;
+
+struct dentry *get_monitors_root(void)
+{
+ return rv_root.monitors_dir;
+}
+
+/*
+ * Monitoring on global switcher!
+ */
+bool __read_mostly monitoring_on = false;
+EXPORT_SYMBOL_GPL(monitoring_on);
+
+/*
+ * Interface for the monitor register.
+ */
+LIST_HEAD(rv_monitors_list);
+
+/*
+ * This section collects the monitor/ files and folders.
+ */
+static ssize_t monitor_enable_read_data(struct file *filp,
+ char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct rv_monitor_def *mdef = filp->private_data;
+ char buff[4];
+
+ memset(buff, 0, sizeof(buff));
+
+ mutex_lock(&interface_lock);
+ sprintf(buff, "%x\n", mdef->monitor->enabled);
+ mutex_unlock(&interface_lock);
+
+ return simple_read_from_buffer(user_buf, count, ppos,
+ buff, strlen(buff)+1);
+}
+
+/*
+ * Disable a given runtime monitor.
+ */
+void disable_monitor(struct rv_monitor_def *mdef)
+{
+ if (mdef->monitor->enabled) {
+ mdef->monitor->enabled = 0;
+ mdef->monitor->stop();
+ }
+
+ mdef->enabled = 0;
+}
+
+/*
+ * Enable a given monitor.
+ */
+void enable_monitor(struct rv_monitor_def *mdef)
+{
+ /*
+ * Reset all internal monitors before starting.
+ */
+ mdef->monitor->reset();
+ if (!mdef->monitor->enabled)
+ mdef->monitor->start();
+
+ mdef->monitor->enabled = 1;
+ mdef->enabled = 1;
+}
+
+/*
+ * interface for enabling/disabling a monitor.
+ */
+static ssize_t monitor_enable_write_data(struct file *filp,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct rv_monitor_def *mdef = filp->private_data;
+ int retval;
+ u64 val;
+
+ retval = kstrtoull_from_user(user_buf, count, 10, &val);
+ if (retval)
+ return retval;
+
+ retval = count;
+
+ mutex_lock(&interface_lock);
+
+ switch (val) {
+ case 0:
+ disable_monitor(mdef);
+ break;
+ case 1:
+ enable_monitor(mdef);
+ break;
+ default:
+ retval = -EINVAL;
+ }
+
+ mutex_unlock(&interface_lock);
+
+ return retval;
+}
+
+static const struct file_operations interface_enable_fops = {
+ .open = simple_open,
+ .llseek = no_llseek,
+ .write = monitor_enable_write_data,
+ .read = monitor_enable_read_data,
+};
+
+/*
+ * Interface to read the enable/disable status of a monitor.
+ */
+static ssize_t
+monitor_desc_read_data(struct file *filp, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct rv_monitor_def *mdef = filp->private_data;
+ char buf[MAX_RV_MONITOR_NAME_SIZE];
+
+ memset(buf, 0, sizeof(buf));
+
+ mutex_lock(&interface_lock);
+ sprintf(buf, "%s\n", mdef->monitor->description);
+ mutex_unlock(&interface_lock);
+
+ return simple_read_from_buffer(user_buf, count, ppos,
+ buf, strlen(buf)+1);
+}
+
+static const struct file_operations interface_desc_fops = {
+ .open = simple_open,
+ .llseek = no_llseek,
+ .read = monitor_desc_read_data,
+};
+
+/*
+ * During the registration of a monitor, this function creates
+ * the monitor dir, where the specific options of the monitor
+ * is exposed.
+ */
+static int create_monitor_dir(struct rv_monitor_def *mdef)
+{
+ struct dentry *root = get_monitors_root();
+ struct dentry *tmp;
+ const char *name = mdef->monitor->name;
+ int retval = 0;
+
+ mdef->root_d = rv_create_dir(name, root);
+
+ if (!mdef->root_d)
+ return -ENOMEM;
+
+ tmp = rv_create_file("enable", 0600,
+ mdef->root_d, mdef,
+ &interface_enable_fops);
+ if (!tmp) {
+ retval = -ENOMEM;
+ goto out_remove_root;
+ }
+
+ tmp = rv_create_file("desc", 0400,
+ mdef->root_d, mdef,
+ &interface_desc_fops);
+ if (!tmp) {
+ retval = -ENOMEM;
+ goto out_remove_root;
+ }
+
+ return retval;
+
+out_remove_root:
+ rv_remove(mdef->root_d);
+ return retval;
+}
+
+/*
+ * Available/Enable monitor shared seq functions.
+ */
+static int monitors_show(struct seq_file *m, void *p)
+{
+ struct rv_monitor_def *mon_def = p;
+ seq_printf(m, "%s\n", mon_def->monitor->name);
+ return 0;
+}
+
+/*
+ * Used by the seq file operations at the end of a read
+ * operation.
+ */
+static void monitors_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&interface_lock);
+}
+
+/*
+ * Available monitor seq functions:
+ */
+static void *available_monitors_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&interface_lock);
+ return seq_list_start(&rv_monitors_list, *pos);
+}
+
+static void *available_monitors_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &rv_monitors_list, pos);
+}
+
+/*
+ * Enable monitor seq functions:
+ */
+
+static void *enabled_monitors_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ struct rv_monitor_def *m_def = p;
+
+ (*pos)++;
+
+ list_for_each_entry_continue(m_def, &rv_monitors_list, list) {
+ if (m_def->monitor->enabled)
+ return m_def;
+ }
+
+ return NULL;
+}
+
+static void *enabled_monitors_start(struct seq_file *m, loff_t *pos)
+{
+ struct rv_monitor_def *m_def;
+ loff_t l;
+
+ mutex_lock(&interface_lock);
+ m_def = list_entry(&rv_monitors_list, struct rv_monitor_def, list);
+
+ for (l = 0; l <= *pos; ) {
+ m_def = enabled_monitors_next(m, m_def, &l);
+ if (!m_def)
+ break;
+ }
+
+ return m_def;
+}
+
+/*
+ * available/enabled monitors seq definition.
+ */
+static const struct seq_operations available_monitors_seq_ops = {
+ .start = available_monitors_start,
+ .next = available_monitors_next,
+ .stop = monitors_stop,
+ .show = monitors_show
+};
+
+static const struct seq_operations enabled_monitors_seq_ops = {
+ .start = enabled_monitors_start,
+ .next = enabled_monitors_next,
+ .stop = monitors_stop,
+ .show = monitors_show
+};
+
+/*
+ * available_monitors interface.
+ */
+static int available_monitors_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &available_monitors_seq_ops);
+};
+
+static struct file_operations available_monitors_ops = {
+ .open = available_monitors_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+/*
+ * enabled_monitors interface
+ */
+static void disable_all_monitors(void)
+{
+ struct rv_monitor_def *mdef;
+
+ list_for_each_entry(mdef, &rv_monitors_list, list)
+ disable_monitor(mdef);
+
+ return;
+}
+
+static int enabled_monitors_open(struct inode *inode, struct file *file)
+{
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
+ disable_all_monitors();
+
+ return seq_open(file, &enabled_monitors_seq_ops);
+};
+
+static ssize_t
+enabled_monitors_write(struct file *filp, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buff[MAX_RV_MONITOR_NAME_SIZE+1];
+ struct rv_monitor_def *mdef;
+ int retval = -EINVAL;
+ bool enable = true;
+ char *ptr = buff;
+ int len;
+
+ if (count < 1 || count > MAX_RV_MONITOR_NAME_SIZE+1)
+ return -EINVAL;
+
+ memset(buff, 0, sizeof(buff));
+
+ retval = simple_write_to_buffer(buff, sizeof(buff)-1, ppos, user_buf,
+ count);
+ if (!retval)
+ return -EFAULT;
+
+ if (buff[0] == '-') {
+ enable=false;
+ ptr++;
+ }
+
+ len = strlen(ptr);
+ if (!len)
+ return count;
+ /*
+ * remove the \n
+ */
+ ptr[len-1]='\0';
+
+ mutex_lock(&interface_lock);
+
+ retval = -EINVAL;
+
+ list_for_each_entry(mdef, &rv_monitors_list, list) {
+ if (strcmp(ptr, mdef->monitor->name) == 0) {
+ /*
+ * Monitor found!
+ */
+ if (enable)
+ enable_monitor(mdef);
+ else
+ disable_monitor(mdef);
+
+ retval=count;
+ break;
+ }
+ }
+
+ mutex_unlock(&interface_lock);
+
+ return retval;
+}
+
+static struct file_operations enabled_monitors_ops = {
+ .open = enabled_monitors_open,
+ .read = seq_read,
+ .write = enabled_monitors_write,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/*
+ * monitoring_on general switcher
+ */
+static ssize_t monitoring_on_read_data(struct file *filp,
+ char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buff[4];
+
+ memset(buff, 0, sizeof(buff));
+
+ mutex_lock(&interface_lock);
+ sprintf(buff, "%d\n", monitoring_on);
+ mutex_unlock(&interface_lock);
+
+ return simple_read_from_buffer(user_buf, count, ppos,
+ buff, strlen(buff)+1);
+}
+
+static void turn_monitoring_off(void)
+{
+ monitoring_on=false;
+}
+
+static void turn_monitoring_on(void)
+{
+ reset_all_monitors();
+ monitoring_on=true;
+
+ return;
+}
+
+static ssize_t monitoring_on_write_data(struct file *filp,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ int retval;
+ u64 val;
+
+ retval = kstrtoull_from_user(user_buf, count, 10, &val);
+ if (retval)
+ return retval;
+
+ retval = count;
+
+ mutex_lock(&interface_lock);
+
+ switch (val) {
+ case 0:
+ turn_monitoring_off();
+ break;
+ case 1:
+ turn_monitoring_on();
+ break;
+ default:
+ retval = -EINVAL;
+ }
+
+ mutex_unlock(&interface_lock);
+
+ return retval;
+}
+
+static const struct file_operations monitoring_on_fops = {
+ .open = simple_open,
+ .llseek = no_llseek,
+ .write = monitoring_on_write_data,
+ .read = monitoring_on_read_data,
+};
+
+/*
+ * Monitor API.
+ */
+static void destroy_monitor_dir(struct rv_monitor_def *mdef)
+{
+ rv_remove(mdef->root_d);
+}
+
+/**
+ * rv_register_monitor - register a rv monitor.
+ * @monitor: The rv_monitor to be registered.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int rv_register_monitor(struct rv_monitor *monitor)
+{
+ struct rv_monitor_def *r;
+ int retval = 0;
+
+ if (strlen(monitor->name) >= MAX_RV_MONITOR_NAME_SIZE) {
+ pr_info("Monitor %s has a name longer than %d\n",
+ monitor->name, MAX_RV_MONITOR_NAME_SIZE);
+ return -1;
+ }
+
+ mutex_lock(&interface_lock);
+
+ list_for_each_entry(r, &rv_monitors_list, list) {
+ if (strcmp(monitor->name, r->monitor->name) == 0) {
+ pr_info("Monitor %s is already registered\n",
+ monitor->name);
+ retval = -1;
+ goto out_unlock;
+ }
+ }
+
+ r = kzalloc(sizeof(struct rv_monitor_def), GFP_KERNEL);
+ if (!r) {
+ retval = -ENOMEM;
+ goto out_unlock;
+ }
+
+ r->monitor = monitor;
+
+ create_monitor_dir(r);
+
+ list_add_tail(&r->list, &rv_monitors_list);
+
+out_unlock:
+ mutex_unlock(&interface_lock);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(rv_register_monitor);
+
+/**
+ * rv_unregister_monitor - unregister a rv monitor.
+ * @monitor: The rv_monitor to be unregistered.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int rv_unregister_monitor(struct rv_monitor *monitor)
+{
+ struct rv_monitor_def *ptr, *next;
+
+ mutex_lock(&interface_lock);
+
+ list_for_each_entry_safe(ptr, next, &rv_monitors_list, list) {
+ if (strcmp(monitor->name, ptr->monitor->name) == 0) {
+ list_del(&ptr->list);
+ destroy_monitor_dir(ptr);
+ }
+ }
+
+ mutex_unlock(&interface_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(rv_unregister_monitor);
+
+void reset_all_monitors(void)
+{
+ struct rv_monitor_def *mdef;
+
+ /*
+ * Reset all monitors before re-enabling monitoring.
+ */
+ list_for_each_entry(mdef, &rv_monitors_list, list) {
+ if (mdef->monitor->enabled)
+ mdef->monitor->reset();
+ }
+
+}
+
+int __init rv_init_interface(void)
+{
+ rv_root.root_dir = rv_create_dir("rv", NULL);
+ rv_root.monitors_dir = rv_create_dir("monitors", rv_root.root_dir);
+
+ rv_create_file("available_monitors", 0400, rv_root.root_dir, NULL,
+ &available_monitors_ops);
+ rv_create_file("enabled_monitors", 0600, rv_root.root_dir, NULL,
+ &enabled_monitors_ops);
+ rv_create_file("monitoring_on", 0600, rv_root.root_dir, NULL,
+ &monitoring_on_fops);
+
+ monitoring_on=true;
+
+ return 0;
+}
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
new file mode 100644
index 000000000000..30056469e514
--- /dev/null
+++ b/kernel/trace/rv/rv.h
@@ -0,0 +1,31 @@
+#include <linux/mutex.h>
+
+struct rv_interface {
+ struct dentry *root_dir;
+ struct dentry *monitors_dir;
+};
+
+#include "../trace.h"
+#include <linux/tracefs.h>
+#include <linux/rv.h>
+
+#define rv_create_dir tracefs_create_dir
+#define rv_create_file tracefs_create_file
+#define rv_remove tracefs_remove
+
+#define MAX_RV_MONITOR_NAME_SIZE 100
+
+extern struct mutex interface_lock;
+
+struct rv_monitor_def {
+ struct list_head list;
+ struct rv_monitor *monitor;
+ struct dentry *root_d;
+ bool enabled;
+ bool reacting;
+};
+
+extern bool monitoring_on;
+struct dentry *get_monitors_root(void);
+void reset_all_monitors(void);
+int init_rv_monitors(struct dentry *root_dir);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a21ef9cd2aae..2d87c6d14167 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9539,6 +9539,10 @@ static __init int tracer_init_tracefs(void)
update_tracer_options(&global_trace);
+#ifdef CONFIG_RV
+ rv_init_interface();
+#endif
+
return 0;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cd80d046c7a5..51cb706e3fbe 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1952,4 +1952,6 @@ static inline bool is_good_name(const char *name)
return true;
}
+extern int rv_init_interface(void);
+
#endif /* _LINUX_KERNEL_TRACE_H */
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [RFC PATCH 01/16] rv: Add Runtime Verification (RV) interface
2021-05-19 11:36 ` [RFC PATCH 01/16] rv: Add " Daniel Bristot de Oliveira
@ 2021-05-19 18:10 ` Randy Dunlap
2021-05-20 6:54 ` Daniel Bristot de Oliveira
0 siblings, 1 reply; 26+ messages in thread
From: Randy Dunlap @ 2021-05-19 18:10 UTC (permalink / raw)
To: Daniel Bristot de Oliveira, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
> new file mode 100644
> index 000000000000..e8e65cfc7959
> --- /dev/null
> +++ b/kernel/trace/rv/Kconfig
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +menuconfig RV
> + bool "Runtime Verification"
> + depends on TRACING
> + default y if DEBUG_KERNEL
No need for default y. There are other reasons to use DEBUG_KERNEL
without wanting RV turned on.
> + help
> + Enable the kernel runtime verification infrastructure. RV is a
> + lightweight (yet rigorous) method that complements classical
> + exhaustive verification techniques (such as model checking and
> + theorem proving). RV works by analyzing the trace of the system's
> + actual execution, comparing it against a formal specification of
> + the system behavior.
And in the cover/patch 00:
tlrd:
should be
tl;dr:
or at least
tldr:
:)
--
~Randy
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [RFC PATCH 01/16] rv: Add Runtime Verification (RV) interface
2021-05-19 18:10 ` Randy Dunlap
@ 2021-05-20 6:54 ` Daniel Bristot de Oliveira
2021-08-04 1:31 ` Steven Rostedt
0 siblings, 1 reply; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-20 6:54 UTC (permalink / raw)
To: Randy Dunlap, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 8:10 PM, Randy Dunlap wrote:
> On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
>> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
>> new file mode 100644
>> index 000000000000..e8e65cfc7959
>> --- /dev/null
>> +++ b/kernel/trace/rv/Kconfig
>> @@ -0,0 +1,13 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +#
>> +menuconfig RV
>> + bool "Runtime Verification"
>> + depends on TRACING
>> + default y if DEBUG_KERNEL
>
> No need for default y. There are other reasons to use DEBUG_KERNEL
> without wanting RV turned on.
yes, you are right, I will remove it.
>> + help
>> + Enable the kernel runtime verification infrastructure. RV is a
>> + lightweight (yet rigorous) method that complements classical
>> + exhaustive verification techniques (such as model checking and
>> + theorem proving). RV works by analyzing the trace of the system's
>> + actual execution, comparing it against a formal specification of
>> + the system behavior.
>
> And in the cover/patch 00:
> tlrd:
> should be
> tl;dr:
> or at least
> tldr:
> :)
Ack!
Thanks!
-- Daniel
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [RFC PATCH 01/16] rv: Add Runtime Verification (RV) interface
2021-05-20 6:54 ` Daniel Bristot de Oliveira
@ 2021-08-04 1:31 ` Steven Rostedt
0 siblings, 0 replies; 26+ messages in thread
From: Steven Rostedt @ 2021-08-04 1:31 UTC (permalink / raw)
To: Daniel Bristot de Oliveira
Cc: Randy Dunlap, linux-kernel, Tommaso Cucinotta, Kate Carcia,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
On Thu, 20 May 2021 08:54:39 +0200
Daniel Bristot de Oliveira <bristot@redhat.com> wrote:
> > No need for default y. There are other reasons to use DEBUG_KERNEL
> > without wanting RV turned on.
>
> yes, you are right, I will remove it.
Can you send a new updated version. I'd like to review whatever you
have as the latest.
Thanks!
-- Steve
^ permalink raw reply [flat|nested] 26+ messages in thread
* [RFC PATCH 02/16] rv: Add runtime reactors interface
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 01/16] rv: Add " Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 03/16] rv/include: Add helper functions for deterministic automata Daniel Bristot de Oliveira
` (13 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
A runtime monitor can cause a reaction to the detection of an
exception on the model's execution. By default, the monitors have
tracing reactions, printing the monitor output via tracepoints.
But other reactions can be added (on-demand) via this interface.
The user interface resembles the kernel tracing interface and
presents these files:
"available_reactors"
- Reading shows the available reactors, one per line.
For example:
[root@f32 rv]# cat available_reactors
nop
panic
printk
"reacting_on"
- It is an on/off general switch for reactors, disabling
all reactions.
"monitors/MONITOR/reactors"
- List available reactors, with the select reaction for the given
MONITOR inside []. The default one is the nop (no operation)
reactor.
- Writing the name of a reactor enables it to the given
MONITOR.
For example:
[root@f32 rv]# cat monitors/wip/reactors
[nop]
panic
printk
[root@f32 rv]# echo panic > monitors/wip/reactors
[root@f32 rv]# cat monitors/wip/reactors
nop
[panic]
printk
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
include/linux/rv.h | 10 +
kernel/trace/rv/Kconfig | 14 +
kernel/trace/rv/Makefile | 1 +
kernel/trace/rv/rv.c | 17 +-
kernel/trace/rv/rv.h | 19 ++
kernel/trace/rv/rv_reactors.c | 478 ++++++++++++++++++++++++++++++++++
6 files changed, 537 insertions(+), 2 deletions(-)
create mode 100644 kernel/trace/rv/rv_reactors.c
diff --git a/include/linux/rv.h b/include/linux/rv.h
index 04f94919ebb0..1568b48f07a7 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -6,6 +6,11 @@
*
* Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
*/
+struct rv_reactor {
+ char *name;
+ char *description;
+ void (*react)(char *);
+};
struct rv_monitor {
const char *name;
@@ -14,8 +19,13 @@ struct rv_monitor {
int (*start)(void);
void (*stop)(void);
void (*reset)(void);
+ void (*react)(char *);
};
extern bool monitoring_on;
int rv_unregister_monitor(struct rv_monitor *monitor);
int rv_register_monitor(struct rv_monitor *monitor);
+
+extern bool reacting_on;
+int rv_unregister_reactor(struct rv_reactor *reactor);
+int rv_register_reactor(struct rv_reactor *reactor);
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index e8e65cfc7959..74eb2f216255 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -11,3 +11,17 @@ menuconfig RV
theorem proving). RV works by analyzing the trace of the system's
actual execution, comparing it against a formal specification of
the system behavior.
+
+if RV
+
+config RV_REACTORS
+ bool "Runtime verification reactors"
+ default y if RV
+ help
+ Enables the online runtime verification reactors. A runtime
+ monitor can cause a reaction to the detection of an exception
+ on the model's execution. By default, the monitors have
+ tracing reactions, printing the monitor output via tracepoints,
+ but other reactions can be added (on-demand) via this interface.
+
+endif # RV
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index fd995379df67..8944274d9b41 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_RV) += rv.o
+obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
diff --git a/kernel/trace/rv/rv.c b/kernel/trace/rv/rv.c
index e6e1acfc8666..9c7ea300fab6 100644
--- a/kernel/trace/rv/rv.c
+++ b/kernel/trace/rv/rv.c
@@ -312,8 +312,13 @@ static int create_monitor_dir(struct rv_monitor_def *mdef)
retval = -ENOMEM;
goto out_remove_root;
}
+#ifdef CONFIG_RV_REACTORS
+ retval = reactor_create_monitor_files(mdef);
+ if (retval)
+ goto out_remove_root;
+#endif
- return retval;
+ return 0;
out_remove_root:
rv_remove(mdef->root_d);
@@ -621,7 +626,11 @@ int rv_register_monitor(struct rv_monitor *monitor)
r->monitor = monitor;
- create_monitor_dir(r);
+ retval = create_monitor_dir(r);
+ if (retval) {
+ kfree(r);
+ goto out_unlock;
+ }
list_add_tail(&r->list, &rv_monitors_list);
@@ -681,6 +690,10 @@ int __init rv_init_interface(void)
rv_create_file("monitoring_on", 0600, rv_root.root_dir, NULL,
&monitoring_on_fops);
+#ifdef CONFIG_RV_REACTORS
+ init_rv_reactors(rv_root.root_dir);
+ reacting_on=true;
+#endif
monitoring_on=true;
return 0;
diff --git a/kernel/trace/rv/rv.h b/kernel/trace/rv/rv.h
index 30056469e514..82f64c2b6a50 100644
--- a/kernel/trace/rv/rv.h
+++ b/kernel/trace/rv/rv.h
@@ -14,12 +14,25 @@ struct rv_interface {
#define rv_remove tracefs_remove
#define MAX_RV_MONITOR_NAME_SIZE 100
+#define MAX_RV_REACTOR_NAME_SIZE 100
extern struct mutex interface_lock;
+#ifdef CONFIG_RV_REACTORS
+struct rv_reactor_def {
+ struct list_head list;
+ struct rv_reactor *reactor;
+ /* protected by the monitor interface lock */
+ int counter;
+};
+#endif
+
struct rv_monitor_def {
struct list_head list;
struct rv_monitor *monitor;
+#ifdef CONFIG_RV_REACTORS
+ struct rv_reactor_def *rdef;
+#endif
struct dentry *root_d;
bool enabled;
bool reacting;
@@ -29,3 +42,9 @@ extern bool monitoring_on;
struct dentry *get_monitors_root(void);
void reset_all_monitors(void);
int init_rv_monitors(struct dentry *root_dir);
+
+#ifdef CONFIG_RV_REACTORS
+extern bool reacting_on;
+int reactor_create_monitor_files(struct rv_monitor_def *mdef);
+int init_rv_reactors(struct dentry *root_dir);
+#endif
diff --git a/kernel/trace/rv/rv_reactors.c b/kernel/trace/rv/rv_reactors.c
new file mode 100644
index 000000000000..042a264851e6
--- /dev/null
+++ b/kernel/trace/rv/rv_reactors.c
@@ -0,0 +1,478 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Runtime reactor interface.
+ *
+ * A runtime monitor can cause a reaction to the detection of an
+ * exception on the model's execution. By default, the monitors have
+ * tracing reactions, printing the monitor output via tracepoints.
+ * But other reactions can be added (on-demand) via this interface.
+ *
+ * == Registering reactors ==
+ *
+ * The struct rv_reactor defines a callback function to be executed
+ * in case of a model exception happens. The callback function
+ * receives a message to be (optionally) printed before executing
+ * the reaction.
+ *
+ * A RV reactor is registered via:
+ * int rv_register_reactor(struct rv_reactor *reactor)
+ * And unregistered via:
+ * int rv_unregister_reactor(struct rv_reactor *reactor)
+ *
+ * These functions are exported to modules, enabling reactors to be
+ * dynamically loaded.
+ *
+ * == User interface ==
+ *
+ * The user interface resembles the kernel tracing interface and
+ * presents these files:
+ *
+ * "available_reactors"
+ * - List the available reactors, one per line.
+ *
+ * For example:
+ * [root@f32 rv]# cat available_reactors
+ * nop
+ * panic
+ * printk
+ *
+ * "reacting_on"
+ * - It is an on/off general switch for reactors, disabling
+ * all reactions.
+ *
+ * "monitors/MONITOR/reactors"
+ * - List available reactors, with the select reaction for the given
+ * MONITOR inside []. The defaul one is the nop (no operation)
+ * reactor.
+ * - Writing the name of an reactor enables it to the given
+ * MONITOR.
+ *
+ * For example:
+ * [root@f32 rv]# cat monitors/wip/reactors
+ * [nop]
+ * panic
+ * printk
+ * [root@f32 rv]# echo panic > monitors/wip/reactors
+ * [root@f32 rv]# cat monitors/wip/reactors
+ * nop
+ * [panic]
+ * printk
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+#include <linux/slab.h>
+
+#include "rv.h"
+
+bool __read_mostly reacting_on = false;
+EXPORT_SYMBOL_GPL(reacting_on);
+
+/*
+ * Interface for the reactor register.
+ */
+LIST_HEAD(rv_reactors_list);
+
+struct rv_reactor_def *get_reactor_rdef_by_name(char *name)
+{
+ struct rv_reactor_def *r;
+ list_for_each_entry(r, &rv_reactors_list, list) {
+ if (strcmp(name, r->reactor->name) == 0)
+ return r;
+ }
+
+ return NULL;
+}
+
+/*
+ * Available reactors seq functions.
+ */
+static int reactors_show(struct seq_file *m, void *p)
+{
+ struct rv_reactor_def *rea_def = p;
+ seq_printf(m, "%s\n", rea_def->reactor->name);
+ return 0;
+}
+
+static void reactors_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&interface_lock);
+}
+
+static void *reactors_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&interface_lock);
+ return seq_list_start(&rv_reactors_list, *pos);
+}
+
+static void *reactors_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &rv_reactors_list, pos);
+}
+
+
+/*
+ * available reactors seq definition.
+ */
+static const struct seq_operations available_reactors_seq_ops = {
+ .start = reactors_start,
+ .next = reactors_next,
+ .stop = reactors_stop,
+ .show = reactors_show
+};
+
+/*
+ * available_reactors interface.
+ */
+static int available_reactors_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &available_reactors_seq_ops);
+};
+
+static struct file_operations available_reactors_ops = {
+ .open = available_reactors_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release
+};
+
+/*
+ * Monitor reactor file.
+ */
+static int monitor_reactor_show(struct seq_file *m, void *p)
+{
+ struct rv_monitor_def *mdef = m->private;
+ struct rv_reactor_def *rdef = p;
+
+ if (mdef->rdef == rdef)
+ seq_printf(m, "[%s]\n", rdef->reactor->name);
+ else
+ seq_printf(m, "%s\n", rdef->reactor->name);
+ return 0;
+}
+
+/*
+ * available reactors seq definition.
+ */
+static const struct seq_operations monitor_reactors_seq_ops = {
+ .start = reactors_start,
+ .next = reactors_next,
+ .stop = reactors_stop,
+ .show = monitor_reactor_show
+};
+
+static ssize_t
+monitor_reactors_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buff[MAX_RV_REACTOR_NAME_SIZE+1];
+ struct rv_monitor_def *mdef;
+ struct rv_reactor_def *rdef;
+ struct seq_file *seq_f;
+ int retval = -EINVAL;
+ char *ptr = buff;
+ int len;
+
+ if (count < 1 || count > MAX_RV_REACTOR_NAME_SIZE+1)
+ return -EINVAL;
+
+ memset(buff, 0, sizeof(buff));
+
+ retval = simple_write_to_buffer(buff, sizeof(buff)-1, ppos, user_buf,
+ count);
+ if (!retval)
+ return -EFAULT;
+
+ len = strlen(ptr);
+ if (!len)
+ return count;
+ /*
+ * remove the \n
+ */
+ ptr[len-1]='\0';
+
+ /*
+ * See monitor_reactors_open()
+ */
+ seq_f = file->private_data;
+ mdef = seq_f->private;
+
+ mutex_lock(&interface_lock);
+
+ retval = -EINVAL;
+
+ /*
+ * nop special case: disable reacting.
+ */
+ if (strcmp(ptr, "nop") == 0) {
+
+ if (mdef->monitor->enabled)
+ mdef->monitor->stop();
+
+ mdef->rdef = get_reactor_rdef_by_name("nop");
+ mdef->reacting = false;
+ mdef->monitor->react = NULL;
+
+ if (mdef->monitor->enabled)
+ mdef->monitor->start();
+
+ retval = count;
+ goto unlock;
+ }
+
+ list_for_each_entry(rdef, &rv_reactors_list, list) {
+ if (strcmp(ptr, rdef->reactor->name) == 0) {
+ /*
+ * found!
+ */
+ if (mdef->monitor->enabled)
+ mdef->monitor->stop();
+
+ mdef->rdef = rdef;
+ mdef->reacting = true;
+ mdef->monitor->react = rdef->reactor->react;
+
+ if (mdef->monitor->enabled)
+ mdef->monitor->start();
+
+ retval=count;
+ break;
+ }
+ }
+
+unlock:
+ mutex_unlock(&interface_lock);
+
+ return retval;
+}
+
+/*
+ * available_reactors interface.
+ */
+static int monitor_reactors_open(struct inode *inode, struct file *file)
+{
+ /*
+ * create file "private" info is stored in the inode->i_private
+ */
+ struct rv_monitor_def *mdef = inode->i_private;
+ struct seq_file *seq_f;
+ int ret;
+
+
+ ret = seq_open(file, &monitor_reactors_seq_ops);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * seq_open stores the seq_file on the file->private data.
+ */
+ seq_f = file->private_data;
+ /*
+ * Copy the create file "private" data to the seq_file
+ * private data.
+ */
+ seq_f->private = mdef;
+
+ return 0;
+};
+
+static struct file_operations monitor_reactors_ops = {
+ .open = monitor_reactors_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .write = monitor_reactors_write
+};
+
+static int __rv_register_reactor(struct rv_reactor *reactor)
+{
+ struct rv_reactor_def *r;
+
+ list_for_each_entry(r, &rv_reactors_list, list) {
+ if (strcmp(reactor->name, r->reactor->name) == 0) {
+ pr_info("Reactor %s is already registered\n",
+ reactor->name);
+ return -EINVAL;
+ }
+ }
+
+ r = kzalloc(sizeof(struct rv_reactor_def), GFP_KERNEL);
+ if (!r)
+ return -ENOMEM;
+
+ r->reactor = reactor;
+ r->counter = 0;
+
+ list_add_tail(&r->list, &rv_reactors_list);
+
+ return 0;
+}
+
+/**
+ * rv_register_reactor - register a rv reactor.
+ * @reactor: The rv_reactor to be registered.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int rv_register_reactor(struct rv_reactor *reactor)
+{
+ int retval = 0;
+
+ if (strlen(reactor->name) >= MAX_RV_REACTOR_NAME_SIZE) {
+ pr_info("Reactor %s has a name longer than %d\n",
+ reactor->name, MAX_RV_MONITOR_NAME_SIZE);
+ return -EINVAL;
+ }
+
+ mutex_lock(&interface_lock);
+ retval = __rv_register_reactor(reactor);
+ mutex_unlock(&interface_lock);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(rv_register_reactor);
+
+/**
+ * rv_unregister_reactor - unregister a rv reactor.
+ * @reactor: The rv_reactor to be unregistered.
+ *
+ * Returns 0 if successful, error otherwise.
+ */
+int rv_unregister_reactor(struct rv_reactor *reactor)
+{
+ struct rv_reactor_def *ptr, *next;
+
+ mutex_lock(&interface_lock);
+
+ list_for_each_entry_safe(ptr, next, &rv_reactors_list, list) {
+ if (strcmp(reactor->name, ptr->reactor->name) == 0) {
+
+ if (!ptr->counter) {
+ list_del(&ptr->list);
+ } else {
+ printk("rv: the rv_reactor %s is in use by %d monitor(s)\n",
+ ptr->reactor->name, ptr->counter);
+ printk("rv: the rv_reactor %s cannot be removed\n",
+ ptr->reactor->name);
+ return -EBUSY;
+ }
+
+ }
+ }
+
+ mutex_unlock(&interface_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(rv_unregister_reactor);
+
+/*
+ * reacting_on interface.
+ */
+static ssize_t reacting_on_read_data(struct file *filp,
+ char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buff[4];
+
+ memset(buff, 0, sizeof(buff));
+
+ mutex_lock(&interface_lock);
+ sprintf(buff, "%d\n", reacting_on);
+ mutex_unlock(&interface_lock);
+
+ return simple_read_from_buffer(user_buf, count, ppos,
+ buff, strlen(buff)+1);
+}
+
+static void turn_reacting_off(void)
+{
+ reacting_on=false;
+}
+
+static void turn_reacting_on(void)
+{
+ reacting_on=true;
+}
+
+static ssize_t
+reacting_on_write_data(struct file *filp, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ int retval;
+ u64 val;
+
+ retval = kstrtoull_from_user(user_buf, count, 10, &val);
+ if (retval)
+ return retval;
+
+ retval = count;
+
+ mutex_lock(&interface_lock);
+
+ switch (val) {
+ case 0:
+ turn_reacting_off();
+ break;
+ case 1:
+ turn_reacting_on();
+ break;
+ default:
+ retval = -EINVAL;
+ }
+
+ mutex_unlock(&interface_lock);
+
+ return retval;
+}
+
+static const struct file_operations reacting_on_fops = {
+ .open = simple_open,
+ .llseek = no_llseek,
+ .write = reacting_on_write_data,
+ .read = reacting_on_read_data,
+};
+
+
+int reactor_create_monitor_files(struct rv_monitor_def *mdef)
+{
+ struct dentry *tmp;
+
+ tmp = rv_create_file("reactors", 0400, mdef->root_d, mdef,
+ &monitor_reactors_ops);
+ if (!tmp)
+ return -ENOMEM;
+
+ /*
+ * Configure as the rv_nop reactor.
+ */
+ mdef->rdef = get_reactor_rdef_by_name("nop");
+ mdef->reacting = false;
+ return 0;
+}
+
+/*
+ * None reactor register
+ */
+static void rv_nop_reaction(char *msg)
+{
+ return;
+}
+
+struct rv_reactor rv_nop = {
+ .name = "nop",
+ .description = "no-operation reactor: do nothing.",
+ .react = rv_nop_reaction
+};
+
+/*
+ * This section collects the rv/ root dir files and folders.
+ */
+int init_rv_reactors(struct dentry *root_dir)
+{
+ rv_create_file("available_reactors", 0400, root_dir, NULL,
+ &available_reactors_ops);
+ rv_create_file("reacting_on", 0600, root_dir, NULL, &reacting_on_fops);
+
+ __rv_register_reactor(&rv_nop);
+
+ return 0;
+}
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 03/16] rv/include: Add helper functions for deterministic automata
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 01/16] rv: Add " Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 02/16] rv: Add runtime reactors interface Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros Daniel Bristot de Oliveira
` (12 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Formally, a deterministic automaton, denoted by G, is defined as a
quintuple:
G = { X, E, f, x_0, X_m }
where:
- X is the set of states;
- E is the finite set of events;
- x_0 is the initial state;
- X_m (subset of X) is the set of marked states.
- f : X x E -> X $ is the transition function. It defines the
state transition in the occurrence of a event from E in
the state X. In the special case of deterministic automata,
the occurence of the event in E in a state in X has a
deterministic next state from X.
An automaton can also be represented using a graphical format of
vertices (nodes) and edges. The open-source tool Graphviz can produce
this graphic format using the (textual) DOT language as the source code.
The dot2c tool presented in this paper:
DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.
Translates a deterministic automaton in the DOT format into a C
source code representation that to be used for monitoring.
This header file implements helper functions to facilitate the usage
of the C output from dot2c for monitoring.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
include/rv/automata.h | 52 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
create mode 100644 include/rv/automata.h
diff --git a/include/rv/automata.h b/include/rv/automata.h
new file mode 100644
index 000000000000..b95941bf78ac
--- /dev/null
+++ b/include/rv/automata.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Deterministic automata helper functions, to be used with the automata
+ * models in C generated by the dot2k tool.
+ *
+ * The dot2k tool is available at https://gitlab.com/linux-rv-tools/dot2/.
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+#define DECLARE_AUTOMATA_HELPERS(name, type) \
+ \
+static inline void *model_get_model_##name(void) \
+{ \
+ return (void *) &automaton_##name; \
+} \
+ \
+char *model_get_state_name_##name(enum states_##name state) \
+{ \
+ return automaton_##name.state_names[state]; \
+} \
+ \
+char *model_get_event_name_##name(enum events_##name event) \
+{ \
+ return automaton_##name.event_names[event]; \
+} \
+ \
+static inline type model_get_init_state_##name(void) \
+{ \
+ return automaton_##name.initial_state; \
+} \
+ \
+static inline type \
+model_get_next_state_##name(enum states_##name curr_state, \
+ enum events_##name event) \
+{ \
+ if ((curr_state < 0) || (curr_state > state_max)) \
+ return -1; \
+ \
+ if ((event < 0) || (event > event_max)) \
+ return -1; \
+ \
+ return automaton_##name.function[curr_state][event]; \
+} \
+ \
+static inline bool model_is_final_state_##name(enum states_##name state) \
+{ \
+ if ((state < 0) || (state > state_max)) \
+ return 0; \
+ \
+ return !!automaton_##name.final_states[state]; \
+}
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (2 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 03/16] rv/include: Add helper functions for deterministic automata Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 18:27 ` Peter Zijlstra
2021-05-19 11:36 ` [RFC PATCH 05/16] rv/include: Add tracing helper functions Daniel Bristot de Oliveira
` (11 subsequent siblings)
15 siblings, 1 reply; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
In Linux terms, the runtime verification monitors are encapsulated
inside the "RV monitor" abstraction. The "RV monitor" includes a set
of instances of the monitor (per-cpu monitor, per-task monitor, and
so on), the helper functions that glue the monitor to the system
reference model, and the trace output as a reaction for event parsing
and exceptions, as depicted below:
Linux +----- RV Monitor ----------------------------------+ Formal
Realm | | Realm
+-------------------+ +----------------+ +-----------------+
| Linux kernel | | Monitor | | Reference |
| Tracing | -> | Instance(s) | <- | Model |
| (instrumentation) | | (verification) | | (specification) |
+-------------------+ +----------------+ +-----------------+
| | |
| V |
| +----------+ |
| | Reaction | |
| +--+--+--+-+ |
| | | | |
| | | +-> trace output ? |
+------------------------|--|----------------------+
| +----> panic ?
+-------> <user-specified>
The dot2c tool presented in this paper:
DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.
Translates a deterministic automaton in the DOT format into a C
source code representation that to be used for monitoring connecting
the Formal Reaml to Linux-like code.
This header file goes beyond, extending the code generation to the
verification stage, generating the code to the Monitor Instance(s)
level using C macros. The trace event code inspires this approach.
The benefits of the usage of macro for monitor synthesis is 3-fold:
- Reduces the code duplication;
- Facilitates the bug fix/improvement;
(but mainly:)
- Avoids the case of developers changing the core of the monitor
code to manipulate the model in a (let's say) non-standard
way.
This initial implementation presents two different types of monitor
instances:
- #define DECLARE_DA_MON_PER_CPU(name, type)
- #define DECLARE_DA_MON_PER_TASK(name, type)
The first declares the functions for deterministic automata monitor
with per-cpu instances, and the second with per-task instances.
In both cases, the name is a string that identifies the monitor,
and the type is the data type used by dot2c/k on the representation
of the model.
For example, the model "wip" below:
preempt_disable sched_waking
+############+ >------------------> +################+ >------------+
-># preemptive # # non-preemptive # |
+############+ <-----------------< +################+ <------------+
preempt_enable
with two states and three events can be stored in a 'char' type.
Considering that the preemption control is a per-cpu behavior, the
monitor declaration will be:
DECLARE_DA_MON_PER_CPU(wip, char);
The monitor is executed by sending events to be processed via the
functions presented below:
da_handle_event_$(MONITOR_NAME)($(event from event enum));
da_handle_init_event_$(MONITOR_NAME)($(event from event enum));
The function da_handle_event_$(MONITOR_NAME) is the regular case,
while the function da_handle_init_event_$(MONITOR_NAME)() is a
special case used to synchronize the system with the model.
When a monitor is enabled, it is placed in the initial state of the
automata. However, the monitor does not know if the system is in
the initial state. Hence, the monitor ignores events sent by
sent by da_handle_event_$(MONITOR_NAME) until the function
da_handle_init_event_$(MONITOR_NAME)() is called.
The function da_handle_init_event_$(MONITOR_NAME)() should be used for
the case in which the system generates the event is the one that returns
the automata to the initial state.
After receiving a da_handle_init_event_$(MONITOR_NAME)() event, the
monitor will know that it is in sync with the system and hence will
start processing the next events.
Using the wip model as example, the events "preempt_disable" and
"sched_waking" should be sent to to monitor, respectively, via:
da_handle_event_wip(preempt_disable);
da_handle_event_wip(sched_waking);
While the event "preempt_enabled" will use:
da_handle_init_event_wip(preempt_enable);
To notify the monitor that the system will be returning to the initial
state, so the system and the monitor should be in sync.
With the monitor synthesis in place, using these headers and dot2k,
the developer's work should be limited to the instrumentation of
the system, increasing the confidence in the overall approach.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
include/rv/da_monitor.h | 336 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 336 insertions(+)
create mode 100644 include/rv/da_monitor.h
diff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h
new file mode 100644
index 000000000000..6ed95a898d2b
--- /dev/null
+++ b/include/rv/da_monitor.h
@@ -0,0 +1,336 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Deterministic automata (DA) monitor functions, to be used togheter
+ * with automata models in C generated by the dot2k tool.
+ *
+ * The dot2k tool is available at tools/tracing/rv/
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+#include <rv/automata.h>
+#include <rv/trace_helpers.h>
+
+struct da_monitor {
+ char curr_state;
+ bool monitoring;
+ void *model;
+};
+
+#define MAX_PID 1024000
+
+/*
+ * Generic helpers for all types of deterministic automata monitors.
+ */
+#define DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
+static char REACT_MSG[1024]; \
+ \
+static inline char \
+*format_react_msg(type curr_state, type event) \
+{ \
+ snprintf(REACT_MSG, 1024, \
+ "rv: monitor %s does not allow event %s on state %s\n", \
+ MODULE_NAME, \
+ model_get_event_name_##name(event), \
+ model_get_state_name_##name(curr_state)); \
+ return REACT_MSG; \
+} \
+ \
+static inline void da_monitor_reset_##name(struct da_monitor *da_mon) \
+{ \
+ da_mon->monitoring = 0; \
+ da_mon->curr_state = model_get_init_state_##name(); \
+} \
+ \
+static inline type da_monitor_curr_state_##name(struct da_monitor *da_mon) \
+{ \
+ return da_mon->curr_state; \
+} \
+ \
+static inline void \
+da_monitor_set_state_##name(struct da_monitor *da_mon, enum states_##name state)\
+{ \
+ da_mon->curr_state = state; \
+} \
+static inline void da_monitor_start_##name(struct da_monitor *da_mon) \
+{ \
+ da_mon->monitoring = 1; \
+} \
+ \
+static inline bool da_monitoring_##name(struct da_monitor *da_mon) \
+{ \
+ return da_mon->monitoring; \
+}
+
+
+/*
+ * Event handler for implict monitors. Implicity monitor is the one which the
+ * handler does not need to specify which da_monitor to manilupulate. Examples
+ * of implicit monitor are the per_cpu or the global ones.
+ */
+#define DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
+static inline void \
+trace_event_##name(type state, type event, type next_state, bool safe); \
+static inline void trace_error_##name(type state, type event); \
+ \
+static inline bool \
+da_event_##name(struct da_monitor *da_mon, enum events_##name event) \
+{ \
+ type curr_state = da_monitor_curr_state_##name(da_mon); \
+ type next_state = model_get_next_state_##name(curr_state, event); \
+ \
+ if (next_state >= 0) { \
+ da_monitor_set_state_##name(da_mon, next_state); \
+ \
+ trace_event_##name(curr_state, event, next_state, \
+ model_is_final_state_##name(next_state)); \
+ \
+ return true; \
+ } \
+ \
+ if (reacting_on && rv_##name.react) \
+ rv_##name.react(format_react_msg(curr_state, event)); \
+ \
+ trace_error_##name(curr_state, event); \
+ \
+ return false; \
+} \
+
+/*
+ * Event handler for per_task monitors.
+ */
+#define DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type) \
+ \
+static inline void \
+trace_event_##name(pid_t pid, type state, type event, \
+ type next_state, bool safe); \
+static inline void trace_error_##name(pid_t pid, type state, type event); \
+ \
+static inline type \
+da_event_##name(struct da_monitor *da_mon, pid_t pid, enum events_##name event) \
+{ \
+ type curr_state = da_monitor_curr_state_##name(da_mon); \
+ type next_state = model_get_next_state_##name(curr_state, event); \
+ \
+ if (next_state >= 0) { \
+ da_monitor_set_state_##name(da_mon, next_state); \
+ \
+ trace_event_##name(pid, curr_state, event, next_state, \
+ model_is_final_state_##name(next_state)); \
+ \
+ return true; \
+ } \
+ \
+ if (reacting_on && rv_##name.react) \
+ rv_##name.react(format_react_msg(curr_state, event)); \
+ \
+ trace_error_##name(pid, curr_state, event); \
+ \
+ return false; \
+}
+
+/*
+ * Functions to define, init and get a per-cpu monitor.
+ *
+ * XXX: Make it dynamic.
+ */
+#define DECLARE_DA_MON_INIT_PER_CPU(name, type) \
+ \
+DEFINE_PER_CPU(struct da_monitor, da_mon_##name); \
+ \
+struct da_monitor *da_get_monitor_##name(void) \
+{ \
+ return this_cpu_ptr(&da_mon_##name); \
+} \
+ \
+void da_monitor_reset_all_##name(void) \
+{ \
+ struct da_monitor *da_mon; \
+ int cpu; \
+ for_each_cpu(cpu, cpu_online_mask) { \
+ da_mon = per_cpu_ptr(&da_mon_##name, cpu); \
+ da_monitor_reset_##name(da_mon); \
+ } \
+} \
+ \
+static inline void da_monitor_init_##name(void) \
+{ \
+ struct da_monitor *da_mon; \
+ int cpu; \
+ for_each_cpu(cpu, cpu_online_mask) { \
+ da_mon = per_cpu_ptr(&da_mon_##name, cpu); \
+ da_mon->curr_state = model_get_init_state_##name(); \
+ da_mon->monitoring = 0; \
+ da_mon->model = model_get_model_##name(); \
+ } \
+} \
+
+
+/*
+ * Functions to define, init and get a per-task monitor.
+ *
+ * XXX: Make it dynamic? make it part of the task structure?
+ */
+#define DECLARE_DA_MON_INIT_PER_TASK(name, type) \
+ \
+struct da_monitor da_mon_##name[MAX_PID]; \
+ \
+static inline struct da_monitor *da_get_monitor_##name(pid_t pid) \
+{ \
+ return &da_mon_##name[pid]; \
+} \
+ \
+void da_monitor_reset_all_##name(void) \
+{ \
+ struct da_monitor *mon = da_mon_##name; \
+ int i; \
+ for (i = 0; i < MAX_PID; i++) \
+ da_monitor_reset_##name(&mon[i]); \
+} \
+ \
+static void da_monitor_init_##name(void) \
+{ \
+ struct da_monitor *mon = da_mon_##name; \
+ int i; \
+ \
+ for (i = 0; i < MAX_PID; i++) { \
+ mon[i].curr_state = model_get_init_state_##name(); \
+ mon[i].monitoring = 0; \
+ mon[i].model = model_get_model_##name(); \
+ } \
+} \
+
+/*
+ * Handle event for implicit monitor: da_get_monitor_##name() will figure out
+ * the monitor.
+ */
+#define DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type) \
+ \
+static inline void __da_handle_event_##name(struct da_monitor *da_mon, \
+ enum events_##name event) \
+{ \
+ int retval; \
+ \
+ if (unlikely(!monitoring_on)) \
+ return; \
+ \
+ if (unlikely(!rv_##name.enabled)) \
+ return; \
+ \
+ if (unlikely(!da_monitoring_##name(da_mon))) \
+ return; \
+ \
+ retval = da_event_##name(da_mon, event); \
+ \
+ if (!retval) \
+ da_monitor_reset_##name(da_mon); \
+} \
+ \
+static inline void da_handle_event_##name(enum events_##name event) \
+{ \
+ struct da_monitor *da_mon = da_get_monitor_##name(); \
+ __da_handle_event_##name(da_mon, event); \
+} \
+ \
+static inline bool da_handle_init_event_##name(enum events_##name event) \
+{ \
+ struct da_monitor *da_mon; \
+ \
+ if (unlikely(!rv_##name.enabled)) \
+ return false; \
+ \
+ da_mon = da_get_monitor_##name(); \
+ \
+ if (unlikely(!da_monitoring_##name(da_mon))) { \
+ da_monitor_start_##name(da_mon); \
+ return false; \
+ } \
+ \
+ __da_handle_event_##name(da_mon, event); \
+ \
+ return true; \
+}
+
+/*
+ * Handle event for per task.
+ */
+#define DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type) \
+ \
+static inline void \
+__da_handle_event_##name(struct da_monitor *da_mon, pid_t pid, \
+ enum events_##name event) \
+{ \
+ int retval; \
+ \
+ if (unlikely(!monitoring_on)) \
+ return; \
+ \
+ if (unlikely(!rv_##name.enabled)) \
+ return; \
+ \
+ if (unlikely(!da_monitoring_##name(da_mon))) \
+ return; \
+ \
+ retval = da_event_##name(da_mon, pid, event); \
+ \
+ if (!retval) \
+ da_monitor_reset_##name(da_mon); \
+} \
+ \
+static inline void \
+da_handle_event_##name(pid_t pid, enum events_##name event) \
+{ \
+ struct da_monitor *da_mon = da_get_monitor_##name(pid); \
+ __da_handle_event_##name(da_mon, pid, event); \
+} \
+ \
+static inline bool \
+da_handle_init_event_##name(pid_t pid, enum events_##name event) \
+{ \
+ struct da_monitor *da_mon; \
+ \
+ if (unlikely(!rv_##name.enabled)) \
+ return false; \
+ \
+ da_mon = da_get_monitor_##name(pid); \
+ \
+ if (unlikely(!da_monitoring_##name(da_mon))) { \
+ da_monitor_start_##name(da_mon); \
+ return false; \
+ } \
+ \
+ __da_handle_event_##name(da_mon, pid, event); \
+ \
+ return true; \
+}
+
+
+/*
+ * Entry point for the per-cpu monitor.
+ */
+#define DECLARE_DA_MON_PER_CPU(name, type) \
+ \
+DECLARE_AUTOMATA_HELPERS(name, type); \
+ \
+DECLARE_DA_MON_GENERIC_HELPERS(name, type); \
+ \
+DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type); \
+ \
+DECLARE_DA_MON_INIT_PER_CPU(name, type); \
+ \
+DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type);
+
+/*
+ * Entry point for the per-cpu monitor.
+ */
+#define DECLARE_DA_MON_PER_TASK(name, type) \
+ \
+DECLARE_AUTOMATA_HELPERS(name, type); \
+ \
+DECLARE_DA_MON_GENERIC_HELPERS(name, type); \
+ \
+DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type); \
+ \
+DECLARE_DA_MON_INIT_PER_TASK(name, type); \
+ \
+DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type);
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros
2021-05-19 11:36 ` [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros Daniel Bristot de Oliveira
@ 2021-05-19 18:27 ` Peter Zijlstra
2021-05-20 7:13 ` Daniel Bristot de Oliveira
0 siblings, 1 reply; 26+ messages in thread
From: Peter Zijlstra @ 2021-05-19 18:27 UTC (permalink / raw)
To: Daniel Bristot de Oliveira
Cc: linux-kernel, Steven Rostedt, Tommaso Cucinotta, Kate Carcia,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Will Deacon, Catalin Marinas, Paul E. McKenney,
Joel Fernandes, Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli,
Clark Williams, linux-doc
On Wed, May 19, 2021 at 01:36:25PM +0200, Daniel Bristot de Oliveira wrote:
> +struct da_monitor {
> + char curr_state;
> + bool monitoring;
> + void *model;
> +};
> +
> +#define MAX_PID 1024000
> +/*
> + * Functions to define, init and get a per-task monitor.
> + *
> + * XXX: Make it dynamic? make it part of the task structure?
Yes !
I'd start with maybe adding a list_head to da_monitor and embedding a
single copy into task_struct and link from there. Yes lists suck, but
how many monitors do you realistically expect to run concurrently?
> + */
> +#define DECLARE_DA_MON_INIT_PER_TASK(name, type) \
> + \
> +struct da_monitor da_mon_##name[MAX_PID]; \
That's ~16M of memory, which seems somewhat silly.
> + \
> +static inline struct da_monitor *da_get_monitor_##name(pid_t pid) \
> +{ \
> + return &da_mon_##name[pid]; \
> +} \
> + \
> +void da_monitor_reset_all_##name(void) \
> +{ \
> + struct da_monitor *mon = da_mon_##name; \
> + int i; \
> + for (i = 0; i < MAX_PID; i++) \
> + da_monitor_reset_##name(&mon[i]); \
> +} \
> + \
> +static void da_monitor_init_##name(void) \
> +{ \
> + struct da_monitor *mon = da_mon_##name; \
> + int i; \
> + \
> + for (i = 0; i < MAX_PID; i++) { \
> + mon[i].curr_state = model_get_init_state_##name(); \
> + mon[i].monitoring = 0; \
> + mon[i].model = model_get_model_##name(); \
> + } \
> +} \
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros
2021-05-19 18:27 ` Peter Zijlstra
@ 2021-05-20 7:13 ` Daniel Bristot de Oliveira
0 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-20 7:13 UTC (permalink / raw)
To: Peter Zijlstra
Cc: linux-kernel, Steven Rostedt, Tommaso Cucinotta, Kate Carcia,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Will Deacon, Catalin Marinas, Paul E. McKenney,
Joel Fernandes, Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli,
Clark Williams, linux-doc
On 5/19/21 8:27 PM, Peter Zijlstra wrote:
> On Wed, May 19, 2021 at 01:36:25PM +0200, Daniel Bristot de Oliveira wrote:
>
>> +struct da_monitor {
>> + char curr_state;
>> + bool monitoring;
>> + void *model;
>> +};
>> +
>> +#define MAX_PID 1024000
>
>> +/*
>> + * Functions to define, init and get a per-task monitor.
>> + *
>> + * XXX: Make it dynamic? make it part of the task structure?
>
> Yes !
>
> I'd start with maybe adding a list_head to da_monitor and embedding a
> single copy into task_struct and link from there. Yes lists suck, but
> how many monitors do you realistically expect to run concurrently?
Good to know I can use the task struct! This will make my life easier. I did it
this way because I started doing the code all "out-of-tree," as modules... but
being in kernel gives such possibilities.
I will try to implement your idea! I do not see many concurrent monitors
running, and as the list search will be linear to the number of active
monitors... it might not even justify any more complex data structure.
Thanks Peter!
-- Daniel
>> + */
>> +#define DECLARE_DA_MON_INIT_PER_TASK(name, type) \
>> + \
>> +struct da_monitor da_mon_##name[MAX_PID]; \
>
> That's ~16M of memory, which seems somewhat silly.
>
>> + \
>> +static inline struct da_monitor *da_get_monitor_##name(pid_t pid) \
>> +{ \
>> + return &da_mon_##name[pid]; \
>> +} \
>> + \
>> +void da_monitor_reset_all_##name(void) \
>> +{ \
>> + struct da_monitor *mon = da_mon_##name; \
>> + int i; \
>> + for (i = 0; i < MAX_PID; i++) \
>> + da_monitor_reset_##name(&mon[i]); \
>> +} \
>> + \
>> +static void da_monitor_init_##name(void) \
>> +{ \
>> + struct da_monitor *mon = da_mon_##name; \
>> + int i; \
>> + \
>> + for (i = 0; i < MAX_PID; i++) { \
>> + mon[i].curr_state = model_get_init_state_##name(); \
>> + mon[i].monitoring = 0; \
>> + mon[i].model = model_get_model_##name(); \
>> + } \
>> +} \
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* [RFC PATCH 05/16] rv/include: Add tracing helper functions
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (3 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 04/16] rv/include: Add deterministic automata monitor definition via C macros Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 06/16] tools/rv: Add dot2c Daniel Bristot de Oliveira
` (10 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Tracing helper functions to facilitate the instrumentation of
auto-generated RV monitors create by dot2k.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
include/rv/trace_helpers.h | 69 ++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
create mode 100644 include/rv/trace_helpers.h
diff --git a/include/rv/trace_helpers.h b/include/rv/trace_helpers.h
new file mode 100644
index 000000000000..1a8b6f246d0d
--- /dev/null
+++ b/include/rv/trace_helpers.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Helper functions to facilitate the instrumentation of auto-generated
+ * RV monitors create by dot2k.
+ *
+ * The dot2k tool is available at tools/tracing/rv/dot2/
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ */
+
+#include <linux/ftrace.h>
+
+struct tracepoint_hook_helper {
+ struct tracepoint *tp;
+ void *probe;
+ int registered;
+ char *name;
+};
+
+static inline void thh_compare_name(struct tracepoint *tp, void *priv)
+{
+ struct tracepoint_hook_helper *thh = priv;
+
+ if (!strcmp(thh->name, tp->name))
+ thh->tp = tp;
+}
+
+static inline bool thh_fill_struct_tracepoint(struct tracepoint_hook_helper *thh)
+{
+ for_each_kernel_tracepoint(thh_compare_name, thh);
+
+ return !!thh->tp;
+}
+
+static inline void thh_unhook_probes(struct tracepoint_hook_helper *thh, int helpers_count)
+{
+ int i;
+
+ for (i = 0; i < helpers_count; i++) {
+ if (!thh[i].registered)
+ continue;
+
+ tracepoint_probe_unregister(thh[i].tp, thh[i].probe, NULL);
+ }
+}
+
+static inline int thh_hook_probes(struct tracepoint_hook_helper *thh, int helpers_count)
+{
+ int retval;
+ int i;
+
+ for (i = 0; i < helpers_count; i++) {
+ retval = thh_fill_struct_tracepoint(&thh[i]);
+ if (!retval)
+ goto out_err;
+
+ retval = tracepoint_probe_register(thh[i].tp, thh[i].probe, NULL);
+
+ if (retval)
+ goto out_err;
+
+ thh[i].registered = 1;
+ }
+ return 0;
+
+out_err:
+ thh_unhook_probes(thh, helpers_count);
+ return -EINVAL;
+}
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 06/16] tools/rv: Add dot2c
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (4 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 05/16] rv/include: Add tracing helper functions Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 07/16] tools/rv: Add dot2k Daniel Bristot de Oliveira
` (9 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
dot2c is a tool that transforms an automata in the graphiviz .dot file
into an C representation of the automata.
usage: dot2c [-h] dot_file
dot2c: converts a .dot file into a C structure
positional arguments:
dot_file The dot file to be converted
optional arguments:
-h, --help show this help message and exit
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
tools/tracing/rv/dot2/Makefile | 21 +++
tools/tracing/rv/dot2/automata.py | 179 ++++++++++++++++++++++
tools/tracing/rv/dot2/dot2c | 30 ++++
tools/tracing/rv/dot2/dot2c.py | 240 ++++++++++++++++++++++++++++++
4 files changed, 470 insertions(+)
create mode 100644 tools/tracing/rv/dot2/Makefile
create mode 100644 tools/tracing/rv/dot2/automata.py
create mode 100644 tools/tracing/rv/dot2/dot2c
create mode 100644 tools/tracing/rv/dot2/dot2c.py
diff --git a/tools/tracing/rv/dot2/Makefile b/tools/tracing/rv/dot2/Makefile
new file mode 100644
index 000000000000..9dd59ec8a733
--- /dev/null
+++ b/tools/tracing/rv/dot2/Makefile
@@ -0,0 +1,21 @@
+INSTALL=install
+
+prefix ?= /usr
+bindir ?= $(prefix)/bin
+mandir ?= $(prefix)/share/man
+miscdir ?= $(prefix)/share/dot2
+srcdir ?= $(prefix)/src
+
+PYLIB ?= $(shell python3 -c 'import distutils.sysconfig; print (distutils.sysconfig.get_python_lib())')
+
+.PHONY: all
+all:
+
+.PHONY: clean
+clean:
+
+.PHONY: install
+install:
+ $(INSTALL) automata.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/automata.py
+ $(INSTALL) dot2c.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/dot2c.py
+ $(INSTALL) dot2c -D -m 755 $(DESTDIR)$(bindir)/
diff --git a/tools/tracing/rv/dot2/automata.py b/tools/tracing/rv/dot2/automata.py
new file mode 100644
index 000000000000..832f554d18c1
--- /dev/null
+++ b/tools/tracing/rv/dot2/automata.py
@@ -0,0 +1,179 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# automata object: parse a dot file into a python object
+# For more information, see:
+# https://bristot.me/efficient-formal-verification-for-the-linux-kernel/
+#
+# This program was written in the development of this paper:
+# de Oliveira, D. B. and Cucinotta, T. and de Oliveira, R. S.
+# "Efficient Formal Verification for the Linux Kernel." International
+# Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
+#
+# Copyright 2018-2020 Red Hat, Inc.
+#
+# Author:
+# Daniel Bristot de Oliveira <bristot@redhat.com>
+
+import ntpath
+
+class Automata:
+ """Automata class: Reads a dot file and part it as an automata.
+
+ Attributes:
+ dot_file: A dot file with an state_automaton definition.
+ """
+
+ def __init__(self, file_path):
+ self.__dot_path=file_path
+ self.name=self.__get_model_name()
+ self.__dot_lines = self.__open_dot()
+ self.states, self.initial_state, self.final_states = self.__get_state_variables()
+ self.events = self.__get_event_variables()
+ self.function = self.__create_matrix()
+
+ def __get_model_name(self):
+ basename=ntpath.basename(self.__dot_path)
+ if basename.endswith(".dot") == False:
+ print("not a dot file")
+ raise Exception("not a dot file: %s" % self.__dot_path)
+
+ model_name=basename[0:-4]
+ if model_name.__len__() == 0:
+ raise Exception("not a dot file: %s" % self.__dot_path)
+
+ return model_name
+
+ def __open_dot(self):
+ cursor = 0
+ dot_lines = []
+ try:
+ dot_file = open(self.__dot_path)
+ except:
+ raise Exception("Cannot open the file: %s" % self.__dot_path)
+
+ dot_lines = dot_file.read().splitlines()
+ dot_file.close()
+
+ # checking the first line:
+ line = dot_lines[cursor].split()
+
+ if (line[0] != "digraph") and (line[1] != "state_automaton"):
+ raise Exception("Not a valid .dot format: %s" % self.__dot_path)
+ else:
+ cursor = cursor + 1
+ return dot_lines
+
+ def __get_cursor_begin_states(self):
+ cursor = 0
+ while self.__dot_lines[cursor].split()[0] != "{node":
+ cursor += 1
+ return cursor
+
+ def __get_cursor_begin_events(self):
+ cursor = 0
+ while self.__dot_lines[cursor].split()[0] != "{node":
+ cursor += 1
+ while self.__dot_lines[cursor].split()[0] == "{node":
+ cursor += 1
+ # skip initial state transition
+ cursor += 1
+ return cursor
+
+ def __get_state_variables(self):
+ # wait for node declaration
+ states = []
+ final_states=[]
+
+ has_final_states = False
+ cursor = self.__get_cursor_begin_states()
+
+ # process nodes
+ while self.__dot_lines[cursor].split()[0] == "{node":
+ line = self.__dot_lines[cursor].split()
+ raw_state = line[-1]
+
+ # "enabled_fired"}; -> enabled_fired
+ state = raw_state.replace('"', '').replace('};', '').replace(',','_')
+ if state[0:7] == "__init_":
+ initial_state = state[7:]
+ else:
+ states.append(state)
+ if self.__dot_lines[cursor].__contains__("doublecircle") == True:
+ final_states.append(state)
+ has_final_states = True
+
+ if self.__dot_lines[cursor].__contains__("ellipse") == True:
+ final_states.append(state)
+ has_final_states = True
+
+ cursor = cursor + 1
+
+ states = sorted(set(states))
+ states.remove(initial_state)
+
+ # Insert the initial state at the bein og the states
+ states.insert(0, initial_state)
+
+ if has_final_states == False:
+ final_states.append(initial_state)
+
+ return states, initial_state, final_states
+
+ def __get_event_variables(self):
+ # here we are at the begin of transitions, take a note, we will return later.
+ cursor = self.__get_cursor_begin_events()
+
+ events = []
+ while self.__dot_lines[cursor][1] == '"':
+ # transitions have the format:
+ # "all_fired" -> "both_fired" [ label = "disable_irq" ];
+ # ------------ event is here ------------^^^^^
+ if self.__dot_lines[cursor].split()[1] == "->":
+ line = self.__dot_lines[cursor].split()
+ event = line[-2].replace('"','')
+
+ # when a transition has more than one lables, they are like this
+ # "local_irq_enable\nhw_local_irq_enable_n"
+ # so split them.
+
+ event = event.replace("\\n", " ")
+ for i in event.split():
+ events.append(i)
+ cursor = cursor + 1
+
+ return sorted(set(events))
+
+ def __create_matrix(self):
+ # transform the array into a dictionary
+ events = self.events
+ states = self.states
+ events_dict = {}
+ states_dict = {}
+ nr_event = 0
+ for event in events:
+ events_dict[event] = nr_event
+ nr_event += 1
+
+ nr_state = 0
+ for state in states:
+ states_dict[state] = nr_state
+ nr_state = nr_state + 1
+
+ # declare the matrix....
+ matrix = [['-1' for x in range(nr_event)] for y in range(nr_state)]
+
+ # and we are back! Let's fill the matrix
+ cursor = self.__get_cursor_begin_events()
+
+ while self.__dot_lines[cursor][1] == '"':
+ if self.__dot_lines[cursor].split()[1] == "->":
+ line = self.__dot_lines[cursor].split()
+ origin_state = line[0].replace('"','').replace(',','_')
+ dest_state = line[2].replace('"','').replace(',','_')
+ possible_events = line[-2].replace('"','').replace("\\n", " ")
+ for event in possible_events.split():
+ matrix[states_dict[origin_state]][events_dict[event]] = dest_state
+ cursor = cursor + 1
+
+ return matrix
diff --git a/tools/tracing/rv/dot2/dot2c b/tools/tracing/rv/dot2/dot2c
new file mode 100644
index 000000000000..be87e7ff2305
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2c
@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# dot2m: transform dot files into C structures.
+# For more information, see:
+# https://bristot.me/efficient-formal-verification-for-the-linux-kernel/
+#
+# This program was written in the development of this paper:
+# de Oliveira, D. B. and Cucinotta, T. and de Oliveira, R. S.
+# "Efficient Formal Verification for the Linux Kernel." International
+# Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
+#
+# Copyright 2018-2020 Red Hat, Inc.
+#
+# Author:
+# Daniel Bristot de Oliveira <bristot@redhat.com>
+
+if __name__ == '__main__':
+ from dot2 import dot2c
+ import argparse
+ import ntpath
+ import sys
+
+ parser = argparse.ArgumentParser(description='dot2c: converts a .dot file into a C structure')
+ parser.add_argument('dot_file', help='The dot file to be converted')
+
+
+ args = parser.parse_args()
+ d=dot2c.Dot2c(args.dot_file)
+ d.print_model_classic()
diff --git a/tools/tracing/rv/dot2/dot2c.py b/tools/tracing/rv/dot2/dot2c.py
new file mode 100644
index 000000000000..d8d6697d70a2
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2c.py
@@ -0,0 +1,240 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# dot2c: transform dot files into C structures.
+# For more information, see:
+# https://bristot.me/efficient-formal-verification-for-the-linux-kernel/
+#
+# This program was written in the development of this paper:
+# de Oliveira, D. B. and Cucinotta, T. and de Oliveira, R. S.
+# "Efficient Formal Verification for the Linux Kernel." International
+# Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
+#
+# Copyright 2018-2020 Red Hat, Inc.
+#
+# Author:
+# Daniel Bristot de Oliveira <bristot@redhat.com>
+
+from dot2.automata import Automata
+
+class Dot2c(Automata):
+ enum_states_def="states"
+ enum_events_def="events"
+ struct_automaton_def="automaton"
+ var_automaton_def="aut"
+
+ def __init__(self, file_path):
+ super().__init__(file_path)
+ self.line_length=80
+
+ def __buff_to_string(self, buff):
+ string=""
+
+ for line in buff:
+ string=string + line + "\n"
+
+ # cut off the last \n
+ return string[:-1]
+
+ def __get_enum_states_content(self):
+ buff=[]
+ buff.append("\t%s = 0," % self.initial_state)
+ for state in self.states:
+ if state != self.initial_state:
+ buff.append("\t%s," % state)
+ buff.append("\tstate_max")
+
+ return buff
+
+ def get_enum_states_string(self):
+ buff=self.__get_enum_states_content()
+ return self.__buff_to_string(buff)
+
+ def format_states_enum(self):
+ buff=[]
+ buff.append("enum %s {" % self.enum_states_def)
+ buff.append(self.get_enum_states_string())
+ buff.append("};\n")
+
+ return buff
+
+ def __get_enum_events_content(self):
+ buff=[]
+ first=True
+ for event in self.events:
+ if first:
+ buff.append("\t%s = 0," % event)
+ first=False
+ else:
+ buff.append("\t%s," % event)
+ buff.append("\tevent_max")
+
+ return buff
+
+ def get_enum_events_string(self):
+ buff=self.__get_enum_events_content()
+ return self.__buff_to_string(buff)
+
+ def format_events_enum(self):
+ buff=[]
+ buff.append("enum %s {" % self.enum_events_def)
+ buff.append(self.get_enum_events_string())
+ buff.append("};\n")
+
+ return buff
+
+ def get_minimun_type(self):
+ min_type="char"
+
+ if self.states.__len__() > 255:
+ min_type="short"
+
+ if self.states.__len__() > 65535:
+ min_type="int"
+
+ return min_type
+
+ def format_automaton_definition(self):
+ min_type = self.get_minimun_type()
+ buff=[]
+ buff.append("struct %s {" % self.struct_automaton_def)
+ buff.append("\tchar *state_names[state_max];")
+ buff.append("\tchar *event_names[event_max];")
+ buff.append("\t%s function[state_max][event_max];" % min_type)
+ buff.append("\t%s initial_state;" % min_type)
+ buff.append("\tchar final_states[state_max];")
+ buff.append("};\n")
+ return buff
+
+ def format_aut_init_header(self):
+ buff=[]
+ buff.append("struct %s %s = {" % (self.struct_automaton_def, self.var_automaton_def))
+ return buff
+
+ def __get_string_vector_per_line_content(self, buff):
+ first=True
+ string=""
+ for entry in buff:
+ if first:
+ string = string + "\t\t\"" + entry
+ first=False;
+ else:
+ string = string + "\",\n\t\t\"" + entry
+ string = string + "\""
+
+ return string
+
+ def get_aut_init_events_string(self):
+ return self.__get_string_vector_per_line_content(self.events)
+
+ def get_aut_init_states_string(self):
+ return self.__get_string_vector_per_line_content(self.states)
+
+ def format_aut_init_events_string(self):
+ buff=[]
+ buff.append("\t.event_names = {")
+ buff.append(self.get_aut_init_events_string())
+ buff.append("\t},")
+ return buff
+
+ def format_aut_init_states_string(self):
+ buff=[]
+ buff.append("\t.state_names = {")
+ buff.append(self.get_aut_init_states_string())
+ buff.append("\t},")
+
+ return buff
+
+ def __get_max_strlen_of_states(self):
+ return max(self.states, key=len).__len__()
+
+ def __get_state_string_length(self):
+ maxlen = self.__get_max_strlen_of_states()
+ return "%" + str(maxlen) + "s"
+
+ def get_aut_init_function(self):
+ nr_states=self.states.__len__()
+ nr_events=self.events.__len__()
+ buff=[]
+
+ strformat = self.__get_state_string_length()
+
+ for x in range(nr_states):
+ line="\t\t{ "
+ for y in range(nr_events):
+ if y != nr_events-1:
+ line = line + strformat % self.function[x][y] + ", "
+ else:
+ line = line + strformat % self.function[x][y] + " },"
+ buff.append(line)
+
+ return self.__buff_to_string(buff)
+
+ def format_aut_init_function(self):
+ buff=[]
+ buff.append("\t.function = {")
+ buff.append(self.get_aut_init_function())
+ buff.append("\t},")
+
+ return buff
+
+ def get_aut_init_initial_state(self):
+ return self.initial_state
+
+ def format_aut_init_initial_state(self):
+ buff=[]
+ initial_state=self.get_aut_init_initial_state()
+ buff.append("\t.initial_state = " + initial_state + ",")
+
+ return buff
+
+
+ def get_aut_init_final_states(self):
+ line=""
+ first=True
+ for state in self.states:
+ if first == False:
+ line = line + ', '
+ else:
+ first = False
+
+ if self.final_states.__contains__(state):
+ line = line + '1'
+ else:
+ line = line + '0'
+ return line
+
+ def format_aut_init_final_states(self):
+ buff=[]
+ buff.append("\t.final_states = { %s }," % self.get_aut_init_final_states())
+
+ return buff
+
+ def __get_automaton_initialization_footer_string(self):
+ footer="};"
+ return footer
+
+ def format_aut_init_footer(self):
+ buff=[]
+ buff.append(self.__get_automaton_initialization_footer_string())
+
+ return buff
+
+ def format_model(self):
+ buff=[]
+ buff += self.format_states_enum()
+ buff += self.format_events_enum()
+ buff += self.format_automaton_definition()
+ buff += self.format_aut_init_header()
+ buff += self.format_aut_init_states_string()
+ buff += self.format_aut_init_events_string()
+ buff += self.format_aut_init_function()
+ buff += self.format_aut_init_initial_state()
+ buff += self.format_aut_init_final_states()
+ buff += self.format_aut_init_footer()
+
+ return buff
+
+ def print_model_classic(self):
+ buff=self.format_model()
+ print(self.__buff_to_string(buff))
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 07/16] tools/rv: Add dot2k
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (5 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 06/16] tools/rv: Add dot2c Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 08/16] rv/monitors: Add the wip monitor skeleton created by dot2k Daniel Bristot de Oliveira
` (8 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
transform .dot file into kernel rv monitor
usage: dot2k [-h] -d DOT_FILE -t MONITOR_TYPE [-n MODEL_NAME] [-D DESCRIPTION]
optional arguments:
-h, --help show this help message and exit
-d DOT_FILE, --dot DOT_FILE
-t MONITOR_TYPE, --monitor_type MONITOR_TYPE
-n MODEL_NAME, --model_name MODEL_NAME
-D DESCRIPTION, --description DESCRIPTION
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
tools/tracing/rv/dot2/Makefile | 5 +
tools/tracing/rv/dot2/dot2k | 49 +++++
tools/tracing/rv/dot2/dot2k.py | 184 ++++++++++++++++++
.../rv/dot2/dot2k_templates/main_global.c | 96 +++++++++
.../rv/dot2/dot2k_templates/main_global.h | 64 ++++++
.../rv/dot2/dot2k_templates/main_per_cpu.c | 96 +++++++++
.../rv/dot2/dot2k_templates/main_per_cpu.h | 64 ++++++
.../rv/dot2/dot2k_templates/main_per_task.c | 96 +++++++++
.../rv/dot2/dot2k_templates/main_per_task.h | 70 +++++++
9 files changed, 724 insertions(+)
create mode 100644 tools/tracing/rv/dot2/dot2k
create mode 100644 tools/tracing/rv/dot2/dot2k.py
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_global.c
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_global.h
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.c
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.h
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_per_task.c
create mode 100644 tools/tracing/rv/dot2/dot2k_templates/main_per_task.h
diff --git a/tools/tracing/rv/dot2/Makefile b/tools/tracing/rv/dot2/Makefile
index 9dd59ec8a733..fcec4bf2bb11 100644
--- a/tools/tracing/rv/dot2/Makefile
+++ b/tools/tracing/rv/dot2/Makefile
@@ -19,3 +19,8 @@ install:
$(INSTALL) automata.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/automata.py
$(INSTALL) dot2c.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/dot2c.py
$(INSTALL) dot2c -D -m 755 $(DESTDIR)$(bindir)/
+ $(INSTALL) dot2k.py -D -m 644 $(DESTDIR)$(PYLIB)/dot2/dot2k.py
+ $(INSTALL) dot2k -D -m 755 $(DESTDIR)$(bindir)/
+
+ mkdir -p ${miscdir}/
+ cp -rp dot2k_templates $(DESTDIR)$(miscdir)/
diff --git a/tools/tracing/rv/dot2/dot2k b/tools/tracing/rv/dot2/dot2k
new file mode 100644
index 000000000000..5f9f7c2252f5
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k
@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# dot2k: transform dot files into a monitor for the Linux kernel.
+#
+# For more information, see:
+# https://bristot.me/efficient-formal-verification-for-the-linux-kernel/
+#
+# Copyright 2018-2020 Red Hat, Inc.
+#
+# Author:
+# Daniel Bristot de Oliveira <bristot@redhat.com>
+
+if __name__ == '__main__':
+ from dot2.dot2k import dot2k
+ import argparse
+ import ntpath
+ import os
+ import platform
+ import sys
+ import sys
+ import argparse
+
+ parser = argparse.ArgumentParser(description='transform .dot file into kernel rv monitor')
+ parser.add_argument('-d', "--dot", dest="dot_file", required=True)
+ parser.add_argument('-t', "--monitor_type", dest="monitor_type", required=True)
+ parser.add_argument('-n', "--model_name", dest="model_name", required=False)
+ parser.add_argument("-D", "--description", dest="description", required=False)
+ params = parser.parse_args()
+
+ print("Opening and parsing the dot file %s" % params.dot_file)
+ try:
+ monitor=dot2k(params.dot_file, params.monitor_type)
+ except Exception as e:
+ print('Error: '+ str(e))
+ print("Sorry : :-(")
+ sys.exit(1)
+
+ # easier than using argparse action.
+ if params.model_name != None:
+ print(params.model_name)
+
+ print("Writing the monitor into the directory %s" % monitor.name)
+ monitor.print_files()
+ print("Done, now edit the %s/%s.c to add the instrumentation" % (monitor.name, monitor.name))
+ print("Then, move the monitor folder to the KERNEL_DIR/tools/rv/monitors")
+ print("and add the following line to KERNEL_DIR/tools/rv/Makefile")
+ print(" obj-m += rv/monitors/%s/%s.o" % (monitor.name, monitor.name))
+ print("and we are done!")
diff --git a/tools/tracing/rv/dot2/dot2k.py b/tools/tracing/rv/dot2/dot2k.py
new file mode 100644
index 000000000000..022441d08885
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k.py
@@ -0,0 +1,184 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# dot2k: transform dot files into a monitor for the Linux kernel.
+#
+# For more information, see:
+# https://bristot.me/efficient-formal-verification-for-the-linux-kernel/
+#
+# Copyright 2018-2020 Red Hat, Inc.
+#
+# Author:
+# Daniel Bristot de Oliveira <bristot@redhat.com>
+
+from dot2.dot2c import Dot2c
+import platform
+import os
+
+class dot2k(Dot2c):
+ monitor_types={ "global" : 1, "per_cpu" : 2, "per_task" : 3 }
+ monitor_templates_dir="dot2k/rv_templates/"
+ monitor_type="per_cpu"
+
+ def __init__(self, file_path, MonitorType):
+ super().__init__(file_path)
+
+ self.monitor_type=self.monitor_types.get(MonitorType)
+ if self.monitor_type == None:
+ raise Exception("Unknown monitor type: %s" % MonitorType)
+
+ self.monitor_type=MonitorType
+ self.__fill_rv_templates_dir()
+ self.main_h = self.__open_file(self.monitor_templates_dir + "main_" + MonitorType + ".h")
+ self.main_c = self.__open_file(self.monitor_templates_dir + "main_" + MonitorType + ".c")
+
+ def __fill_rv_templates_dir(self):
+
+ if os.path.exists(self.monitor_templates_dir) == True:
+ return
+
+ if platform.system() != "Linux":
+ raise Exception("I can only run on Linux.")
+
+ kernel_path="/lib/modules/%s/build/tools/rv/%s" % (platform.release(), self.monitor_templates_dir)
+
+ if os.path.exists(kernel_path) == True:
+ self.monitor_templates_dir=kernel_path
+ return
+
+ if os.path.exists("/usr/share/dot2/dot2k_templates/") == True:
+ self.monitor_templates_dir="/usr/share/dot2/dot2k_templates/"
+ return
+
+ raise Exception("Could not find the template directory, do you have the kernel source installed?")
+
+
+ def __open_file(self, path):
+ try:
+ fd = open(path)
+ except OSError:
+ raise Exception("Cannot open the file: %s" % path)
+
+ content = fd.read()
+
+ return content
+
+ def __buff_to_string(self, buff):
+ string=""
+
+ for line in buff:
+ string=string + line + "\n"
+
+ # cut off the last \n
+ return string[:-1]
+
+ def fill_monitor_h(self):
+ monitor_h = self.monitor_h
+
+ min_type=self.get_minimun_type()
+
+ monitor_h = monitor_h.replace("MIN_TYPE", min_type)
+
+ return monitor_h
+
+ def fill_tracepoint_handlers_skel(self):
+ buff=[]
+ for event in self.events:
+ buff.append("void handle_%s(void *data, /* XXX: fill header */)" % event)
+ buff.append("{")
+ if self.monitor_type == "per_task":
+ buff.append("\tpid_t pid = /* XXX how do I get the pid? */;");
+ buff.append("\tda_handle_event_%s(pid, %s);" % (self.name, event));
+ else:
+ buff.append("\tda_handle_event_%s(%s);" % (self.name, event));
+ buff.append("}")
+ buff.append("")
+ return self.__buff_to_string(buff)
+
+ def fill_tracepoint_hook_helper(self):
+ buff=[]
+ for event in self.events:
+ buff.append("\t{")
+ buff.append("\t\t.probe = handle_%s," % event)
+ buff.append("\t\t.name = /* XXX: tracepoint name here */,")
+ buff.append("\t\t.registered = 0")
+ buff.append("\t},")
+ return self.__buff_to_string(buff)
+
+ def fill_main_c(self):
+ main_c = self.main_c
+ min_type=self.get_minimun_type()
+ nr_events=self.events.__len__()
+ tracepoint_handlers=self.fill_tracepoint_handlers_skel()
+ tracepoint_hook_helpers=self.fill_tracepoint_hook_helper()
+
+ main_c = main_c.replace("MIN_TYPE", min_type)
+ main_c = main_c.replace("MODEL_NAME", self.name)
+ main_c = main_c.replace("NR_EVENTS", str(nr_events))
+ main_c = main_c.replace("TRACEPOINT_HANDLERS_SKEL", tracepoint_handlers)
+ main_c = main_c.replace("TRACEPOINT_HOOK_HELPERS", tracepoint_hook_helpers)
+
+ return main_c
+
+ def fill_main_h(self):
+ main_h = self.main_h
+ main_h = main_h.replace("MIN_TYPE", self.get_minimun_type())
+ main_h = main_h.replace("MODEL_NAME_BIG", self.name.upper())
+ main_h = main_h.replace("MODEL_NAME", self.name)
+
+ return main_h
+
+ def fill_model_h(self):
+ #
+ # Adjust the definition names
+ #
+ self.enum_states_def="states_%s" % self.name
+ self.enum_events_def="events_%s" % self.name
+ self.struct_automaton_def="automaton_%s" % self.name
+ self.var_automaton_def="automaton_%s" % self.name
+
+ buff=self.format_model()
+
+ return self.__buff_to_string(buff)
+
+ def __create_directory(self):
+ try:
+ os.mkdir(self.name)
+ except FileExistsError:
+ return
+ except:
+ print("Fail creating the output dir: %s" % self.name)
+
+ def __create_file(self, file_name, content):
+ path="%s/%s" % (self.name, file_name)
+ try:
+ file = open(path, 'w')
+ except FileExistsError:
+ return
+ except:
+ print("Fail creating file: %s" % path)
+
+ file.write(content)
+
+ file.close()
+
+ def __get_main_name(self):
+ path="%s/%s" % (self.name, "main.c")
+ if os.path.exists(path) == False:
+ return "main.c"
+ return "__main.c"
+
+ def print_files(self):
+ main_h=self.fill_main_h()
+ main_c=self.fill_main_c()
+ model_h=self.fill_model_h()
+
+ self.__create_directory()
+
+ path="%s.h" % self.name
+ self.__create_file(path, main_h)
+
+ path="%s.c" % self.name
+ self.__create_file(path, main_c)
+
+ self.__create_file("model.h", model_h)
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_global.c b/tools/tracing/rv/dot2/dot2k_templates/main_global.c
new file mode 100644
index 000000000000..ef7e93368fdd
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_global.c
@@ -0,0 +1,96 @@
+#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/monitor.h>
+
+#define MODULE_NAME "MODEL_NAME"
+
+/*
+ * 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_MODEL_NAME;
+DECLARE_DA_MON_GLOBAL(MODEL_NAME, MIN_TYPE);
+
+#define CREATE_TRACE_POINTS
+#include "MODEL_NAME.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.
+ *
+ */
+
+TRACEPOINT_HANDLERS_SKEL
+#define NR_TP NR_EVENTS
+static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+TRACEPOINT_HOOK_HELPERS
+};
+
+static int start_MODEL_NAME(void)
+{
+ int retval;
+
+ da_monitor_init_MODEL_NAME();
+
+ retval = thh_hook_probes(tracepoints_to_hook, NR_TP);
+ if (retval)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ return -EINVAL;
+}
+
+static void stop_MODEL_NAME(void)
+{
+ rv_MODEL_NAME.enabled = 0;
+ thh_unhook_probes(tracepoints_to_hook, NR_TP);
+ return;
+}
+
+/*
+ * This is the monitor register section.
+ */
+struct rv_monitor rv_MODEL_NAME = {
+ .name = "MODEL_NAME",
+ .description = "auto-generated MODEL_NAME",
+ .start = start_MODEL_NAME,
+ .stop = stop_MODEL_NAME,
+ .reset = da_monitor_reset_all_MODEL_NAME,
+ .enabled = 0,
+};
+
+int register_MODEL_NAME(void)
+{
+ rv_register_monitor(&rv_MODEL_NAME);
+ return 0;
+}
+
+void unregister_MODEL_NAME(void)
+{
+ if (rv_MODEL_NAME.enabled)
+ stop_MODEL_NAME();
+
+ rv_unregister_monitor(&rv_MODEL_NAME);
+}
+
+module_init(register_MODEL_NAME);
+module_exit(unregister_MODEL_NAME);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("dot2k: auto-generated");
+MODULE_DESCRIPTION("MODEL_NAME");
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_global.h b/tools/tracing/rv/dot2/dot2k_templates/main_global.h
new file mode 100644
index 000000000000..d55cb8b83463
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_global.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rv
+
+#if !defined(_MODEL_NAME_BIG_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _MODEL_NAME_BIG_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(event_MODEL_NAME,
+
+ 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_MODEL_NAME(__entry->state),
+ model_get_event_name_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->next_state),
+ __entry->safe ? "(safe)" : "")
+);
+
+TRACE_EVENT(error_MODEL_NAME,
+
+ 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_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->state))
+);
+
+#endif /* _MODEL_NAME_BIG_H */
+
+/* This part ust be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE MODEL_NAME
+#include <trace/define_trace.h>
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.c b/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.c
new file mode 100644
index 000000000000..05f5b461623d
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.c
@@ -0,0 +1,96 @@
+#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/monitor.h>
+
+#define MODULE_NAME "MODEL_NAME"
+
+/*
+ * 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_MODEL_NAME;
+DECLARE_DA_MON_PER_CPU(MODEL_NAME, MIN_TYPE);
+
+#define CREATE_TRACE_POINTS
+#include "MODEL_NAME.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.
+ *
+ */
+
+TRACEPOINT_HANDLERS_SKEL
+#define NR_TP NR_EVENTS
+static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+TRACEPOINT_HOOK_HELPERS
+};
+
+static int start_MODEL_NAME(void)
+{
+ int retval;
+
+ da_monitor_init_MODEL_NAME();
+
+ retval = thh_hook_probes(tracepoints_to_hook, NR_TP);
+ if (retval)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ return -EINVAL;
+}
+
+static void stop_MODEL_NAME(void)
+{
+ rv_MODEL_NAME.enabled = 0;
+ thh_unhook_probes(tracepoints_to_hook, NR_TP);
+ return;
+}
+
+/*
+ * This is the monitor register section.
+ */
+struct rv_monitor rv_MODEL_NAME = {
+ .name = "MODEL_NAME",
+ .description = "auto-generated MODEL_NAME",
+ .start = start_MODEL_NAME,
+ .stop = stop_MODEL_NAME,
+ .reset = da_monitor_reset_all_MODEL_NAME,
+ .enabled = 0,
+};
+
+int register_MODEL_NAME(void)
+{
+ rv_register_monitor(&rv_MODEL_NAME);
+ return 0;
+}
+
+void unregister_MODEL_NAME(void)
+{
+ if (rv_MODEL_NAME.enabled)
+ stop_MODEL_NAME();
+
+ rv_unregister_monitor(&rv_MODEL_NAME);
+}
+
+module_init(register_MODEL_NAME);
+module_exit(unregister_MODEL_NAME);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("dot2k: auto-generated");
+MODULE_DESCRIPTION("MODEL_NAME");
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.h b/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.h
new file mode 100644
index 000000000000..d55cb8b83463
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_per_cpu.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rv
+
+#if !defined(_MODEL_NAME_BIG_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _MODEL_NAME_BIG_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(event_MODEL_NAME,
+
+ 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_MODEL_NAME(__entry->state),
+ model_get_event_name_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->next_state),
+ __entry->safe ? "(safe)" : "")
+);
+
+TRACE_EVENT(error_MODEL_NAME,
+
+ 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_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->state))
+);
+
+#endif /* _MODEL_NAME_BIG_H */
+
+/* This part ust be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE MODEL_NAME
+#include <trace/define_trace.h>
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_per_task.c b/tools/tracing/rv/dot2/dot2k_templates/main_per_task.c
new file mode 100644
index 000000000000..8ad817acfa72
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_per_task.c
@@ -0,0 +1,96 @@
+#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/monitor.h>
+
+#define MODULE_NAME "MODEL_NAME"
+
+/*
+ * 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_MODEL_NAME;
+DECLARE_DA_MON_PER_TASK(MODEL_NAME, MIN_TYPE);
+
+#define CREATE_TRACE_POINTS
+#include "MODEL_NAME.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.
+ *
+ */
+
+TRACEPOINT_HANDLERS_SKEL
+#define NR_TP NR_EVENTS
+static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+TRACEPOINT_HOOK_HELPERS
+};
+
+static int start_MODEL_NAME(void)
+{
+ int retval;
+
+ da_monitor_init_MODEL_NAME();
+
+ retval = thh_hook_probes(tracepoints_to_hook, NR_TP);
+ if (retval)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ return -EINVAL;
+}
+
+static void stop_MODEL_NAME(void)
+{
+ rv_MODEL_NAME.enabled = 0;
+ thh_unhook_probes(tracepoints_to_hook, NR_TP);
+ return;
+}
+
+/*
+ * This is the monitor register section.
+ */
+struct rv_monitor rv_MODEL_NAME = {
+ .name = "MODEL_NAME",
+ .description = "auto-generated MODEL_NAME",
+ .start = start_MODEL_NAME,
+ .stop = stop_MODEL_NAME,
+ .reset = da_monitor_reset_all_MODEL_NAME,
+ .enabled = 0,
+};
+
+int register_MODEL_NAME(void)
+{
+ rv_register_monitor(&rv_MODEL_NAME);
+ return 0;
+}
+
+void unregister_MODEL_NAME(void)
+{
+ if (rv_MODEL_NAME.enabled)
+ stop_MODEL_NAME();
+
+ rv_unregister_monitor(&rv_MODEL_NAME);
+}
+
+module_init(register_MODEL_NAME);
+module_exit(unregister_MODEL_NAME);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("dot2k: auto-generated");
+MODULE_DESCRIPTION("MODEL_NAME");
diff --git a/tools/tracing/rv/dot2/dot2k_templates/main_per_task.h b/tools/tracing/rv/dot2/dot2k_templates/main_per_task.h
new file mode 100644
index 000000000000..55fb47265344
--- /dev/null
+++ b/tools/tracing/rv/dot2/dot2k_templates/main_per_task.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rv
+
+#if !defined(_MODEL_NAME_BIG_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _MODEL_NAME_BIG_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(event_MODEL_NAME,
+
+ TP_PROTO(pid_t pid, MIN_TYPE state, MIN_TYPE event, MIN_TYPE next_state, bool safe),
+
+ TP_ARGS(pid, state, event, next_state, safe),
+
+ TP_STRUCT__entry(
+ __field( pid_t, pid )
+ __field( MIN_TYPE, state )
+ __field( MIN_TYPE, event )
+ __field( MIN_TYPE, next_state )
+ __field( bool, safe )
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ __entry->state = state;
+ __entry->event = event;
+ __entry->next_state = next_state;
+ __entry->safe = safe;
+ ),
+
+ TP_printk("%d: %s x %s -> %s %s",
+ __entry->pid,
+ model_get_state_name_MODEL_NAME(__entry->state),
+ model_get_event_name_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->next_state),
+ __entry->safe ? "(safe)" : "")
+);
+
+TRACE_EVENT(error_MODEL_NAME,
+
+ TP_PROTO(pid_t pid, MIN_TYPE state, MIN_TYPE event),
+
+ TP_ARGS(pid, state, event),
+
+ TP_STRUCT__entry(
+ __field( pid_t, pid )
+ __field( MIN_TYPE, state )
+ __field( MIN_TYPE, event )
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ __entry->state = state;
+ __entry->event = event;
+ ),
+
+ TP_printk("%d event %s not expected in the state %s",
+ __entry->pid,
+ model_get_event_name_MODEL_NAME(__entry->event),
+ model_get_state_name_MODEL_NAME(__entry->state))
+);
+
+#endif /* _MODEL_NAME_BIG_H */
+
+/* This part ust be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE MODEL_NAME
+#include <trace/define_trace.h>
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 08/16] rv/monitors: Add the wip monitor skeleton created by dot2k
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (6 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 07/16] tools/rv: Add dot2k Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
` (7 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
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@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/monitors/wip/model.h | 38 ++++++++
kernel/trace/rv/monitors/wip/wip.c | 124 +++++++++++++++++++++++++++
kernel/trace/rv/monitors/wip/wip.h | 64 ++++++++++++++
3 files changed, 226 insertions(+)
create mode 100644 kernel/trace/rv/monitors/wip/model.h
create mode 100644 kernel/trace/rv/monitors/wip/wip.c
create mode 100644 kernel/trace/rv/monitors/wip/wip.h
diff --git a/kernel/trace/rv/monitors/wip/model.h b/kernel/trace/rv/monitors/wip/model.h
new file mode 100644
index 000000000000..5212ba5b1dfb
--- /dev/null
+++ b/kernel/trace/rv/monitors/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/monitors/wip/wip.c b/kernel/trace/rv/monitors/wip/wip.c
new file mode 100644
index 000000000000..1aec75e683d2
--- /dev/null
+++ b/kernel/trace/rv/monitors/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/monitors/wip/wip.h b/kernel/trace/rv/monitors/wip/wip.h
new file mode 100644
index 000000000000..7a751a8896e9
--- /dev/null
+++ b/kernel/trace/rv/monitors/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>
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (7 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 08/16] rv/monitors: Add the wip monitor skeleton created by dot2k Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 18:14 ` Randy Dunlap
2021-05-19 11:36 ` [RFC PATCH 10/16] rv/monitors: Add the wwnr monitor skeleton created by dot2k Daniel Bristot de Oliveira
` (6 subsequent siblings)
15 siblings, 1 reply; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Adds the instrumentation to the previously created wip monitor, as an
example of the developer work. It also adds a Makefile and Kconfig
entries.
This is a good example of the manual work that is left for the
developer to do.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/Kconfig | 7 +++++++
kernel/trace/rv/Makefile | 1 +
kernel/trace/rv/monitors/wip/wip.c | 16 ++++++++--------
kernel/trace/rv/monitors/wip/wip.h | 2 +-
4 files changed, 17 insertions(+), 9 deletions(-)
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 74eb2f216255..4a1088c5ba68 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -14,6 +14,13 @@ menuconfig RV
if RV
+config RV_MON_WIP
+ depends on PREEMPTIRQ_TRACEPOINTS
+ tristate "WIP monitor"
+ help
+ Enable WIP sample monitor, this is a sample monitor that
+ illustrates the usage of per-cpu monitors.
+
config RV_REACTORS
bool "Runtime verification reactors"
default y if RV
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index 8944274d9b41..b41109d2750a 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_RV) += rv.o
obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
+obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
diff --git a/kernel/trace/rv/monitors/wip/wip.c b/kernel/trace/rv/monitors/wip/wip.c
index 1aec75e683d2..dd35a042e727 100644
--- a/kernel/trace/rv/monitors/wip/wip.c
+++ b/kernel/trace/rv/monitors/wip/wip.c
@@ -33,36 +33,36 @@ DECLARE_DA_MON_PER_CPU(wip, char);
*
*/
-void handle_preempt_disable(void *data, /* XXX: fill header */)
+void handle_preempt_disable(void *data, unsigned long ip, unsigned long parent_ip)
{
da_handle_event_wip(preempt_disable);
}
-void handle_preempt_enable(void *data, /* XXX: fill header */)
+void handle_preempt_enable(void *data, unsigned long ip, unsigned long parent_ip)
{
- da_handle_event_wip(preempt_enable);
+ da_handle_init_event_wip(preempt_enable);
}
-void handle_sched_waking(void *data, /* XXX: fill header */)
+void handle_sched_waking(void *data, struct task_struct *task)
{
da_handle_event_wip(sched_waking);
}
-#define NR_TP 3
+#define NR_TP 3
static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
{
.probe = handle_preempt_disable,
- .name = /* XXX: tracepoint name here */,
+ .name = "preempt_disable",
.registered = 0
},
{
.probe = handle_preempt_enable,
- .name = /* XXX: tracepoint name here */,
+ .name = "preempt_enable",
.registered = 0
},
{
.probe = handle_sched_waking,
- .name = /* XXX: tracepoint name here */,
+ .name = "sched_wakeup",
.registered = 0
},
};
diff --git a/kernel/trace/rv/monitors/wip/wip.h b/kernel/trace/rv/monitors/wip/wip.h
index 7a751a8896e9..f980b5e85940 100644
--- a/kernel/trace/rv/monitors/wip/wip.h
+++ b/kernel/trace/rv/monitors/wip/wip.h
@@ -59,6 +59,6 @@ TRACE_EVENT(error_wip,
/* This part ust be outside protection */
#undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_PATH ../kernel/trace/rv/monitors/wip/
#define TRACE_INCLUDE_FILE wip
#include <trace/define_trace.h>
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries
2021-05-19 11:36 ` [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
@ 2021-05-19 18:14 ` Randy Dunlap
2021-05-20 6:57 ` Daniel Bristot de Oliveira
0 siblings, 1 reply; 26+ messages in thread
From: Randy Dunlap @ 2021-05-19 18:14 UTC (permalink / raw)
To: Daniel Bristot de Oliveira, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
> index 74eb2f216255..4a1088c5ba68 100644
> --- a/kernel/trace/rv/Kconfig
> +++ b/kernel/trace/rv/Kconfig
> @@ -14,6 +14,13 @@ menuconfig RV
>
> if RV
>
> +config RV_MON_WIP
> + depends on PREEMPTIRQ_TRACEPOINTS
> + tristate "WIP monitor"
> + help
> + Enable WIP sample monitor, this is a sample monitor that
monitor. This
> + illustrates the usage of per-cpu monitors.
What does WIP mean here? I didn't see that in patch 08 (though
I could have missed it -- I did look).
--
~Randy
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries
2021-05-19 18:14 ` Randy Dunlap
@ 2021-05-20 6:57 ` Daniel Bristot de Oliveira
0 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-20 6:57 UTC (permalink / raw)
To: Randy Dunlap, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 8:14 PM, Randy Dunlap wrote:
> On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
>> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
>> index 74eb2f216255..4a1088c5ba68 100644
>> --- a/kernel/trace/rv/Kconfig
>> +++ b/kernel/trace/rv/Kconfig
>> @@ -14,6 +14,13 @@ menuconfig RV
>>
>> if RV
>>
>> +config RV_MON_WIP
>> + depends on PREEMPTIRQ_TRACEPOINTS
>> + tristate "WIP monitor"
>> + help
>> + Enable WIP sample monitor, this is a sample monitor that
>
> monitor. This
>
>> + illustrates the usage of per-cpu monitors.
>
> What does WIP mean here? I didn't see that in patch 08 (though
> I could have missed it -- I did look).
>
>
WIP means "Wakeup In Preemptive." I will add the long name to the first
occurrence in patch 08, and to the Kconfig.
Thanks!
-- Daniel
^ permalink raw reply [flat|nested] 26+ messages in thread
* [RFC PATCH 10/16] rv/monitors: Add the wwnr monitor skeleton created by dot2k
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (8 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 09/16] rv/monitors: wip instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
` (5 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Per task wakeup while not running (wwnr) monitor, generated by dot2k
with this command line:
$ dot2k -d wwnr.dot -t per_task
The model is:
----- %< -----
digraph state_automaton {
center = true;
size = "7,11";
{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";
}
}
----- >% -----
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: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/monitors/wwnr/model.h | 38 ++++++++
kernel/trace/rv/monitors/wwnr/wwnr.c | 127 ++++++++++++++++++++++++++
kernel/trace/rv/monitors/wwnr/wwnr.h | 70 ++++++++++++++
3 files changed, 235 insertions(+)
create mode 100644 kernel/trace/rv/monitors/wwnr/model.h
create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.c
create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.h
diff --git a/kernel/trace/rv/monitors/wwnr/model.h b/kernel/trace/rv/monitors/wwnr/model.h
new file mode 100644
index 000000000000..7840ffbda98d
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/model.h
@@ -0,0 +1,38 @@
+enum states_wwnr {
+ not_running = 0,
+ running,
+ state_max
+};
+
+enum events_wwnr {
+ switch_in = 0,
+ switch_out,
+ wakeup,
+ event_max
+};
+
+struct automaton_wwnr {
+ 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_wwnr automaton_wwnr = {
+ .state_names = {
+ "not_running",
+ "running"
+ },
+ .event_names = {
+ "switch_in",
+ "switch_out",
+ "wakeup"
+ },
+ .function = {
+ { running, -1, not_running },
+ { -1, not_running, -1 },
+ },
+ .initial_state = not_running,
+ .final_states = { 1, 0 },
+};
\ No newline at end of file
diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.c b/kernel/trace/rv/monitors/wwnr/wwnr.c
new file mode 100644
index 000000000000..91cb3b70a6a7
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.c
@@ -0,0 +1,127 @@
+#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 "wwnr"
+
+/*
+ * 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_wwnr;
+DECLARE_DA_MON_PER_TASK(wwnr, char);
+
+#define CREATE_TRACE_POINTS
+#include "wwnr.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_switch_in(void *data, /* XXX: fill header */)
+{
+ pid_t pid = /* XXX how do I get the pid? */;
+ da_handle_event_wwnr(pid, switch_in);
+}
+
+void handle_switch_out(void *data, /* XXX: fill header */)
+{
+ pid_t pid = /* XXX how do I get the pid? */;
+ da_handle_event_wwnr(pid, switch_out);
+}
+
+void handle_wakeup(void *data, /* XXX: fill header */)
+{
+ pid_t pid = /* XXX how do I get the pid? */;
+ da_handle_event_wwnr(pid, wakeup);
+}
+
+#define NR_TP 3
+static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+ {
+ .probe = handle_switch_in,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+ {
+ .probe = handle_switch_out,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+ {
+ .probe = handle_wakeup,
+ .name = /* XXX: tracepoint name here */,
+ .registered = 0
+ },
+};
+
+static int start_wwnr(void)
+{
+ int retval;
+
+ da_monitor_init_wwnr();
+
+ retval = thh_hook_probes(tracepoints_to_hook, NR_TP);
+ if (retval)
+ goto out_err;
+
+ return 0;
+
+out_err:
+ return -EINVAL;
+}
+
+static void stop_wwnr(void)
+{
+ rv_wwnr.enabled = 0;
+ thh_unhook_probes(tracepoints_to_hook, NR_TP);
+ return;
+}
+
+/*
+ * This is the monitor register section.
+ */
+struct rv_monitor rv_wwnr = {
+ .name = "wwnr",
+ .description = "auto-generated wwnr",
+ .start = start_wwnr,
+ .stop = stop_wwnr,
+ .reset = da_monitor_reset_all_wwnr,
+ .enabled = 0,
+};
+
+int register_wwnr(void)
+{
+ rv_register_monitor(&rv_wwnr);
+ return 0;
+}
+
+void unregister_wwnr(void)
+{
+ if (rv_wwnr.enabled)
+ stop_wwnr();
+
+ rv_unregister_monitor(&rv_wwnr);
+}
+
+module_init(register_wwnr);
+module_exit(unregister_wwnr);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("dot2k: auto-generated");
+MODULE_DESCRIPTION("wwnr");
diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.h b/kernel/trace/rv/monitors/wwnr/wwnr.h
new file mode 100644
index 000000000000..4af1827d2f16
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rv
+
+#if !defined(_WWNR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _WWNR_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(event_wwnr,
+
+ TP_PROTO(pid_t pid, char state, char event, char next_state, bool safe),
+
+ TP_ARGS(pid, state, event, next_state, safe),
+
+ TP_STRUCT__entry(
+ __field( pid_t, pid )
+ __field( char, state )
+ __field( char, event )
+ __field( char, next_state )
+ __field( bool, safe )
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ __entry->state = state;
+ __entry->event = event;
+ __entry->next_state = next_state;
+ __entry->safe = safe;
+ ),
+
+ TP_printk("%d: %s x %s -> %s %s",
+ __entry->pid,
+ model_get_state_name_wwnr(__entry->state),
+ model_get_event_name_wwnr(__entry->event),
+ model_get_state_name_wwnr(__entry->next_state),
+ __entry->safe ? "(safe)" : "")
+);
+
+TRACE_EVENT(error_wwnr,
+
+ TP_PROTO(pid_t pid, char state, char event),
+
+ TP_ARGS(pid, state, event),
+
+ TP_STRUCT__entry(
+ __field( pid_t, pid )
+ __field( char, state )
+ __field( char, event )
+ ),
+
+ TP_fast_assign(
+ __entry->pid = pid;
+ __entry->state = state;
+ __entry->event = event;
+ ),
+
+ TP_printk("%d event %s not expected in the state %s",
+ __entry->pid,
+ model_get_event_name_wwnr(__entry->event),
+ model_get_state_name_wwnr(__entry->state))
+);
+
+#endif /* _WWNR_H */
+
+/* This part ust be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE wwnr
+#include <trace/define_trace.h>
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (9 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 10/16] rv/monitors: Add the wwnr monitor skeleton created by dot2k Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 18:16 ` Randy Dunlap
2021-05-19 11:36 ` [RFC PATCH 12/16] rv/reactors: Add the printk reactor Daniel Bristot de Oliveira
` (4 subsequent siblings)
15 siblings, 1 reply; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Adds the instrumentation to the previously created wwnr monitor, as an
example of the developer work. It also adds a Makefile and Kconfig
entries.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/Kconfig | 7 ++++++
kernel/trace/rv/Makefile | 1 +
kernel/trace/rv/monitors/wwnr/wwnr.c | 35 ++++++++++++----------------
kernel/trace/rv/monitors/wwnr/wwnr.h | 2 +-
4 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 4a1088c5ba68..612b36b97663 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -21,6 +21,13 @@ config RV_MON_WIP
Enable WIP sample monitor, this is a sample monitor that
illustrates the usage of per-cpu monitors.
+config RV_MON_WWNR
+ tristate "WWNR monitor"
+ help
+ Enable WWNR sample monitor, this is a sample monitor that
+ illustrates the usage of per-task monitor. The model is
+ broken on purpose: it serves to test reactors.
+
config RV_REACTORS
bool "Runtime verification reactors"
default y if RV
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
index 91cb3b70a6a7..cb364a02639b 100644
--- a/kernel/trace/rv/monitors/wwnr/wwnr.c
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.c
@@ -33,39 +33,34 @@ DECLARE_DA_MON_PER_TASK(wwnr, char);
*
*/
-void handle_switch_in(void *data, /* XXX: fill header */)
+static void handle_switch(void *data, bool preempt, struct task_struct *p, struct task_struct *n)
{
- pid_t pid = /* XXX how do I get the pid? */;
- da_handle_event_wwnr(pid, switch_in);
-}
+ int ppid = p->pid;
+ int npid = n->pid;
-void handle_switch_out(void *data, /* XXX: fill header */)
-{
- pid_t pid = /* XXX how do I get the pid? */;
- da_handle_event_wwnr(pid, switch_out);
+ if (ppid && ppid < MAX_PID)
+ da_handle_init_event_wwnr(ppid, switch_out);
+
+ if (npid && npid < MAX_PID)
+ da_handle_event_wwnr(npid, switch_in);
}
-void handle_wakeup(void *data, /* XXX: fill header */)
+static void handle_wakeup(void *data, struct task_struct *p)
{
- pid_t pid = /* XXX how do I get the pid? */;
- da_handle_event_wwnr(pid, wakeup);
+ if (p->pid && p->pid < MAX_PID)
+ da_handle_event_wwnr(p->pid, wakeup);
}
-#define NR_TP 3
+#define NR_TP 2
static struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
{
- .probe = handle_switch_in,
- .name = /* XXX: tracepoint name here */,
- .registered = 0
- },
- {
- .probe = handle_switch_out,
- .name = /* XXX: tracepoint name here */,
+ .probe = handle_switch,
+ .name = "sched_switch",
.registered = 0
},
{
.probe = handle_wakeup,
- .name = /* XXX: tracepoint name here */,
+ .name = "sched_wakeup",
.registered = 0
},
};
diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.h b/kernel/trace/rv/monitors/wwnr/wwnr.h
index 4af1827d2f16..ed817952821e 100644
--- a/kernel/trace/rv/monitors/wwnr/wwnr.h
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.h
@@ -65,6 +65,6 @@ TRACE_EVENT(error_wwnr,
/* This part ust be outside protection */
#undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_PATH ../kernel/trace/rv/monitors/wwnr/
#define TRACE_INCLUDE_FILE wwnr
#include <trace/define_trace.h>
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* Re: [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries
2021-05-19 11:36 ` [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
@ 2021-05-19 18:16 ` Randy Dunlap
2021-05-20 6:59 ` Daniel Bristot de Oliveira
0 siblings, 1 reply; 26+ messages in thread
From: Randy Dunlap @ 2021-05-19 18:16 UTC (permalink / raw)
To: Daniel Bristot de Oliveira, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
> index 4a1088c5ba68..612b36b97663 100644
> --- a/kernel/trace/rv/Kconfig
> +++ b/kernel/trace/rv/Kconfig
> @@ -21,6 +21,13 @@ config RV_MON_WIP
> Enable WIP sample monitor, this is a sample monitor that
> illustrates the usage of per-cpu monitors.
>
> +config RV_MON_WWNR
> + tristate "WWNR monitor"
> + help
> + Enable WWNR sample monitor, this is a sample monitor that
monitor. This is
> + illustrates the usage of per-task monitor. The model is
> + broken on purpose: it serves to test reactors.
and please tell the user what WWNR means, either in the prompt
or in the help text.
--
~Randy
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries
2021-05-19 18:16 ` Randy Dunlap
@ 2021-05-20 6:59 ` Daniel Bristot de Oliveira
0 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-20 6:59 UTC (permalink / raw)
To: Randy Dunlap, linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Jonathan Corbet, Ingo Molnar,
Mauro Carvalho Chehab, Thomas Gleixner, Peter Zijlstra,
Will Deacon, Catalin Marinas, Paul E. McKenney, Joel Fernandes,
Mathieu Desnoyers, Gabriele Paoloni, Juri Lelli, Clark Williams,
linux-doc
On 5/19/21 8:16 PM, Randy Dunlap wrote:
> On 5/19/21 4:36 AM, Daniel Bristot de Oliveira wrote:
>> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
>> index 4a1088c5ba68..612b36b97663 100644
>> --- a/kernel/trace/rv/Kconfig
>> +++ b/kernel/trace/rv/Kconfig
>> @@ -21,6 +21,13 @@ config RV_MON_WIP
>> Enable WIP sample monitor, this is a sample monitor that
>> illustrates the usage of per-cpu monitors.
>>
>> +config RV_MON_WWNR
>> + tristate "WWNR monitor"
>> + help
>> + Enable WWNR sample monitor, this is a sample monitor that
>
> monitor. This is
>
>> + illustrates the usage of per-task monitor. The model is
>> + broken on purpose: it serves to test reactors.
>
> and please tell the user what WWNR means, either in the prompt
> or in the help text.
>
yeah, I will do so.
(WWNR stands for "Wakeup while not running")
Thanks!
-- Daniel
^ permalink raw reply [flat|nested] 26+ messages in thread
* [RFC PATCH 12/16] rv/reactors: Add the printk reactor
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (10 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 11/16] rv/monitors: wwnr instrumentation and Makefile/Kconfig entries Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 13/16] rv/reactors: Add the panic reactor Daniel Bristot de Oliveira
` (3 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Sample reactor that printks the reaction message.
Note: do not use this reactor with rq_lock taken, it will lock the
system until printk can handle that.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/Kconfig | 8 ++++++
kernel/trace/rv/Makefile | 3 ++-
kernel/trace/rv/reactors/printk.c | 43 +++++++++++++++++++++++++++++++
3 files changed, 53 insertions(+), 1 deletion(-)
create mode 100644 kernel/trace/rv/reactors/printk.c
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 612b36b97663..6cbfb0f9cf76 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -38,4 +38,12 @@ config RV_REACTORS
tracing reactions, printing the monitor output via tracepoints,
but other reactions can be added (on-demand) via this interface.
+config RV_REACT_PRINTK
+ tristate "Printk reactor"
+ depends on RV_REACTORS
+ default y if RV_REACTORS
+ help
+ Enables the printk reactor. The printk reactor emmits a printk()
+ message if an exception is found.
+
endif # RV
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index af0ff9a46418..a57cb3c3d410 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
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
+obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
+obj-$(CONFIG_RV_REACT_PRINTK) += reactors/printk.o
diff --git a/kernel/trace/rv/reactors/printk.c b/kernel/trace/rv/reactors/printk.c
new file mode 100644
index 000000000000..f929eead6000
--- /dev/null
+++ b/kernel/trace/rv/reactors/printk.c
@@ -0,0 +1,43 @@
+/*
+ * Printk RV reactor:
+ * Prints the exception msg to the kernel message log.
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ *
+ * 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>
+
+static void rv_printk_reaction(char *msg)
+{
+ printk(msg);
+}
+
+struct rv_reactor rv_printk = {
+ .name = "printk",
+ .description = "prints the exception msg to the kernel message log",
+ .react = rv_printk_reaction
+};
+
+int register_react_printk(void)
+{
+ rv_register_reactor(&rv_printk);
+ return 0;
+}
+
+void unregister_react_printk(void)
+{
+ rv_unregister_reactor(&rv_printk);
+}
+
+module_init(register_react_printk);
+module_exit(unregister_react_printk);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Daniel Bristot de Oliveira");
+MODULE_DESCRIPTION("printk rv reactor: printk if an exception is hit");
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 13/16] rv/reactors: Add the panic reactor
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (11 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 12/16] rv/reactors: Add the printk reactor Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 14/16] rv/docs: Add a basic documentation Daniel Bristot de Oliveira
` (2 subsequent siblings)
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Sample reactor that panics the system when an exception is found. This
is useful both to capture a vmcore, or to fail-safe a critical system.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
kernel/trace/rv/Kconfig | 8 ++++++
kernel/trace/rv/Makefile | 1 +
kernel/trace/rv/reactors/panic.c | 44 ++++++++++++++++++++++++++++++++
3 files changed, 53 insertions(+)
create mode 100644 kernel/trace/rv/reactors/panic.c
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 6cbfb0f9cf76..32de3e7702ec 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -46,4 +46,12 @@ config RV_REACT_PRINTK
Enables the printk reactor. The printk reactor emmits a printk()
message if an exception is found.
+config RV_REACT_PANIC
+ tristate "Panic reactor"
+ depends on RV_REACTORS
+ default y if RV_REACTORS
+ help
+ Enables the panic reactor. The panic reactor emmits a printk()
+ message if an exception is found and panic()s the system.
+
endif # RV
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index a57cb3c3d410..995f199d0348 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o
obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
obj-$(CONFIG_RV_REACT_PRINTK) += reactors/printk.o
+obj-$(CONFIG_RV_REACT_PANIC) += reactors/panic.o
diff --git a/kernel/trace/rv/reactors/panic.c b/kernel/trace/rv/reactors/panic.c
new file mode 100644
index 000000000000..2605d77f8802
--- /dev/null
+++ b/kernel/trace/rv/reactors/panic.c
@@ -0,0 +1,44 @@
+/*
+ * Panic RV reactor:
+ * Prints the exception msg to the kernel message log and panic().
+ *
+ * Copyright (C) 2019-2021 Daniel Bristot de Oliveira <bristot@redhat.com>
+ *
+ * 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>
+
+static void rv_panic_reaction(char *msg)
+{
+ panic(msg);
+}
+
+struct rv_reactor rv_panic = {
+ .name = "panic",
+ .description = "panic the system if an exception is found.",
+ .react = rv_panic_reaction
+};
+
+int register_react_panic(void)
+{
+ rv_register_reactor(&rv_panic);
+ return 0;
+}
+
+void unregister_react_panic(void)
+{
+ rv_unregister_reactor(&rv_panic);
+}
+
+module_init(register_react_panic);
+module_exit(unregister_react_panic);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Daniel Bristot de Oliveira");
+MODULE_DESCRIPTION("panic rv reactor: panic if an exception is found");
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 14/16] rv/docs: Add a basic documentation
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (12 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 13/16] rv/reactors: Add the panic reactor Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 15/16] rv/docs: Add deterministic automata monitor synthesis documentation Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 16/16] rv/docs: Add deterministic automata instrumentation documentation Daniel Bristot de Oliveira
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Add the runtime-verification.rst document, explaining the basics of RV
and how to use the interface.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
Documentation/trace/index.rst | 1 +
Documentation/trace/rv/index.rst | 9 +
.../trace/rv/runtime-verification.rst | 233 ++++++++++++++++++
kernel/trace/rv/Kconfig | 3 +
4 files changed, 246 insertions(+)
create mode 100644 Documentation/trace/rv/index.rst
create mode 100644 Documentation/trace/rv/runtime-verification.rst
diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst
index f634b36fd3aa..fd3d26a6c6b8 100644
--- a/Documentation/trace/index.rst
+++ b/Documentation/trace/index.rst
@@ -28,3 +28,4 @@ Linux Tracing Technologies
stm
sys-t
coresight/index
+ rv/index
diff --git a/Documentation/trace/rv/index.rst b/Documentation/trace/rv/index.rst
new file mode 100644
index 000000000000..92338dceffab
--- /dev/null
+++ b/Documentation/trace/rv/index.rst
@@ -0,0 +1,9 @@
+===================================
+RV - Runtime Verification Interface
+===================================
+
+.. toctree::
+ :maxdepth: 2
+ :glob:
+
+ *
diff --git a/Documentation/trace/rv/runtime-verification.rst b/Documentation/trace/rv/runtime-verification.rst
new file mode 100644
index 000000000000..5ee22c866183
--- /dev/null
+++ b/Documentation/trace/rv/runtime-verification.rst
@@ -0,0 +1,233 @@
+====================
+Runtime Verification
+====================
+
+Runtime Verification (RV) is a lightweight (yet rigorous) method that
+complements classical exhaustive verification techniques (such as *model
+checking* and *theorem proving*) with a more practical approach for complex
+systems.
+
+
+Instead of relying on a fine-grained model of a system (e.g., a
+re-implementation a instruction level), RV works by analyzing the trace of the
+system's actual execution, comparing it against a formal specification of
+the system behavior.
+
+The main advantage is that RV can give precise information on the runtime
+behavior of the monitored system, without the pitfalls of developing models
+that require a re-implementation of the entire system in a modeling language.
+Moreover, given an efficient monitoring method, it is possible execute an
+*online* verification of a system, enabling the *reaction* for unexpected
+events, avoiding, for example, the propagation of a failure on safety-critical
+systems.
+
+Runtime Monitors and Reactors
+=============================
+
+A monitor is the central part of the runtime verification of a system. The
+monitor stands in between the formal specification of the desired (or
+undesired) behavior, and the trace of the actual system system.
+
+In Linux terms, the runtime verification monitors are encapsulated inside the
+*RV monitor* abstraction. A *RV monitor* includes a reference model of the
+system, a set of instances of the monitor (per-cpu monitor, per-task monitor,
+and so on), and the helper functions that glue the monitor to the system via
+trace, as depicted bellow::
+
+ Linux +---- RV Monitor ----------------------------------+ Formal
+ Realm | | Realm
+ +-------------------+ +----------------+ +-----------------+
+ | Linux kernel | | Monitor | | Reference |
+ | Tracing | -> | Instance(s) | <- | Model |
+ | (instrumentation) | | (verification) | | (specification) |
+ +-------------------+ +----------------+ +-----------------+
+ | | |
+ | V |
+ | +----------+ |
+ | | Reaction | |
+ | +--+--+--+-+ |
+ | | | | |
+ | | | +-> trace output ? |
+ +------------------------|--|----------------------+
+ | +----> panic ?
+ +-------> <user-specified>
+
+In addition to the verification and monitoring of the system, a monitor can
+react to an unexpected event. The forms of reaction can vary from logging the
+event occurrence to the enforcement of the correct behavior to the extreme
+action of taking a system down to avoid the propagation of a failure.
+
+In Linux terms, a *reactor* is an reaction method available for *RV monitors*.
+By default, all monitors should provide a trace output of their actions,
+which is already a reaction. In addition, other reactions will be available
+so the user can enable them as needed.
+
+For further information about the principles of runtime verification and
+RV applied to Linux:
+
+ BARTOCCI, Ezio, et al. *Introduction to runtime verification.* In: Lectures on
+ Runtime Verification. Springer, Cham, 2018. p. 1-33.
+
+ FALCONE, Yliès, et al. *A taxonomy for classifying runtime verification tools.*
+ In: International Conference on Runtime Verification. Springer, Cham, 2018. p.
+ 241-262.
+
+ DE OLIVEIRA, Daniel Bristot, et al. *Automata-based formal analysis and
+ verification of the real-time Linux kernel.* Ph.D. Thesis, 2020.
+
+Online RV monitors
+==================
+
+Monitors can be classified as *offline* and *online* monitors. *Offline*
+monitor process the traces generated by a system after the events, generally by
+reading the trace execution from a permanent storage system. *Online* monitors
+process the trace during the execution of the system. Online monitors are said
+to be *synchronous* if the processing of an event is attached to the system
+execution, blocking the system during the event monitoring. On the other hand,
+an *asynchronous* monitor has its execution detached from the system. Each type
+of monitor has a set of advantages. For example, *offline* monitors can be
+executed on different machines but require operations to save the log to a
+file. In contrast, *synchronous online* method can react at the exact moment
+a violation occurs.
+
+Another important aspect regarding monitors is the overhead associated with the
+event analysis. If the system generates events at a frequency higher than the
+monitor's ability to process them in the same system, only the *offline*
+methods are viable. On the other hand, if the tracing of the events incurs
+on higher overhead than the simple handling of an event by a monitor, then a
+*synchronous online* monitors will incur on lower overhead.
+
+Indeed, the research presented in:
+
+ DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Rômulo Silva.
+ *Efficient formal verification for the Linux kernel.* In: International
+ Conference on Software Engineering and Formal Methods. Springer, Cham, 2019.
+ p. 315-332.
+
+Shows that for Deterministic Automata models, the synchronous processing of
+events in-kernel causes lower overhead than saving the same events to the trace
+buffer, not even considering collecting the trace for user-space analysis.
+This motivated the development of an in-kernel interface for online monitors.
+
+For further information about modeling of Linux kernel behavior using automata,
+please read:
+
+ DE OLIVEIRA, Daniel B.; DE OLIVEIRA, Rômulo S.; CUCINOTTA, Tommaso. *A thread
+ synchronization model for the PREEMPT_RT Linux kernel.* Journal of Systems
+ Architecture, 2020, 107: 101729.
+
+The user interface
+==================
+
+The user interface resembles the tracing interface (on purpose). It is
+currently at "/sys/kernel/tracing/rv/".
+
+The following files/folders are currently available:
+
+**available_monitors**
+
+- Reading list the available monitors, one per line
+
+For example::
+
+ [root@f32 rv]# cat available_monitors
+ wip
+ wwnr
+
+**available_reactors**
+
+- Reading shows the available reactors, one per line.
+
+For example::
+
+ [root@f32 rv]# cat available_reactors
+ nop
+ panic
+ printk
+
+**enabled_monitors**:
+
+- Reading lists the enabled monitors, one per line
+- Writing to it enables a given monitor
+- Writing a monitor name with a '-' prefix disables it
+- Truncating the file disables all enabled monitors
+
+For example::
+
+ [root@f32 rv]# cat enabled_monitors
+ [root@f32 rv]# echo wip > enabled_monitors
+ [root@f32 rv]# echo wwnr >> enabled_monitors
+ [root@f32 rv]# cat enabled_monitors
+ wip
+ wwnr
+ [root@f32 rv]# echo -wip >> enabled_monitors
+ [root@f32 rv]# cat enabled_monitors
+ wwnr
+ [root@f32 rv]# echo > enabled_monitors
+ [root@f32 rv]# cat enabled_monitors
+ [root@f32 rv]#
+
+Note that it is possible to enable more than one monitor concurrently.
+
+
+**monitoring_on**
+
+This is an on/off general switcher for monitoring. It resembles the
+"tracing_on" switcher in the trace interface.
+
+- Writing "0" stops the monitoring
+- Writing "1" continues the monitoring
+- Reading returns the current status of the monitoring
+
+Note that it does not disable enabled monitors but stop the per-entity
+monitors monitoring the events received from the system.
+
+**reacting_on**
+
+- Writing "0" prevents reactions for happening
+- Writing "1" enable reactions
+- Reading returns the current status of the monitoring
+
+**monitors/**
+
+Each monitor will have its own directory inside "monitors/". There the
+monitor-specific files will be presented. The "monitors/" directory resembles
+the "events" directory on tracefs.
+
+For example::
+
+ [root@f32 rv]# cd monitors/wip/
+ [root@f32 wip]# ls
+ desc enable
+ [root@f32 wip]# cat desc
+ auto-generated wakeup in preemptive monitor.
+ [root@f32 wip]# cat enable
+ 0
+
+**monitors/$MONITOR/desc**
+
+- Reading shows a description of the monitor *$MONITOR*
+
+**monitors/$MONITOR/enable**
+
+- Writing "0" disables the *$MONITOR*
+- Writing "1" enables the *$MONITOR*
+- Reading return the current status of the *$MONITOR*
+
+**monitors/$MONITOR/reactors**
+
+- List available reactors, with the select reaction for the given *MONITOR*
+ inside "[]". The default one is the nop (no operation) reactor.
+- Writing the name of a reactor enables it to the given MONITOR.
+
+For example::
+
+ [root@f32 rv]# cat monitors/wip/reactors
+ [nop]
+ panic
+ printk
+ [root@f32 rv]# echo panic > monitors/wip/reactors
+ [root@f32 rv]# cat monitors/wip/reactors
+ nop
+ [panic]
+ printk
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 32de3e7702ec..41132a1d481c 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -12,6 +12,9 @@ menuconfig RV
actual execution, comparing it against a formal specification of
the system behavior.
+ For further information, see:
+ Documentation/trace/rv/runtime-verification.rst
+
if RV
config RV_MON_WIP
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 15/16] rv/docs: Add deterministic automata monitor synthesis documentation
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (13 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 14/16] rv/docs: Add a basic documentation Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
2021-05-19 11:36 ` [RFC PATCH 16/16] rv/docs: Add deterministic automata instrumentation documentation Daniel Bristot de Oliveira
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Add the da_monitor_synthesis.rst introduces some concepts behind the
Deterministic Automata (DA) monitor synthesis and interface.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
.../trace/rv/da_monitor_synthesis.rst | 286 ++++++++++++++++++
1 file changed, 286 insertions(+)
create mode 100644 Documentation/trace/rv/da_monitor_synthesis.rst
diff --git a/Documentation/trace/rv/da_monitor_synthesis.rst b/Documentation/trace/rv/da_monitor_synthesis.rst
new file mode 100644
index 000000000000..697eb5a45910
--- /dev/null
+++ b/Documentation/trace/rv/da_monitor_synthesis.rst
@@ -0,0 +1,286 @@
+Deterministic Automata Monitor Synthesis
+========================================
+
+The starting point for the application of runtime verification (RV) technics is
+the *specification* or *modeling* of the desired (or undesired) behavior of the
+system under scrutiny.
+
+The formal representation needs to be then *synthesized* into a *monitor* that
+can then be used in the analysis of the trace of the system. The *monitor*
+conects to the system via an *instrumentation* layer, that converts the events
+from the *system* to the events of the *specification*.
+
+This document introduces some concepts behind the **Deterministic Automata
+(DA)** monitor synthesis.
+
+DA monitor synthesis in a nutshell
+------------------------------------------------------
+
+The synthesis of automata-based models into the Linux *RV monitor* abstraction
+is automatized by a tool named "dot2k", and the "rv/da_monitor.h" provided
+by the RV interface.
+
+Given a file "wip.dot", representing a per-cpu monitor, with this content::
+
+ 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";
+ }
+ }
+
+Run the dot2k tool with the model, specifying that it is a "per-cpu"
+model::
+
+ $ dot2k -d ~/wip.dot -t per_cpu
+
+This will create a directory named "wip/" with the following files:
+
+- model.h: the wip in C
+- wip.h: tracepoints that report the execution of the events by the
+ monitor
+- wip.c: the RV monitor
+
+The following line in the "wip.c" file is responsible for the monitor
+synthesis::
+
+ DECLARE_DA_MON_PER_CPU(wip, char);
+
+With that in place, the work left to be done is the *instrumentation* of
+the monitor, which is already initialized by dot2k.
+
+DA: Introduction and representation formats
+---------------------------------------------------------------
+
+Formally, a deterministic automaton, denoted by G, is defined as a quintuple:
+
+ *G* = { *X*, *E*, *f*, x\ :subscript:`0`, X\ :subscript:`m` }
+
+where:
+
+- *X* is the set of states;
+- *E* is the finite set of events;
+- x\ :subscript:`0` is the initial state;
+- X\ :subscript:`m` (subset of *X*) is the set of marked states.
+- *f* : *X* x *E* -> *X* $ is the transition function. It defines the state
+ transition in the occurrence of an event from *E* in the state *X*. In the
+ special case of deterministic automata, the occurrence of the event in *E*
+ in a state in *X* has a deterministic next state from *X*.
+
+One of the most evident benefits for the practical application of the automata
+formalism is its *graphic representation*, represented using vertices (nodes)
+and edges, which is very intuitive for *operating system* practitioners.
+
+For example, given an automata wip, with a regular representation of:
+
+- *X* = { ``preemptive``, ``non_preemptive``}
+- *E* = { ``preempt_enable``, ``preempt_disable``, ``sched_waking``}
+- x\ :subscript:`0` = ``preemptive``
+- X\ :subscript:`m` = {``preemptive``}
+- *f* =
+ - *f*\ (``preemptive``, ``preempt_disable``) = ``non_preemptive``
+ - *f*\ (``non_preemptive``, ``sched_waking``) = ``non_preemptive``
+ - *f*\ (``non_preemptive``, ``preempt_enable``) = ``preemptive``
+
+
+It can also be represented in a graphic format, without any loss, using this
+format::
+
+ preempt_enable
+ +---------------------------------+
+ v |
+ #============# preempt_disable +------------------+
+ --> H preemptive H -----------------> | non_preemptive |
+ #============# +------------------+
+ ^ sched_waking |
+ +--------------+
+
+The Graphviz open-source tool can produce this graphic format using the
+(textual) DOT language as the source code. The DOT format is widely
+used and can be converted to many other formats, including the ASCII art above.
+
+The dot2c tool presented in:
+
+ DE OLIVEIRA, Daniel Bristot; CUCINOTTA, Tommaso; DE OLIVEIRA, Rômulo
+ Silva. Efficient formal verification for the Linux kernel. In:
+ International Conference on Software Engineering and Formal Methods.
+ Springer, Cham, 2019. p. 315-332.
+
+Translates a deterministic automaton in the DOT format into a C source
+code. For instance, using the wip model as input for dot2c results in
+the following C representation::
+
+ enum states {
+ preemptive = 0,
+ non_preemptive,
+ state_max
+ };
+
+ enum events {
+ preempt_disable = 0,
+ preempt_enable,
+ sched_waking,
+ event_max
+ };
+
+ struct automaton {
+ 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 aut = {
+ .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 },
+ };
+
+DA monitor synthesis for Linux
+------------------------------
+
+In Linux terms, the runtime verification monitors are encapsulated
+inside the "RV monitor" abstraction. The "RV monitor" includes a set
+of instances of the monitor (per-cpu monitor, per-task monitor, and
+so on), the helper functions that glue the monitor to the system
+reference model, and the trace output as a reaction for event parsing
+and exceptions, as depicted below::
+
+ Linux +----- RV Monitor ----------------------------------+ Formal
+ Realm | | Realm
+ +-------------------+ +----------------+ +-----------------+
+ | Linux kernel | | Monitor | | Reference |
+ | Tracing | -> | Instance(s) | <- | Model |
+ | (instrumentation) | | (verification) | | (specification) |
+ +-------------------+ +----------------+ +-----------------+
+ | | |
+ | V |
+ | +----------+ |
+ | | Reaction | |
+ | +--+--+--+-+ |
+ | | | | |
+ | | | +-> trace output ? |
+ +------------------------|--|----------------------+
+ | +----> panic ?
+ +-------> <user-specified>
+
+
+The dot2c tool works connecting the *Reference Model* to the *RV Monitor*
+abstraction by translating the *formal notation* into *code*.
+
+The "rv/da_monitor.h" header goes beyond dot2c, extending the code
+generation to the verification stage, generating the code to the *Monitor
+Instance(s)* level using C macros. The trace event code inspires this
+approach.
+
+The benefits of the usage of macro for monitor synthesis is 3-fold:
+
+- Reduces the code duplication;
+- Facilitates the bug fix/improvement;
+- Avoids the case of developers changing the core of the monitor code
+ to manipulate the model in a (let's say) non-standard way.
+
+This initial implementation presents two different types of monitor instances:
+
+- ``#define DECLARE_DA_MON_PER_CPU(name, type)``
+- ``#define DECLARE_DA_MON_PER_TASK(name, type)``
+
+The first declares the functions for deterministic automata monitor with
+per-cpu instances, and the second with per-task instances.
+
+In both cases, the name is a string that identifies the monitor, and the type
+is the data type used by dot2c/k on the representation of the model.
+
+For example, the "wip" model with two states and three events can be
+stored in a "char" type. Considering that the preemption control is a
+per-cpu behavior, the monitor declaration will be::
+
+ DECLARE_DA_MON_PER_CPU(wip, char);
+
+The monitor is executed by sending events to be processed via the functions
+presented below::
+
+ da_handle_event_$(MONITOR_NAME)($(event from event enum));
+ da_handle_init_event_$(MONITOR_NAME)($(event from event enum));
+
+The function ``da_handle_event_$(MONITOR_NAME)()`` is the regular case,
+while the function ``da_handle_init_event_$(MONITOR_NAME)()`` is a special
+case used to synchronize the system with the model.
+
+When a monitor is enabled, it is placed in the initial state of the automata.
+However, the monitor does not know if the system is in the *initial state*.
+Hence, the monitor ignores events sent by sent by
+``da_handle_event_$(MONITOR_NAME)()`` until the function
+``da_handle_init_event_$(MONITOR_NAME)()`` is called.
+
+The function ``da_handle_init_event_$(MONITOR_NAME)()`` should be used for
+the case in which the system generates the event is the one that returns
+the automata to the initial state.
+
+After receiving a ``da_handle_init_event_$(MONITOR_NAME)()`` event, the
+monitor will know that it is in sync with the system and hence will
+start processing the next events.
+
+Using the wip model as example, the events "preempt_disable" and
+"sched_waking" should be sent to to monitor, respectively, via::
+
+ da_handle_event_wip(preempt_disable);
+ da_handle_event_wip(sched_waking);
+
+While the event "preempt_enabled" will use::
+
+ da_handle_init_event_wip(preempt_enable);
+
+To notify the monitor that the system will be returning to the initial state,
+so the system and the monitor should be in sync.
+
+rv/da_monitor.h
+-------------------------------------------
+
+The "rv/da_monitor.h" is, mostly, a set of C macros that create function
+definitions based on the paremeters passed via ``DECLARE_DA_MON_*``.
+
+In fewer words, the declaration of a monitor generates:
+
+- Helper functions for getting information from the automata model generated
+ by dot2k.
+- Helper functions for the analysis of a deterministic automata model
+- Functions for the initialization of the monitor instances
+- The definition of the structure to store the monitor instances' data
+
+One important aspect is that the monitor does not call external functions
+for the handling of the events sent by the instrumentation, except for
+generating *tracing events* or *reactions*.
+
+Final remarks
+-------------
+
+With the monitor synthesis in place using, the "rv/da_monitor.h" and
+dot2k, the developer's work should be limited to the instrumentation
+of the system, increasing the confidence in the overall approach.
--
2.26.2
^ permalink raw reply related [flat|nested] 26+ messages in thread* [RFC PATCH 16/16] rv/docs: Add deterministic automata instrumentation documentation
2021-05-19 11:36 [RFC PATCH 00/16] The Runtime Verification (RV) interface Daniel Bristot de Oliveira
` (14 preceding siblings ...)
2021-05-19 11:36 ` [RFC PATCH 15/16] rv/docs: Add deterministic automata monitor synthesis documentation Daniel Bristot de Oliveira
@ 2021-05-19 11:36 ` Daniel Bristot de Oliveira
15 siblings, 0 replies; 26+ messages in thread
From: Daniel Bristot de Oliveira @ 2021-05-19 11:36 UTC (permalink / raw)
To: linux-kernel, Steven Rostedt
Cc: Tommaso Cucinotta, Kate Carcia, Daniel Bristot de Oliveira,
Jonathan Corbet, Ingo Molnar, Mauro Carvalho Chehab,
Thomas Gleixner, Peter Zijlstra, Will Deacon, Catalin Marinas,
Paul E. McKenney, Joel Fernandes, Mathieu Desnoyers,
Gabriele Paoloni, Juri Lelli, Clark Williams, linux-doc
Add the da_monitor_instrumentation.rst. It describes the basics
of RV monitor instrumentation.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gabriele.paoloni@intel.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
.../trace/rv/da_monitor_instrumentation.rst | 230 ++++++++++++++++++
1 file changed, 230 insertions(+)
create mode 100644 Documentation/trace/rv/da_monitor_instrumentation.rst
diff --git a/Documentation/trace/rv/da_monitor_instrumentation.rst b/Documentation/trace/rv/da_monitor_instrumentation.rst
new file mode 100644
index 000000000000..6c5188f76cba
--- /dev/null
+++ b/Documentation/trace/rv/da_monitor_instrumentation.rst
@@ -0,0 +1,230 @@
+Deterministic Automata Instrumentation
+========================================
+
+This document introduces some concepts behind the **Deterministic Automata
+(DA)** monitor instrumentation.
+
+The synthesis of automata-based models into the Linux *RV monitor* abstraction
+is automatized by a tool named dot2k, and the "rv/da_monitor.h" provided
+by the RV interface.
+
+For example, given a file "wip.dot", representing a per-cpu monitor, with
+this content::
+
+ 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";
+ }
+ }
+
+That is the "DOT" representation of this automata model::
+
+ preempt_enable
+ +---------------------------------+
+ v |
+ #============# preempt_disable +------------------+
+ --> H preemptive H -----------------> | non_preemptive |
+ #============# +------------------+
+ ^ sched_waking |
+ +--------------+
+
+
+Run the dot2k tool with the model, specifying that it is a "per-cpu"
+model::
+
+ $ dot2k -d ~/wip.dot -t per_cpu
+
+This will create a directory named "wip/" with the following files:
+
+- model.h: the wip in C
+- wip.h: tracepoints that report the execution of the events by the
+ monitor
+- wip.c: the RV monitor
+
+The monitor instrumentation should be done entirely in the RV monitor,
+in the example above, in the wip.c file.
+
+The RV monitor instrumentation section
+--------------------------------------
+
+The RV monitor file created by dot2k, with the name "$MODEL_NAME.c"
+will include a section dedicated to instrumentation.
+
+In the example of the wip.dot above, it will look like::
+
+ /*
+ * 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
+ 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
+ },
+ };
+
+The comment at the top of the section explains the general idea: the
+instrumentation section translates *kernel events* into the *events
+accepted by the model*.
+
+Tracing callback functions
+-----------------------------
+
+The first three functions are skeletons for callback *handler functions* for
+each of the three events from the wip model. The developer does not
+necessarily need to use them: they are just starting points.
+
+Using the example of::
+
+ void handle_preempt_disable(void *data, /* XXX: fill header */)
+ {
+ da_handle_event_wip(preempt_disable);
+ }
+
+The "preempt_disable" event from the model conects directly to the
+"preemptirq:preempt_disable". The "preemptirq:preempt_disable" event
+has the following signature, from "include/trace/events/preemptirq.h"::
+
+ TP_PROTO(unsigned long ip, unsigned long parent_ip)
+
+Hence, the "handle_preempt_disable()" function will look like::
+
+ void handle_preempt_disable(void *data, unsigned long ip, unsigned long parent_ip)
+
+In this case, the kernel even translates one to one with the automata event,
+and indeed, no other change is needed for this function.
+
+The next handler function, "handle_preempt_enable()" has the same argument
+list from the "handle_preempt_disable()". The difference is that the
+"preempt_enable" event will be used to synchronize the system to the model.
+
+Initially, the *model* is placed in the initial state. However, the *system*
+might, or might not be in the initial state. The monitor cannot start
+processing events until it knows that the system reached the initial state. Otherwise the monitor and the system could be out-of-sync.
+
+Looking at the automata definition, it is possible to see that the system
+and the model are expected to return to the initial state after the
+"preempt_enable" execution. Hence, it can be used to synchronize the
+system and the model at the initialization of the monitoring section.
+
+The initialization is informed via an special handle function, the
+"da_handle_init_event_$(MONITOR)(event)", in this case::
+
+ da_handle_event_wip(preempt_disable);
+
+So, the callback function will look like::
+
+ void handle_preempt_enable(void *data, unsigned long ip, unsigned long parent_ip)
+ {
+ da_handle_init_event_wip(preempt_enable);
+ }
+
+Finally, the "handle_sched_waking()" will look like::
+
+ void handle_sched_waking(void *data, struct task_struct *task)
+ {
+ da_handle_event_wip(sched_waking);
+ }
+
+And the explanation is left for the reader as an exercise.
+
+Tracepoint hook helpers
+--------------------------
+
+Still in the previous example, the next code section is the
+"tracepoint_to_hook" definition, which is a structure that aims to help to
+connect a monitor *handler function* with a given "tracepoint". Note that
+this is just a suggestion. Indeed, the *handler functions* can hook to anything
+that is possible to hook in the kernel, not even limited to the
+tracing interface.
+
+For the specific case of wip, the "tracepoints_to_hook" structure was
+defined as::
+
+ #define NR_TP 3
+ struct tracepoint_hook_helper tracepoints_to_hook[NR_TP] = {
+ {
+ .probe = handle_preempt_disable,
+ .name = "preempt_disable",
+ .registered = 0
+ },
+ {
+ .probe = handle_preempt_enable,
+ .name = "preempt_enable",
+ .registered = 0
+ },
+ {
+ .probe = handle_sched_waking,
+ .name = "sched_wakeup",
+ .registered = 0
+ },
+ };
+
+And that is the instrumentation required for the wip sample model.
+
+Start and Stop functions
+------------------------
+
+Finally, dot2k automatically creates two special functions::
+
+ start_$MODELNAME()
+ stop_$MODELNAME()
+
+These functions are called when the monitor is enabled and disabled,
+respectivelly.
+They should be used to *hook* and *unhook* the instrumentation to the running
+system. The developer must add to the relative function all that is needed to
+*hook* and *unhook* its monitor to the system.
+
+For the wip case, these functions were named::
+
+ start_wip()
+ stop_wip()
+
+But no change was required because: by default, these functions *hook* and
+*unhook* the tracepoints_to_hook, which was enough for this case.
--
2.26.2
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