Merge tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull runtime verification updates from Steven Rostedt:

 - Refactor da_monitor header to share handlers across monitor types

   No functional changes, only less code duplication.

 - Add Hybrid Automata model class

   Add a new model class that extends deterministic automata by adding
   constraints on transitions and states. Those constraints can take
   into account wall-clock time and as such allow RV monitor to make
   assertions on real time. Add documentation and code generation
   scripts.

 - Add stall monitor as hybrid automaton example

   Add a monitor that triggers a violation when a task is stalling as an
   example of automaton working with real time variables.

 - Convert the opid monitor to a hybrid automaton

   The opid monitor can be heavily simplified if written as a hybrid
   automaton: instead of tracking preempt and interrupt enable/disable
   events, it can just run constraints on the preemption/interrupt
   states when events like wakeup and need_resched verify.

 - Add support for per-object monitors in DA/HA

   Allow writing deterministic and hybrid automata monitors for generic
   objects (e.g. any struct), by exploiting a hash table where objects
   are saved. This allows to track more than just tasks in RV. For
   instance it will be used to track deadline entities in deadline
   monitors.

 - Add deadline tracepoints and move some deadline utilities

   Prepare the ground for deadline monitors by defining events and
   exporting helpers.

 - Add nomiss deadline monitor

   Add first example of deadline monitor asserting all entities complete
   before their deadline.

 - Improve rvgen error handling

   Introduce AutomataError exception class and better handle expected
   exceptions while showing a backtrace for unexpected ones.

 - Improve python code quality in rvgen

   Refactor the rvgen generation scripts to align with python best
   practices: use f-strings instead of %, use len() instead of
   __len__(), remove semicolons, use context managers for file
   operations, fix whitespace violations, extract magic strings into
   constants, remove unused imports and methods.

 - Fix small bugs in rvgen

   The generator scripts presented some corner case bugs: logical error
   in validating what a correct dot file looks like, fix an isinstance()
   check, enforce a dot file has an initial state, fix type annotations
   and typos in comments.

 - rvgen refactoring

   Refactor automata.py to use iterator-based parsing and handle
   required arguments directly in argparse.

 - Allow epoll in rtapp-sleep monitor

   The epoll_wait call is now rt-friendly so it should be allowed in the
   sleep monitor as a valid sleep method.

* tag 'trace-rv-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (32 commits)
  rv: Allow epoll in rtapp-sleep monitor
  rv/rvgen: fix _fill_states() return type annotation
  rv/rvgen: fix unbound loop variable warning
  rv/rvgen: enforce presence of initial state
  rv/rvgen: extract node marker string to class constant
  rv/rvgen: fix isinstance check in Variable.expand()
  rv/rvgen: make monitor arguments required in rvgen
  rv/rvgen: remove unused __get_main_name method
  rv/rvgen: remove unused sys import from dot2c
  rv/rvgen: refactor automata.py to use iterator-based parsing
  rv/rvgen: use class constant for init marker
  rv/rvgen: fix DOT file validation logic error
  rv/rvgen: fix PEP 8 whitespace violations
  rv/rvgen: fix typos in automata and generator docstring and comments
  rv/rvgen: use context managers for file operations
  rv/rvgen: remove unnecessary semicolons
  rv/rvgen: replace __len__() calls with len()
  rv/rvgen: replace % string formatting with f-strings
  rv/rvgen: remove bare except clauses in generator
  rv/rvgen: introduce AutomataError exception class
  ...

2 files changed, 66 insertions, 0 deletions

diff --git a/include/linux/rv.h b/include/linux/rv.h
index 58774eb3aecf..541ba404926a 100644
--- a/include/linux/rv.h
+++ b/include/linux/rv.h
@@ -13,6 +13,7 @@
 #define RV_MON_GLOBAL   0
 #define RV_MON_PER_CPU  1
 #define RV_MON_PER_TASK 2
+#define RV_MON_PER_OBJ  3
 
 #ifdef CONFIG_RV
 #include <linux/array_size.h>
@@ -81,11 +82,49 @@ struct ltl_monitor {};
 
 #endif /* CONFIG_RV_LTL_MONITOR */
 
+#ifdef CONFIG_RV_HA_MONITOR
+/*
+ * In the future, hybrid automata may rely on multiple
+ * environment variables, e.g. different clocks started at
+ * different times or running at different speed.
+ * For now we support only 1 variable.
+ */
+#define MAX_HA_ENV_LEN 1
+
+/*
+ * Monitors can pick the preferred timer implementation:
+ * No timer: if monitors don't have state invariants.
+ * Timer wheel: lightweight invariants check but far less precise.
+ * Hrtimer: accurate invariants check with higher overhead.
+ */
+#define HA_TIMER_NONE 0
+#define HA_TIMER_WHEEL 1
+#define HA_TIMER_HRTIMER 2
+
+/*
+ * Hybrid automaton per-object variables.
+ */
+struct ha_monitor {
+	struct da_monitor da_mon;
+	u64 env_store[MAX_HA_ENV_LEN];
+	union {
+		struct hrtimer hrtimer;
+		struct timer_list timer;
+	};
+};
+
+#else
+
+struct ha_monitor { };
+
+#endif /* CONFIG_RV_HA_MONITOR */
+
 #define RV_PER_TASK_MONITOR_INIT	(CONFIG_RV_PER_TASK_MONITORS)
 
 union rv_task_monitor {
 	struct da_monitor	da_mon;
 	struct ltl_monitor	ltl_mon;
+	struct ha_monitor	ha_mon;
 };
 
 #ifdef CONFIG_RV_REACTORS
diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h
index c40115d4e34d..1198138cb839 100644
--- a/include/linux/sched/deadline.h
+++ b/include/linux/sched/deadline.h
@@ -37,4 +37,31 @@ extern void dl_clear_root_domain_cpu(int cpu);
 extern u64 dl_cookie;
 extern bool dl_bw_visited(int cpu, u64 cookie);
 
+static inline bool dl_server(struct sched_dl_entity *dl_se)
+{
+	return dl_se->dl_server;
+}
+
+static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
+{
+	BUG_ON(dl_server(dl_se));
+	return container_of(dl_se, struct task_struct, dl);
+}
+
+/*
+ * Regarding the deadline, a task with implicit deadline has a relative
+ * deadline == relative period. A task with constrained deadline has a
+ * relative deadline <= relative period.
+ *
+ * We support constrained deadline tasks. However, there are some restrictions
+ * applied only for tasks which do not have an implicit deadline. See
+ * update_dl_entity() to know more about such restrictions.
+ *
+ * The dl_is_implicit() returns true if the task has an implicit deadline.
+ */
+static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
+{
+	return dl_se->dl_deadline == dl_se->dl_period;
+}
+
 #endif /* _LINUX_SCHED_DEADLINE_H */