diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-10-02 12:17:24 -0700 |
| commit | 3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch) | |
| tree | b767d7f6e26bc64334d3f14f8422d187239dc45d /include/rv | |
| download | linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip | |
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe:
- Fix a task_work add use-after-free with SQPOLL.
The sqpoll thread could pop and complete the last request while
io_req_normal_work_add() was still looking at them after the mpscq
push.
Use the same approach as DEFER_TASKRUN to protect from that, holding
an RCU read lock across the add, and have exit wait for an RCU grace
period for SQPOLL rings as well.
- CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
rings
- Mark the source filter table as COW when cloning bpf filters, so
registering another filter on the source doesn't modify the shared
table in place
- Initialize the task context before running the BPF loop
- Requeue zcrx multishot receives stopped by a local resource
- End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)
* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix task_work add use-after-free with SQPOLL
io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
io_uring/zcrx: requeue multishot receives stopped by a local resource
io_uring: initialize task context before running the BPF loop
io_uring: zero big_cqe for aux CQEs on CQE32 rings
io_uring: fix free entry check for 32b CQEs on CQE32 rings
io_uring: only post the dummy skip CQE on CQE_MIXED rings
io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'include/rv')
| -rw-r--r-- | include/rv/automata.h | 81 | ||||
| -rw-r--r-- | include/rv/da_monitor.h | 934 | ||||
| -rw-r--r-- | include/rv/ha_monitor.h | 550 | ||||
| -rw-r--r-- | include/rv/instrumentation.h | 29 | ||||
| -rw-r--r-- | include/rv/kunit.h | 73 | ||||
| -rw-r--r-- | include/rv/ltl_monitor.h | 182 |
6 files changed, 1849 insertions, 0 deletions
diff --git a/include/rv/automata.h b/include/rv/automata.h new file mode 100644 index 000000000..4a4eb40cf --- /dev/null +++ b/include/rv/automata.h @@ -0,0 +1,81 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org> + * + * Deterministic automata helper functions, to be used with the automata + * models in C generated by the dot2k tool. + */ + +#ifndef _RV_AUTOMATA_H +#define _RV_AUTOMATA_H + +#ifndef MONITOR_NAME +#error "MONITOR_NAME macro is not defined. Did you include $(MODEL_NAME).h generated by rvgen?" +#endif + +#define RV_AUTOMATON_NAME CONCATENATE(automaton_, MONITOR_NAME) +#define EVENT_MAX CONCATENATE(event_max_, MONITOR_NAME) +#define STATE_MAX CONCATENATE(state_max_, MONITOR_NAME) +#define events CONCATENATE(events_, MONITOR_NAME) +#define states CONCATENATE(states_, MONITOR_NAME) + +/* + * model_get_state_name - return the (string) name of the given state + */ +static char *model_get_state_name(enum states state) +{ + if ((state < 0) || (state >= STATE_MAX)) + return "INVALID"; + + return RV_AUTOMATON_NAME.state_names[state]; +} + +/* + * model_get_event_name - return the (string) name of the given event + */ +static char *model_get_event_name(enum events event) +{ + if ((event < 0) || (event >= EVENT_MAX)) + return "INVALID"; + + return RV_AUTOMATON_NAME.event_names[event]; +} + +/* + * model_get_initial_state - return the automaton's initial state + */ +static inline enum states model_get_initial_state(void) +{ + return RV_AUTOMATON_NAME.initial_state; +} + +/* + * model_get_next_state - process an automaton event occurrence + * + * Given the current state (curr_state) and the event (event), returns + * the next state, or INVALID_STATE in case of error. + */ +static inline enum states model_get_next_state(enum states curr_state, + enum events event) +{ + if ((curr_state < 0) || (curr_state >= STATE_MAX)) + return INVALID_STATE; + + if ((event < 0) || (event >= EVENT_MAX)) + return INVALID_STATE; + + return RV_AUTOMATON_NAME.function[curr_state][event]; +} + +/* + * model_is_final_state - check if the given state is a final state + */ +static inline bool model_is_final_state(enum states state) +{ + if ((state < 0) || (state >= STATE_MAX)) + return 0; + + return RV_AUTOMATON_NAME.final_states[state]; +} + +#endif diff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h new file mode 100644 index 000000000..6fc5ef814 --- /dev/null +++ b/include/rv/da_monitor.h @@ -0,0 +1,934 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org> + * + * Deterministic automata (DA) monitor functions, to be used together + * with automata models in C generated by the rvgen tool. + * + * The rvgen tool is available at tools/verification/rvgen/ + * + * For further information, see: + * Documentation/trace/rv/monitor_synthesis.rst + */ + +#ifndef _RV_DA_MONITOR_H +#define _RV_DA_MONITOR_H + +#include <rv/automata.h> +#include <linux/rv.h> +#include <rv/kunit.h> +#include <linux/stringify.h> +#include <linux/bug.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/hashtable.h> + +/* + * Per-cpu variables require a unique name although static in some + * configurations (e.g. alpha modules). + */ +#define DA_MON_NAME CONCATENATE(da_mon_, MONITOR_NAME) + +static struct rv_monitor rv_this; + +/* + * Hook to allow the implementation of hybrid automata: define it with a + * function that takes curr_state, event and next_state and returns true if the + * environment constraints (e.g. timing) are satisfied, false otherwise. + */ +#ifndef da_monitor_event_hook +#define da_monitor_event_hook(...) true +#endif + +/* + * Hook to allow the implementation of hybrid automata: define it with a + * function that takes the da_monitor and performs further initialisation + * (e.g. reset set up timers). + */ +#ifndef da_monitor_init_hook +#define da_monitor_init_hook(da_mon) +#endif + +/* + * Hook to allow the implementation of hybrid automata: define it with a + * function that takes the da_monitor and performs further reset (e.g. reset + * all clocks). + */ +#ifndef da_monitor_reset_hook +#define da_monitor_reset_hook(da_mon) +#endif + +/* + * Hook to allow the implementation of hybrid automata: define it with a + * function that waits for the termination of all monitors background + * activities (e.g. all timers). This hook can sleep. + */ +#ifndef da_monitor_sync_hook +#define da_monitor_sync_hook() +#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 + * int in the event tracepoint. + * Unused for implicit monitors. + */ +#ifndef da_id_type +#define da_id_type int +#endif + +static void react(enum states curr_state, enum events event) +{ + rv_react(&rv_this, + "rv: monitor %s does not allow event %s on state %s\n", + __stringify(MONITOR_NAME), + model_get_event_name(event), + model_get_state_name(curr_state)); +} + +/* + * da_monitor_reset_state - reset a monitor and setting it to init state + */ +static inline void da_monitor_reset_state(struct da_monitor *da_mon) +{ + WRITE_ONCE(da_mon->monitoring, 0); + /* Pair with load in __ha_monitor_timer_callback */ + smp_store_release(&da_mon->curr_state, model_get_initial_state()); +} + +/* + * da_monitor_reset - reset a monitor and setting it to init state + */ +static inline void da_monitor_reset(struct da_monitor *da_mon) +{ + da_monitor_reset_hook(da_mon); + da_monitor_reset_state(da_mon); +} + +/* + * da_monitor_start - start monitoring + * + * The monitor will ignore all events until monitoring is set to true. This + * function needs to be called to tell the monitor to start monitoring. + */ +static inline void da_monitor_start(struct da_monitor *da_mon) +{ + da_mon->curr_state = model_get_initial_state(); + da_monitor_init_hook(da_mon); + /* Pairs with smp_load_acquire in da_monitoring(). */ + smp_store_release(&da_mon->monitoring, 1); +} + +/* + * da_monitoring - returns true if the monitor is processing events + */ +static inline bool da_monitoring(struct da_monitor *da_mon) +{ + /* Pairs with smp_store_release in da_monitor_start(). */ + return smp_load_acquire(&da_mon->monitoring); +} + +/* + * da_monitor_enabled - checks if the monitor is enabled + */ +static inline bool da_monitor_enabled(void) +{ + /* global switch */ + if (unlikely(!rv_monitoring_on())) + return 0; + + /* monitor enabled */ + if (unlikely(!rv_this.enabled)) + return 0; + + return 1; +} + +/* + * da_monitor_handling_event - checks if the monitor is ready to handle events + */ +static inline bool da_monitor_handling_event(struct da_monitor *da_mon) +{ + if (!da_monitor_enabled()) + return 0; + + /* monitor is actually monitoring */ + if (unlikely(!da_monitoring(da_mon))) + return 0; + + return 1; +} + +#if RV_MON_TYPE == RV_MON_GLOBAL +/* + * Functions to define, init and get a global monitor. + */ + +/* + * global monitor (a single variable) + */ +static struct da_monitor DA_MON_NAME; + +/* + * da_get_monitor - return the global monitor address + */ +static struct da_monitor *da_get_monitor(void) +{ + return &DA_MON_NAME; +} + +/* + * __da_monitor_reset_all - reset the single monitor + */ +static void __da_monitor_reset_all(void (*reset)(struct da_monitor *)) +{ + reset(da_get_monitor()); +} + +/* + * da_monitor_reset_all - reset the single monitor + */ +static void da_monitor_reset_all(void) +{ + __da_monitor_reset_all(da_monitor_reset); +} + +/* + * da_monitor_reset_state_all - reset the single monitor + */ +static inline void da_monitor_reset_state_all(void) +{ + __da_monitor_reset_all(da_monitor_reset_state); +} + +/* + * da_monitor_init - initialize a monitor + */ +static inline int da_monitor_init(void) +{ + da_monitor_reset_state_all(); + return 0; +} + +/* + * da_monitor_destroy - destroy the monitor + */ +static inline void da_monitor_destroy(void) +{ + da_monitor_reset_all(); + da_monitor_sync_hook(); +} + +#ifndef da_implicit_guard +#define da_implicit_guard() +#endif + +#elif RV_MON_TYPE == RV_MON_PER_CPU +/* + * Functions to define, init and get a per-cpu monitor. + */ + +/* + * per-cpu monitor variables + */ +static DEFINE_PER_CPU(struct da_monitor, DA_MON_NAME); + +/* + * da_get_monitor - return current CPU monitor address + */ +static struct da_monitor *da_get_monitor(void) +{ + return this_cpu_ptr(&DA_MON_NAME); +} + +/* + * __da_monitor_reset_all - reset all CPUs' monitor + */ +static void __da_monitor_reset_all(void (*reset)(struct da_monitor *)) +{ + struct da_monitor *da_mon; + int cpu; + + for_each_cpu(cpu, cpu_online_mask) { + da_mon = per_cpu_ptr(&DA_MON_NAME, cpu); + reset(da_mon); + } +} + +/* + * da_monitor_reset_all - reset all CPUs' monitor + */ +static void da_monitor_reset_all(void) +{ + __da_monitor_reset_all(da_monitor_reset); +} + +/* + * da_monitor_reset_state_all - reset all CPUs' monitor + */ +static inline void da_monitor_reset_state_all(void) +{ + __da_monitor_reset_all(da_monitor_reset_state); +} + +/* + * da_monitor_init - initialize all CPUs' monitor + */ +static inline int da_monitor_init(void) +{ + da_monitor_reset_state_all(); + return 0; +} + +/* + * da_monitor_destroy - destroy the monitor + */ +static inline void da_monitor_destroy(void) +{ + da_monitor_reset_all(); + da_monitor_sync_hook(); +} + +#ifndef da_implicit_guard +#define da_implicit_guard() guard(migrate)() +#endif + +#elif RV_MON_TYPE == RV_MON_PER_TASK +/* + * Functions to define, init and get a per-task monitor. + */ + +/* + * The per-task monitor is stored a vector in the task struct. This variable + * stores the position on the vector reserved for this monitor. + */ +static int task_mon_slot = RV_PER_TASK_MONITOR_INIT; + +/* + * da_get_monitor - return the monitor in the allocated slot for tsk + */ +static inline struct da_monitor *da_get_monitor(struct task_struct *tsk) +{ + return &tsk->rv[task_mon_slot].da_mon; +} + +static inline void da_reset(struct task_struct *tsk) +{ + da_monitor_reset(da_get_monitor(tsk)); +} + +/* + * da_get_target - return the task associated to the monitor + */ +static inline struct task_struct *da_get_target(struct da_monitor *da_mon) +{ + return container_of(da_mon, struct task_struct, rv[task_mon_slot].da_mon); +} + +/* + * da_get_id - return the id associated to the monitor + * + * For per-task monitors, the id is the task's PID. + */ +static inline da_id_type da_get_id(struct da_monitor *da_mon) +{ + return da_get_target(da_mon)->pid; +} + +static void __da_monitor_reset_all(void (*reset)(struct da_monitor *)) +{ + struct task_struct *g, *p; + int cpu; + + scoped_guard(read_lock, &tasklist_lock) { + for_each_process_thread(g, p) + reset(da_get_monitor(p)); + } + for_each_present_cpu(cpu) + reset(da_get_monitor(idle_task(cpu))); +} + +static void da_monitor_reset_all(void) +{ + __da_monitor_reset_all(da_monitor_reset); +} + +static inline void da_monitor_reset_state_all(void) +{ + __da_monitor_reset_all(da_monitor_reset_state); +} + +/* + * da_monitor_init - initialize the per-task monitor + * + * Try to allocate a slot in the task's vector of monitors. If there + * is an available slot, use it and reset all task's monitor. + */ +static int da_monitor_init(void) +{ + int slot; + + slot = rv_get_task_monitor_slot(); + if (slot < 0 || slot >= RV_PER_TASK_MONITOR_INIT) + return slot; + + task_mon_slot = slot; + + da_monitor_reset_state_all(); + return 0; +} + +/* + * da_monitor_destroy - return the allocated slot + * + * Wait for all in-flight handlers before returning the slot to avoid + * out-of-bound accesses. + */ +static inline void da_monitor_destroy(void) +{ + if (task_mon_slot == RV_PER_TASK_MONITOR_INIT) { + WARN_ONCE(1, "Disabling a disabled monitor: " __stringify(MONITOR_NAME)); + return; + } + + tracepoint_synchronize_unregister(); + da_monitor_reset_all(); + da_monitor_sync_hook(); + + rv_put_task_monitor_slot(task_mon_slot); + task_mon_slot = RV_PER_TASK_MONITOR_INIT; +} + +#elif RV_MON_TYPE == RV_MON_PER_OBJ +/* + * Functions to define, init and get a per-object monitor. + */ + +struct da_monitor_storage { + da_id_type id; + monitor_target target; + union rv_task_monitor rv; + struct hlist_node node; + struct rcu_head rcu; +}; + +#ifndef DA_MONITOR_HT_BITS +#define DA_MONITOR_HT_BITS 10 +#endif +static DEFINE_HASHTABLE(da_monitor_ht, DA_MONITOR_HT_BITS); + +/* + * da_create_empty_storage - pre-allocate an empty storage + */ +static inline struct da_monitor_storage *da_create_empty_storage(da_id_type id) +{ + struct da_monitor_storage *mon_storage; + + mon_storage = kmalloc_nolock(sizeof(struct da_monitor_storage), + __GFP_ZERO, NUMA_NO_NODE); + if (!mon_storage) + return NULL; + + hash_add_rcu(da_monitor_ht, &mon_storage->node, id); + mon_storage->id = id; + return mon_storage; +} + +/* + * da_create_storage - create the per-object storage + * + * The caller is responsible to synchronise writers, either with locks or + * implicitly. For instance, if da_create_storage is only called from a single + * event for target (e.g. sched_switch), it's safe to call this without locks. + */ +static inline struct da_monitor *da_create_storage(da_id_type id, + monitor_target target, + struct da_monitor *da_mon) +{ + struct da_monitor_storage *mon_storage; + + if (da_mon) + return da_mon; + + mon_storage = da_create_empty_storage(id); + if (!mon_storage) + return NULL; + + mon_storage->target = target; + return &mon_storage->rv.da_mon; +} + +/* + * __da_get_mon_storage - get the monitor storage from the hash table + */ +static inline struct da_monitor_storage *__da_get_mon_storage(da_id_type id) +{ + struct da_monitor_storage *mon_storage; + + lockdep_assert_in_rcu_read_lock(); + hash_for_each_possible_rcu(da_monitor_ht, mon_storage, node, id) { + if (mon_storage->id == id) + return mon_storage; + } + + return NULL; +} + +/* + * da_get_monitor - return the monitor for target + */ +static struct da_monitor *da_get_monitor(da_id_type id, monitor_target target) +{ + struct da_monitor_storage *mon_storage; + + mon_storage = __da_get_mon_storage(id); + return mon_storage ? &mon_storage->rv.da_mon : NULL; +} + +/* + * da_get_target - return the object associated to the monitor + */ +static inline monitor_target da_get_target(struct da_monitor *da_mon) +{ + return container_of(da_mon, struct da_monitor_storage, rv.da_mon)->target; +} + +/* + * da_get_id - return the id associated to the monitor + */ +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 + * + * Can be used as a substitute of da_create_storage when starting a monitor in + * an environment where allocation is unsafe. + */ +static inline struct da_monitor *da_fill_empty_storage(da_id_type id, + monitor_target target, + struct da_monitor *da_mon) +{ + if (unlikely(da_mon && !da_get_target(da_mon))) + container_of(da_mon, struct da_monitor_storage, rv.da_mon)->target = target; + return da_mon; +} + +/* + * da_get_target_by_id - return the object associated to the id + */ +static inline monitor_target da_get_target_by_id(da_id_type id) +{ + struct da_monitor_storage *mon_storage; + + guard(rcu)(); + mon_storage = __da_get_mon_storage(id); + + if (unlikely(!mon_storage)) + return NULL; + return mon_storage->target; +} + +/* + * 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(). + */ +static inline void da_destroy_storage(da_id_type id) +{ + struct da_monitor_storage *mon_storage; + + guard(rcu)(); + mon_storage = __da_get_mon_storage(id); + + if (!mon_storage) + return; + da_monitor_reset_hook(&mon_storage->rv.da_mon); + hash_del_rcu(&mon_storage->node); + kfree_rcu(mon_storage, rcu); +} + +static void __da_monitor_reset_all(void (*reset)(struct da_monitor *)) +{ + struct da_monitor_storage *mon_storage; + int bkt; + + guard(rcu)(); + hash_for_each_rcu(da_monitor_ht, bkt, mon_storage, node) + reset(&mon_storage->rv.da_mon); +} + +static void da_monitor_reset_all(void) +{ + __da_monitor_reset_all(da_monitor_reset); +} + +static inline void da_monitor_reset_state_all(void) +{ + __da_monitor_reset_all(da_monitor_reset_state); +} + +static inline int da_monitor_init(void) +{ + hash_init(da_monitor_ht); + return 0; +} + +static inline void da_monitor_destroy(void) +{ + struct da_monitor_storage *mon_storage; + 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); + } +} + +/* + * 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. + */ +#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 */ + +#endif /* RV_MON_TYPE */ + +#if RV_MON_TYPE == RV_MON_GLOBAL || RV_MON_TYPE == RV_MON_PER_CPU +/* + * Trace events for implicit monitors. Implicit monitor is the one which the + * handler does not need to specify which da_monitor to manipulate. Examples + * of implicit monitor are the per_cpu or the global ones. + */ + +static inline void da_trace_event(struct da_monitor *da_mon, + char *curr_state, char *event, + char *next_state, bool is_final, + da_id_type id) +{ + CONCATENATE(trace_event_, MONITOR_NAME)(curr_state, event, next_state, + is_final); +} + +static inline void da_trace_error(struct da_monitor *da_mon, + char *curr_state, char *event, + da_id_type id) +{ + CONCATENATE(trace_error_, MONITOR_NAME)(curr_state, event); +} + +/* + * da_get_id - unused for implicit monitors + */ +static inline da_id_type da_get_id(struct da_monitor *da_mon) +{ + return 0; +} + +#elif RV_MON_TYPE == RV_MON_PER_TASK || RV_MON_TYPE == RV_MON_PER_OBJ +/* + * Trace events for per_task/per_object monitors, report the target id. + */ + +static inline void da_trace_event(struct da_monitor *da_mon, + char *curr_state, char *event, + char *next_state, bool is_final, + da_id_type id) +{ + CONCATENATE(trace_event_, MONITOR_NAME)(id, curr_state, event, + next_state, is_final); +} + +static inline void da_trace_error(struct da_monitor *da_mon, + char *curr_state, char *event, + da_id_type id) +{ + CONCATENATE(trace_error_, MONITOR_NAME)(id, curr_state, event); +} +#endif /* RV_MON_TYPE */ + +/* + * da_event - handle an event for the da_mon + * + * This function is valid for both implicit and id monitors. + * Retry in case there is a race between getting and setting the next state, + * warn and reset the monitor if it runs out of retries. The monitor should be + * able to handle various orders. + */ +static inline bool da_event(struct da_monitor *da_mon, enum events event, da_id_type id) +{ + enum states curr_state, next_state; + + curr_state = READ_ONCE(da_mon->curr_state); + for (int i = 0; i < MAX_DA_RETRY_RACING_EVENTS; i++) { + next_state = model_get_next_state(curr_state, event); + if (next_state == INVALID_STATE) { + react(curr_state, event); + da_trace_error(da_mon, model_get_state_name(curr_state), + model_get_event_name(event), id); + return false; + } + if (likely(try_cmpxchg(&da_mon->curr_state, &curr_state, next_state))) { + if (!da_monitor_event_hook(da_mon, curr_state, event, next_state, id)) + return false; + da_trace_event(da_mon, model_get_state_name(curr_state), + model_get_event_name(event), + model_get_state_name(next_state), + model_is_final_state(next_state), id); + return true; + } + } + + trace_rv_retries_error(__stringify(MONITOR_NAME), model_get_event_name(event)); + pr_warn("rv: " __stringify(MAX_DA_RETRY_RACING_EVENTS) + " retries reached for event %s, resetting monitor %s", + model_get_event_name(event), __stringify(MONITOR_NAME)); + return false; +} + +static inline void __da_handle_event_common(struct da_monitor *da_mon, + enum events event, da_id_type id) +{ + if (!da_event(da_mon, event, id)) + da_monitor_reset(da_mon); +} + +static inline void __da_handle_event(struct da_monitor *da_mon, + enum events event, da_id_type id) +{ + if (da_monitor_handling_event(da_mon)) + __da_handle_event_common(da_mon, event, id); +} + +static inline bool __da_handle_start_event(struct da_monitor *da_mon, + enum events event, da_id_type id) +{ + if (!da_monitor_enabled()) + return 0; + if (unlikely(!da_monitoring(da_mon))) { + da_monitor_start(da_mon); + return 0; + } + + __da_handle_event_common(da_mon, event, id); + + return 1; +} + +static inline bool __da_handle_start_run_event(struct da_monitor *da_mon, + enum events event, da_id_type id) +{ + if (!da_monitor_enabled()) + return 0; + if (unlikely(!da_monitoring(da_mon))) + da_monitor_start(da_mon); + + __da_handle_event_common(da_mon, event, id); + + return 1; +} + +#if RV_MON_TYPE == RV_MON_GLOBAL || RV_MON_TYPE == RV_MON_PER_CPU +/* + * Handle event for implicit monitor: da_get_monitor() will figure out + * the monitor. + */ + +/* + * da_handle_event - handle an event + */ +static inline void da_handle_event(enum events event) +{ + da_implicit_guard(); + __da_handle_event(da_get_monitor(), event, 0); +} + +/* + * da_handle_start_event - start monitoring or handle event + * + * This function is used to notify the monitor that the system is returning + * to the initial state, so the monitor can start monitoring in the next event. + * Thus: + * + * If the monitor already started, handle the event. + * If the monitor did not start yet, start the monitor but skip the event. + */ +static inline bool da_handle_start_event(enum events event) +{ + da_implicit_guard(); + return __da_handle_start_event(da_get_monitor(), event, 0); +} + +/* + * da_handle_start_run_event - start monitoring and handle event + * + * This function is used to notify the monitor that the system is in the + * initial state, so the monitor can start monitoring and handling event. + */ +static inline bool da_handle_start_run_event(enum events event) +{ + da_implicit_guard(); + return __da_handle_start_run_event(da_get_monitor(), event, 0); +} + +#elif RV_MON_TYPE == RV_MON_PER_TASK +/* + * Handle event for per task. + */ + +/* + * da_handle_event - handle an event + */ +static inline void da_handle_event(struct task_struct *tsk, enum events event) +{ + __da_handle_event(da_get_monitor(tsk), event, tsk->pid); +} + +/* + * da_handle_start_event - start monitoring or handle event + * + * This function is used to notify the monitor that the system is returning + * to the initial state, so the monitor can start monitoring in the next event. + * Thus: + * + * If the monitor already started, handle the event. + * If the monitor did not start yet, start the monitor but skip the event. + */ +static inline bool da_handle_start_event(struct task_struct *tsk, + enum events event) +{ + return __da_handle_start_event(da_get_monitor(tsk), event, tsk->pid); +} + +/* + * da_handle_start_run_event - start monitoring and handle event + * + * This function is used to notify the monitor that the system is in the + * initial state, so the monitor can start monitoring and handling event. + */ +static inline bool da_handle_start_run_event(struct task_struct *tsk, + enum events event) +{ + return __da_handle_start_run_event(da_get_monitor(tsk), event, tsk->pid); +} + +#elif RV_MON_TYPE == RV_MON_PER_OBJ +/* + * Handle event for per object. + */ + +/* + * da_handle_event - handle an event + */ +static inline void da_handle_event(da_id_type id, monitor_target target, enum events event) +{ + struct da_monitor *da_mon; + + guard(rcu)(); + da_mon = da_get_monitor(id, target); + if (likely(da_mon)) + __da_handle_event(da_mon, event, id); +} + +/* + * da_handle_start_event - start monitoring or handle event + * + * This function is used to notify the monitor that the system is returning + * to the initial state, so the monitor can start monitoring in the next event. + * Thus: + * + * If the monitor already started, handle the event. + * If the monitor did not start yet, start the monitor but skip the event. + */ +static inline bool da_handle_start_event(da_id_type id, monitor_target target, + enum events event) +{ + struct da_monitor *da_mon; + + guard(rcu)(); + da_mon = da_get_monitor(id, target); + da_mon = da_prepare_storage(id, target, da_mon); + if (unlikely(!da_mon)) + return 0; + return __da_handle_start_event(da_mon, event, id); +} + +/* + * da_handle_start_run_event - start monitoring and handle event + * + * This function is used to notify the monitor that the system is in the + * initial state, so the monitor can start monitoring and handling event. + */ +static inline bool da_handle_start_run_event(da_id_type id, monitor_target target, + enum events event) +{ + struct da_monitor *da_mon; + + guard(rcu)(); + da_mon = da_get_monitor(id, target); + da_mon = da_prepare_storage(id, target, da_mon); + if (unlikely(!da_mon)) + return 0; + return __da_handle_start_run_event(da_mon, event, id); +} + +static inline void da_reset(da_id_type id, monitor_target target) +{ + struct da_monitor *da_mon; + + guard(rcu)(); + da_mon = da_get_monitor(id, target); + if (likely(da_mon)) + da_monitor_reset(da_mon); +} +#endif /* RV_MON_TYPE */ + +#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST) +#if RV_MON_TYPE == RV_MON_PER_TASK +#define RV_MON_OPS_INIT() { \ + .rv_this = &rv_this, \ + .is_per_task = true, \ + .task_slot = &task_mon_slot, \ + .task_reset = da_reset, \ +} +#else +#define RV_MON_OPS_INIT() { \ + .rv_this = &rv_this, \ + .monitor_init = da_monitor_init, \ + .monitor_destroy = da_monitor_destroy, \ +} +#endif /* RV_MON_TYPE */ +#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */ + +#endif diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h new file mode 100644 index 000000000..6e1c7fe54 --- /dev/null +++ b/include/rv/ha_monitor.h @@ -0,0 +1,550 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2025-2028 Red Hat, Inc. Gabriele Monaco <gmonaco@redhat.com> + * + * Hybrid automata (HA) monitor functions, to be used together + * with automata models in C generated by the rvgen tool. + * + * This type of monitors extends the Deterministic automata (DA) class by + * adding a set of environment variables (e.g. clocks) that can be used to + * constraint the valid transitions. + * + * The rvgen tool is available at tools/verification/rvgen/ + * + * For further information, see: + * Documentation/trace/rv/monitor_synthesis.rst + */ + +#ifndef _RV_HA_MONITOR_H +#define _RV_HA_MONITOR_H + +#include <rv/automata.h> + +#ifndef da_id_type +#define da_id_type int +#endif + +static inline void ha_monitor_init_env(struct da_monitor *da_mon); +static inline void ha_monitor_reset_env(struct da_monitor *da_mon); +static inline void ha_setup_timer(struct ha_monitor *ha_mon); +static inline bool ha_cancel_timer(struct ha_monitor *ha_mon); +static inline void ha_cancel_timer_sync(struct ha_monitor *ha_mon); +static bool ha_monitor_handle_constraint(struct da_monitor *da_mon, + enum states curr_state, + enum events event, + enum states next_state, + da_id_type id); +#define da_monitor_event_hook ha_monitor_handle_constraint +#define da_monitor_init_hook ha_monitor_init_env +#define da_monitor_reset_hook ha_monitor_reset_env +#define da_monitor_sync_hook() synchronize_rcu() + +#if !defined(HA_SKIP_AUTO_CLEANUP) && RV_MON_TYPE == RV_MON_PER_TASK +/* + * Automatic cleanup handlers for per-task HA monitors, only skip if you know + * what you are doing (e.g. you want to implement cleanup manually in another + * handler doing more things). + */ +static void ha_handle_sched_process_exit(void *data, struct task_struct *p, + bool group_dead); + +#define ha_monitor_enable_hook() \ + rv_attach_trace_probe(__stringify(MONITOR_NAME), sched_process_exit, \ + ha_handle_sched_process_exit) +#define ha_monitor_disable_hook() \ + rv_detach_trace_probe(__stringify(MONITOR_NAME), sched_process_exit, \ + ha_handle_sched_process_exit) +#else +#define ha_monitor_enable_hook() ((void)0) +#define ha_monitor_disable_hook() ((void)0) +#endif + +#include <rv/da_monitor.h> +#include <linux/seq_buf.h> + +/* This simplifies things since da_mon and ha_mon coexist in the same union */ +_Static_assert(offsetof(struct ha_monitor, da_mon) == 0, + "da_mon must be the first element in an ha_mon!"); +#define to_ha_monitor(da) container_of(da, struct ha_monitor, da_mon) + +#define ENV_MAX CONCATENATE(env_max_, MONITOR_NAME) +#define ENV_MAX_STORED CONCATENATE(env_max_stored_, MONITOR_NAME) +#define envs CONCATENATE(envs_, MONITOR_NAME) + +/* Environment storage before being reset */ +#define ENV_INVALID_VALUE U64_MAX +/* Error with no event occurs only on timeouts */ +#define EVENT_NONE EVENT_MAX +#define EVENT_NONE_LBL "none" +#define ENV_BUFFER_SIZE 64 + +#ifdef CONFIG_RV_REACTORS + +/* + * ha_react - trigger the reaction after a failed environment constraint + * + * The transition from curr_state with event is otherwise valid, but the + * environment constraint is false. This function can be called also with no + * event from a timer (state constraints only). + */ +static void ha_react(enum states curr_state, enum events event, char *env) +{ + rv_react(&rv_this, + "rv: monitor %s does not allow event %s on state %s with env %s\n", + __stringify(MONITOR_NAME), + event == EVENT_NONE ? EVENT_NONE_LBL : model_get_event_name(event), + model_get_state_name(curr_state), env); +} + +#else /* CONFIG_RV_REACTOR */ + +static void ha_react(enum states curr_state, enum events event, char *env) { } +#endif + +/* + * model_get_state_name - return the (string) name of the given state + */ +static char *model_get_env_name(enum envs env) +{ + if ((env < 0) || (env >= ENV_MAX)) + return "INVALID"; + + return RV_AUTOMATON_NAME.env_names[env]; +} + +/* + * Monitors requiring a timer implementation need to request it explicitly. + */ +#ifndef HA_TIMER_TYPE +#define HA_TIMER_TYPE HA_TIMER_NONE +#endif + +#if HA_TIMER_TYPE == HA_TIMER_WHEEL +static void ha_monitor_timer_callback(struct timer_list *timer); +#elif HA_TIMER_TYPE == HA_TIMER_HRTIMER +static enum hrtimer_restart ha_monitor_timer_callback(struct hrtimer *hrtimer); +#endif + +/* + * ktime_get_ns is expensive, since we usually don't require precise accounting + * of changes within the same event, cache the current time at the beginning of + * the constraint handler and use the cache for subsequent calls. + * Monitors without ns clocks automatically skip this. + */ +#ifdef HA_CLK_NS +#define ha_get_ns() ktime_get_ns() +#else +#define ha_get_ns() 0 +#endif /* HA_CLK_NS */ + +static bool ha_mon_destroying; + +static int ha_monitor_init(void) +{ + int ret; + + WRITE_ONCE(ha_mon_destroying, false); + ret = da_monitor_init(); + if (ret == 0) + ha_monitor_enable_hook(); + return ret; +} + +static void ha_monitor_destroy(void) +{ + WRITE_ONCE(ha_mon_destroying, true); + ha_monitor_disable_hook(); + da_monitor_destroy(); +} + +/* Should be supplied by the monitor */ +static u64 ha_get_env(struct ha_monitor *ha_mon, enum envs env, u64 time_ns); +static bool ha_verify_constraint(struct ha_monitor *ha_mon, + enum states curr_state, + enum events event, + enum states next_state, + u64 time_ns); + +/* + * ha_monitor_reset_all_stored - reset all environment variables in the monitor + */ +static inline void ha_monitor_reset_all_stored(struct ha_monitor *ha_mon) +{ + for (int i = 0; i < ENV_MAX_STORED; i++) + WRITE_ONCE(ha_mon->env_store[i], ENV_INVALID_VALUE); +} + +/* + * ha_monitor_init_env - setup timer and reset all environment + * + * Called from a hook in the DA start functions, it supplies the da_mon + * corresponding to the current ha_mon. + * Not all hybrid automata require the timer, still set it for simplicity. + */ +static inline void ha_monitor_init_env(struct da_monitor *da_mon) +{ + struct ha_monitor *ha_mon = to_ha_monitor(da_mon); + + ha_monitor_reset_all_stored(ha_mon); + ha_setup_timer(ha_mon); +} + +/* + * ha_monitor_reset_env - stop timer and reset all environment + * + * Called from a hook in the DA reset functions, it supplies the da_mon + * corresponding to the current ha_mon. + * Not all hybrid automata require the timer, still clear it for simplicity. + * Monitors that never started have their timer uninitialized, do not stop those. + */ +static inline void ha_monitor_reset_env(struct da_monitor *da_mon) +{ + struct ha_monitor *ha_mon = to_ha_monitor(da_mon); + + if (likely(da_monitoring(da_mon))) + ha_cancel_timer(ha_mon); +} + +/* + * ha_monitor_env_invalid - return true if env has not been initialised + */ +static inline bool ha_monitor_env_invalid(struct ha_monitor *ha_mon, enum envs env) +{ + return READ_ONCE(ha_mon->env_store[env]) == ENV_INVALID_VALUE; +} + +static inline void ha_get_env_string(struct seq_buf *s, + struct ha_monitor *ha_mon, u64 time_ns) +{ + const char *format_str = "%s=%llu"; + + for (int i = 0; i < ENV_MAX; i++) { + seq_buf_printf(s, format_str, model_get_env_name(i), + ha_get_env(ha_mon, i, time_ns)); + format_str = ",%s=%llu"; + } +} + +#if RV_MON_TYPE == RV_MON_GLOBAL || RV_MON_TYPE == RV_MON_PER_CPU +static inline void ha_trace_error_env(struct ha_monitor *ha_mon, + char *curr_state, char *event, char *env, + da_id_type id) +{ + CONCATENATE(trace_error_env_, MONITOR_NAME)(curr_state, event, env); +} +#elif RV_MON_TYPE == RV_MON_PER_TASK || RV_MON_TYPE == RV_MON_PER_OBJ + +#define ha_get_target(ha_mon) da_get_target(&ha_mon->da_mon) + +static inline void ha_trace_error_env(struct ha_monitor *ha_mon, + char *curr_state, char *event, char *env, + da_id_type id) +{ + CONCATENATE(trace_error_env_, MONITOR_NAME)(id, curr_state, event, env); +} + +#if !defined(HA_SKIP_AUTO_CLEANUP) && RV_MON_TYPE == RV_MON_PER_TASK +static void ha_handle_sched_process_exit(void *data, struct task_struct *p, + bool group_dead) +{ + struct da_monitor *da_mon = da_get_monitor(p); + + if (likely(da_monitoring(da_mon))) { + da_monitor_reset(da_mon); + ha_cancel_timer_sync(to_ha_monitor(da_mon)); + } +} +#endif + +#endif /* RV_MON_TYPE */ + +/* + * ha_get_monitor - return the current monitor + */ +#define ha_get_monitor(...) to_ha_monitor(da_get_monitor(__VA_ARGS__)) + +/* + * ha_monitor_handle_constraint - handle the constraint on the current transition + * + * If the monitor implementation defines a constraint in the transition from + * curr_state to event, react and trace appropriately as well as return false. + * This function is called from the hook in the DA event handle function and + * triggers a failure in the monitor. + */ +static bool ha_monitor_handle_constraint(struct da_monitor *da_mon, + enum states curr_state, + enum events event, + enum states next_state, + da_id_type id) +{ + struct ha_monitor *ha_mon = to_ha_monitor(da_mon); + u64 time_ns = ha_get_ns(); + DECLARE_SEQ_BUF(env_string, ENV_BUFFER_SIZE); + + if (ha_verify_constraint(ha_mon, curr_state, event, next_state, time_ns)) + return true; + + ha_get_env_string(&env_string, ha_mon, time_ns); + ha_react(curr_state, event, env_string.buffer); + ha_trace_error_env(ha_mon, + model_get_state_name(curr_state), + model_get_event_name(event), + env_string.buffer, id); + return false; +} + +/* + * __ha_monitor_timer_callback - generic callback representation + * + * This callback runs in an RCU read-side critical section to allow the + * destruction sequence to easily synchronize_rcu() with all pending timers + * after asynchronously disabling them. The ha_mon_destroying check ensures + * any callback entering the RCU section after synchronize_rcu() completes + * will see the flag and bail out immediately. + */ +static inline void __ha_monitor_timer_callback(struct ha_monitor *ha_mon) +{ + DECLARE_SEQ_BUF(env_string, ENV_BUFFER_SIZE); + enum states curr_state; + u64 time_ns; + + guard(rcu)(); + if (unlikely(READ_ONCE(ha_mon_destroying))) + return; + /* Ensure consistent curr_state if we race with da_monitor_reset */ + curr_state = smp_load_acquire(&ha_mon->da_mon.curr_state); + if (unlikely(!da_monitor_handling_event(&ha_mon->da_mon))) + return; + + time_ns = ha_get_ns(); + ha_get_env_string(&env_string, ha_mon, time_ns); + ha_react(curr_state, EVENT_NONE, env_string.buffer); + ha_trace_error_env(ha_mon, model_get_state_name(curr_state), + EVENT_NONE_LBL, env_string.buffer, + da_get_id(&ha_mon->da_mon)); + + da_monitor_reset(&ha_mon->da_mon); +} + +/* + * The clock variables store the time epoch - the timestamp when the clock was last reset. + * They are read by subtracting the time epoch from the current time. + */ + +/* + * Helper functions for env variables describing clocks with ns granularity + */ +static inline u64 ha_get_clk_ns(struct ha_monitor *ha_mon, enum envs env, u64 time_ns) +{ + return time_ns - READ_ONCE(ha_mon->env_store[env]); +} +static inline void ha_reset_clk_ns(struct ha_monitor *ha_mon, enum envs env, u64 time_ns) +{ + WRITE_ONCE(ha_mon->env_store[env], time_ns); +} +static inline bool ha_check_invariant_ns(struct ha_monitor *ha_mon, enum envs env, + u64 time_ns, u64 expire_ns) +{ + return READ_ONCE(ha_mon->env_store[env]) >= time_ns - expire_ns; +} +/* + * ha_invariant_passed_ns - prepare the invariant and return the time since reset + */ +static inline u64 ha_invariant_passed_ns(struct ha_monitor *ha_mon, enum envs env, u64 time_ns) +{ + if (env < 0 || env >= ENV_MAX_STORED) + return 0; + if (ha_monitor_env_invalid(ha_mon, env)) + return 0; + return ha_get_env(ha_mon, env, time_ns); +} + +/* + * Helper functions for env variables describing clocks with jiffy granularity + */ +static inline u64 ha_get_clk_jiffy(struct ha_monitor *ha_mon, enum envs env) +{ + return get_jiffies_64() - READ_ONCE(ha_mon->env_store[env]); +} +static inline void ha_reset_clk_jiffy(struct ha_monitor *ha_mon, enum envs env) +{ + WRITE_ONCE(ha_mon->env_store[env], get_jiffies_64()); +} +static inline bool ha_check_invariant_jiffy(struct ha_monitor *ha_mon, enum envs env, + u64 time_ns, u64 expire_jiffy) +{ + return time_after64(READ_ONCE(ha_mon->env_store[env]), get_jiffies_64() - expire_jiffy); +} +/* + * ha_invariant_passed_jiffy - prepare the invariant and return the time since reset + */ +static inline u64 ha_invariant_passed_jiffy(struct ha_monitor *ha_mon, enum envs env, u64 time_ns) +{ + if (env < 0 || env >= ENV_MAX_STORED) + return 0; + if (ha_monitor_env_invalid(ha_mon, env)) + return 0; + return ha_get_env(ha_mon, env, time_ns); +} + +/* + * Retrieve the last reset time (guard representation) from the invariant + * representation (expiration). + * It the caller's responsibility to make sure the storage was actually in the + * invariant representation (e.g. the current state has an invariant). + * The provided value must be the same used when starting the invariant. + * + * This function's access to the storage is NOT atomic, due to the rarity when + * this is used. If a monitor allows writes concurrent to this, likely + * other things are broken and need rethinking the model or additional locking. + */ +static inline void ha_inv_to_guard(struct ha_monitor *ha_mon, enum envs env, + u64 value, u64 time_ns) +{ + WRITE_ONCE(ha_mon->env_store[env], READ_ONCE(ha_mon->env_store[env]) - value); +} + +#if HA_TIMER_TYPE == HA_TIMER_WHEEL +/* + * Helper functions to handle the monitor timer. + * Not all monitors require a timer, in such case the timer will be set up but + * never armed. + * Timers start since the last reset of the supplied env or from now if env is + * not an environment variable. If env was not initialised no timer starts. + * Timers can expire on any CPU unless the monitor is per-cpu, + * where we assume every event occurs on the local CPU. + */ +static void ha_monitor_timer_callback(struct timer_list *timer) +{ + struct ha_monitor *ha_mon = container_of(timer, struct ha_monitor, timer); + + __ha_monitor_timer_callback(ha_mon); +} +static inline void ha_setup_timer(struct ha_monitor *ha_mon) +{ + int mode = 0; + + if (RV_MON_TYPE == RV_MON_PER_CPU) + mode |= TIMER_PINNED; + timer_setup(&ha_mon->timer, ha_monitor_timer_callback, mode); +} +static inline void ha_start_timer_jiffy(struct ha_monitor *ha_mon, enum envs env, + u64 expire, u64 time_ns) +{ + u64 passed = ha_invariant_passed_jiffy(ha_mon, env, time_ns); + + mod_timer(&ha_mon->timer, get_jiffies_64() + expire - passed); +} +static inline void ha_start_timer_ns(struct ha_monitor *ha_mon, enum envs env, + u64 expire, u64 time_ns) +{ + u64 passed = ha_invariant_passed_ns(ha_mon, env, time_ns); + + ha_start_timer_jiffy(ha_mon, ENV_MAX_STORED, + nsecs_to_jiffies(expire - passed + TICK_NSEC - 1), time_ns); +} +/* + * ha_cancel_timer - Cancel the timer + * + * Returns: + * * 1 when the timer was active + * * 0 when the timer was not active or running a callback + */ +static inline bool ha_cancel_timer(struct ha_monitor *ha_mon) +{ + return timer_delete(&ha_mon->timer); +} +static inline void ha_cancel_timer_sync(struct ha_monitor *ha_mon) +{ + timer_delete_sync(&ha_mon->timer); +} +#elif HA_TIMER_TYPE == HA_TIMER_HRTIMER +/* + * Helper functions to handle the monitor timer. + * Not all monitors require a timer, in such case the timer will be set up but + * never armed. + * Timers start since the last reset of the supplied env or from now if env is + * not an environment variable. If env was not initialised no timer starts. + * Timers can expire on any CPU unless the monitor is per-cpu, + * where we assume every event occurs on the local CPU. + */ +static enum hrtimer_restart ha_monitor_timer_callback(struct hrtimer *hrtimer) +{ + struct ha_monitor *ha_mon = container_of(hrtimer, struct ha_monitor, hrtimer); + + __ha_monitor_timer_callback(ha_mon); + return HRTIMER_NORESTART; +} +static inline void ha_setup_timer(struct ha_monitor *ha_mon) +{ + hrtimer_setup(&ha_mon->hrtimer, ha_monitor_timer_callback, + CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); +} +static inline void ha_start_timer_ns(struct ha_monitor *ha_mon, enum envs env, + u64 expire, u64 time_ns) +{ + int mode = HRTIMER_MODE_REL_HARD; + u64 passed = ha_invariant_passed_ns(ha_mon, env, time_ns); + + if (RV_MON_TYPE == RV_MON_PER_CPU) + mode |= HRTIMER_MODE_PINNED; + hrtimer_start(&ha_mon->hrtimer, ns_to_ktime(expire - passed), mode); +} +static inline void ha_start_timer_jiffy(struct ha_monitor *ha_mon, enum envs env, + u64 expire, u64 time_ns) +{ + u64 passed = ha_invariant_passed_jiffy(ha_mon, env, time_ns); + + ha_start_timer_ns(ha_mon, ENV_MAX_STORED, + jiffies_to_nsecs(expire - passed), time_ns); +} +/* + * ha_cancel_timer - Cancel the timer + * + * Returns: + * * 1 when the timer was active + * * 0 when the timer was not active or running a callback + */ +static inline bool ha_cancel_timer(struct ha_monitor *ha_mon) +{ + return hrtimer_try_to_cancel(&ha_mon->hrtimer) == 1; +} +static inline void ha_cancel_timer_sync(struct ha_monitor *ha_mon) +{ + hrtimer_cancel(&ha_mon->hrtimer); +} +#else /* HA_TIMER_NONE */ +/* + * Start function is intentionally not defined, monitors using timers must + * set HA_TIMER_TYPE to either HA_TIMER_WHEEL or HA_TIMER_HRTIMER. + */ +static inline void ha_setup_timer(struct ha_monitor *ha_mon) { } +static inline bool ha_cancel_timer(struct ha_monitor *ha_mon) +{ + return false; +} +static inline void ha_cancel_timer_sync(struct ha_monitor *ha_mon) { } +#endif + +#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST) +#ifdef RV_MON_OPS_INIT +#undef RV_MON_OPS_INIT +#endif + +#if RV_MON_TYPE == RV_MON_PER_TASK +#define RV_MON_OPS_INIT() { \ + .rv_this = &rv_this, \ + .is_per_task = true, \ + .task_slot = &task_mon_slot, \ + .task_reset = da_reset, \ +} +#else +#define RV_MON_OPS_INIT() { \ + .rv_this = &rv_this, \ + .monitor_init = ha_monitor_init, \ + .monitor_destroy = ha_monitor_destroy, \ +} +#endif /* RV_MON_TYPE */ +#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */ + +#endif diff --git a/include/rv/instrumentation.h b/include/rv/instrumentation.h new file mode 100644 index 000000000..d4e7a02ed --- /dev/null +++ b/include/rv/instrumentation.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org> + * + * Helper functions to facilitate the instrumentation of auto-generated + * RV monitors create by dot2k. + * + * The dot2k tool is available at tools/verification/dot2/ + */ + +#include <linux/ftrace.h> + +/* + * rv_attach_trace_probe - check and attach a handler function to a tracepoint + */ +#define rv_attach_trace_probe(monitor, tp, rv_handler) \ + do { \ + check_trace_callback_type_##tp(rv_handler); \ + WARN_ONCE(register_trace_##tp(rv_handler, NULL), \ + "fail attaching " #monitor " " #tp "handler"); \ + } while (0) + +/* + * rv_detach_trace_probe - detach a handler function to a tracepoint + */ +#define rv_detach_trace_probe(monitor, tp, rv_handler) \ + do { \ + unregister_trace_##tp(rv_handler, NULL); \ + } while (0) diff --git a/include/rv/kunit.h b/include/rv/kunit.h new file mode 100644 index 000000000..31e0b93c4 --- /dev/null +++ b/include/rv/kunit.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2026-2029 Red Hat, Inc. Gabriele Monaco <gmonaco@redhat.com> + * + * Declaration of wrappers to allow mocking core functionality, like current, + * and other testing utilities. + * Necessary only when mocking may be needed. If the RV KUnit test is + * enabled, the wrappers incur an additional function call overhead. + */ + +#ifndef _RV_KUNIT_H +#define _RV_KUNIT_H + +#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST) + +#include <kunit/test.h> +#include <kunit/test-bug.h> +#include <linux/delay.h> + +int rv_set_testing(struct kunit_suite *suite); +void rv_clear_testing(struct kunit_suite *suite); + +#define RV_KUNIT_MAX_MOCK_TASKS 8 + +struct rv_kunit_ctx { + int reactions, expected; + int mock_task_count; + struct task_struct *mock_tasks[RV_KUNIT_MAX_MOCK_TASKS]; +}; + +#define RV_KUNIT_EXPECT_REACTION(test, ctx) \ + do { \ + KUNIT_EXPECT_EQ(test, ctx->reactions, ++ctx->expected); \ + if (ctx->reactions != ctx->expected) \ + ctx->expected = ctx->reactions; \ + } while (0) + +#define RV_KUNIT_EXPECT_NO_REACTION(test, ctx) \ + do { \ + KUNIT_EXPECT_EQ(test, ctx->reactions, ctx->expected); \ + if (ctx->reactions != ctx->expected) \ + ctx->expected = ctx->reactions; \ + } while (0) + +#define RV_KUNIT_EXPECT_REACTION_HERE(test, ctx) \ + for (int __done = ({ RV_KUNIT_EXPECT_NO_REACTION(test, ctx); 0; }); \ + !__done; \ + __done = ({ RV_KUNIT_EXPECT_REACTION(test, ctx); 1; })) + +struct rv_kunit_mon { + struct rv_monitor *rv_this; + int (*monitor_init)(void); + void (*monitor_destroy)(void); + bool is_per_task; + int *task_slot; + void (*task_reset)(struct task_struct *task); +}; + +void prepare_test(struct kunit *test, const struct rv_kunit_mon *mon); +void teardown_test(void *arg); +struct task_struct *rv_kunit_alloc_mock_task(struct kunit *test); + +void rv_mock_current(struct task_struct *tsk); +struct task_struct *rv_get_mock_current(void); + +#define rv_get_current() (unlikely(kunit_get_current_test()) ? rv_get_mock_current() : current) + +#else /* !CONFIG_RV_MONITORS_KUNIT_TEST */ + +#define rv_get_current() current + +#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */ +#endif /* _RV_KUNIT_H */ diff --git a/include/rv/ltl_monitor.h b/include/rv/ltl_monitor.h new file mode 100644 index 000000000..e9fd8265a --- /dev/null +++ b/include/rv/ltl_monitor.h @@ -0,0 +1,182 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/** + * This file must be combined with the $(MODEL_NAME).h file generated by + * tools/verification/rvgen. + */ + +#include <linux/args.h> +#include <linux/rv.h> +#include <linux/stringify.h> +#include <linux/seq_buf.h> +#include <rv/instrumentation.h> +#include <rv/kunit.h> +#include <trace/events/task.h> +#include <trace/events/sched.h> + +#ifndef MONITOR_NAME +#error "Please include $(MODEL_NAME).h generated by rvgen" +#endif + +static struct rv_monitor rv_this; + +static int ltl_monitor_slot = RV_PER_TASK_MONITOR_INIT; + +static void ltl_atoms_fetch(struct task_struct *task, struct ltl_monitor *mon); +static void ltl_atoms_init(struct task_struct *task, struct ltl_monitor *mon, bool task_creation); + +static struct ltl_monitor *ltl_get_monitor(struct task_struct *task) +{ + return &task->rv[ltl_monitor_slot].ltl_mon; +} + +static void ltl_task_init(struct task_struct *task, bool task_creation) +{ + struct ltl_monitor *mon = ltl_get_monitor(task); + + memset(&mon->states, 0, sizeof(mon->states)); + + for (int i = 0; i < LTL_NUM_ATOM; ++i) + __set_bit(i, mon->unknown_atoms); + + ltl_atoms_init(task, mon, task_creation); + ltl_atoms_fetch(task, mon); +} + +static void handle_task_newtask(void *data, struct task_struct *task, u64 flags) +{ + ltl_task_init(task, true); +} + +static int ltl_monitor_init(void) +{ + struct task_struct *g, *p; + int ret, cpu; + + ret = rv_get_task_monitor_slot(); + if (ret < 0) + return ret; + + ltl_monitor_slot = ret; + + rv_attach_trace_probe(name, task_newtask, handle_task_newtask); + + read_lock(&tasklist_lock); + + for_each_process_thread(g, p) + ltl_task_init(p, false); + + for_each_present_cpu(cpu) + ltl_task_init(idle_task(cpu), false); + + read_unlock(&tasklist_lock); + + return 0; +} + +static void ltl_monitor_destroy(void) +{ + rv_detach_trace_probe(name, task_newtask, handle_task_newtask); + + tracepoint_synchronize_unregister(); + rv_put_task_monitor_slot(ltl_monitor_slot); + ltl_monitor_slot = RV_PER_TASK_MONITOR_INIT; +} + +static void ltl_illegal_state(struct task_struct *task, struct ltl_monitor *mon) +{ + CONCATENATE(trace_error_, MONITOR_NAME)(task); + rv_react(&rv_this, "rv: "__stringify(MONITOR_NAME)": %s[%d]: violation detected\n", + task->comm, task->pid); +} + +static void ltl_attempt_start(struct task_struct *task, struct ltl_monitor *mon) +{ + if (rv_ltl_all_atoms_known(mon)) + ltl_start(task, mon); +} + +static inline void ltl_atom_set(struct ltl_monitor *mon, enum ltl_atom atom, bool value) +{ + __clear_bit(atom, mon->unknown_atoms); + if (value) + __set_bit(atom, mon->atoms); + else + __clear_bit(atom, mon->atoms); +} + +static void +ltl_trace_event(struct task_struct *task, struct ltl_monitor *mon, unsigned long *next_state) +{ + const char *format_str = "%s"; + DECLARE_SEQ_BUF(atoms, 64); + char states[32], next[32]; + int i; + + if (!CONCATENATE(CONCATENATE(trace_event_, MONITOR_NAME), _enabled)()) + return; + + snprintf(states, sizeof(states), "%*pbl", RV_MAX_BA_STATES, mon->states); + snprintf(next, sizeof(next), "%*pbl", RV_MAX_BA_STATES, next_state); + + for (i = 0; i < LTL_NUM_ATOM; ++i) { + if (test_bit(i, mon->atoms)) { + seq_buf_printf(&atoms, format_str, ltl_atom_str(i)); + format_str = ",%s"; + } + } + + CONCATENATE(trace_event_, MONITOR_NAME)(task, states, atoms.buffer, next); +} + +static void ltl_validate(struct task_struct *task, struct ltl_monitor *mon) +{ + DECLARE_BITMAP(next_states, RV_MAX_BA_STATES) = {0}; + + if (!rv_ltl_valid_state(mon)) + return; + + for (unsigned int i = 0; i < RV_NUM_BA_STATES; ++i) { + if (test_bit(i, mon->states)) + ltl_possible_next_states(mon, i, next_states); + } + + ltl_trace_event(task, mon, next_states); + + memcpy(mon->states, next_states, sizeof(next_states)); + + if (!rv_ltl_valid_state(mon)) + ltl_illegal_state(task, mon); +} + +static void ltl_atom_update(struct task_struct *task, enum ltl_atom atom, bool value) +{ + struct ltl_monitor *mon = ltl_get_monitor(task); + + ltl_atom_set(mon, atom, value); + ltl_atoms_fetch(task, mon); + + if (!rv_ltl_valid_state(mon)) { + ltl_attempt_start(task, mon); + return; + } + + ltl_validate(task, mon); +} + +static void __maybe_unused ltl_atom_pulse(struct task_struct *task, enum ltl_atom atom, bool value) +{ + struct ltl_monitor *mon = ltl_get_monitor(task); + + ltl_atom_update(task, atom, value); + + ltl_atom_set(mon, atom, !value); + ltl_validate(task, mon); +} + +#if IS_ENABLED(CONFIG_RV_MONITORS_KUNIT_TEST) +#define RV_MON_OPS_INIT() { \ + .rv_this = &rv_this, \ + .is_per_task = true, \ + .task_slot = <l_monitor_slot, \ +} +#endif /* CONFIG_RV_MONITORS_KUNIT_TEST */ |
