Re: [PATCH v2 2/5] rv/ltl: Support per-cpu monitors

[Gabriele Monaco <gmonaco@redhat.com>]

On Wed, 2025-08-06 at 10:01 +0200, Nam Cao wrote:
> Add support for per-cpu run-time verification linear temporal logic
> monitors. This is analogous to deterministic automaton per-cpu
> monitors.
> 
> Signed-off-by: Nam Cao <namcao@linutronix.de>
> ---
> v2: Rename "implicit" to "cpu"

Looks good to me.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>

Thanks,
Gabriele

> ---
>  include/rv/ltl_monitor.h   | 32 ++++++++++++++++++++++++++
>  kernel/trace/rv/Kconfig    |  4 ++++
>  kernel/trace/rv/rv_trace.h | 46
> ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 82 insertions(+)
> 
> diff --git a/include/rv/ltl_monitor.h b/include/rv/ltl_monitor.h
> index 9dabc5b133a3..4ad08b5b9f2d 100644
> --- a/include/rv/ltl_monitor.h
> +++ b/include/rv/ltl_monitor.h
> @@ -23,12 +23,21 @@
>  
>  typedef struct task_struct *monitor_target;
>  
> +#elif LTL_MONITOR_TYPE == RV_MON_PER_CPU
> +
> +#define TARGET_PRINT_FORMAT "%u"
> +#define TARGET_PRINT_ARGS(cpu) cpu
> +
> +typedef unsigned int monitor_target;
> +
>  #endif
>  
>  #ifdef CONFIG_RV_REACTORS
>  #define RV_MONITOR_NAME CONCATENATE(rv_, MONITOR_NAME)
>  static struct rv_monitor RV_MONITOR_NAME;
>  
> +static struct ltl_monitor *ltl_get_monitor(monitor_target target);
> +
>  static void rv_cond_react(monitor_target target)
>  {
>  	if (!rv_reacting_on() || !RV_MONITOR_NAME.react)
> @@ -54,6 +63,13 @@ static struct ltl_monitor
> *ltl_get_monitor(monitor_target target)
>  {
>  	return &target->rv[ltl_monitor_slot].ltl_mon;
>  }
> +#elif LTL_MONITOR_TYPE == RV_MON_PER_CPU
> +static struct ltl_monitor *ltl_get_monitor(unsigned int cpu)
> +{
> +	static DEFINE_PER_CPU(struct ltl_monitor, ltl_monitor);
> +
> +	return per_cpu_ptr(&ltl_monitor, cpu);
> +}
>  #endif
>  
>  static void ltl_target_init(monitor_target target, bool
> target_creation)
> @@ -108,6 +124,22 @@ static void ltl_monitor_destroy(void)
>  	rv_put_task_monitor_slot(ltl_monitor_slot);
>  	ltl_monitor_slot = RV_PER_TASK_MONITOR_INIT;
>  }
> +
> +#elif LTL_MONITOR_TYPE == RV_MON_PER_CPU
> +
> +static int ltl_monitor_init(void)
> +{
> +	unsigned int cpu;
> +
> +	for_each_possible_cpu(cpu)
> +		ltl_target_init(cpu, false);
> +	return 0;
> +}
> +
> +static void ltl_monitor_destroy(void)
> +{
> +}
> +
>  #endif
>  
>  static void ltl_illegal_state(monitor_target target, struct
> ltl_monitor *mon)
> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
> index 5b4be87ba59d..7ef89006ed50 100644
> --- a/kernel/trace/rv/Kconfig
> +++ b/kernel/trace/rv/Kconfig
> @@ -16,6 +16,10 @@ config DA_MON_EVENTS_ID
>  	select RV_MON_MAINTENANCE_EVENTS
>  	bool
>  
> +config LTL_MON_EVENTS_CPU
> +	select RV_MON_EVENTS
> +	bool
> +
>  config LTL_MON_EVENTS_ID
>  	select RV_MON_EVENTS
>  	bool
> diff --git a/kernel/trace/rv/rv_trace.h b/kernel/trace/rv/rv_trace.h
> index 4a6faddac614..bf7cca6579ec 100644
> --- a/kernel/trace/rv/rv_trace.h
> +++ b/kernel/trace/rv/rv_trace.h
> @@ -177,8 +177,54 @@ DECLARE_EVENT_CLASS(error_ltl_monitor_id,
>  #include <monitors/pagefault/pagefault_trace.h>
>  #include <monitors/sleep/sleep_trace.h>
>  // Add new monitors based on CONFIG_LTL_MON_EVENTS_ID here
> +
>  #endif /* CONFIG_LTL_MON_EVENTS_ID */
>  
> +#ifdef CONFIG_LTL_MON_EVENTS_CPU
> +DECLARE_EVENT_CLASS(event_ltl_monitor_cpu,
> +
> +	TP_PROTO(unsigned int cpu, char *states, char *atoms, char
> *next),
> +
> +	TP_ARGS(cpu, states, atoms, next),
> +
> +	TP_STRUCT__entry(
> +		__field(unsigned int, cpu)
> +		__string(states, states)
> +		__string(atoms, atoms)
> +		__string(next, next)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->cpu = cpu;
> +		__assign_str(states);
> +		__assign_str(atoms);
> +		__assign_str(next);
> +	),
> +
> +	TP_printk("cpu%u: (%s) x (%s) -> (%s)", __entry->cpu,
> +		  __get_str(states), __get_str(atoms),
> __get_str(next))
> +);
> +
> +DECLARE_EVENT_CLASS(error_ltl_monitor_cpu,
> +
> +	TP_PROTO(unsigned int cpu),
> +
> +	TP_ARGS(cpu),
> +
> +	TP_STRUCT__entry(
> +		__field(unsigned int, cpu)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->cpu = cpu;
> +	),
> +
> +	TP_printk("cpu%u: violation detected", __entry->cpu)
> +);
> +// Add new monitors based on CONFIG_LTL_MON_EVENTS_CPU here
> +
> +#endif /* CONFIG_LTL_MON_EVENTS_CPU */
> +
>  #ifdef CONFIG_RV_MON_MAINTENANCE_EVENTS
>  /* Tracepoint useful for monitors development, currenly only used in
> DA */
>  TRACE_EVENT(rv_retries_error,