Per task wakeup while not running (wwnr) monitor. This model is broken, the reason is that a task can be running in the processor without being set as RUNNABLE. Think about a task about to sleep: 1: set_current_state(TASK_UNINTERRUPTIBLE); 2: schedule(); And then imagine an IRQ happening in between the lines one and two, waking the task up. BOOM, the wakeup will happen while the task is running. Q: Why do we need this model, so? A: To test the reactors. Cc: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx> Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Cc: Gabriele Paoloni <gpaoloni@xxxxxxxxxx> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx> Cc: Clark Williams <williams@xxxxxxxxxx> Cc: Tao Zhou <tao.zhou@xxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: linux-doc@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-trace-devel@xxxxxxxxxxxxxxx Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> --- Documentation/trace/rv/index.rst | 1 + Documentation/trace/rv/monitor_wwnr.rst | 45 +++++++++++++ include/trace/events/rv.h | 12 ++++ kernel/trace/rv/Kconfig | 12 ++++ kernel/trace/rv/Makefile | 1 + kernel/trace/rv/monitors/wwnr/wwnr.c | 90 +++++++++++++++++++++++++ kernel/trace/rv/monitors/wwnr/wwnr.h | 46 +++++++++++++ tools/verification/models/wwnr.dot | 16 +++++ 8 files changed, 223 insertions(+) create mode 100644 Documentation/trace/rv/monitor_wwnr.rst create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.c create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.h create mode 100644 tools/verification/models/wwnr.dot diff --git a/Documentation/trace/rv/index.rst b/Documentation/trace/rv/index.rst index 4cb71ed628b8..15fa966102c0 100644 --- a/Documentation/trace/rv/index.rst +++ b/Documentation/trace/rv/index.rst @@ -11,3 +11,4 @@ Runtime Verification da_monitor_synthesis.rst da_monitor_instrumentation.rst monitor_wip.rst + monitor_wwnr.rst diff --git a/Documentation/trace/rv/monitor_wwnr.rst b/Documentation/trace/rv/monitor_wwnr.rst new file mode 100644 index 000000000000..80f1777b85aa --- /dev/null +++ b/Documentation/trace/rv/monitor_wwnr.rst @@ -0,0 +1,45 @@ +Monitor wwnr +============ + +- Name: wwrn - wakeup while not running +- Type: per-task deterministic automaton +- Author: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> + +Description +----------- + +This is a per-task sample monitor, with the following +definition:: + + | + | + v + wakeup +-------------+ + +--------- | | + | | not_running | + +--------> | | <+ + +-------------+ | + | | + | switch_in | switch_out + v | + +-------------+ | + | running | -+ + +-------------+ + +This model is borken, the reason is that a task can be running +in the processor without being set as RUNNABLE. Think about a +task about to sleep:: + + 1: set_current_state(TASK_UNINTERRUPTIBLE); + 2: schedule(); + +And then imagine an IRQ happening in between the lines one and two, +waking the task up. BOOM, the wakeup will happen while the task is +running. + +- Why do we need this model, so? +- To test the reactors. + +Specification +------------- +Grapviz Dot file in tools/verification/models/wwnr.dot diff --git a/include/trace/events/rv.h b/include/trace/events/rv.h index e972f27d8df3..56592da9301c 100644 --- a/include/trace/events/rv.h +++ b/include/trace/events/rv.h @@ -122,6 +122,18 @@ DECLARE_EVENT_CLASS(error_da_monitor_id, __entry->event, __entry->state) ); + +#ifdef CONFIG_RV_MON_WWNR +/* id is the pid of the task */ +DEFINE_EVENT(event_da_monitor_id, event_wwnr, + 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_wwnr, + TP_PROTO(int id, char *state, char *event), + TP_ARGS(id, state, event)); +#endif /* CONFIG_RV_MON_WWNR */ + #endif /* CONFIG_DA_MON_EVENTS_ID */ #endif /* _TRACE_RV_H */ diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig index 8755ad74ec22..d8c40fd67e88 100644 --- a/kernel/trace/rv/Kconfig +++ b/kernel/trace/rv/Kconfig @@ -41,6 +41,18 @@ config RV_MON_WIP For further information, see: Documentation/trace/rv/monitor_wip.rst +config RV_MON_WWNR + depends on RV + select DA_MON_EVENTS_ID + bool "wwnr monitor" + help + Enable wwnr (wakeup while not running) sample monitor, this is a + sample monitor that illustrates the usage of per-task monitor. + The model is borken on purpose: it serves to test reactors. + + For further information, see: + Documentation/trace/rv/monitor_wwnr.rst + config RV_REACTORS bool "Runtime verification reactors" default y diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile index b41109d2750a..af0ff9a46418 100644 --- a/kernel/trace/rv/Makefile +++ b/kernel/trace/rv/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_RV) += rv.o obj-$(CONFIG_RV_REACTORS) += rv_reactors.o obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o +obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.c b/kernel/trace/rv/monitors/wwnr/wwnr.c new file mode 100644 index 000000000000..55028a0fa388 --- /dev/null +++ b/kernel/trace/rv/monitors/wwnr/wwnr.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/ftrace.h> +#include <linux/tracepoint.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/rv.h> +#include <rv/instrumentation.h> +#include <rv/da_monitor.h> + +#define MODULE_NAME "wwnr" + +#include <trace/events/rv.h> +#include <trace/events/sched.h> + +#include "wwnr.h" + +struct rv_monitor rv_wwnr; +DECLARE_DA_MON_PER_TASK(wwnr, unsigned char); + +static void handle_switch(void *data, bool preempt, struct task_struct *p, + struct task_struct *n, unsigned int prev_state) +{ + /* start monitoring only after the first suspension */ + if (prev_state == TASK_INTERRUPTIBLE) + da_handle_start_event_wwnr(p, switch_out_wwnr); + else + da_handle_event_wwnr(p, switch_out_wwnr); + + da_handle_event_wwnr(n, switch_in_wwnr); +} + +static void handle_wakeup(void *data, struct task_struct *p) +{ + da_handle_event_wwnr(p, wakeup_wwnr); +} + +static int enable_wwnr(void) +{ + int retval; + + retval = da_monitor_init_wwnr(); + if (retval) + return retval; + + rv_attach_trace_probe("wwnr", sched_switch, handle_switch); + rv_attach_trace_probe("wwnr", sched_wakeup, handle_wakeup); + + return 0; +} + +static void disable_wwnr(void) +{ + rv_wwnr.enabled = 0; + + rv_detach_trace_probe("wwnr", sched_switch, handle_switch); + rv_detach_trace_probe("wwnr", sched_wakeup, handle_wakeup); + + da_monitor_destroy_wwnr(); +} + +struct rv_monitor rv_wwnr = { + .name = "wwnr", + .description = "wakeup while not running per-task testing model.", + .enable = enable_wwnr, + .disable = disable_wwnr, + .reset = da_monitor_reset_all_wwnr, + .enabled = 0, +}; + +static int register_wwnr(void) +{ + rv_register_monitor(&rv_wwnr); + return 0; +} + +static void unregister_wwnr(void) +{ + if (rv_wwnr.enabled) + disable_wwnr(); + + rv_unregister_monitor(&rv_wwnr); +} + +module_init(register_wwnr); +module_exit(unregister_wwnr); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>"); +MODULE_DESCRIPTION("wwnr: wakeup while not running monitor"); diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.h b/kernel/trace/rv/monitors/wwnr/wwnr.h new file mode 100644 index 000000000000..d1afe55cdd4c --- /dev/null +++ b/kernel/trace/rv/monitors/wwnr/wwnr.h @@ -0,0 +1,46 @@ +/* + * Automatically generated C representation of wwnr automaton + * For further information about this format, see kernel documentation: + * Documentation/trace/rv/deterministic_automata.rst + */ + +enum states_wwnr { + not_running_wwnr = 0, + running_wwnr, + state_max_wwnr +}; + +#define INVALID_STATE state_max_wwnr + +enum events_wwnr { + switch_in_wwnr = 0, + switch_out_wwnr, + wakeup_wwnr, + event_max_wwnr +}; + +struct automaton_wwnr { + char *state_names[state_max_wwnr]; + char *event_names[event_max_wwnr]; + unsigned char function[state_max_wwnr][event_max_wwnr]; + unsigned char initial_state; + bool final_states[state_max_wwnr]; +}; + +struct automaton_wwnr automaton_wwnr = { + .state_names = { + "not_running", + "running" + }, + .event_names = { + "switch_in", + "switch_out", + "wakeup" + }, + .function = { + { running_wwnr, INVALID_STATE, not_running_wwnr }, + { INVALID_STATE, not_running_wwnr, INVALID_STATE }, + }, + .initial_state = not_running_wwnr, + .final_states = { 1, 0 }, +}; diff --git a/tools/verification/models/wwnr.dot b/tools/verification/models/wwnr.dot new file mode 100644 index 000000000000..1b206e83129c --- /dev/null +++ b/tools/verification/models/wwnr.dot @@ -0,0 +1,16 @@ +digraph state_automaton { + {node [shape = plaintext, style=invis, label=""] "__init_not_running"}; + {node [shape = ellipse] "not_running"}; + {node [shape = plaintext] "not_running"}; + {node [shape = plaintext] "running"}; + "__init_not_running" -> "not_running"; + "not_running" [label = "not_running", color = green3]; + "not_running" -> "not_running" [ label = "wakeup" ]; + "not_running" -> "running" [ label = "switch_in" ]; + "running" [label = "running"]; + "running" -> "not_running" [ label = "switch_out" ]; + { rank = min ; + "__init_not_running"; + "not_running"; + } +} -- 2.35.1