[PATCH v4 0/8] rv/tlob: Add task latency over budget RV monitor

[PATCH v4 0/8] rv/tlob: Add task latency over budget RV monitor

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

This series introduces tlob (task latency over budget), a per-task
hybrid automaton RV monitor that measures elapsed wall-clock time across
a user-delimited code section and emits an error when the elapsed time
exceeds a configurable budget.

The monitor tracks three states (running, waiting, sleeping) driven by
sched_switch and sched_wakeup tracepoints.  A single clock invariant,
clk_elapsed < BUDGET_NS(), is enforced by a per-task hrtimer
(HRTIMER_MODE_REL_HARD).  On expiry, error_env_tlob is emitted,
followed by detail_env_tlob carrying a per-state time breakdown
(running_ns, waiting_ns, sleeping_ns).

Tasks are registered for monitoring by writing to the tracefs monitor
file:

  echo "p /path/to/binary:OFFSET_START OFFSET_STOP threshold=NS" \
       > /sys/kernel/tracing/rv/monitors/tlob/monitor

Two uprobes delimit the measured section without modifying the target
binary.  Multiple uprobe pairs can be active simultaneously.

Series structure
----------------
Patch 1: rv/da: introduce DA_MON_ALLOCATION_STRATEGY
  Compile-time allocation strategy selector for per-object DA storage.
  Three strategies: DA_ALLOC_AUTO (default kmalloc), DA_ALLOC_POOL
  (pre-allocated llist pool), DA_ALLOC_MANUAL (caller-managed).

Patch 2: rv: add generic uprobe infrastructure for RV monitors
  Thin wrapper over uprobe_consumer for path resolution, registration,
  and safe synchronous teardown.

Patch 3: rv/tlob: add tlob model DOT file
  Graphviz DOT specification of the tlob hybrid automaton.

Patch 4: rv/ha: fix ha_invariant_passed_ns silent bypass
  Without this fix, ha_invariant_passed_ns() returns 0 on first call and
  leaves env_store at U64_MAX.  Every subsequent state transition resets
  the hrtimer to the full budget instead of the remaining time, so the
  budget never expires for tasks that transition between states.  This
  causes tlob's detail_sleeping and detail_waiting selftests to hang.

  This patch is a minimal fix in the current dual-representation framework.
  Nam's series [1] refactors ha_monitor.h to a single-representation
  model; once it lands, tlob will need to be updated to the new API and
  this patch will be superseded by Gabriele's planned framework-level
  initialisation improvement.  We carry it here to keep the series
  self-contained and testable.

  [1] https://lore.kernel.org/lkml/08188c28f274da63a3f8549add3086a92aef45e5.1780908661.git.namcao@linutronix.de

Patches 5: rv/ha: make da_monitor_reset_hook and EVENT_NONE_LBL
  #ifndef guards for da_monitor_reset_hook and EVENT_NONE_LBL.

Patch 6: rv/tlob: add tlob hybrid automaton monitor
  Main tlob implementation.

Patches 7-8: Tests
  KUnit tests for the uprobe-line parser; seven ftrace-style selftests.

Changes since v3
----------------
Patch 1 (rv/da):
- Pool redesigned from spinlock+pointer-stack to lock-free llist
  (cmpxchg-based): pool release from RCU callback context is now safe
  without acquiring a lock
- DA_MON_POOL_SIZE alone selects pool mode; no separate
  DA_MON_ALLOCATION_STRATEGY define required for monitors
- All strategy dispatch uses plain C if() (no ifdeffery in functions)
- da_monitor_destroy_pool() calls da_monitor_reset_all() and
  da_monitor_sync_hook() before the hash iteration, preventing hrtimer
  UAF when timer callbacks are still in flight

Patch 2 (rv_uprobe):
- struct rv_uprobe now embeds struct uprobe_consumer directly; no
  separate heap allocation per probe, no rv_uprobe_free()
- path_put() moved after uprobe_register() to keep the inode
  referenced across the call as required by the uprobe API

Patch 6 (tlob monitor):
- da_get_target_by_id() wrapped in scoped_guard(rcu) in
  tlob_start_task(): hash_for_each_possible_rcu() requires an explicit
  RCU read-side CS on PREEMPT_RT where spinlock_t does not provide one
- tlob_monitor_read() releases mutex before simple_read_from_buffer()
  to avoid holding the mutex across copy_to_user()
- kmem_cache replaced with a pre-allocated llist pool for
  tlob_task_state, eliminating GFP_ATOMIC in the measurement window
- EXPORT_SYMBOL_IF_KUNIT added for tlob_parse_uprobe_line() and
  tlob_parse_remove_line() (required when CONFIG_TLOB_KUNIT_TEST=m)
- tlob_parse_remove_line() rejects negative offsets
- Unnecessary includes removed; Kconfig entry placed after the
  deadline monitors marker

Patch 7 (KUnit):
- Tests now call tlob_parse_uprobe_line() and tlob_parse_remove_line()
  directly; no tracepoint enrollment, no uprobe or filesystem state

Patch 8 (selftests):
- ftracetest walk-up algorithm (Gabriele's suggestion) incorporated;
  the separate verificationtest-ktap fix patch is dropped and the
  series shrinks from 9 to 8 patches
- All test scripts use "! cmd || false" throughout

Testing
-------
Tested on x86_64 with CONFIG_PREEMPT_RT=y (kernel 7.1 + virtme-ng):
- All KUnit tests pass
- All 7 selftests pass (uprobe_bind, uprobe_violation, uprobe_no_event,
  uprobe_multi, uprobe_detail_{running,sleeping,waiting})


Wen Yang (8):
  rv/da: introduce DA_MON_ALLOCATION_STRATEGY
  rv: add generic uprobe infrastructure for RV monitors
  rv/tlob: add tlob model DOT file
  rv/ha: fix ha_invariant_passed_ns silent bypass of invariant check
  rv/ha: make da_monitor_reset_hook and EVENT_NONE_LBL overridable
  rv/tlob: add tlob hybrid automaton monitor
  rv/tlob: add KUnit tests for the tlob monitor
  selftests/verification: add tlob selftests

 Documentation/trace/rv/index.rst              |   1 +
 Documentation/trace/rv/monitor_tlob.rst       | 177 ++++
 include/rv/da_monitor.h                       | 247 ++++-
 include/rv/ha_monitor.h                       |  24 +-
 include/rv/rv_uprobe.h                        |  93 ++
 kernel/trace/rv/Kconfig                       |   8 +
 kernel/trace/rv/Makefile                      |   3 +
 kernel/trace/rv/monitors/nomiss/nomiss.c      |   6 +-
 kernel/trace/rv/monitors/tlob/.kunitconfig    |   8 +
 kernel/trace/rv/monitors/tlob/Kconfig         |  19 +
 kernel/trace/rv/monitors/tlob/tlob.c          | 970 ++++++++++++++++++
 kernel/trace/rv/monitors/tlob/tlob.h          | 153 +++
 kernel/trace/rv/monitors/tlob/tlob_kunit.c    | 139 +++
 kernel/trace/rv/monitors/tlob/tlob_trace.h    |  52 +
 kernel/trace/rv/rv_trace.h                    |   1 +
 kernel/trace/rv/rv_uprobe.c                   | 104 ++
 tools/testing/selftests/ftrace/ftracetest     |  18 +-
 .../testing/selftests/verification/.gitignore |   2 +
 tools/testing/selftests/verification/Makefile |  19 +-
 .../verification/test.d/tlob/Makefile         |  28 +
 .../test.d/tlob/run_tlob_tests.sh             |  90 ++
 .../verification/test.d/tlob/tlob_sym.c       | 209 ++++
 .../verification/test.d/tlob/tlob_target.c    | 138 +++
 .../verification/test.d/tlob/uprobe_bind.tc   |  37 +
 .../test.d/tlob/uprobe_detail_running.tc      |  51 +
 .../test.d/tlob/uprobe_detail_sleeping.tc     |  50 +
 .../test.d/tlob/uprobe_detail_waiting.tc      |  66 ++
 .../verification/test.d/tlob/uprobe_multi.tc  |  64 ++
 .../test.d/tlob/uprobe_no_event.tc            |  19 +
 .../test.d/tlob/uprobe_violation.tc           |  67 ++
 tools/verification/models/tlob.dot            |  22 +
 31 files changed, 2839 insertions(+), 46 deletions(-)
 create mode 100644 Documentation/trace/rv/monitor_tlob.rst
 create mode 100644 include/rv/rv_uprobe.h
 create mode 100644 kernel/trace/rv/monitors/tlob/.kunitconfig
 create mode 100644 kernel/trace/rv/monitors/tlob/Kconfig
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob.c
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob.h
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob_kunit.c
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob_trace.h
 create mode 100644 kernel/trace/rv/rv_uprobe.c
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/Makefile
 create mode 100755 tools/testing/selftests/verification/test.d/tlob/run_tlob_tests.sh
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/tlob_sym.c
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/tlob_target.c
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_bind.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_running.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_sleeping.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_waiting.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_multi.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_no_event.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_violation.tc
 create mode 100644 tools/verification/models/tlob.dot

-- 
2.25.1

[PATCH v4 1/8] rv/da: introduce DA_MON_ALLOCATION_STRATEGY

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Per-object DA storage allocation is currently limited to kmalloc on
demand. Add a compile-time selector so monitors can choose among three
strategies:

  DA_ALLOC_AUTO   (default) - kmalloc per object on the monitor path
  DA_ALLOC_POOL             - pre-allocated fixed-size llist pool;
                              selected by defining DA_MON_POOL_SIZE
  DA_ALLOC_MANUAL           - caller pre-inserts storage; framework
                              only links the target field

The pool strategy uses a lock-free llist (cmpxchg, no spinlock) so
pool release is safe from RCU callback context without acquiring a
lock. Moving allocation before the measurement window also prevents
kmalloc latency.

nomiss is updated to DA_ALLOC_MANUAL.

Suggested-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 include/rv/da_monitor.h                  | 247 +++++++++++++++++++----
 include/rv/ha_monitor.h                  |   6 +
 kernel/trace/rv/monitors/nomiss/nomiss.c |   6 +-
 3 files changed, 221 insertions(+), 38 deletions(-)

diff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h
index 34b8fba9ecd4..9c9acc123e3b 100644
--- a/include/rv/da_monitor.h
+++ b/include/rv/da_monitor.h
@@ -14,7 +14,56 @@
 #ifndef _RV_DA_MONITOR_H
 #define _RV_DA_MONITOR_H
 
+/*
+ * Allocation strategies for RV_MON_PER_OBJ monitors.
+ *
+ * Select the strategy with a single define before including this header:
+ *
+ *   #define DA_MON_POOL_SIZE N          - pool mode; N pre-allocated slots.
+ *                                         Implies DA_ALLOC_POOL automatically.
+ *   #define DA_MON_ALLOCATION_STRATEGY \
+ *           DA_ALLOC_MANUAL             - manual mode (see below).
+ *   (neither)                           - auto mode (default).
+ *
+ * Do not define both DA_MON_POOL_SIZE and DA_MON_ALLOCATION_STRATEGY.
+ *
+ * DA_ALLOC_AUTO   - lock-free kmalloc on the hot path; unbounded capacity.
+ * DA_ALLOC_POOL   - pre-allocated fixed-size pool; set by defining DA_MON_POOL_SIZE.
+ * DA_ALLOC_MANUAL - caller inserts storage before da_handle_start_event();
+ *                   the framework only links the target field.
+ */
+#define DA_ALLOC_AUTO   0
+#define DA_ALLOC_POOL   1
+#define DA_ALLOC_MANUAL 2
+
+#ifdef DA_MON_POOL_SIZE
+#ifdef DA_MON_ALLOCATION_STRATEGY
+#error "Define only one of DA_MON_POOL_SIZE or DA_MON_ALLOCATION_STRATEGY"
+#endif
+#if DA_MON_POOL_SIZE == 0
+#error "DA_MON_POOL_SIZE must be non-zero"
+#endif
+#define DA_MON_ALLOCATION_STRATEGY DA_ALLOC_POOL
+#endif
+
+#ifndef DA_MON_ALLOCATION_STRATEGY
+#define DA_MON_ALLOCATION_STRATEGY DA_ALLOC_AUTO
+#endif
+
+/*
+ * Provide a zero default so da_monitor_init() can reference
+ * DA_MON_POOL_SIZE in a plain C if() without an #if guard; the
+ * compiler eliminates the dead branch.
+ */
+#ifndef DA_MON_POOL_SIZE
+#if DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL
+#error "DA_ALLOC_POOL requires DA_MON_POOL_SIZE to be defined and non-zero"
+#endif
+#define DA_MON_POOL_SIZE 0
+#endif
+
 #include <rv/automata.h>
+#include <linux/llist.h>
 #include <linux/rv.h>
 #include <linux/stringify.h>
 #include <linux/bug.h>
@@ -66,6 +115,16 @@ static struct rv_monitor rv_this;
 #define da_monitor_sync_hook()
 #endif
 
+/*
+ * Per-object teardown hook, called after da_monitor_reset_all() +
+ * da_monitor_sync_hook() and before hash_del_rcu() for each entry.
+ * All HA timer callbacks have completed at this point.
+ * Define before including this header.  Default: no-op.
+ */
+#ifndef da_extra_cleanup
+#define da_extra_cleanup(da_mon)
+#endif
+
 /*
  * Type for the target id, default to int but can be overridden.
  * A long type can work as hash table key (PER_OBJ) but will be downgraded to
@@ -404,6 +463,12 @@ struct da_monitor_storage {
 	union rv_task_monitor rv;
 	struct hlist_node node;
 	struct rcu_head rcu;
+	/*
+	 * Mutually exclusive with rcu: rcu is live during the RCU callback
+	 * flight; free_node when the slot is in da_pool_free_list.
+	 * Present in all monitors to avoid #if-gating the pool helpers.
+	 */
+	struct llist_node free_node;
 };
 
 #ifndef DA_MONITOR_HT_BITS
@@ -495,18 +560,6 @@ static inline da_id_type da_get_id(struct da_monitor *da_mon)
 	return container_of(da_mon, struct da_monitor_storage, rv.da_mon)->id;
 }
 
-/*
- * da_create_or_get - create the per-object storage if not already there
- *
- * This needs a lookup so should be guarded by RCU, the condition is checked
- * directly in da_create_storage()
- */
-static inline void da_create_or_get(da_id_type id, monitor_target target)
-{
-	guard(rcu)();
-	da_create_storage(id, target, da_get_monitor(id, target));
-}
-
 /*
  * da_fill_empty_storage - store the target in a pre-allocated storage
  *
@@ -537,15 +590,79 @@ static inline monitor_target da_get_target_by_id(da_id_type id)
 	return mon_storage->target;
 }
 
+/*
+ * Lock-free llist (cmpxchg) rather than kmem_cache/mempool: on
+ * PREEMPT_RT spinlock_t becomes a sleeping lock, which is forbidden
+ * in the rcuc kthread context where RCU callbacks run.
+ *
+ * Multiple producers (any context, any CPU) call llist_add; a single
+ * consumer (llist_del_first, serialised by the monitor's start lock)
+ * needs no additional synchronisation.
+ *
+ * Per-TU statics: each PER_OBJ monitor gets its own pool instance;
+ * da_pool_storage and da_pool_free_list are NULL/empty and the pool
+ * paths are dead code for non-pool monitors.
+ */
+static struct da_monitor_storage *da_pool_storage;
+static LLIST_HEAD(da_pool_free_list);
+
+static void da_pool_return_cb(struct rcu_head *head)
+{
+	struct da_monitor_storage *ms =
+		container_of(head, struct da_monitor_storage, rcu);
+
+	llist_add(&ms->free_node, &da_pool_free_list);
+}
+
+/*
+ * da_create_pool_storage - pop a free pool slot and insert it into the hash.
+ *
+ * Returns the new da_monitor, or NULL if the pool is exhausted.  Finding
+ * an existing entry for the same id fires WARN_ON_ONCE (double-start bug).
+ *
+ * Caller must hold an RCU read-side CS and the monitor's serialisation lock.
+ */
+static inline struct da_monitor *
+da_create_pool_storage(da_id_type id, monitor_target target,
+		       struct da_monitor *da_mon)
+{
+	struct da_monitor_storage *mon_storage, *existing;
+	struct llist_node *node;
+
+	if (da_mon)
+		return da_mon;
+
+	node = llist_del_first(&da_pool_free_list);
+	if (!node)
+		return NULL;
+	mon_storage = llist_entry(node, struct da_monitor_storage, free_node);
+
+	mon_storage->id = id;
+	mon_storage->target = target;
+
+	/*
+	 * The caller's serialization lock ensures llist_del_first() is
+	 * single-consumer, so no concurrent start for the same id is possible.
+	 * Reaching here indicates a programming error (double-start for the
+	 * same pid).
+	 */
+	existing = __da_get_mon_storage(id);
+	if (WARN_ON_ONCE(existing)) {
+		llist_add(&mon_storage->free_node, &da_pool_free_list);
+		return NULL;
+	}
+	hash_add_rcu(da_monitor_ht, &mon_storage->node, id);
+	return &mon_storage->rv.da_mon;
+}
+
 /*
  * da_destroy_storage - destroy the per-object storage
  *
- * The caller is responsible to synchronise writers, either with locks or
- * implicitly. For instance, if da_destroy_storage is called at sched_exit and
- * da_create_storage can never occur after that, it's safe to call this without
- * locks.
- * This function includes an RCU read-side critical section to synchronise
- * against da_monitor_destroy().
+ * Pool mode: removes from hash and returns the slot via call_rcu().
+ * Kmalloc mode: removes from hash and frees via kfree_rcu().
+ *
+ * Includes an RCU read-side critical section to synchronise against
+ * da_monitor_destroy().
  */
 static inline void da_destroy_storage(da_id_type id)
 {
@@ -558,7 +675,10 @@ static inline void da_destroy_storage(da_id_type id)
 		return;
 	da_monitor_reset_hook(&mon_storage->rv.da_mon);
 	hash_del_rcu(&mon_storage->node);
-	kfree_rcu(mon_storage, rcu);
+	if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL)
+		call_rcu(&mon_storage->rcu, da_pool_return_cb);
+	else
+		kfree_rcu(mon_storage, rcu);
 }
 
 static void __da_monitor_reset_all(void (*reset)(struct da_monitor *))
@@ -581,41 +701,98 @@ static inline void da_monitor_reset_state_all(void)
 	__da_monitor_reset_all(da_monitor_reset_state);
 }
 
+/* Not part of the public API; called only by da_monitor_init(). */
+static inline int __da_monitor_init_pool(unsigned int prealloc_count)
+{
+	unsigned int i;
+
+	da_pool_storage = kcalloc(prealloc_count, sizeof(*da_pool_storage),
+				  GFP_KERNEL);
+	if (!da_pool_storage)
+		return -ENOMEM;
+
+	for (i = 0; i < prealloc_count; i++)
+		llist_add(&da_pool_storage[i].free_node, &da_pool_free_list);
+	return 0;
+}
+
+/*
+ * da_monitor_init - initialise the per-object monitor
+ */
 static inline int da_monitor_init(void)
 {
 	hash_init(da_monitor_ht);
+	if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL)
+		return __da_monitor_init_pool(DA_MON_POOL_SIZE);
 	return 0;
 }
 
+/*
+ * da_monitor_destroy - tear down the per-object monitor
+ *
+ * tracepoint_synchronize_unregister() flushes all in-flight tracepoint
+ * handlers and performs synchronize_rcu(), so no RCU reader holds a
+ * reference to any da_monitor_storage after it returns.
+ * da_monitor_reset_all() disables monitoring; combined with
+ * da_monitor_sync_hook() (synchronize_rcu() for HA), no timer callback
+ * can fire or be re-armed after this sequence.
+ *
+ * Pool mode: remaining hash entries are returned to the free list
+ * directly (no call_rcu needed -- see above).  rcu_barrier() drains any
+ * da_pool_return_cb() callbacks queued by earlier da_destroy_storage()
+ * calls before the backing array is freed.
+ */
 static inline void da_monitor_destroy(void)
 {
-	struct da_monitor_storage *mon_storage;
+	struct da_monitor_storage *ms;
 	struct hlist_node *tmp;
 	int bkt;
 
 	tracepoint_synchronize_unregister();
 	da_monitor_reset_all();
 	da_monitor_sync_hook();
-	/*
-	 * This function is called after all probes are disabled and no longer
-	 * pending, we can safely assume no concurrent user.
-	 */
-	hash_for_each_safe(da_monitor_ht, bkt, tmp, mon_storage, node) {
-		hash_del_rcu(&mon_storage->node);
-		kfree(mon_storage);
+
+	hash_for_each_safe(da_monitor_ht, bkt, tmp, ms, node) {
+		da_extra_cleanup(&ms->rv.da_mon);
+		hash_del_rcu(&ms->node);
+		/* No RCU readers remain; skip the grace period. */
+		if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL) {
+			llist_add(&ms->free_node, &da_pool_free_list);
+		} else {
+			kfree(ms);
+		}
+	}
+
+	if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL) {
+		/*
+		 * Flush any da_pool_return_cb callbacks queued by
+		 * da_destroy_storage() during normal monitor operation.
+		 * After rcu_barrier(), no callback can reference pool slots;
+		 * the backing array is safe to free.
+		 */
+		rcu_barrier();
+		init_llist_head(&da_pool_free_list);
+		kfree(da_pool_storage);
+		da_pool_storage = NULL;
 	}
 }
 
 /*
- * Allow the per-object monitors to run allocation manually, necessary if the
- * start condition is in a context problematic for allocation (e.g. scheduling).
- * In such case, if the storage was pre-allocated without a target, set it now.
+ * da_prepare_storage - allocate or retrieve storage for a monitoring session
+ *
+ * Dispatches to the strategy selected by DA_MON_ALLOCATION_STRATEGY.
+ * Caller must hold an RCU read-side CS.
  */
-#ifdef DA_SKIP_AUTO_ALLOC
-#define da_prepare_storage da_fill_empty_storage
-#else
-#define da_prepare_storage da_create_storage
-#endif /* DA_SKIP_AUTO_ALLOC */
+static inline struct da_monitor *
+da_prepare_storage(da_id_type id, monitor_target target,
+		   struct da_monitor *da_mon)
+{
+	if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_POOL)
+		return da_create_pool_storage(id, target, da_mon);
+	if (DA_MON_ALLOCATION_STRATEGY == DA_ALLOC_MANUAL)
+		return da_fill_empty_storage(id, target, da_mon);
+	return da_create_storage(id, target, da_mon);
+}
 
 #endif /* RV_MON_TYPE */
 
diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h
index 28d3c74cabfc..83199f90afe8 100644
--- a/include/rv/ha_monitor.h
+++ b/include/rv/ha_monitor.h
@@ -365,6 +365,12 @@ static inline bool ha_check_invariant_ns(struct ha_monitor *ha_mon,
 }
 /*
  * ha_invariant_passed_ns - prepare the invariant and return the time since reset
+ *
+ * If the env has not been initialised yet (first entry into a state with an
+ * invariant), anchor the guard clock at the current time so that the full
+ * budget is available from this point.  This preserves the documented
+ * guard->invariant ordering: ha_set_invariant_ns() is always preceded by a
+ * valid guard representation in env_store.
  */
 static inline u64 ha_invariant_passed_ns(struct ha_monitor *ha_mon, enum envs env,
 				   u64 expire, u64 time_ns)
diff --git a/kernel/trace/rv/monitors/nomiss/nomiss.c b/kernel/trace/rv/monitors/nomiss/nomiss.c
index 8ead8783c29f..ac4d334e757f 100644
--- a/kernel/trace/rv/monitors/nomiss/nomiss.c
+++ b/kernel/trace/rv/monitors/nomiss/nomiss.c
@@ -17,8 +17,8 @@
 
 #define RV_MON_TYPE RV_MON_PER_OBJ
 #define HA_TIMER_TYPE HA_TIMER_WHEEL
-/* The start condition is on sched_switch, it's dangerous to allocate there */
-#define DA_SKIP_AUTO_ALLOC
+/* Allocate storage in sched_setscheduler; sched_switch is too hot to alloc. */
+#define DA_MON_ALLOCATION_STRATEGY DA_ALLOC_MANUAL
 typedef struct sched_dl_entity *monitor_target;
 #include "nomiss.h"
 #include <rv/ha_monitor.h>
@@ -214,7 +214,7 @@ static void handle_sys_enter(void *data, struct pt_regs *regs, long id)
 	if (p->policy == SCHED_DEADLINE)
 		da_reset(EXPAND_ID_TASK(p));
 	else if (new_policy == SCHED_DEADLINE)
-		da_create_or_get(EXPAND_ID_TASK(p));
+		da_create_empty_storage(get_entity_id(&p->dl, task_cpu(p), DL_TASK));
 }
 
 static void handle_sched_wakeup(void *data, struct task_struct *tsk)
-- 
2.25.1

[PATCH v4 2/8] rv: add generic uprobe infrastructure for RV monitors

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Monitors that instrument user-space function boundaries need to resolve
paths, register uprobes, and deregister them safely.  Provide a thin
wrapper so monitors share a single implementation of this boilerplate.

struct rv_uprobe embeds struct uprobe_consumer directly, avoiding a
separate heap allocation per probe.  Embedding is safe after
rv_uprobe_unregister(): rv_uprobe_sync() calls uprobe_unregister_sync()
which performs synchronize_rcu_tasks_trace(), waiting for all
rcu_read_lock_trace() readers (handler_chain()) to complete on all CPUs
before returning; the caller may then free the containing struct.

The API provides register, synchronous and nosync unregister, a global
handler barrier (rv_uprobe_sync), and an active-state predicate.
Handlers receive the uprobe_consumer pointer and recover per-probe state
via container_of(uc, struct rv_uprobe, uc) or the containing struct.

Suggested-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 include/rv/rv_uprobe.h      |  93 ++++++++++++++++++++++++++++++++
 kernel/trace/rv/Kconfig     |   7 +++
 kernel/trace/rv/Makefile    |   1 +
 kernel/trace/rv/rv_uprobe.c | 104 ++++++++++++++++++++++++++++++++++++
 4 files changed, 205 insertions(+)
 create mode 100644 include/rv/rv_uprobe.h
 create mode 100644 kernel/trace/rv/rv_uprobe.c

diff --git a/include/rv/rv_uprobe.h b/include/rv/rv_uprobe.h
new file mode 100644
index 000000000000..2eab5d193e13
--- /dev/null
+++ b/include/rv/rv_uprobe.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Generic uprobe infrastructure for RV monitors.
+ *
+ */
+
+#ifndef _RV_UPROBE_H
+#define _RV_UPROBE_H
+
+#include <linux/types.h>
+#include <linux/uprobes.h>
+
+struct pt_regs;
+struct inode;
+
+/**
+ * struct rv_uprobe - embeddable uprobe handle for RV monitors
+ *
+ * Embed via DECLARE_RV_UPROBE() in the caller's struct and pass &name to
+ * rv_uprobe_register().
+ *
+ * Lifetime: after rv_uprobe_unregister() (or rv_uprobe_unregister_nosync()
+ * followed by rv_uprobe_sync()) returns, synchronize_rcu_tasks_trace() has
+ * completed and no handler_chain() iteration can reference this struct.
+ * The caller may free the containing struct immediately after.
+ *
+ * @uc:     embedded uprobe_consumer; set uc.handler / uc.ret_handler before
+ *          calling rv_uprobe_register(); use container_of(uc, rv_uprobe, uc)
+ *          inside handlers to reach this struct or its container
+ * @uprobe: registered uprobe pointer (NULL when not registered)
+ * @inode:  inode of the probed binary (valid while registered)
+ */
+struct rv_uprobe {
+	struct uprobe_consumer	uc;
+	struct uprobe		*uprobe;
+	struct inode		*inode;
+};
+
+/* Embed a named rv_uprobe inside a caller struct */
+#define DECLARE_RV_UPROBE(name)		struct rv_uprobe name
+
+/**
+ * rv_uprobe_is_registered - test whether an uprobe is currently active
+ * @p: probe to test; may be NULL
+ */
+bool rv_uprobe_is_registered(const struct rv_uprobe *p);
+
+/**
+ * rv_uprobe_register - initialise and register an uprobe
+ * @binpath: absolute path to the target binary
+ * @offset:  byte offset within the binary
+ * @p:       caller-provided rv_uprobe (embedded via DECLARE_RV_UPROBE);
+ *           p->uc.handler and/or p->uc.ret_handler must be set before this call
+ *
+ * Resolves the path and registers p->uc with the uprobe subsystem.
+ * No heap allocation is performed.
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+int rv_uprobe_register(const char *binpath, loff_t offset, struct rv_uprobe *p);
+
+/**
+ * rv_uprobe_unregister - synchronously unregister a uprobe
+ * @p: probe to unregister; may be NULL (no-op)
+ *
+ * Removes the consumer from the uprobe subsystem and waits for all in-flight
+ * handlers to complete (via synchronize_rcu_tasks_trace()).  After this
+ * returns, the containing struct may be safely freed by the caller.
+ * Use rv_uprobe_unregister_nosync() + rv_uprobe_sync() to batch multiple
+ * deregistrations before a single synchronisation.
+ */
+void rv_uprobe_unregister(struct rv_uprobe *p);
+
+/**
+ * rv_uprobe_unregister_nosync - dequeue an uprobe without waiting
+ * @p: probe to dequeue; may be NULL (no-op)
+ *
+ * Removes the consumer without waiting for in-flight handlers.  The caller
+ * must call rv_uprobe_sync() before freeing the containing struct.
+ */
+void rv_uprobe_unregister_nosync(struct rv_uprobe *p);
+
+/**
+ * rv_uprobe_sync - wait for all in-flight uprobe handlers to complete
+ *
+ * Global barrier: calls uprobe_unregister_sync() which performs
+ * synchronize_rcu_tasks_trace() + synchronize_srcu(&uretprobes_srcu).
+ * After this returns, no handler_chain() iteration referencing any
+ * previously deregistered consumer is still in progress.
+ */
+void rv_uprobe_sync(void);
+
+#endif /* _RV_UPROBE_H */
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 3884b14df375..5bad1d63f411 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -59,6 +59,13 @@ config RV_PER_TASK_MONITORS
 	  This option configures the maximum number of per-task RV monitors that can run
 	  simultaneously.
 
+config RV_UPROBE
+	bool
+	depends on RV && UPROBES
+	help
+	  Generic uprobe infrastructure for RV monitors.  Provides path
+	  resolution, registration, and safe synchronous teardown.
+
 source "kernel/trace/rv/monitors/wip/Kconfig"
 source "kernel/trace/rv/monitors/wwnr/Kconfig"
 
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index 94498da35b37..f139b904bea3 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_RV_MON_STALL) += monitors/stall/stall.o
 obj-$(CONFIG_RV_MON_DEADLINE) += monitors/deadline/deadline.o
 obj-$(CONFIG_RV_MON_NOMISS) += monitors/nomiss/nomiss.o
 # Add new monitors here
+obj-$(CONFIG_RV_UPROBE) += rv_uprobe.o
 obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
 obj-$(CONFIG_RV_REACT_PRINTK) += reactor_printk.o
 obj-$(CONFIG_RV_REACT_PANIC) += reactor_panic.o
diff --git a/kernel/trace/rv/rv_uprobe.c b/kernel/trace/rv/rv_uprobe.c
new file mode 100644
index 000000000000..a80bfa64578b
--- /dev/null
+++ b/kernel/trace/rv/rv_uprobe.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic uprobe infrastructure for RV monitors.
+ *
+ * struct rv_uprobe embeds struct uprobe_consumer directly.  This is safe
+ * because rv_uprobe_sync() calls uprobe_unregister_sync(), which calls
+ * synchronize_rcu_tasks_trace().  handler_chain() runs under
+ * rcu_read_lock_trace(), so after synchronize_rcu_tasks_trace() returns,
+ * all in-flight handler_chain() iterations, including any pending
+ * uc->cons_node.next reads, have completed on all CPUs.  The caller may
+ * then free the struct containing rv_uprobe immediately.
+ */
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/uprobes.h>
+#include <rv/rv_uprobe.h>
+
+/**
+ * rv_uprobe_register - initialise and register an uprobe
+ */
+int rv_uprobe_register(const char *binpath, loff_t offset, struct rv_uprobe *p)
+{
+	struct inode *inode;
+	struct path path;
+	int ret;
+
+	if (!p->uc.handler && !p->uc.ret_handler)
+		return -EINVAL;
+
+	ret = kern_path(binpath, LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ret;
+
+	if (!d_is_reg(path.dentry)) {
+		path_put(&path);
+		return -EINVAL;
+	}
+
+	inode = d_real_inode(path.dentry);
+	p->inode = inode;
+
+	/*
+	 * uprobe_register() requires the inode (and mount) to remain
+	 * referenced across the call.  Keep the path alive until after
+	 * uprobe_register() has stored its own reference, then release it.
+	 */
+	p->uprobe = uprobe_register(inode, offset, 0, &p->uc);
+	path_put(&path);
+	if (IS_ERR(p->uprobe)) {
+		ret = PTR_ERR(p->uprobe);
+		p->uprobe = NULL;
+		p->inode = NULL;
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rv_uprobe_register);
+
+/**
+ * rv_uprobe_is_registered - test whether an uprobe is currently active
+ */
+bool rv_uprobe_is_registered(const struct rv_uprobe *p)
+{
+	return p && p->uprobe;
+}
+EXPORT_SYMBOL_GPL(rv_uprobe_is_registered);
+
+/**
+ * rv_uprobe_unregister - synchronously unregister a uprobe
+ */
+void rv_uprobe_unregister(struct rv_uprobe *p)
+{
+	if (!p || !p->uprobe)
+		return;
+
+	rv_uprobe_unregister_nosync(p);
+	rv_uprobe_sync();
+}
+EXPORT_SYMBOL_GPL(rv_uprobe_unregister);
+
+/**
+ * rv_uprobe_unregister_nosync - dequeue an uprobe without waiting
+ */
+void rv_uprobe_unregister_nosync(struct rv_uprobe *p)
+{
+	if (!p || !p->uprobe)
+		return;
+
+	uprobe_unregister_nosync(p->uprobe, &p->uc);
+	p->uprobe = NULL;
+	p->inode = NULL;
+}
+EXPORT_SYMBOL_GPL(rv_uprobe_unregister_nosync);
+
+/**
+ * rv_uprobe_sync - wait for all in-flight uprobe handlers to complete
+ */
+void rv_uprobe_sync(void)
+{
+	uprobe_unregister_sync();
+}
+EXPORT_SYMBOL_GPL(rv_uprobe_sync);
-- 
2.25.1

[PATCH v4 3/8] rv/tlob: add tlob model DOT file

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Add the Graphviz DOT specification of the tlob hybrid automaton to
tools/verification/models/.  The model has three states (running,
waiting, sleeping), four transitions (switch_in, preempt, wakeup,
sleep), and a single clock invariant clk_elapsed < BUDGET_NS() active
in all states.

Suggested-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 tools/verification/models/tlob.dot | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 tools/verification/models/tlob.dot

diff --git a/tools/verification/models/tlob.dot b/tools/verification/models/tlob.dot
new file mode 100644
index 000000000000..a1834daff2ed
--- /dev/null
+++ b/tools/verification/models/tlob.dot
@@ -0,0 +1,22 @@
+digraph state_automaton {
+	center = true;
+	size = "7,11";
+	{node [shape = plaintext, style=invis, label=""] "__init_running"};
+	{node [shape = ellipse] "running"};
+	{node [shape = plaintext] "running"};
+	{node [shape = plaintext] "waiting"};
+	{node [shape = plaintext] "sleeping"};
+	"__init_running" -> "running";
+	"running"  -> "running"  [ label = "start;reset(clk_elapsed)" ];
+	"running"  [label = "running\nclk_elapsed < BUDGET_NS()",  color = green3];
+	"waiting"  [label = "waiting\nclk_elapsed < BUDGET_NS()"];
+	"sleeping" [label = "sleeping\nclk_elapsed < BUDGET_NS()"];
+	"running"  -> "sleeping" [ label = "sleep" ];
+	"running"  -> "waiting"  [ label = "preempt" ];
+	"waiting"  -> "running"  [ label = "switch_in" ];
+	"sleeping" -> "waiting"  [ label = "wakeup" ];
+	{ rank = min ;
+		"__init_running";
+		"running";
+	}
+}
-- 
2.25.1

[PATCH v4 4/8] rv/ha: fix ha_invariant_passed_ns silent bypass of invariant check

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

When env_store is U64_MAX (its initial sentinel value),
ha_invariant_passed_ns() returns 0 immediately without initializing
env_store to the current clock.  Subsequent calls to
ha_check_invariant_ns() then find env_store still at U64_MAX, causing
the elapsed comparison to wrap and always report the invariant as
satisfied, silently masking any violations.

Fix by calling ha_reset_clk_ns() to establish the guard on the first
invocation instead of returning early.  Apply the same fix to
ha_invariant_passed_jiffy().

Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 include/rv/ha_monitor.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h
index 83199f90afe8..dddf5694bcc8 100644
--- a/include/rv/ha_monitor.h
+++ b/include/rv/ha_monitor.h
@@ -375,12 +375,12 @@ static inline bool ha_check_invariant_ns(struct ha_monitor *ha_mon,
 static inline u64 ha_invariant_passed_ns(struct ha_monitor *ha_mon, enum envs env,
 				   u64 expire, u64 time_ns)
 {
-	u64 passed = 0;
+	u64 passed;
 
 	if (env < 0 || env >= ENV_MAX_STORED)
 		return 0;
 	if (ha_monitor_env_invalid(ha_mon, env))
-		return 0;
+		ha_reset_clk_ns(ha_mon, env, time_ns);
 	passed = ha_get_env(ha_mon, env, time_ns);
 	ha_set_invariant_ns(ha_mon, env, expire - passed, time_ns);
 	return passed;
@@ -414,12 +414,12 @@ static inline bool ha_check_invariant_jiffy(struct ha_monitor *ha_mon,
 static inline u64 ha_invariant_passed_jiffy(struct ha_monitor *ha_mon, enum envs env,
 				      u64 expire, u64 time_ns)
 {
-	u64 passed = 0;
+	u64 passed;
 
 	if (env < 0 || env >= ENV_MAX_STORED)
 		return 0;
 	if (ha_monitor_env_invalid(ha_mon, env))
-		return 0;
+		ha_reset_clk_jiffy(ha_mon, env);
 	passed = ha_get_env(ha_mon, env, time_ns);
 	ha_set_invariant_jiffy(ha_mon, env, expire - passed);
 	return passed;
-- 
2.25.1

[PATCH v4 5/8] rv/ha: make da_monitor_reset_hook and EVENT_NONE_LBL overridable

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Wrap both definitions with #ifndef guards so HA-based monitors can
substitute their own implementations before including this header.
tlob uses this to define a reset hook that cancels per-task hrtimers
on monitor teardown.

Overrides must still call ha_monitor_reset_env() or cancel outstanding
timers to avoid timer UAF.

No behaviour change for monitors that do not override either macro.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 include/rv/ha_monitor.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h
index dddf5694bcc8..6d526eef8348 100644
--- a/include/rv/ha_monitor.h
+++ b/include/rv/ha_monitor.h
@@ -36,7 +36,15 @@ static bool ha_monitor_handle_constraint(struct da_monitor *da_mon,
 					 da_id_type id);
 #define da_monitor_event_hook ha_monitor_handle_constraint
 #define da_monitor_init_hook ha_monitor_init_env
+
+/*
+ * Allow monitors to override da_monitor_reset_hook before including this
+ * header. The override must still call ha_monitor_reset_env() or cancel
+ * timers explicitly.
+ */
+#ifndef da_monitor_reset_hook
 #define da_monitor_reset_hook ha_monitor_reset_env
+#endif
 #define da_monitor_sync_hook() synchronize_rcu()
 
 #if !defined(HA_SKIP_AUTO_CLEANUP) && RV_MON_TYPE == RV_MON_PER_TASK
@@ -75,7 +83,9 @@ _Static_assert(offsetof(struct ha_monitor, da_mon) == 0,
 #define ENV_INVALID_VALUE U64_MAX
 /* Error with no event occurs only on timeouts */
 #define EVENT_NONE EVENT_MAX
+#ifndef EVENT_NONE_LBL
 #define EVENT_NONE_LBL "none"
+#endif
 #define ENV_BUFFER_SIZE 64
 
 #ifdef CONFIG_RV_REACTORS
-- 
2.25.1

[PATCH v4 6/8] rv/tlob: add tlob hybrid automaton monitor

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

tlob (task latency over budget) is a per-task hybrid automaton RV
monitor that tracks wall-clock time across a user-delimited code
section and emits an error when elapsed time exceeds a configurable
budget.

The automaton has three states (running, waiting, sleeping) driven by
sched_switch and sched_wakeup tracepoints, with a single clock
invariant enforced by a per-task HRTIMER_MODE_REL_HARD timer.  On
budget expiry the monitor records a per-state time breakdown
(running_ns, waiting_ns, sleeping_ns) before emitting error_env_tlob.

Uprobe pairs are registered through a tracefs monitor file as
"p PATH:OFFSET_START OFFSET_STOP threshold=NS" so arbitrary code
sections can be delimited without modifying the target binary.

Per-task state is allocated from a pre-allocated llist pool so the
uprobe entry handler incurs no dynamic allocation inside the [T0, T1]
measurement window.  DA_ALLOC_POOL is used for the same reason on the
da_monitor_storage side.

tlob_start_lock is a spinlock_t because the uprobe handler runs under
rcu_read_lock_trace() (Tasks Trace SRCU), which permits sleeping on
PREEMPT_RT where spinlock_t is an rt_mutex.  da_get_target_by_id() is
wrapped in scoped_guard(rcu) because hash_for_each_possible_rcu()
requires an RCU read-side critical section independent of the lock.

Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 Documentation/trace/rv/index.rst           |   1 +
 Documentation/trace/rv/monitor_tlob.rst    | 177 ++++
 kernel/trace/rv/Kconfig                    |   1 +
 kernel/trace/rv/Makefile                   |   1 +
 kernel/trace/rv/monitors/tlob/Kconfig      |  12 +
 kernel/trace/rv/monitors/tlob/tlob.c       | 969 +++++++++++++++++++++
 kernel/trace/rv/monitors/tlob/tlob.h       | 151 ++++
 kernel/trace/rv/monitors/tlob/tlob_trace.h |  52 ++
 kernel/trace/rv/rv_trace.h                 |   1 +
 9 files changed, 1365 insertions(+)
 create mode 100644 Documentation/trace/rv/monitor_tlob.rst
 create mode 100644 kernel/trace/rv/monitors/tlob/Kconfig
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob.c
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob.h
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob_trace.h

diff --git a/Documentation/trace/rv/index.rst b/Documentation/trace/rv/index.rst
index 29769f06bb0f..1501545b5f08 100644
--- a/Documentation/trace/rv/index.rst
+++ b/Documentation/trace/rv/index.rst
@@ -16,5 +16,6 @@ Runtime Verification
    monitor_wwnr.rst
    monitor_sched.rst
    monitor_rtapp.rst
+   monitor_tlob.rst
    monitor_stall.rst
    monitor_deadline.rst
diff --git a/Documentation/trace/rv/monitor_tlob.rst b/Documentation/trace/rv/monitor_tlob.rst
new file mode 100644
index 000000000000..327c9832bf31
--- /dev/null
+++ b/Documentation/trace/rv/monitor_tlob.rst
@@ -0,0 +1,177 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Monitor tlob
+============
+
+- Name: tlob - task latency over budget
+- Type: per-object hybrid automaton (RV_MON_PER_OBJ)
+- Author: Wen Yang <wen.yang@linux.dev>
+
+Description
+-----------
+
+The tlob monitor tracks per-task elapsed wall-clock time (CLOCK_MONOTONIC,
+spanning running, waiting, and sleeping states) and reports a violation when
+the monitored task exceeds a configurable per-invocation budget threshold.
+
+The monitor implements a three-state hybrid automaton with a single clock
+environment variable ``clk_elapsed``.  The clock invariant
+``clk_elapsed < BUDGET_NS()`` is active in all three states; when it is
+violated the HA timer fires and the framework emits ``error_env_tlob``
+then calls ``da_monitor_reset()`` automatically::
+
+                  | (initial, via task_start)
+                  v
+           +--------------+
+           |   running    | <-----------+
+           +--------------+             |
+             |         |                |
+           sleep     preempt        switch_in
+             |         |                |
+             v         v                |
+        +---------+  +---------+        |
+        | sleeping|  | waiting | -------+
+        +---------+  +---------+
+             |            ^
+             +---wakeup---+
+
+  Key transitions:
+    running  --(sleep)------> sleeping   (task blocks waiting for a resource)
+    running  --(preempt)----> waiting    (task preempted, back in runqueue)
+    sleeping --(wakeup)-----> waiting    (resource available, enters runqueue)
+    waiting  --(switch_in)--> running    (scheduler picks task, back on CPU)
+
+  ``tlob_start_task()`` calls ``da_handle_start_run_event(task->pid, ws, start_tlob)``.
+  The ``start_tlob`` self-loop on the ``running`` state triggers
+  ``ha_setup_invariants()``, which resets ``clk_elapsed`` and arms the budget
+  timer automatically.  ``tlob_stop_task()`` cancels the HA timer synchronously
+  via ``ha_cancel_timer_sync()``, then calls ``da_monitor_reset()``.
+
+The non-running condition (monitor not yet started or reset after a
+stop/violation) is handled implicitly by the RV framework
+(``da_mon->monitoring == 0``) - it is not an explicit DA state.
+
+Per-task state lives in ``struct tlob_task_state`` which is stored as
+``monitor_target`` in the framework's ``da_monitor_storage``, indexed by
+pid.  The per-invocation ``threshold_ns`` is read via
+``ha_get_target(ha_mon)->threshold_ns`` inside the HA constraint functions,
+following the same pattern as the ``nomiss`` monitor.
+
+Usage
+-----
+
+tracefs interface (uprobe-based external monitoring)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``monitor`` tracefs file instruments an unmodified binary via uprobes.
+The format follows the ftrace ``uprobe_events`` convention (``PATH:OFFSET``
+for the probe location, ``key=value`` for configuration parameters)::
+
+  p PATH:OFFSET_START OFFSET_STOP threshold=NS
+
+The uprobe at ``OFFSET_START`` fires ``tlob_start_task()``; the uprobe at
+``OFFSET_STOP`` fires ``tlob_stop_task()``.  Both offsets are ELF file
+offsets of entry points in ``PATH``.  ``PATH`` may contain ``:``; the last
+``:`` in the ``PATH:OFFSET_START`` token is the separator.
+
+To remove a binding, use ``-PATH:OFFSET_START``::
+
+  echo 1 > /sys/kernel/tracing/rv/monitors/tlob/enable
+
+  echo "p /usr/bin/myapp:0x12a0 0x12f0 threshold=5000000" \
+      > /sys/kernel/tracing/rv/monitors/tlob/monitor
+
+  # Remove a binding
+  echo "-/usr/bin/myapp:0x12a0" > /sys/kernel/tracing/rv/monitors/tlob/monitor
+
+  # List registered bindings
+  cat /sys/kernel/tracing/rv/monitors/tlob/monitor
+
+  # Read violations from the trace buffer
+  cat /sys/kernel/tracing/trace
+
+Violation tracepoints
+~~~~~~~~~~~~~~~~~~~~~
+
+Two tracepoints are emitted together on a budget violation:
+
+``error_env_tlob``
+  Standard HA clock-invariant tracepoint (emitted by the RV framework).
+  Fields: ``id`` (task pid), ``state``, ``event`` (``"budget_exceeded"``),
+  ``env`` (``"clk_elapsed"``).
+
+``detail_env_tlob``
+  Tlob-specific breakdown of elapsed time per DA state.
+  Fields: ``id`` (task pid), ``threshold_ns``, ``running_ns``,
+  ``waiting_ns``, ``sleeping_ns``.
+
+  Use ``detail_env_tlob`` to diagnose *which phase* consumed the budget:
+  high ``sleeping_ns`` indicates I/O latency; high ``waiting_ns`` indicates
+  scheduler pressure; high ``running_ns`` indicates a compute overrun.
+
+Example: correlate the two tracepoints to see the breakdown::
+
+  trace-cmd record -e error_env_tlob -e detail_env_tlob &
+  # ... run workload ...
+  trace-cmd report
+
+tracefs files
+~~~~~~~~~~~~~
+
+The following files are specific to tlob under
+``/sys/kernel/tracing/rv/monitors/tlob/``:
+
+``monitor`` (rw)
+  Write ``p PATH:OFFSET_START OFFSET_STOP threshold=NS``
+  to bind two entry uprobes.  Write ``-PATH:OFFSET_START`` to remove a
+  binding.  Read to list registered bindings in the same format.
+  See the `tracefs interface (uprobe-based external monitoring)`_ section above.
+
+Kernel API
+----------
+
+``tlob_start_task`` and ``tlob_stop_task`` are the implementation-level
+functions called by the uprobe entry/exit handlers; the interface is
+driven from userspace.
+
+.. kernel-doc:: kernel/trace/rv/monitors/tlob/tlob.c
+   :functions: tlob_start_task tlob_stop_task
+
+``tlob_start_task(task, threshold_ns)``
+  Begin monitoring *task* with a total latency budget of *threshold_ns*
+  nanoseconds.  Allocates per-task state, sets initial DA state to
+  ``running``, resets ``clk_elapsed``, and arms the HA budget timer.
+  Returns 0, -ENODEV (monitor disabled), -ERANGE (threshold out of range),
+  -EALREADY (already monitoring), -ENOSPC (at capacity), or -ENOMEM.
+
+``tlob_stop_task(task)``
+  Stop monitoring *task*.  Synchronously cancels the HA timer via
+  ``ha_cancel_timer_sync()``, checks ``da_monitoring()`` to determine outcome.
+  Returns 0 (clean stop, within budget), -EOVERFLOW (budget was exceeded),
+  -ESRCH (not monitored), or -EAGAIN (concurrent stop racing).
+
+Design notes
+------------
+
+Limitations:
+
+- The initial DA state is always ``running``, set by feeding the synthetic
+  event ``switch_in_tlob`` to ``da_handle_start_event()``.  Monitoring a non-current
+  task that is already in waiting or sleeping state at call time misclassifies
+  the first interval as ``running_ns``.
+- ``TASK_STOPPED`` and ``TASK_TRACED`` carry ``prev_state != 0`` and are
+  therefore counted as ``sleeping_ns``, indistinguishable from
+  I/O-blocked time.
+- ``sched_wakeup_new`` is not hooked.  In practice this is not an issue
+  because ``tlob_start_task`` is always called from a running context.
+
+Specification
+-------------
+
+Graphviz DOT file in tools/verification/models/tlob.dot.
+
+KUnit tests under ``kernel/trace/rv/monitors/tlob/tlob_kunit.c``
+(CONFIG_TLOB_KUNIT_TEST).
+
+User-space integration tests under ``tools/testing/selftests/verification/``
+(requires CONFIG_RV_MON_TLOB=y and root).
diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
index 5bad1d63f411..ed0dc8241691 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -90,6 +90,7 @@ source "kernel/trace/rv/monitors/deadline/Kconfig"
 source "kernel/trace/rv/monitors/nomiss/Kconfig"
 # Add new deadline monitors here
 
+source "kernel/trace/rv/monitors/tlob/Kconfig"
 # Add new monitors here
 
 config RV_REACTORS
diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index f139b904bea3..ae59e97f8682 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_RV_MON_OPID) += monitors/opid/opid.o
 obj-$(CONFIG_RV_MON_STALL) += monitors/stall/stall.o
 obj-$(CONFIG_RV_MON_DEADLINE) += monitors/deadline/deadline.o
 obj-$(CONFIG_RV_MON_NOMISS) += monitors/nomiss/nomiss.o
+obj-$(CONFIG_RV_MON_TLOB) += monitors/tlob/tlob.o
 # Add new monitors here
 obj-$(CONFIG_RV_UPROBE) += rv_uprobe.o
 obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
diff --git a/kernel/trace/rv/monitors/tlob/Kconfig b/kernel/trace/rv/monitors/tlob/Kconfig
new file mode 100644
index 000000000000..aa43382073d2
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+config RV_MON_TLOB
+	bool "tlob monitor"
+	depends on RV && UPROBES && HIGH_RES_TIMERS
+	select HA_MON_EVENTS_ID
+	select RV_UPROBE
+	help
+	  Enable the tlob (task latency over budget) hybrid-automaton RV
+	  monitor.  tlob tracks per-task elapsed wall-clock time across a
+	  user-delimited code section and emits error_env_tlob when the
+	  elapsed time exceeds a configurable per-invocation budget.
diff --git a/kernel/trace/rv/monitors/tlob/tlob.c b/kernel/trace/rv/monitors/tlob/tlob.c
new file mode 100644
index 000000000000..b45e84195131
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/tlob.c
@@ -0,0 +1,969 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tlob: task latency over budget monitor
+ *
+ * Track the elapsed wall-clock time of a marked code path and detect when
+ * a monitored task exceeds its per-task latency budget.  CLOCK_MONOTONIC
+ * is used so both on-CPU and off-CPU time count toward the budget.
+ *
+ * On a budget violation, two tracepoints are emitted from the hrtimer
+ * callback: error_env_tlob signals the violation, and detail_env_tlob
+ * provides a per-state time breakdown (running_ns, waiting_ns, sleeping_ns)
+ * that pinpoints whether the overrun occurred in the running, waiting,
+ * or sleeping state.
+ *
+ * The monitor uses RV_MON_PER_OBJ: per-task state (struct tlob_task_state)
+ * is stored as monitor_target in the framework's hash table.
+ *
+ * One HA clock invariant is enforced:
+ *   clk_elapsed < BUDGET_NS()   (active in all states)
+ *
+ * Copyright (C) 2026 Wen Yang <wen.yang@linux.dev>
+ */
+#include <linux/kernel.h>
+#include <linux/llist.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/rv.h>
+#include <linux/slab.h>
+#include <kunit/visibility.h>
+#include <rv/instrumentation.h>
+#include <rv/rv_uprobe.h>
+#include <rv.h>
+
+#define MODULE_NAME "tlob"
+
+#include <trace/events/sched.h>
+#include <rv_trace.h>
+
+/*
+ * Per-task latency monitoring state.  One instance per monitoring window.
+ * Stored as monitor_target in da_monitor_storage; freed via call_rcu.
+ */
+enum tlob_acc_idx {
+	TLOB_ACC_RUNNING,
+	TLOB_ACC_WAITING,
+	TLOB_ACC_SLEEPING,
+	TLOB_ACC_MAX,
+};
+
+struct tlob_task_state {
+	struct task_struct	*task;		/* via get_task_struct */
+	u64			threshold_ns;	/* budget in nanoseconds */
+
+	/* 1 = cleanup claimed; ha_setup_invariants won't restart the timer. */
+	atomic_t		stopping;
+
+	/* Serialises accs_ns[]; held briefly (hardirq-safe). */
+	raw_spinlock_t		entry_lock;
+	u64			accs_ns[TLOB_ACC_MAX]; /* per-state elapsed ns */
+	ktime_t			last_ts;
+
+	struct rcu_head		rcu;
+	/* Free-list node; active only between call_rcu() return and next alloc. */
+	struct llist_node	free_node;
+};
+
+#define RV_MON_TYPE RV_MON_PER_OBJ
+#define HA_TIMER_TYPE HA_TIMER_HRTIMER
+
+typedef struct tlob_task_state *monitor_target;
+
+static inline void tlob_reset_notify(struct da_monitor *da_mon);
+#define da_monitor_reset_hook tlob_reset_notify
+
+static inline void tlob_extra_cleanup(struct da_monitor *da_mon);
+#define da_extra_cleanup tlob_extra_cleanup
+
+#define EVENT_NONE_LBL "budget_exceeded"
+
+#include "tlob.h"
+
+#define DA_MON_POOL_SIZE TLOB_MAX_MONITORED
+
+#include <rv/ha_monitor.h>
+
+/*
+ * Called from da_monitor_reset() on both normal stop and hrtimer expiry.
+ * On violation (stopping==0), emits detail_env_tlob.
+ */
+static inline void tlob_reset_notify(struct da_monitor *da_mon)
+{
+	struct ha_monitor *ha_mon = to_ha_monitor(da_mon);
+	struct tlob_task_state *ws;
+
+	ha_monitor_reset_env(da_mon);
+
+	if (!trace_detail_env_tlob_enabled())
+		return;
+
+	ws = ha_get_target(ha_mon);
+	if (!ws)
+		return;
+
+	/*
+	 * Emit per-state breakdown on budget violation only.
+	 * stopping==0: timer callback owns this path (genuine overrun).
+	 * stopping==1: normal stop claimed ownership first; skip.
+	 */
+	if (!atomic_read(&ws->stopping)) {
+		unsigned int curr_state = READ_ONCE(da_mon->curr_state);
+		u64 accs[TLOB_ACC_MAX], partial_ns;
+		unsigned long flags;
+
+		/*
+		 * Snapshot accumulators; partial_ns covers curr_state time
+		 * not yet folded in (transition-out pending).
+		 */
+		raw_spin_lock_irqsave(&ws->entry_lock, flags);
+		partial_ns = ktime_get_ns() - ktime_to_ns(ws->last_ts);
+		accs[TLOB_ACC_RUNNING]  = ws->accs_ns[TLOB_ACC_RUNNING]  +
+					  (curr_state == running_tlob  ? partial_ns : 0);
+		accs[TLOB_ACC_WAITING]  = ws->accs_ns[TLOB_ACC_WAITING]  +
+					  (curr_state == waiting_tlob  ? partial_ns : 0);
+		accs[TLOB_ACC_SLEEPING] = ws->accs_ns[TLOB_ACC_SLEEPING] +
+					  (curr_state == sleeping_tlob ? partial_ns : 0);
+		raw_spin_unlock_irqrestore(&ws->entry_lock, flags);
+
+		trace_detail_env_tlob(da_get_id(da_mon), ws->threshold_ns,
+				      accs[TLOB_ACC_RUNNING],
+				      accs[TLOB_ACC_WAITING],
+				      accs[TLOB_ACC_SLEEPING]);
+	}
+}
+
+#define BUDGET_NS(ha_mon) (ha_get_target(ha_mon)->threshold_ns)
+
+/* HA constraint functions (called by ha_monitor_handle_constraint) */
+
+static u64 ha_get_env(struct ha_monitor *ha_mon, enum envs_tlob env,
+		      u64 time_ns)
+{
+	if (env == clk_elapsed_tlob)
+		return ha_get_clk_ns(ha_mon, env, time_ns);
+	return ENV_INVALID_VALUE;
+}
+
+/*
+ * ha_verify_invariants - clk_elapsed < BUDGET_NS must hold in all states.
+ *
+ * The invariant is uniform across running/waiting/sleeping; check it
+ * unconditionally rather than enumerating each state.
+ */
+static inline bool ha_verify_invariants(struct ha_monitor *ha_mon,
+					enum states curr_state, enum events event,
+					enum states next_state, u64 time_ns)
+{
+	return ha_check_invariant_ns(ha_mon, clk_elapsed_tlob, time_ns);
+}
+
+/*
+ * Convert invariant (deadline) to guard (reset anchor) on state transitions.
+ *
+ * The conversion is identical for every departing state; skip only self-loops.
+ */
+static inline void ha_convert_inv_guard(struct ha_monitor *ha_mon,
+					enum states curr_state, enum events event,
+					enum states next_state, u64 time_ns)
+{
+	if (curr_state != next_state)
+		ha_inv_to_guard(ha_mon, clk_elapsed_tlob, BUDGET_NS(ha_mon), time_ns);
+}
+
+/* No per-event guard conditions for tlob; invariants suffice. */
+static inline bool ha_verify_guards(struct ha_monitor *ha_mon,
+				    enum states curr_state, enum events event,
+				    enum states next_state, u64 time_ns)
+{
+	return true;
+}
+
+/*
+ * Guard on stopping: a sched_switch arriving after ha_cancel_timer_sync()
+ * would re-arm the timer and trigger an ODEBUG "activate active" splat.
+ * _acquire pairs with cmpxchg_release in tlob_stop_task.
+ */
+static inline void ha_setup_invariants(struct ha_monitor *ha_mon,
+				       enum states curr_state, enum events event,
+				       enum states next_state, u64 time_ns)
+{
+	if (atomic_read_acquire(&ha_get_target(ha_mon)->stopping))
+		return;
+	if (next_state < state_max_tlob)
+		ha_start_timer_ns(ha_mon, clk_elapsed_tlob, BUDGET_NS(ha_mon), time_ns);
+	else
+		ha_cancel_timer(ha_mon);
+}
+
+static bool ha_verify_constraint(struct ha_monitor *ha_mon,
+				 enum states curr_state, enum events event,
+				 enum states next_state, u64 time_ns)
+{
+	if (!ha_verify_invariants(ha_mon, curr_state, event, next_state, time_ns))
+		return false;
+
+	ha_convert_inv_guard(ha_mon, curr_state, event, next_state, time_ns);
+
+	if (!ha_verify_guards(ha_mon, curr_state, event, next_state, time_ns))
+		return false;
+
+	ha_setup_invariants(ha_mon, curr_state, event, next_state, time_ns);
+
+	return true;
+}
+
+/*
+ * Pre-allocated pool for tlob_task_state slots.  Lock-free llist so that
+ * tlob_ws_return_cb() (RCU callback) can return slots without acquiring a
+ * spinlock.  Same concurrency model as da_pool_storage (see da_monitor.h).
+ */
+static struct tlob_task_state *tlob_ws_storage;
+static LLIST_HEAD(tlob_ws_free_list);
+
+static void tlob_ws_return_cb(struct rcu_head *head)
+{
+	struct tlob_task_state *ws =
+		container_of(head, struct tlob_task_state, rcu);
+
+	llist_add(&ws->free_node, &tlob_ws_free_list);
+}
+
+/* Direct return to free list without RCU delay (ws was never published). */
+static void tlob_ws_direct_return(struct tlob_task_state *ws)
+{
+	llist_add(&ws->free_node, &tlob_ws_free_list);
+}
+
+static struct tlob_task_state *tlob_ws_alloc(void)
+{
+	struct llist_node *node = llist_del_first(&tlob_ws_free_list);
+
+	if (!node)
+		return NULL;
+
+	struct tlob_task_state *ws =
+		llist_entry(node, struct tlob_task_state, free_node);
+
+	memset(ws, 0, sizeof(*ws));
+	return ws;
+}
+
+/* Uprobe binding list; protected by tlob_uprobe_mutex. */
+static LIST_HEAD(tlob_uprobe_list);
+static DEFINE_MUTEX(tlob_uprobe_mutex);
+
+/*
+ * Serialises duplicate-check + da_handle_start_run_event() per pid.
+ * spinlock_t not raw_spinlock_t: uprobe handlers run under Tasks Trace
+ * SRCU (rcu_read_lock_trace()), which permits sleeping on PREEMPT_RT.
+ */
+static DEFINE_SPINLOCK(tlob_start_lock);
+
+/* Per-uprobe-binding state: a start + stop probe pair for one binary region. */
+struct tlob_uprobe_binding {
+	struct list_head	list;
+	u64			threshold_ns;
+	char			binpath[TLOB_MAX_PATH];
+	loff_t			offset_start;
+	loff_t			offset_stop;
+	DECLARE_RV_UPROBE(start_probe);
+	DECLARE_RV_UPROBE(stop_probe);
+};
+
+/*
+ * Per-task teardown invoked by da_monitor_destroy() for each hash entry.
+ * CAS on stopping (0->1) claims exclusive cleanup ownership.
+ *
+ * No per-entry ha_cancel_timer_sync(): da_monitor_destroy() calls
+ * da_monitor_reset_all() + synchronize_rcu() before this hook, and
+ * ha_mon_destroying prevents new timer callbacks from running.
+ */
+static inline void tlob_extra_cleanup(struct da_monitor *da_mon)
+{
+	struct ha_monitor *ha_mon = to_ha_monitor(da_mon);
+	struct tlob_task_state *ws = ha_get_target(ha_mon);
+
+	if (!ws)
+		return;
+
+	if (atomic_cmpxchg_release(&ws->stopping, 0, 1) != 0)
+		return;
+
+	put_task_struct(ws->task);
+	/*
+	 * da_monitor_destroy() has already called synchronize_rcu(); no
+	 * reader holds ws.  Return the slot directly without call_rcu.
+	 */
+	llist_add(&ws->free_node, &tlob_ws_free_list);
+}
+
+static inline bool __tlob_acc(struct task_struct *task, ktime_t now,
+			       enum tlob_acc_idx idx)
+{
+	struct tlob_task_state *ws;
+	unsigned long flags;
+
+	guard(rcu)();
+	ws = da_get_target_by_id(task->pid);
+	if (!ws)
+		return false;
+	raw_spin_lock_irqsave(&ws->entry_lock, flags);
+	ws->accs_ns[idx] += ktime_to_ns(ktime_sub(now, ws->last_ts));
+	ws->last_ts = now;
+	raw_spin_unlock_irqrestore(&ws->entry_lock, flags);
+	return true;
+}
+
+/* Accumulate running_ns for prev; returns true if prev is monitored. */
+static inline bool tlob_acc_running(struct task_struct *task, ktime_t now)
+{
+	return __tlob_acc(task, now, TLOB_ACC_RUNNING);
+}
+
+/* Accumulate waiting_ns for next; returns true if next is monitored. */
+static inline bool tlob_acc_waiting(struct task_struct *task, ktime_t now)
+{
+	return __tlob_acc(task, now, TLOB_ACC_WAITING);
+}
+
+/*
+ * handle_sched_switch - advance the DA on every context switch.
+ *
+ * Generates three DA events:
+ *   prev, prev_state != 0  -> sleep_tlob    (running -> sleeping)
+ *   prev, prev_state == 0  -> preempt_tlob  (running -> waiting)
+ *   next                   -> switch_in_tlob (waiting -> running)
+ *
+ * A single ktime_get() at handler entry is shared by both acc calls so that
+ * prev's running_ns and next's waiting_ns share the same context-switch
+ * timestamp; neither absorbs handler overhead into its accumulator.
+ *
+ * No waiting->sleeping edge exists: a task can only block voluntarily
+ * (call schedule()) while it is executing on CPU, which corresponds to
+ * the running DA state.  A task in the waiting state is TASK_RUNNING in
+ * kernel terms (on the runqueue) and cannot block itself.
+ *
+ * da_handle_event() is called unconditionally: it skips tasks that have no
+ * monitor entry in the hash table.
+ */
+static void handle_sched_switch(void *data, bool preempt_unused,
+				struct task_struct *prev,
+				struct task_struct *next,
+				unsigned int prev_state)
+{
+	ktime_t now = ktime_get();
+	bool prev_preempted = (prev_state == 0);
+
+	if (tlob_acc_running(prev, now))
+		da_handle_event(prev->pid, NULL,
+				prev_preempted ? preempt_tlob : sleep_tlob);
+	if (tlob_acc_waiting(next, now))
+		da_handle_event(next->pid, NULL, switch_in_tlob);
+}
+
+/* Accumulate sleeping_ns on wakeup; returns true if task is monitored. */
+static inline bool tlob_acc_sleeping(struct task_struct *task, ktime_t now)
+{
+	return __tlob_acc(task, now, TLOB_ACC_SLEEPING);
+}
+
+/*
+ * handle_sched_wakeup - sleeping -> waiting transition.
+ *
+ * try_to_wake_up() skips TASK_RUNNING tasks, so this never fires for a
+ * task already in running or waiting state.
+ */
+static void handle_sched_wakeup(void *data, struct task_struct *p)
+{
+	ktime_t now = ktime_get();
+
+	if (tlob_acc_sleeping(p, now))
+		da_handle_event(p->pid, NULL, wakeup_tlob);
+}
+
+/*
+ * handle_sched_process_exit - clean up if a task exits without TRACE_STOP.
+ *
+ * Called in do_exit() context; the task still has a valid pid here.
+ * tlob_stop_task() returns -ESRCH if the task is not monitored, which is fine.
+ */
+static void handle_sched_process_exit(void *data, struct task_struct *p,
+				       bool group_dead)
+{
+	tlob_stop_task(p);
+}
+
+/**
+ * tlob_start_task - begin monitoring @task with budget @threshold_ns ns.
+ * @task:         Task to monitor; may be current or another task.
+ * @threshold_ns: Latency budget in nanoseconds (wall-clock; running +
+ *                waiting + sleeping).
+ *                Must be in [1000, TLOB_MAX_THRESHOLD_NS].
+ *
+ * Returns 0, -ENODEV, -ERANGE, -EALREADY, or -ENOSPC (pool at capacity).
+ */
+int tlob_start_task(struct task_struct *task, u64 threshold_ns)
+{
+	struct tlob_task_state *ws;
+
+	if (!da_monitor_enabled())
+		return -ENODEV;
+
+	if (threshold_ns < TLOB_MIN_THRESHOLD_NS ||
+	    threshold_ns > TLOB_MAX_THRESHOLD_NS)
+		return -ERANGE;
+
+	/* Serialise duplicate-check + pool-slot claim; see tlob_start_lock. */
+	guard(spinlock)(&tlob_start_lock);
+
+	/*
+	 * __da_get_mon_storage() uses hash_for_each_possible_rcu(), which
+	 * requires an RCU read-side critical section.  On PREEMPT_RT,
+	 * spinlock_t is an rt_mutex and does not satisfy this requirement.
+	 */
+	scoped_guard(rcu) {
+		if (da_get_target_by_id(task->pid))
+			return -EALREADY;
+	}
+
+	/*
+	 * Both tlob_ws_alloc() and da_handle_start_run_event() pop from
+	 * pre-allocated pools of size TLOB_MAX_MONITORED; NULL return means
+	 * the pool is at capacity.
+	 */
+	ws = tlob_ws_alloc();
+	if (!ws)
+		return -ENOSPC;
+
+	ws->task = task;
+	get_task_struct(task);
+	ws->threshold_ns = threshold_ns;
+	ws->last_ts = ktime_get();
+	raw_spin_lock_init(&ws->entry_lock);
+
+	/*
+	 * da_handle_start_run_event() claims a pool slot via da_prepare_storage(),
+	 * initialises the monitor, and delivers start_tlob in one step: the
+	 * generated ha_setup_invariants() resets clk_elapsed and arms the timer.
+	 * Returns 0 if the da_monitor_storage pool is exhausted.
+	 */
+	if (!da_handle_start_run_event(task->pid, ws, start_tlob)) {
+		put_task_struct(task);
+		tlob_ws_direct_return(ws);
+		return -ENOSPC;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tlob_start_task);
+
+/**
+ * tlob_stop_task - stop monitoring @task.
+ * @task: Task to stop.
+ *
+ * CAS on ws->stopping (0->1) under RCU claims cleanup ownership;
+ * the winner cancels the timer synchronously and frees all resources.
+ *
+ * Returns 0, -EOVERFLOW (budget exceeded), -ESRCH (not monitored),
+ * or -EAGAIN (concurrent caller claimed cleanup).
+ */
+int tlob_stop_task(struct task_struct *task)
+{
+	struct da_monitor *da_mon;
+	struct ha_monitor *ha_mon;
+	struct tlob_task_state *ws;
+	bool budget_exceeded;
+
+	scoped_guard(rcu) {
+		ws = da_get_target_by_id(task->pid);
+		if (!ws)
+			return -ESRCH;
+
+		da_mon = da_get_monitor(task->pid, NULL);
+		if (unlikely(WARN_ON_ONCE(!da_mon)))
+			return -ESRCH;
+
+		ha_mon = to_ha_monitor(da_mon);
+
+		/*
+		 * CAS (0->1) claims cleanup ownership under RCU (ws guaranteed valid).
+		 * _release pairs with atomic_read_acquire in ha_setup_invariants.
+		 */
+		if (atomic_cmpxchg_release(&ws->stopping, 0, 1) != 0)
+			return -EAGAIN;
+	}
+	/*
+	 * ws and ha_mon are used below outside the RCU guard.  This is safe:
+	 * the winning CAS (stopping: 0->1) is the only path that frees ws,
+	 * and da_destroy_storage() below is the only call that returns the
+	 * pool slot.  No concurrent path can free either object.
+	 */
+
+	/* Wait for in-flight timer callback before reading da_monitoring. */
+	ha_cancel_timer_sync(ha_mon);
+
+	/* Timer fired first -> budget exceeded; otherwise reset normally. */
+	scoped_guard(rcu) {
+		budget_exceeded = !da_monitoring(da_mon);
+		if (!budget_exceeded)
+			da_monitor_reset(da_mon);
+	}
+	da_destroy_storage(task->pid);
+
+	put_task_struct(ws->task);
+	call_rcu(&ws->rcu, tlob_ws_return_cb);
+	return budget_exceeded ? -EOVERFLOW : 0;
+}
+EXPORT_SYMBOL_GPL(tlob_stop_task);
+
+static int tlob_uprobe_entry_handler(struct uprobe_consumer *self,
+				     struct pt_regs *regs, __u64 *data)
+{
+	struct tlob_uprobe_binding *b =
+		container_of(self, struct tlob_uprobe_binding, start_probe.uc);
+
+	tlob_start_task(current, b->threshold_ns);
+	return 0;
+}
+
+static int tlob_uprobe_stop_handler(struct uprobe_consumer *self,
+				    struct pt_regs *regs, __u64 *data)
+{
+	tlob_stop_task(current);
+	return 0;
+}
+
+/*
+ * Register start + stop entry uprobes for a binding.
+ * Called with tlob_uprobe_mutex held.
+ */
+static int tlob_add_uprobe(u64 threshold_ns, const char *binpath,
+			   loff_t offset_start, loff_t offset_stop)
+{
+	struct tlob_uprobe_binding *tmp_b;
+	char pathbuf[TLOB_MAX_PATH];
+	struct inode *inode;
+	struct path path __free(path_put) = {};
+	char *canon;
+	int ret;
+
+	if (binpath[0] != '/')
+		return -EINVAL;
+
+	struct tlob_uprobe_binding *b __free(kfree) = kzalloc_obj(*b, GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	b->threshold_ns = threshold_ns;
+	b->offset_start = offset_start;
+	b->offset_stop  = offset_stop;
+
+	ret = kern_path(binpath, LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ret;
+
+	if (!d_is_reg(path.dentry))
+		return -EINVAL;
+
+	inode = d_real_inode(path.dentry);
+
+	/* Reject duplicate start offset for the same binary inode. */
+	list_for_each_entry(tmp_b, &tlob_uprobe_list, list) {
+		if (tmp_b->offset_start == offset_start &&
+		    rv_uprobe_is_registered(&tmp_b->start_probe) &&
+		    tmp_b->start_probe.inode == inode)
+			return -EEXIST;
+	}
+
+	canon = d_path(&path, pathbuf, sizeof(pathbuf));
+	if (IS_ERR(canon))
+		return PTR_ERR(canon);
+	strscpy(b->binpath, canon, sizeof(b->binpath));
+
+	b->start_probe.uc.handler = tlob_uprobe_entry_handler;
+	ret = rv_uprobe_register(b->binpath, offset_start, &b->start_probe);
+	if (ret)
+		return ret;
+
+	b->stop_probe.uc.handler = tlob_uprobe_stop_handler;
+	ret = rv_uprobe_register(b->binpath, offset_stop, &b->stop_probe);
+	if (ret) {
+		rv_uprobe_unregister(&b->start_probe);
+		return ret;
+	}
+
+	/*
+	 * Do NOT write "b = no_free_ptr(b)": the re-assignment restores b,
+	 * causing __free(kfree) to free a live list node on exit.
+	 */
+	list_add_tail(&no_free_ptr(b)->list, &tlob_uprobe_list);
+	return 0;
+}
+
+static int tlob_remove_uprobe_by_key(loff_t offset_start, const char *binpath)
+{
+	struct tlob_uprobe_binding *b, *tmp;
+	struct path remove_path;
+	struct inode *inode;
+	int ret;
+
+	ret = kern_path(binpath, LOOKUP_FOLLOW, &remove_path);
+	if (ret)
+		return ret;
+
+	inode = d_real_inode(remove_path.dentry);
+
+	ret = -ENOENT;
+	list_for_each_entry_safe(b, tmp, &tlob_uprobe_list, list) {
+		if (b->offset_start != offset_start)
+			continue;
+		if (b->start_probe.inode != inode)
+			continue;
+		list_del(&b->list);
+		/*
+		 * rv_uprobe_sync() may sleep, blocking tlob_monitor_read() on
+		 * tlob_uprobe_mutex.  Safe: list_del() above made the binding
+		 * invisible to new readers before we drop the mutex.
+		 */
+		rv_uprobe_unregister_nosync(&b->start_probe);
+		rv_uprobe_unregister_nosync(&b->stop_probe);
+		rv_uprobe_sync();
+		kfree(b);
+		ret = 0;
+		break;
+	}
+
+	path_put(&remove_path);
+	return ret;
+}
+
+static void tlob_remove_all_uprobes(void)
+{
+	struct tlob_uprobe_binding *b, *tmp;
+	LIST_HEAD(pending);
+
+	mutex_lock(&tlob_uprobe_mutex);
+	list_for_each_entry_safe(b, tmp, &tlob_uprobe_list, list) {
+		list_move(&b->list, &pending);
+		rv_uprobe_unregister_nosync(&b->start_probe);
+		rv_uprobe_unregister_nosync(&b->stop_probe);
+	}
+	mutex_unlock(&tlob_uprobe_mutex);
+
+	if (list_empty(&pending))
+		return;
+
+	/*
+	 * One rv_uprobe_sync() covers all probes dequeued above.
+	 * After this, no handler_chain() iteration can access any consumer.
+	 * The embedded uprobe_consumers in each binding are safe to free.
+	 */
+	rv_uprobe_sync();
+
+	list_for_each_entry_safe(b, tmp, &pending, list) {
+		list_del(&b->list);
+		kfree(b);
+	}
+}
+
+static ssize_t tlob_monitor_read(struct file *file,
+				 char __user *ubuf,
+				 size_t count, loff_t *ppos)
+{
+	const int line_sz = TLOB_MAX_PATH + 128;
+	struct tlob_uprobe_binding *b;
+	char *buf;
+	int n = 0, buf_sz, pos = 0;
+	ssize_t ret;
+
+	mutex_lock(&tlob_uprobe_mutex);
+	list_for_each_entry(b, &tlob_uprobe_list, list)
+		n++;
+
+	buf_sz = (n ? n : 1) * line_sz + 1;
+	buf = kmalloc(buf_sz, GFP_KERNEL);
+	if (!buf) {
+		mutex_unlock(&tlob_uprobe_mutex);
+		return -ENOMEM;
+	}
+
+	list_for_each_entry(b, &tlob_uprobe_list, list) {
+		pos += scnprintf(buf + pos, buf_sz - pos,
+				 "p %s:0x%llx 0x%llx threshold=%llu\n",
+				 b->binpath,
+				 (unsigned long long)b->offset_start,
+				 (unsigned long long)b->offset_stop,
+				 b->threshold_ns);
+	}
+	mutex_unlock(&tlob_uprobe_mutex);
+
+	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * Parse "p PATH:OFFSET_START OFFSET_STOP threshold=NS".
+ * PATH may contain ':'; the last ':' separates path from offset.
+ * Returns 0, -EINVAL, or -ERANGE.
+ */
+static int tlob_parse_uprobe_line(char *buf, u64 *thr_out,
+				  char **path_out,
+				  loff_t *start_out, loff_t *stop_out)
+{
+	unsigned long long thr = 0, stop_val = 0;
+	long long start_val;
+	char *p, *path_token, *token, *colon;
+	bool got_stop = false, got_thr = false;
+	int n;
+
+	/* Must start with "p " */
+	if (buf[0] != 'p' || buf[1] != ' ')
+		return -EINVAL;
+
+	p = buf + 2;
+	while (*p == ' ')
+		p++;
+
+	/* First space-delimited token is PATH:OFFSET_START */
+	path_token = strsep(&p, " \t");
+	if (!path_token || !*path_token)
+		return -EINVAL;
+
+	/* Split at last ':' to handle paths that contain ':'. */
+	colon = strrchr(path_token, ':');
+	if (!colon || colon - path_token < 2)
+		return -EINVAL;
+	*colon = '\0';
+
+	if (path_token[0] != '/')
+		return -EINVAL;
+
+	n = 0;
+	if (sscanf(colon + 1, "%lli%n", &start_val, &n) != 1 || n == 0)
+		return -EINVAL;
+	if (start_val < 0)
+		return -EINVAL;
+
+	/* Remaining tokens: OFFSET_STOP threshold=NS */
+	while (p && (token = strsep(&p, " \t")) != NULL) {
+		if (!*token)
+			continue;
+		if (strncmp(token, "threshold=", 10) == 0) {
+			if (kstrtoull(token + 10, 0, &thr))
+				return -EINVAL;
+			if (thr < TLOB_MIN_THRESHOLD_NS || thr > TLOB_MAX_THRESHOLD_NS)
+				return -ERANGE;
+			got_thr = true;
+		} else if (!got_stop) {
+			long long sv;
+
+			n = 0;
+			if (sscanf(token, "%lli%n", &sv, &n) != 1 || n == 0)
+				return -EINVAL;
+			if (sv < 0)
+				return -EINVAL;
+			stop_val = (unsigned long long)sv;
+			got_stop = true;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	if (!got_stop || !got_thr)
+		return -EINVAL;
+	if (start_val == (long long)stop_val)
+		return -EINVAL;
+
+	*thr_out   = thr;
+	*path_out  = path_token;
+	*start_out = (loff_t)start_val;
+	*stop_out  = (loff_t)stop_val;
+	return 0;
+}
+
+/*
+ * Parse "-PATH:OFFSET_START" (ftrace uprobe_events removal convention).
+ */
+VISIBLE_IF_KUNIT int tlob_parse_remove_line(char *buf, char **path_out,
+					    loff_t *start_out)
+{
+	char *binpath, *colon;
+	long long off;
+	int n = 0;
+
+	if (buf[0] != '-')
+		return -EINVAL;
+	binpath = buf + 1;
+	if (binpath[0] != '/')
+		return -EINVAL;
+	colon = strrchr(binpath, ':');
+	if (!colon || colon - binpath < 2)
+		return -EINVAL;
+	*colon = '\0';
+	if (sscanf(colon + 1, "%lli%n", &off, &n) != 1 || n == 0)
+		return -EINVAL;
+	if (off < 0)
+		return -EINVAL;
+	*path_out  = binpath;
+	*start_out = (loff_t)off;
+	return 0;
+}
+
+VISIBLE_IF_KUNIT int tlob_create_or_delete_uprobe(char *buf)
+{
+	loff_t offset_start, offset_stop;
+	u64 threshold_ns;
+	char *binpath;
+	int ret;
+
+	if (buf[0] == '-') {
+		ret = tlob_parse_remove_line(buf, &binpath, &offset_start);
+		if (ret)
+			return ret;
+		mutex_lock(&tlob_uprobe_mutex);
+		ret = tlob_remove_uprobe_by_key(offset_start, binpath);
+		mutex_unlock(&tlob_uprobe_mutex);
+		return ret;
+	}
+	ret = tlob_parse_uprobe_line(buf, &threshold_ns, &binpath,
+				     &offset_start, &offset_stop);
+	if (ret)
+		return ret;
+	mutex_lock(&tlob_uprobe_mutex);
+	ret = tlob_add_uprobe(threshold_ns, binpath, offset_start, offset_stop);
+	mutex_unlock(&tlob_uprobe_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_IF_KUNIT(tlob_create_or_delete_uprobe);
+
+static ssize_t tlob_monitor_write(struct file *file,
+				  const char __user *ubuf,
+				  size_t count, loff_t *ppos)
+{
+	char buf[TLOB_MAX_PATH + 128];
+
+	if (count >= sizeof(buf))
+		return -EINVAL;
+	if (copy_from_user(buf, ubuf, count))
+		return -EFAULT;
+	buf[count] = '\0';
+	if (count > 0 && buf[count - 1] == '\n')
+		buf[count - 1] = '\0';
+	return tlob_create_or_delete_uprobe(buf) ?: (ssize_t)count;
+}
+
+static const struct file_operations tlob_monitor_fops = {
+	.open	= simple_open,
+	.read	= tlob_monitor_read,
+	.write	= tlob_monitor_write,
+	.llseek	= noop_llseek,
+};
+
+static int __tlob_init_monitor(void)
+{
+	unsigned int i;
+	int retval;
+
+	tlob_ws_storage = kcalloc(TLOB_MAX_MONITORED, sizeof(*tlob_ws_storage),
+				  GFP_KERNEL);
+	if (!tlob_ws_storage)
+		return -ENOMEM;
+
+	for (i = 0; i < TLOB_MAX_MONITORED; i++)
+		llist_add(&tlob_ws_storage[i].free_node, &tlob_ws_free_list);
+
+	retval = ha_monitor_init();
+	if (retval) {
+		kfree(tlob_ws_storage);
+		tlob_ws_storage = NULL;
+		init_llist_head(&tlob_ws_free_list);
+		return retval;
+	}
+
+	rv_this.enabled = 1;
+	return 0;
+}
+
+static void __tlob_destroy_monitor(void)
+{
+	rv_this.enabled = 0;
+	tlob_remove_all_uprobes();
+	ha_monitor_destroy();
+	init_llist_head(&tlob_ws_free_list);
+	kfree(tlob_ws_storage);
+	tlob_ws_storage = NULL;
+}
+
+static int tlob_enable_hooks(void)
+{
+	rv_attach_trace_probe("tlob", sched_switch, handle_sched_switch);
+	rv_attach_trace_probe("tlob", sched_wakeup, handle_sched_wakeup);
+	rv_attach_trace_probe("tlob", sched_process_exit, handle_sched_process_exit);
+	return 0;
+}
+
+static void tlob_disable_hooks(void)
+{
+	rv_detach_trace_probe("tlob", sched_switch, handle_sched_switch);
+	rv_detach_trace_probe("tlob", sched_wakeup, handle_sched_wakeup);
+	rv_detach_trace_probe("tlob", sched_process_exit, handle_sched_process_exit);
+}
+
+static int enable_tlob(void)
+{
+	int retval;
+
+	retval = __tlob_init_monitor();
+	if (retval)
+		return retval;
+
+	return tlob_enable_hooks();
+}
+
+static void disable_tlob(void)
+{
+	tlob_disable_hooks();
+	__tlob_destroy_monitor();
+}
+
+static struct rv_monitor rv_this = {
+	.name		= "tlob",
+	.description	= "Per-task latency-over-budget monitor.",
+	.enable		= enable_tlob,
+	.disable	= disable_tlob,
+	.reset		= da_monitor_reset_all,
+	.enabled	= 0,
+};
+
+static int __init register_tlob(void)
+{
+	int ret;
+
+	ret = rv_register_monitor(&rv_this, NULL);
+	if (ret)
+		return ret;
+
+	if (rv_this.root_d) {
+		if (!rv_create_file("monitor", RV_MODE_WRITE, rv_this.root_d, NULL,
+				    &tlob_monitor_fops)) {
+			rv_unregister_monitor(&rv_this);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static void __exit unregister_tlob(void)
+{
+	rv_unregister_monitor(&rv_this);
+}
+
+module_init(register_tlob);
+module_exit(unregister_tlob);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Wen Yang <wen.yang@linux.dev>");
+MODULE_DESCRIPTION("tlob: task latency over budget per-task monitor.");
diff --git a/kernel/trace/rv/monitors/tlob/tlob.h b/kernel/trace/rv/monitors/tlob/tlob.h
new file mode 100644
index 000000000000..fceeba748c85
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/tlob.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _RV_TLOB_H
+#define _RV_TLOB_H
+
+/*
+ * C representation of the tlob hybrid automaton.
+ *
+ * Three-state HA following sched_stat / wwnr monitor naming conventions:
+ *
+ *   running  (initial) - task on CPU           [sched_stat: runtime]
+ *   waiting             - task in runqueue     [sched_stat: wait   ]
+ *   sleeping            - task blocked         [sched_stat: sleep  ]
+ *
+ * Events (derived from sched_switch / sched_wakeup tracepoints):
+ *   start     - tlob_start_task()    running -> running (resets clock)
+ *   sleep     - sched_switch, prev_state != 0   running  -> sleeping
+ *   preempt   - sched_switch, prev_state == 0   running  -> waiting
+ *   wakeup    - sched_wakeup                    sleeping -> waiting
+ *   switch_in - sched_switch, next == task      waiting  -> running
+ *
+ * One HA clock invariant:
+ *   clk_elapsed < BUDGET_NS()  active in all states  (total latency budget)
+ *
+ * tlob_start_task() uses da_handle_start_run_event(start_tlob) to initialise
+ * the monitor: the DA framework sets the initial state and then processes the
+ * start event, which resets clk_elapsed and arms the budget hrtimer via the
+ * generated ha_setup_invariants().
+ * tlob_stop_task() calls ha_cancel_timer_sync() + da_monitor_reset() directly.
+ *
+ * For the format description see:
+ *   Documentation/trace/rv/deterministic_automata.rst
+ */
+
+#include <linux/rv.h>
+#include <linux/sched.h>
+
+#define MONITOR_NAME tlob
+
+enum states_tlob {
+	running_tlob,
+	sleeping_tlob,
+	waiting_tlob,
+	state_max_tlob,
+};
+
+#define INVALID_STATE state_max_tlob
+
+enum events_tlob {
+	preempt_tlob,
+	sleep_tlob,
+	start_tlob,
+	switch_in_tlob,
+	wakeup_tlob,
+	event_max_tlob,
+};
+
+/*
+ * HA environment variable: clk_elapsed is the only clock.
+ * It measures wall-clock time since task_start and is active in all states.
+ */
+enum envs_tlob {
+	clk_elapsed_tlob,
+	env_max_tlob,
+	env_max_stored_tlob = env_max_tlob,
+};
+
+_Static_assert(env_max_stored_tlob <= MAX_HA_ENV_LEN, "Not enough slots");
+#define HA_CLK_NS
+
+struct automaton_tlob {
+	char *state_names[state_max_tlob];
+	char *event_names[event_max_tlob];
+	char *env_names[env_max_tlob];
+	unsigned char function[state_max_tlob][event_max_tlob];
+	unsigned char initial_state;
+	bool final_states[state_max_tlob];
+};
+
+static const struct automaton_tlob automaton_tlob = {
+	.state_names = {
+		"running",
+		"sleeping",
+		"waiting",
+	},
+	.event_names = {
+		"preempt",
+		"sleep",
+		"start",
+		"switch_in",
+		"wakeup",
+	},
+	.env_names = {
+		"clk_elapsed",
+	},
+	.function = {
+		/* running */
+		{
+			waiting_tlob,	/* preempt   (sched_switch, prev_state == 0) */
+			sleeping_tlob,	/* sleep     (sched_switch, prev_state != 0) */
+			running_tlob,	/* start     (tlob_start_task, resets clock)  */
+			INVALID_STATE,	/* switch_in (already on CPU)                */
+			INVALID_STATE,	/* wakeup    (TASK_RUNNING can't be woken)   */
+		},
+		/* sleeping */
+		{
+			INVALID_STATE,	/* preempt   (not on CPU)                    */
+			INVALID_STATE,	/* sleep     (already sleeping)              */
+			INVALID_STATE,	/* start     (not in running state)          */
+			INVALID_STATE,	/* switch_in (must go through waiting first) */
+			waiting_tlob,	/* wakeup                                    */
+		},
+		/* waiting */
+		{
+			INVALID_STATE,	/* preempt   (not on CPU)                    */
+			INVALID_STATE,	/* sleep     (not on CPU)                    */
+			INVALID_STATE,	/* start     (not in running state)          */
+			running_tlob,	/* switch_in                                 */
+			INVALID_STATE,	/* wakeup    (already TASK_RUNNING)          */
+		},
+	},
+	.initial_state = running_tlob,
+	.final_states = { 1, 0, 0 },
+};
+
+/* Maximum number of concurrently monitored tasks. */
+#define TLOB_MAX_MONITORED	64U
+
+/* Maximum binary path length for uprobe binding. */
+#define TLOB_MAX_PATH		256
+
+/* Minimum monitoring budget (1 us). */
+#define TLOB_MIN_THRESHOLD_NS	1000ULL
+
+/*
+ * Upper bound on the monitoring budget (1 hour = 3 600 000 000 000 ns).
+ * The ns-resolution accumulators (running_ns, waiting_ns, sleeping_ns)
+ * are u64; keeping the window below this limit ensures they stay well
+ * clear of u64 overflow and covers every realistic latency-monitoring
+ * use case.
+ */
+#define TLOB_MAX_THRESHOLD_NS	3600000000000ULL
+
+/* Exported to uprobe layer and KUnit tests */
+int tlob_start_task(struct task_struct *task, u64 threshold_ns);
+int tlob_stop_task(struct task_struct *task);
+
+#if IS_ENABLED(CONFIG_KUNIT)
+int tlob_create_or_delete_uprobe(char *buf);
+#endif /* CONFIG_KUNIT */
+
+#endif /* _RV_TLOB_H */
diff --git a/kernel/trace/rv/monitors/tlob/tlob_trace.h b/kernel/trace/rv/monitors/tlob/tlob_trace.h
new file mode 100644
index 000000000000..7ebdfbe41b86
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/tlob_trace.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Snippet to be included in rv_trace.h
+ */
+
+#ifdef CONFIG_RV_MON_TLOB
+DEFINE_EVENT(event_da_monitor_id, event_tlob,
+	     TP_PROTO(int id, char *state, char *event,
+		      char *next_state, bool final_state),
+	     TP_ARGS(id, state, event, next_state, final_state));
+
+DEFINE_EVENT(error_da_monitor_id, error_tlob,
+	     TP_PROTO(int id, char *state, char *event),
+	     TP_ARGS(id, state, event));
+
+DEFINE_EVENT(error_env_da_monitor_id, error_env_tlob,
+	     TP_PROTO(int id, char *state, char *event, char *env),
+	     TP_ARGS(id, state, event, env));
+
+/*
+ * detail_env_tlob - per-state latency breakdown emitted on budget violation.
+ *
+ * Fired immediately after error_env_tlob from the hrtimer callback.
+ * Fields show how much time was spent in each DA state since tlob_start_task().
+ * running_ns + waiting_ns + sleeping_ns approximately equals total
+ * elapsed time (threshold_ns exceeded).
+ */
+TRACE_EVENT(detail_env_tlob,
+	TP_PROTO(int id, u64 threshold_ns,
+		 u64 running_ns, u64 waiting_ns, u64 sleeping_ns),
+	TP_ARGS(id, threshold_ns, running_ns, waiting_ns, sleeping_ns),
+	TP_STRUCT__entry(
+		__field(int,	id)
+		__field(u64,	threshold_ns)
+		__field(u64,	running_ns)
+		__field(u64,	waiting_ns)
+		__field(u64,	sleeping_ns)
+	),
+	TP_fast_assign(
+		__entry->id		= id;
+		__entry->threshold_ns	= threshold_ns;
+		__entry->running_ns	= running_ns;
+		__entry->waiting_ns	= waiting_ns;
+		__entry->sleeping_ns	= sleeping_ns;
+	),
+	TP_printk("pid=%d threshold_ns=%llu"
+		  " running_ns=%llu waiting_ns=%llu sleeping_ns=%llu",
+		__entry->id, __entry->threshold_ns,
+		__entry->running_ns, __entry->waiting_ns, __entry->sleeping_ns)
+);
+#endif /* CONFIG_RV_MON_TLOB */
diff --git a/kernel/trace/rv/rv_trace.h b/kernel/trace/rv/rv_trace.h
index 9622c269789c..a4bc215c1f15 100644
--- a/kernel/trace/rv/rv_trace.h
+++ b/kernel/trace/rv/rv_trace.h
@@ -189,6 +189,7 @@ DECLARE_EVENT_CLASS(error_env_da_monitor_id,
 
 #include <monitors/stall/stall_trace.h>
 #include <monitors/nomiss/nomiss_trace.h>
+#include <monitors/tlob/tlob_trace.h>
 // Add new monitors based on CONFIG_HA_MON_EVENTS_ID here
 
 #endif
-- 
2.25.1

[PATCH v4 7/8] rv/tlob: add KUnit tests for the tlob monitor

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Add CONFIG_TLOB_KUNIT_TEST (tristate, depends on RV_MON_TLOB && KUNIT,
default KUNIT_ALL_TESTS) with a test suite covering the uprobe-line
parser.

Tests call tlob_parse_uprobe_line() and tlob_parse_remove_line()
directly rather than going through the top-level write handler, so
they exercise parser logic only without touching the uprobe or
filesystem subsystems.

Cases cover valid inputs, malformed paths and offsets (including
negative values), out-of-range thresholds, and valid and invalid
remove lines.

Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 kernel/trace/rv/Makefile                   |   1 +
 kernel/trace/rv/monitors/tlob/.kunitconfig |   8 ++
 kernel/trace/rv/monitors/tlob/Kconfig      |   7 ++
 kernel/trace/rv/monitors/tlob/tlob.c       |   7 +-
 kernel/trace/rv/monitors/tlob/tlob.h       |   4 +-
 kernel/trace/rv/monitors/tlob/tlob_kunit.c | 139 +++++++++++++++++++++
 6 files changed, 162 insertions(+), 4 deletions(-)
 create mode 100644 kernel/trace/rv/monitors/tlob/.kunitconfig
 create mode 100644 kernel/trace/rv/monitors/tlob/tlob_kunit.c

diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
index ae59e97f8682..316d53398345 100644
--- a/kernel/trace/rv/Makefile
+++ b/kernel/trace/rv/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_RV_MON_STALL) += monitors/stall/stall.o
 obj-$(CONFIG_RV_MON_DEADLINE) += monitors/deadline/deadline.o
 obj-$(CONFIG_RV_MON_NOMISS) += monitors/nomiss/nomiss.o
 obj-$(CONFIG_RV_MON_TLOB) += monitors/tlob/tlob.o
+obj-$(CONFIG_TLOB_KUNIT_TEST) += monitors/tlob/tlob_kunit.o
 # Add new monitors here
 obj-$(CONFIG_RV_UPROBE) += rv_uprobe.o
 obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
diff --git a/kernel/trace/rv/monitors/tlob/.kunitconfig b/kernel/trace/rv/monitors/tlob/.kunitconfig
new file mode 100644
index 000000000000..34ebf3b172ac
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/.kunitconfig
@@ -0,0 +1,8 @@
+CONFIG_FTRACE=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_KUNIT=y
+CONFIG_MODULES=y
+CONFIG_RV=y
+CONFIG_RV_MON_TLOB=y
+CONFIG_TLOB_KUNIT_TEST=y
+CONFIG_UPROBES=y
diff --git a/kernel/trace/rv/monitors/tlob/Kconfig b/kernel/trace/rv/monitors/tlob/Kconfig
index aa43382073d2..402ef2e5c076 100644
--- a/kernel/trace/rv/monitors/tlob/Kconfig
+++ b/kernel/trace/rv/monitors/tlob/Kconfig
@@ -10,3 +10,10 @@ config RV_MON_TLOB
 	  monitor.  tlob tracks per-task elapsed wall-clock time across a
 	  user-delimited code section and emits error_env_tlob when the
 	  elapsed time exceeds a configurable per-invocation budget.
+
+config TLOB_KUNIT_TEST
+	tristate "KUnit tests for tlob monitor" if !KUNIT_ALL_TESTS
+	depends on RV_MON_TLOB && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Enable KUnit unit tests for the tlob RV monitor.
diff --git a/kernel/trace/rv/monitors/tlob/tlob.c b/kernel/trace/rv/monitors/tlob/tlob.c
index b45e84195131..a6f9c371646c 100644
--- a/kernel/trace/rv/monitors/tlob/tlob.c
+++ b/kernel/trace/rv/monitors/tlob/tlob.c
@@ -708,7 +708,7 @@ static ssize_t tlob_monitor_read(struct file *file,
  * PATH may contain ':'; the last ':' separates path from offset.
  * Returns 0, -EINVAL, or -ERANGE.
  */
-static int tlob_parse_uprobe_line(char *buf, u64 *thr_out,
+VISIBLE_IF_KUNIT int tlob_parse_uprobe_line(char *buf, u64 *thr_out,
 				  char **path_out,
 				  loff_t *start_out, loff_t *stop_out)
 {
@@ -782,6 +782,7 @@ static int tlob_parse_uprobe_line(char *buf, u64 *thr_out,
 	*stop_out  = (loff_t)stop_val;
 	return 0;
 }
+EXPORT_SYMBOL_IF_KUNIT(tlob_parse_uprobe_line);
 
 /*
  * Parse "-PATH:OFFSET_START" (ftrace uprobe_events removal convention).
@@ -810,8 +811,9 @@ VISIBLE_IF_KUNIT int tlob_parse_remove_line(char *buf, char **path_out,
 	*start_out = (loff_t)off;
 	return 0;
 }
+EXPORT_SYMBOL_IF_KUNIT(tlob_parse_remove_line);
 
-VISIBLE_IF_KUNIT int tlob_create_or_delete_uprobe(char *buf)
+static int tlob_create_or_delete_uprobe(char *buf)
 {
 	loff_t offset_start, offset_stop;
 	u64 threshold_ns;
@@ -836,7 +838,6 @@ VISIBLE_IF_KUNIT int tlob_create_or_delete_uprobe(char *buf)
 	mutex_unlock(&tlob_uprobe_mutex);
 	return ret;
 }
-EXPORT_SYMBOL_IF_KUNIT(tlob_create_or_delete_uprobe);
 
 static ssize_t tlob_monitor_write(struct file *file,
 				  const char __user *ubuf,
diff --git a/kernel/trace/rv/monitors/tlob/tlob.h b/kernel/trace/rv/monitors/tlob/tlob.h
index fceeba748c85..15bdf3b7fade 100644
--- a/kernel/trace/rv/monitors/tlob/tlob.h
+++ b/kernel/trace/rv/monitors/tlob/tlob.h
@@ -145,7 +145,9 @@ int tlob_start_task(struct task_struct *task, u64 threshold_ns);
 int tlob_stop_task(struct task_struct *task);
 
 #if IS_ENABLED(CONFIG_KUNIT)
-int tlob_create_or_delete_uprobe(char *buf);
+int tlob_parse_uprobe_line(char *buf, u64 *thr_out, char **path_out,
+			   loff_t *start_out, loff_t *stop_out);
+int tlob_parse_remove_line(char *buf, char **path_out, loff_t *start_out);
 #endif /* CONFIG_KUNIT */
 
 #endif /* _RV_TLOB_H */
diff --git a/kernel/trace/rv/monitors/tlob/tlob_kunit.c b/kernel/trace/rv/monitors/tlob/tlob_kunit.c
new file mode 100644
index 000000000000..7448f3fab959
--- /dev/null
+++ b/kernel/trace/rv/monitors/tlob/tlob_kunit.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for the tlob RV monitor.
+ *
+ */
+#include <kunit/test.h>
+
+#include "tlob.h"
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+/* Valid "p PATH:START STOP threshold=NS" lines. */
+static const char * const tlob_parse_valid[] = {
+	"p /usr/bin/myapp:4768 4848 threshold=5000000",
+	"p /usr/bin/myapp:0x12a0 0x12f0 threshold=10000000",
+	"p /opt/my:app/bin:0x100 0x200 threshold=1000000",
+};
+
+/* Malformed "p ..." lines that must be rejected with -EINVAL. */
+static const char * const tlob_parse_invalid[] = {
+	"p :0x100 0x200 threshold=5000",
+	"p /usr/bin/myapp:0x100 threshold=5000",
+	"p /usr/bin/myapp:-1 0x200 threshold=5000",
+	"p /usr/bin/myapp:0x100 -1 threshold=5000000",	/* negative stop offset */
+	"p /usr/bin/myapp:0x100 0x200",
+	"p /usr/bin/myapp:0x100 0x100 threshold=5000",
+};
+
+/* threshold_ns out of valid range => -ERANGE. */
+static const char * const tlob_parse_out_of_range[] = {
+	"p /usr/bin/myapp:0x100 0x200 threshold=0",
+	"p /usr/bin/myapp:0x100 0x200 threshold=999",
+	"p /usr/bin/myapp:0x100 0x200 threshold=3600000000001",
+};
+
+/* Valid "-PATH:OFFSET_START" remove lines. */
+static const char * const tlob_remove_valid[] = {
+	"-/usr/bin/myapp:0x100",
+	"-/opt/my:app/bin:0x200",
+};
+
+/* Malformed remove lines that must be rejected with -EINVAL. */
+static const char * const tlob_remove_invalid[] = {
+	"-usr/bin/myapp:0x100",
+	"-/usr/bin/myapp",
+	"-/:0x100",
+	"-/usr/bin/myapp:-1",	/* negative offset */
+	"-/usr/bin/myapp:abc",
+};
+
+static void tlob_parse_valid_accepted(struct kunit *test)
+{
+	u64 thr;
+	char *path;
+	loff_t start, stop;
+	char buf[128];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tlob_parse_valid); i++) {
+		strscpy(buf, tlob_parse_valid[i], sizeof(buf));
+		KUNIT_EXPECT_EQ(test, tlob_parse_uprobe_line(buf, &thr, &path,
+							     &start, &stop), 0);
+	}
+}
+
+static void tlob_parse_invalid_rejected(struct kunit *test)
+{
+	u64 thr;
+	char *path;
+	loff_t start, stop;
+	char buf[128];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tlob_parse_invalid); i++) {
+		strscpy(buf, tlob_parse_invalid[i], sizeof(buf));
+		KUNIT_EXPECT_EQ(test, tlob_parse_uprobe_line(buf, &thr, &path,
+							     &start, &stop), -EINVAL);
+	}
+}
+
+static void tlob_parse_out_of_range_rejected(struct kunit *test)
+{
+	u64 thr;
+	char *path;
+	loff_t start, stop;
+	char buf[128];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tlob_parse_out_of_range); i++) {
+		strscpy(buf, tlob_parse_out_of_range[i], sizeof(buf));
+		KUNIT_EXPECT_EQ(test, tlob_parse_uprobe_line(buf, &thr, &path,
+							     &start, &stop), -ERANGE);
+	}
+}
+
+static void tlob_remove_valid_accepted(struct kunit *test)
+{
+	char *path;
+	loff_t start;
+	char buf[128];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tlob_remove_valid); i++) {
+		strscpy(buf, tlob_remove_valid[i], sizeof(buf));
+		KUNIT_EXPECT_EQ(test, tlob_parse_remove_line(buf, &path, &start), 0);
+	}
+}
+
+static void tlob_remove_invalid_rejected(struct kunit *test)
+{
+	char *path;
+	loff_t start;
+	char buf[128];
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tlob_remove_invalid); i++) {
+		strscpy(buf, tlob_remove_invalid[i], sizeof(buf));
+		KUNIT_EXPECT_EQ(test, tlob_parse_remove_line(buf, &path, &start), -EINVAL);
+	}
+}
+
+static struct kunit_case tlob_parse_cases[] = {
+	KUNIT_CASE(tlob_parse_valid_accepted),
+	KUNIT_CASE(tlob_parse_invalid_rejected),
+	KUNIT_CASE(tlob_parse_out_of_range_rejected),
+	KUNIT_CASE(tlob_remove_valid_accepted),
+	KUNIT_CASE(tlob_remove_invalid_rejected),
+	{}
+};
+
+static struct kunit_suite tlob_parse_suite = {
+	.name       = "tlob_parse",
+	.test_cases = tlob_parse_cases,
+};
+
+kunit_test_suite(tlob_parse_suite);
+
+MODULE_DESCRIPTION("KUnit tests for the tlob RV monitor");
+MODULE_LICENSE("GPL");
-- 
2.25.1

[PATCH v4 8/8] selftests/verification: add tlob selftests

[wen.yang]

From: Wen Yang <wen.yang@linux.dev>

Add seven ftrace-style test scripts for the tlob RV monitor under
tools/testing/selftests/verification/test.d/tlob/.  The tests cover
uprobe binding management, budget violation detection, and per-state
time accounting.

Helper binaries tlob_target and tlob_sym are included in the same
directory so the suite is self-contained.  tlob_sym resolves ELF
symbol offsets for uprobe registration; tlob_target provides busy-spin,
sleep, and preempt workloads.

ftracetest is updated to walk up the directory tree when searching for
test.d/functions, so monitor subdirectories can be passed as the test
directory without placing a dummy functions shim in each new directory.

Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 tools/testing/selftests/ftrace/ftracetest     |  18 +-
 .../testing/selftests/verification/.gitignore |   2 +
 tools/testing/selftests/verification/Makefile |  19 +-
 .../verification/test.d/tlob/Makefile         |  28 +++
 .../test.d/tlob/run_tlob_tests.sh             |  90 ++++++++
 .../verification/test.d/tlob/tlob_sym.c       | 209 ++++++++++++++++++
 .../verification/test.d/tlob/tlob_target.c    | 138 ++++++++++++
 .../verification/test.d/tlob/uprobe_bind.tc   |  37 ++++
 .../test.d/tlob/uprobe_detail_running.tc      |  51 +++++
 .../test.d/tlob/uprobe_detail_sleeping.tc     |  50 +++++
 .../test.d/tlob/uprobe_detail_waiting.tc      |  66 ++++++
 .../verification/test.d/tlob/uprobe_multi.tc  |  64 ++++++
 .../test.d/tlob/uprobe_no_event.tc            |  19 ++
 .../test.d/tlob/uprobe_violation.tc           |  67 ++++++
 14 files changed, 854 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/Makefile
 create mode 100755 tools/testing/selftests/verification/test.d/tlob/run_tlob_tests.sh
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/tlob_sym.c
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/tlob_target.c
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_bind.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_running.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_sleeping.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_detail_waiting.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_multi.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_no_event.tc
 create mode 100644 tools/testing/selftests/verification/test.d/tlob/uprobe_violation.tc

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index 0a56bf209f6c..91c007b0a74a 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -159,9 +159,21 @@ parse_opts() { # opts
   if [ -n "$OPT_TEST_CASES" ]; then
     TEST_CASES=$OPT_TEST_CASES
   fi
-  if [ -n "$OPT_TEST_DIR" -a -f "$OPT_TEST_DIR"/test.d/functions ]; then
-    TOP_DIR=$OPT_TEST_DIR
-    TEST_DIR=$TOP_DIR/test.d
+  if [ -n "$OPT_TEST_DIR" ]; then
+    # Walk up from OPT_TEST_DIR to find the nearest ancestor containing
+    # test.d/functions, allowing monitor subdirectories to be passed directly.
+    dir=$OPT_TEST_DIR
+    while [ "$dir" != "/" ]; do
+      if [ -f "$dir/test.d/functions" ]; then
+        TOP_DIR=$dir
+        TEST_DIR=$TOP_DIR/test.d
+        break
+      fi
+      dir=$(dirname "$dir")
+    done
+    if [ -z "$TOP_DIR" ]; then
+      errexit "no test.d/functions found above $OPT_TEST_DIR"
+    fi
   fi
 }
 
diff --git a/tools/testing/selftests/verification/.gitignore b/tools/testing/selftests/verification/.gitignore
index 2659417cb2c7..cbbd03ee16c7 100644
--- a/tools/testing/selftests/verification/.gitignore
+++ b/tools/testing/selftests/verification/.gitignore
@@ -1,2 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 logs
+test.d/tlob/tlob_sym
+test.d/tlob/tlob_target
diff --git a/tools/testing/selftests/verification/Makefile b/tools/testing/selftests/verification/Makefile
index aa8790c22a71..0b32bdfdb8db 100644
--- a/tools/testing/selftests/verification/Makefile
+++ b/tools/testing/selftests/verification/Makefile
@@ -1,8 +1,25 @@
 # SPDX-License-Identifier: GPL-2.0
-all:
 
 TEST_PROGS := verificationtest-ktap
 TEST_FILES := test.d settings
 EXTRA_CLEAN := $(OUTPUT)/logs/*
 
+# Subdirectories that provide binaries used by the test runner.
+# Each entry must contain a Makefile that accepts OUTDIR= and
+# deposits its binaries there.
+BUILD_SUBDIRS := test.d/tlob
+
 include ../lib.mk
+
+all: $(patsubst %,_build_%,$(BUILD_SUBDIRS))
+
+clean: $(patsubst %,_clean_%,$(BUILD_SUBDIRS))
+
+.PHONY: $(patsubst %,_build_%,$(BUILD_SUBDIRS)) \
+        $(patsubst %,_clean_%,$(BUILD_SUBDIRS))
+
+$(patsubst %,_build_%,$(BUILD_SUBDIRS)): _build_%:
+	$(MAKE) -C $* OUTDIR="$(OUTPUT)" TOOLS_INCLUDES="$(TOOLS_INCLUDES)"
+
+$(patsubst %,_clean_%,$(BUILD_SUBDIRS)): _clean_%:
+	$(MAKE) -C $* OUTDIR="$(OUTPUT)" clean
diff --git a/tools/testing/selftests/verification/test.d/tlob/Makefile b/tools/testing/selftests/verification/test.d/tlob/Makefile
new file mode 100644
index 000000000000..05a2d2599c4e
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+# Builds tlob selftest helper binaries in the directory of this Makefile.
+#
+# Invoked by ../../Makefile via BUILD_SUBDIRS; outputs tlob_sym and
+# tlob_target alongside the .tc scripts so they are self-contained.
+
+CFLAGS += $(TOOLS_INCLUDES)
+
+# For standalone execution via vng
+FTRACETEST := ../../../ftrace/ftracetest
+LOGDIR ?= ../../logs
+
+.PHONY: all
+all: tlob_sym tlob_target
+
+tlob_sym: tlob_sym.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+tlob_target: tlob_target.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+.PHONY: run_tests
+run_tests: all
+	@./run_tlob_tests.sh
+
+.PHONY: clean
+clean:
+	$(RM) tlob_sym tlob_target
diff --git a/tools/testing/selftests/verification/test.d/tlob/run_tlob_tests.sh b/tools/testing/selftests/verification/test.d/tlob/run_tlob_tests.sh
new file mode 100755
index 000000000000..cd949756e713
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/run_tlob_tests.sh
@@ -0,0 +1,90 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Standalone runner for tlob selftests
+# Usage: ./run_tlob_tests.sh [options]
+#
+# Options:
+#   -v, --verbose    Verbose output
+#   -k, --keep       Keep test logs
+#   -l, --logdir DIR Log directory (default: ../../logs)
+#   -h, --help       Show this help
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+FTRACETEST="$SCRIPT_DIR/../../../ftrace/ftracetest"
+LOGDIR="$SCRIPT_DIR/../../logs"
+VERBOSE=""
+KEEP=""
+EXTRA_ARGS=""
+
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -v|--verbose)
+            VERBOSE="-v"
+            shift
+            ;;
+        -k|--keep)
+            KEEP="-k"
+            shift
+            ;;
+        -l|--logdir)
+            LOGDIR="$2"
+            shift 2
+            ;;
+        -h|--help)
+            echo "Usage: $0 [options]"
+            echo ""
+            echo "Options:"
+            echo "  -v, --verbose    Verbose output"
+            echo "  -k, --keep       Keep test logs"
+            echo "  -l, --logdir DIR Log directory (default: ../../logs)"
+            echo "  -h, --help       Show this help"
+            echo ""
+            echo "Examples:"
+            echo "  $0                           # Run all tlob tests"
+            echo "  $0 -v                        # Run with verbose output"
+            echo "  $0 -v -l /tmp/tlob-logs      # Custom log directory"
+            echo ""
+            echo "With vng:"
+            echo "  vng -v --rwdir $LOGDIR -- $0"
+            exit 0
+            ;;
+        *)
+            EXTRA_ARGS="$EXTRA_ARGS $1"
+            shift
+            ;;
+    esac
+done
+
+# Build test helpers
+echo "Building tlob test helpers..."
+make -C "$SCRIPT_DIR" all
+
+# Check ftracetest exists
+if [ ! -x "$FTRACETEST" ]; then
+    echo "Error: $FTRACETEST not found or not executable"
+    echo "Make sure you're running from the correct directory"
+    exit 1
+fi
+
+# Create log directory
+mkdir -p "$LOGDIR"
+
+# Run tests
+echo "Running tlob selftests..."
+echo "Log directory: $LOGDIR"
+echo ""
+
+# Export RV_BINDIR so test scripts can find tlob_target and tlob_sym
+export RV_BINDIR="$SCRIPT_DIR"
+
+# Pass the test directory, not individual .tc files
+# ftracetest will discover all .tc files in the directory
+"$FTRACETEST" -K $VERBOSE $KEEP --rv --logdir "$LOGDIR" \
+    "$SCRIPT_DIR" $EXTRA_ARGS
+
+echo ""
+echo "Tests completed. Logs saved to: $LOGDIR"
diff --git a/tools/testing/selftests/verification/test.d/tlob/tlob_sym.c b/tools/testing/selftests/verification/test.d/tlob/tlob_sym.c
new file mode 100644
index 000000000000..a92fc49d1304
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/tlob_sym.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tlob_sym.c - ELF symbol-to-file-offset utility for tlob selftests
+ *
+ * Usage: tlob_sym sym_offset <binary> <symbol>
+ *
+ *   Prints the ELF file offset of <symbol> in <binary> to stdout.
+ *
+ * Exit: 0 = found, 1 = error / not found.
+ */
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static int sym_offset(const char *binary, const char *symname)
+{
+	int fd;
+	struct stat st;
+	void *map;
+	Elf64_Ehdr *ehdr;
+	Elf32_Ehdr *ehdr32;
+	int is64;
+	uint64_t sym_vaddr = 0;
+	int found = 0;
+	uint64_t file_offset = 0;
+
+	fd = open(binary, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "open %s: %s\n", binary, strerror(errno));
+		return 1;
+	}
+	if (fstat(fd, &st) < 0) {
+		close(fd);
+		return 1;
+	}
+	map = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (map == MAP_FAILED) {
+		fprintf(stderr, "mmap: %s\n", strerror(errno));
+		return 1;
+	}
+
+	ehdr = (Elf64_Ehdr *)map;
+	ehdr32 = (Elf32_Ehdr *)map;
+	if (st.st_size < 4 ||
+	    ehdr->e_ident[EI_MAG0] != ELFMAG0 ||
+	    ehdr->e_ident[EI_MAG1] != ELFMAG1 ||
+	    ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
+	    ehdr->e_ident[EI_MAG3] != ELFMAG3) {
+		fprintf(stderr, "%s: not an ELF file\n", binary);
+		munmap(map, (size_t)st.st_size);
+		return 1;
+	}
+	is64 = (ehdr->e_ident[EI_CLASS] == ELFCLASS64);
+
+	if (is64) {
+		Elf64_Shdr *shdrs;
+		Elf64_Shdr *shstrtab_hdr;
+
+		if (ehdr->e_shnum == 0 || ehdr->e_shstrndx >= ehdr->e_shnum ||
+		    (uint64_t)ehdr->e_shoff +
+		    (uint64_t)ehdr->e_shnum * sizeof(Elf64_Shdr) > (uint64_t)st.st_size) {
+			fprintf(stderr, "%s: malformed ELF section table\n", binary);
+			munmap(map, (size_t)st.st_size);
+			return 1;
+		}
+		shdrs = (Elf64_Shdr *)((char *)map + ehdr->e_shoff);
+		shstrtab_hdr = &shdrs[ehdr->e_shstrndx];
+		const char *shstrtab = (char *)map + shstrtab_hdr->sh_offset;
+		int si;
+
+		for (int pass = 0; pass < 2 && !found; pass++) {
+			const char *target = pass ? ".dynsym" : ".symtab";
+
+			for (si = 0; si < ehdr->e_shnum && !found; si++) {
+				Elf64_Shdr *sh = &shdrs[si];
+				const char *name = shstrtab + sh->sh_name;
+
+				if (strcmp(name, target) != 0)
+					continue;
+
+				Elf64_Shdr *strtab_sh = &shdrs[sh->sh_link];
+				const char *strtab = (char *)map + strtab_sh->sh_offset;
+				Elf64_Sym *syms = (Elf64_Sym *)((char *)map + sh->sh_offset);
+				uint64_t nsyms = sh->sh_size / sizeof(Elf64_Sym);
+				uint64_t j;
+
+				for (j = 0; j < nsyms; j++) {
+					if (strcmp(strtab + syms[j].st_name, symname) == 0) {
+						sym_vaddr = syms[j].st_value;
+						found = 1;
+						break;
+					}
+				}
+			}
+		}
+
+		if (!found) {
+			fprintf(stderr, "symbol '%s' not found in %s\n", symname, binary);
+			munmap(map, (size_t)st.st_size);
+			return 1;
+		}
+
+		Elf64_Phdr *phdrs = (Elf64_Phdr *)((char *)map + ehdr->e_phoff);
+		int pi;
+
+		for (pi = 0; pi < ehdr->e_phnum; pi++) {
+			Elf64_Phdr *ph = &phdrs[pi];
+
+			if (ph->p_type != PT_LOAD)
+				continue;
+			if (sym_vaddr >= ph->p_vaddr &&
+			    sym_vaddr < ph->p_vaddr + ph->p_filesz) {
+				file_offset = sym_vaddr - ph->p_vaddr + ph->p_offset;
+				break;
+			}
+		}
+	} else {
+		Elf32_Shdr *shdrs;
+		Elf32_Shdr *shstrtab_hdr;
+
+		if (ehdr32->e_shnum == 0 || ehdr32->e_shstrndx >= ehdr32->e_shnum ||
+		    (uint64_t)ehdr32->e_shoff +
+		    (uint64_t)ehdr32->e_shnum * sizeof(Elf32_Shdr) > (uint64_t)st.st_size) {
+			fprintf(stderr, "%s: malformed ELF section table\n", binary);
+			munmap(map, (size_t)st.st_size);
+			return 1;
+		}
+		shdrs = (Elf32_Shdr *)((char *)map + ehdr32->e_shoff);
+		shstrtab_hdr = &shdrs[ehdr32->e_shstrndx];
+		const char *shstrtab = (char *)map + shstrtab_hdr->sh_offset;
+		int si;
+		uint32_t sym_vaddr32 = 0;
+
+		for (int pass = 0; pass < 2 && !found; pass++) {
+			const char *target = pass ? ".dynsym" : ".symtab";
+
+			for (si = 0; si < ehdr32->e_shnum && !found; si++) {
+				Elf32_Shdr *sh = &shdrs[si];
+				const char *name = shstrtab + sh->sh_name;
+
+				if (strcmp(name, target) != 0)
+					continue;
+
+				Elf32_Shdr *strtab_sh = &shdrs[sh->sh_link];
+				const char *strtab = (char *)map + strtab_sh->sh_offset;
+				Elf32_Sym *syms = (Elf32_Sym *)((char *)map + sh->sh_offset);
+				uint32_t nsyms = sh->sh_size / sizeof(Elf32_Sym);
+				uint32_t j;
+
+				for (j = 0; j < nsyms; j++) {
+					if (strcmp(strtab + syms[j].st_name, symname) == 0) {
+						sym_vaddr32 = syms[j].st_value;
+						found = 1;
+						break;
+					}
+				}
+			}
+		}
+
+		if (!found) {
+			fprintf(stderr, "symbol '%s' not found in %s\n", symname, binary);
+			munmap(map, (size_t)st.st_size);
+			return 1;
+		}
+
+		Elf32_Phdr *phdrs = (Elf32_Phdr *)((char *)map + ehdr32->e_phoff);
+		int pi;
+
+		for (pi = 0; pi < ehdr32->e_phnum; pi++) {
+			Elf32_Phdr *ph = &phdrs[pi];
+
+			if (ph->p_type != PT_LOAD)
+				continue;
+			if (sym_vaddr32 >= ph->p_vaddr &&
+			    sym_vaddr32 < ph->p_vaddr + ph->p_filesz) {
+				file_offset = sym_vaddr32 - ph->p_vaddr + ph->p_offset;
+				break;
+			}
+		}
+		sym_vaddr = sym_vaddr32;
+	}
+
+	munmap(map, (size_t)st.st_size);
+
+	if (!file_offset && sym_vaddr) {
+		fprintf(stderr, "could not map vaddr 0x%lx to file offset\n",
+			(unsigned long)sym_vaddr);
+		return 1;
+	}
+
+	printf("0x%lx\n", (unsigned long)file_offset);
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	if (argc != 4 || strcmp(argv[1], "sym_offset") != 0) {
+		fprintf(stderr, "Usage: %s sym_offset <binary> <symbol>\n", argv[0]);
+		return 1;
+	}
+	return sym_offset(argv[2], argv[3]);
+}
diff --git a/tools/testing/selftests/verification/test.d/tlob/tlob_target.c b/tools/testing/selftests/verification/test.d/tlob/tlob_target.c
new file mode 100644
index 000000000000..adf4c2397fb3
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/tlob_target.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tlob_target.c - uprobe target binary for tlob selftests.
+ *
+ * Provides three start/stop probe pairs, each designed to exercise a
+ * different dominant component of the detail_env_tlob ns breakdown:
+ *
+ *   tlob_busy_work    / tlob_busy_work_done    - busy-spin: running_ns dominates
+ *   tlob_sleep_work   / tlob_sleep_work_done   - nanosleep: sleeping_ns dominates
+ *   tlob_preempt_work / tlob_preempt_work_done - busy-spin + RT competitor:
+ *                                                waiting_ns dominates
+ *
+ * Usage: tlob_target <duration_ms> [mode]
+ *
+ * mode is one of: busy (default), sleep, preempt.
+ * Loops in 200 ms iterations until <duration_ms> has elapsed
+ * (0 = run for ~24 hours).
+ */
+#define _GNU_SOURCE
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#ifndef noinline
+#define noinline __attribute__((noinline))
+#endif
+
+static inline int timespec_before(const struct timespec *a,
+				   const struct timespec *b)
+{
+	return a->tv_sec < b->tv_sec ||
+	       (a->tv_sec == b->tv_sec && a->tv_nsec < b->tv_nsec);
+}
+
+static void timespec_add_ms(struct timespec *ts, unsigned long ms)
+{
+	ts->tv_sec  += ms / 1000;
+	ts->tv_nsec += (long)(ms % 1000) * 1000000L;
+	if (ts->tv_nsec >= 1000000000L) {
+		ts->tv_sec++;
+		ts->tv_nsec -= 1000000000L;
+	}
+}
+
+/* stop probe; noinline keeps the entry point visible to uprobes */
+noinline void tlob_busy_work_done(void)
+{
+	/* empty: uprobe fires on entry */
+}
+
+/* start probe; busy-spin so running_ns dominates */
+noinline void tlob_busy_work(unsigned long duration_ms)
+{
+	struct timespec start, now;
+	unsigned long elapsed;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	do {
+		clock_gettime(CLOCK_MONOTONIC, &now);
+		elapsed = (unsigned long)(now.tv_sec - start.tv_sec)
+			  * 1000000000UL
+			+ (unsigned long)(now.tv_nsec - start.tv_nsec);
+	} while (elapsed < duration_ms * 1000000UL);
+
+	tlob_busy_work_done();
+}
+
+/* stop probe; noinline keeps the entry point visible to uprobes */
+noinline void tlob_sleep_work_done(void)
+{
+	/* empty: uprobe fires on entry */
+}
+
+/* start probe; nanosleep so sleeping_ns dominates */
+noinline void tlob_sleep_work(unsigned long duration_ms)
+{
+	struct timespec ts = {
+		.tv_sec  = duration_ms / 1000,
+		.tv_nsec = (long)(duration_ms % 1000) * 1000000L,
+	};
+	nanosleep(&ts, NULL);
+	tlob_sleep_work_done();
+}
+
+/* stop probe; noinline keeps the entry point visible to uprobes */
+noinline void tlob_preempt_work_done(void)
+{
+	/* empty: uprobe fires on entry */
+}
+
+/*
+ * start probe; busy-spin so an RT competitor on the same CPU drives
+ * waiting_ns (prev_state==0 -> preempt event, task stays runnable off-CPU).
+ */
+noinline void tlob_preempt_work(unsigned long duration_ms)
+{
+	struct timespec start, now;
+	unsigned long elapsed;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	do {
+		clock_gettime(CLOCK_MONOTONIC, &now);
+		elapsed = (unsigned long)(now.tv_sec - start.tv_sec)
+			  * 1000000000UL
+			+ (unsigned long)(now.tv_nsec - start.tv_nsec);
+	} while (elapsed < duration_ms * 1000000UL);
+
+	tlob_preempt_work_done();
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned long duration_ms = 0;
+	const char *mode = "busy";
+	struct timespec deadline, now;
+
+	if (argc >= 2)
+		duration_ms = strtoul(argv[1], NULL, 10);
+	if (argc >= 3)
+		mode = argv[2];
+
+	clock_gettime(CLOCK_MONOTONIC, &deadline);
+	timespec_add_ms(&deadline, duration_ms ? duration_ms : 86400000UL);
+
+	do {
+		if (strcmp(mode, "sleep") == 0)
+			tlob_sleep_work(200);
+		else if (strcmp(mode, "preempt") == 0)
+			tlob_preempt_work(200);
+		else
+			tlob_busy_work(200);
+		clock_gettime(CLOCK_MONOTONIC, &now);
+	} while (timespec_before(&now, &deadline));
+
+	return 0;
+}
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_bind.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_bind.tc
new file mode 100644
index 000000000000..4a1c18c7485a
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_bind.tc
@@ -0,0 +1,37 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor uprobe binding (visible in monitor file, removable, duplicate rejected)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+busy_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work 2>/dev/null)
+stop_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work_done 2>/dev/null)
+[ -n "$busy_offset" ] || exit_unsupported
+[ -n "$stop_offset" ] || exit_unsupported
+
+"$UPROBE_TARGET" 30000 &
+busy_pid=$!
+sleep 0.05
+
+echo 1 > monitors/tlob/enable
+echo "p ${UPROBE_TARGET}:${busy_offset} ${stop_offset} threshold=5000000000" > "$TLOB_MONITOR"
+
+# Binding must appear in monitor file with canonical hex-offset format.
+grep -qE "^p ${UPROBE_TARGET}:0x[0-9a-f]+ 0x[0-9a-f]+ threshold=[0-9]+$" "$TLOB_MONITOR"
+grep -q "threshold=5000000000" "$TLOB_MONITOR"
+
+# Duplicate offset_start must be rejected.
+! echo "p ${UPROBE_TARGET}:${busy_offset} ${stop_offset} threshold=9999000" > "$TLOB_MONITOR" 2>/dev/null || false
+
+# Remove the binding; it must no longer appear.
+echo "-${UPROBE_TARGET}:${busy_offset}" > "$TLOB_MONITOR"
+! grep -q "^p .*:0x${busy_offset#0x} " "$TLOB_MONITOR" || false
+
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+echo 0 > monitors/tlob/enable
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_running.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_running.tc
new file mode 100644
index 000000000000..afca157b5ea4
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_running.tc
@@ -0,0 +1,51 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor detail running (running_ns dominates when task busy-spins between probes)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+start_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work 2>/dev/null)
+stop_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work_done 2>/dev/null)
+[ -n "$start_offset" ] || exit_unsupported
+[ -n "$stop_offset" ] || exit_unsupported
+
+"$UPROBE_TARGET" 5000 &
+busy_pid=$!
+sleep 0.05
+
+echo 1 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+# 10 us budget; task busy-spins 200 ms per iteration -> running_ns dominates.
+echo "p ${UPROBE_TARGET}:${start_offset} ${stop_offset} threshold=10000" > "$TLOB_MONITOR"
+
+found=0; i=0
+while [ "$i" -lt 30 ]; do
+	sleep 0.1
+	grep -q "detail_env_tlob" /sys/kernel/tracing/trace && { found=1; break; }
+	i=$((i+1))
+done
+
+echo "-${UPROBE_TARGET}:${start_offset}" > "$TLOB_MONITOR" 2>/dev/null
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+echo 0 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 0 > monitors/tlob/enable
+
+[ "$found" = "1" ]
+
+line=$(grep "detail_env_tlob" /sys/kernel/tracing/trace | head -n 1)
+running=$(echo "$line" | sed 's/.*running_ns=\([0-9]*\).*/\1/')
+waiting=$(echo "$line" | sed 's/.*waiting_ns=\([0-9]*\).*/\1/')
+sleeping=$(echo "$line" | sed 's/.*sleeping_ns=\([0-9]*\).*/\1/')
+# Busy-spin keeps the task on-CPU: running_ns must exceed sleeping_ns.
+[ "$running" -gt "$sleeping" ]
+
+echo > /sys/kernel/tracing/trace
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_sleeping.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_sleeping.tc
new file mode 100644
index 000000000000..0a6470b4cadb
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_sleeping.tc
@@ -0,0 +1,50 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor detail sleeping (sleeping_ns dominates when task blocks between probes)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+start_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_sleep_work 2>/dev/null)
+stop_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_sleep_work_done 2>/dev/null)
+[ -n "$start_offset" ] || exit_unsupported
+[ -n "$stop_offset" ] || exit_unsupported
+
+"$UPROBE_TARGET" 5000 sleep &
+busy_pid=$!
+sleep 0.05
+
+echo 1 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+# 50 ms budget; task sleeps 200 ms per iteration -> sleeping_ns dominates.
+echo "p ${UPROBE_TARGET}:${start_offset} ${stop_offset} threshold=50000000" > "$TLOB_MONITOR"
+
+found=0; i=0
+while [ "$i" -lt 30 ]; do
+	sleep 0.1
+	grep -q "detail_env_tlob" /sys/kernel/tracing/trace && { found=1; break; }
+	i=$((i+1))
+done
+
+echo "-${UPROBE_TARGET}:${start_offset}" > "$TLOB_MONITOR" 2>/dev/null
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+echo 0 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 0 > monitors/tlob/enable
+
+[ "$found" = "1" ]
+
+line=$(grep "detail_env_tlob" /sys/kernel/tracing/trace | head -n 1)
+running=$(echo "$line" | sed 's/.*running_ns=\([0-9]*\).*/\1/')
+waiting=$(echo "$line" | sed 's/.*waiting_ns=\([0-9]*\).*/\1/')
+sleeping=$(echo "$line" | sed 's/.*sleeping_ns=\([0-9]*\).*/\1/')
+[ "$sleeping" -gt "$((running + waiting))" ]
+
+echo > /sys/kernel/tracing/trace
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_waiting.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_waiting.tc
new file mode 100644
index 000000000000..ef22fce700fc
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_detail_waiting.tc
@@ -0,0 +1,66 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor detail waiting (waiting_ns dominates when task is preempted between probes)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+command -v chrt    > /dev/null || exit_unsupported
+command -v taskset > /dev/null || exit_unsupported
+
+start_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_preempt_work 2>/dev/null)
+stop_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_preempt_work_done 2>/dev/null)
+[ -n "$start_offset" ] || exit_unsupported
+[ -n "$stop_offset" ]  || exit_unsupported
+
+cpu=0
+
+echo 1 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+# Register probe before the target starts so the start uprobe fires on the
+# first entry to tlob_preempt_work. Budget: 500 ms.
+echo "p ${UPROBE_TARGET}:${start_offset} ${stop_offset} threshold=500000000" > "$TLOB_MONITOR"
+
+# Target starts; start probe fires on tlob_preempt_work entry.
+taskset -c "$cpu" "$UPROBE_TARGET" 5000 preempt &
+busy_pid=$!
+sleep 0.05
+
+# RT hog on the same CPU preempts the target; target stays in waiting state
+# (runnable, off-CPU) until the budget expires -> waiting_ns dominates.
+chrt -f 99 taskset -c "$cpu" sh -c 'while true; do :; done' 2>/dev/null &
+hog_pid=$!
+
+found=0; i=0
+while [ "$i" -lt 30 ]; do
+	sleep 0.1
+	grep -q "detail_env_tlob" /sys/kernel/tracing/trace && { found=1; break; }
+	i=$((i+1))
+done
+
+# Kill the RT hog first so tlob_target can release any in-flight SRCU read
+# section from uprobe_notify_resume; otherwise probe removal blocks in
+# synchronize_srcu with the hog monopolising the CPU at FIFO-99.
+kill "$hog_pid" 2>/dev/null || true; wait "$hog_pid" 2>/dev/null || true
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+echo "-${UPROBE_TARGET}:${start_offset}" > "$TLOB_MONITOR" 2>/dev/null
+echo 0 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 0 > monitors/tlob/enable
+
+[ "$found" = "1" ]
+
+line=$(grep "detail_env_tlob" /sys/kernel/tracing/trace | head -n 1)
+running=$(echo "$line" | sed 's/.*running_ns=\([0-9]*\).*/\1/')
+sleeping=$(echo "$line" | sed 's/.*sleeping_ns=\([0-9]*\).*/\1/')
+waiting=$(echo "$line" | sed 's/.*waiting_ns=\([0-9]*\).*/\1/')
+[ "$waiting" -gt "$((running + sleeping))" ]
+
+echo > /sys/kernel/tracing/trace
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_multi.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_multi.tc
new file mode 100644
index 000000000000..a798f3e9b3fa
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_multi.tc
@@ -0,0 +1,64 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor multiple uprobe bindings (different offsets fire independently)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+busy_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work 2>/dev/null)
+busy_stop=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work_done 2>/dev/null)
+sleep_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_sleep_work 2>/dev/null)
+sleep_stop=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_sleep_work_done 2>/dev/null)
+[ -n "$busy_offset" ]  || exit_unsupported
+[ -n "$busy_stop" ]    || exit_unsupported
+[ -n "$sleep_offset" ] || exit_unsupported
+[ -n "$sleep_stop" ]   || exit_unsupported
+
+"$UPROBE_TARGET" 30000 &       # busy mode: tlob_busy_work fires every 200 ms
+busy_pid=$!
+"$UPROBE_TARGET" 30000 sleep & # sleep mode: tlob_sleep_work fires every 200 ms
+sleep_pid=$!
+sleep 0.05
+
+echo 1 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo 1 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+# Binding A: 5 s budget on the busy probe - must not fire in 200 ms loops.
+echo "p ${UPROBE_TARGET}:${busy_offset} ${busy_stop} threshold=5000000000" > "$TLOB_MONITOR"
+# Binding B: 10 us budget on the sleep probe - fires on first invocation.
+echo "p ${UPROBE_TARGET}:${sleep_offset} ${sleep_stop} threshold=10000" > "$TLOB_MONITOR"
+
+# Wait up to 2 s for error_env_tlob from binding B.
+found=0; i=0
+while [ "$i" -lt 20 ]; do
+	sleep 0.1
+	grep -q "error_env_tlob" /sys/kernel/tracing/trace && { found=1; break; }
+	i=$((i+1))
+done
+
+echo "-${UPROBE_TARGET}:${busy_offset}" > "$TLOB_MONITOR" 2>/dev/null
+echo "-${UPROBE_TARGET}:${sleep_offset}" > "$TLOB_MONITOR" 2>/dev/null
+kill "$sleep_pid" 2>/dev/null || true; wait "$sleep_pid" 2>/dev/null || true
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+
+echo 0 > monitors/tlob/enable
+echo 0 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo 0 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+
+[ "$found" = "1" ]
+# error_env_tlob payload: clock variable must be present.
+# The event field can be "budget_exceeded" (hrtimer path) or the DA event
+# name ("sleep", "preempt") depending on which fires first; don't constrain it.
+grep "error_env_tlob" /sys/kernel/tracing/trace | head -n 1 | grep -q "clk_elapsed="
+# detail_env_tlob must appear alongside the error.
+grep -q "detail_env_tlob" /sys/kernel/tracing/trace
+
+echo > /sys/kernel/tracing/trace
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_no_event.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_no_event.tc
new file mode 100644
index 000000000000..bb2eeef17019
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_no_event.tc
@@ -0,0 +1,19 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor no spurious events without active uprobe binding
+# requires: tlob:monitor
+
+TLOB_MONITOR=monitors/tlob/monitor
+
+echo 1 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+sleep 0.5
+
+! grep -q "error_env_tlob" /sys/kernel/tracing/trace || false
+
+echo 0 > monitors/tlob/enable
+echo 0 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo > /sys/kernel/tracing/trace
diff --git a/tools/testing/selftests/verification/test.d/tlob/uprobe_violation.tc b/tools/testing/selftests/verification/test.d/tlob/uprobe_violation.tc
new file mode 100644
index 000000000000..8a94bd679b88
--- /dev/null
+++ b/tools/testing/selftests/verification/test.d/tlob/uprobe_violation.tc
@@ -0,0 +1,67 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# description: Test tlob monitor budget violation (error_env_tlob and detail_env_tlob fire with correct fields)
+# requires: tlob:monitor
+
+RV_BINDIR="${RV_BINDIR:-$(realpath "$(dirname "${1:-$0}")")}"
+UPROBE_TARGET="${RV_BINDIR}/tlob_target"
+TLOB_SYM="${RV_BINDIR}/tlob_sym"
+[ -x "$UPROBE_TARGET" ] || exit_unsupported
+[ -x "$TLOB_SYM" ]      || exit_unsupported
+TLOB_MONITOR=monitors/tlob/monitor
+
+busy_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work 2>/dev/null)
+stop_offset=$("$TLOB_SYM" sym_offset "$UPROBE_TARGET" tlob_busy_work_done 2>/dev/null)
+[ -n "$busy_offset" ] || exit_unsupported
+[ -n "$stop_offset" ] || exit_unsupported
+
+"$UPROBE_TARGET" 30000 &
+busy_pid=$!
+sleep 0.05
+
+echo 1 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo 1 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 1 > /sys/kernel/tracing/tracing_on
+echo 1 > monitors/tlob/enable
+echo > /sys/kernel/tracing/trace
+
+# 10 us budget - fires almost immediately; task is busy-spinning on-CPU.
+echo "p ${UPROBE_TARGET}:${busy_offset} ${stop_offset} threshold=10000" > "$TLOB_MONITOR"
+
+# wait up to 2 s for detail_env_tlob
+found=0; i=0
+while [ "$i" -lt 20 ]; do
+	sleep 0.1
+	grep -q "detail_env_tlob" /sys/kernel/tracing/trace && { found=1; break; }
+	i=$((i+1))
+done
+
+echo "-${UPROBE_TARGET}:${busy_offset}" > "$TLOB_MONITOR" 2>/dev/null
+kill "$busy_pid" 2>/dev/null || true; wait "$busy_pid" 2>/dev/null || true
+echo 0 > /sys/kernel/tracing/events/rv/error_env_tlob/enable
+echo 0 > /sys/kernel/tracing/events/rv/detail_env_tlob/enable
+echo 0 > monitors/tlob/enable
+
+[ "$found" = "1" ]
+
+# error_env_tlob must carry the clk_elapsed environment field.
+# The event label is "budget_exceeded" when detected by the hrtimer callback,
+# or the triggering sched event name when detected by the constraint path on a
+# preemption that races with the timer (common on PREEMPT_RT / VM).  Both are
+# valid detections; check the env field instead of the label.
+grep "error_env_tlob" /sys/kernel/tracing/trace | head -n 1 | grep -q "clk_elapsed="
+
+# detail_env_tlob must have all five fields with the correct threshold
+line=$(grep "detail_env_tlob" /sys/kernel/tracing/trace | head -n 1)
+echo "$line" | grep -q "pid="
+echo "$line" | grep -q "threshold_ns=10000"
+echo "$line" | grep -q "running_ns="
+echo "$line" | grep -q "waiting_ns="
+echo "$line" | grep -q "sleeping_ns="
+
+# Busy-spin keeps the task on-CPU: running_ns must exceed sleeping_ns.
+running=$(echo "$line" | sed 's/.*running_ns=\([0-9]*\).*/\1/')
+sleeping=$(echo "$line" | sed 's/.*sleeping_ns=\([0-9]*\).*/\1/')
+[ "$running" -gt "$sleeping" ]
+
+echo > /sys/kernel/tracing/trace
-- 
2.25.1