diff options
Diffstat (limited to 'kernel/trace/rv/monitors/sleep')
| -rw-r--r-- | kernel/trace/rv/monitors/sleep/Kconfig | 22 | ||||
| -rw-r--r-- | kernel/trace/rv/monitors/sleep/sleep.c | 237 | ||||
| -rw-r--r-- | kernel/trace/rv/monitors/sleep/sleep.h | 257 | ||||
| -rw-r--r-- | kernel/trace/rv/monitors/sleep/sleep_trace.h | 14 |
4 files changed, 530 insertions, 0 deletions
diff --git a/kernel/trace/rv/monitors/sleep/Kconfig b/kernel/trace/rv/monitors/sleep/Kconfig new file mode 100644 index 000000000000..6b7a122e7b47 --- /dev/null +++ b/kernel/trace/rv/monitors/sleep/Kconfig @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +config RV_MON_SLEEP + depends on RV + select RV_LTL_MONITOR + depends on HAVE_SYSCALL_TRACEPOINTS + depends on RV_MON_RTAPP + select TRACE_IRQFLAGS + default y + select LTL_MON_EVENTS_ID + bool "sleep monitor" + help + Monitor that real-time tasks do not sleep in a manner that may + cause undesirable latency. + + If you are developing a real-time system and not entirely sure whether + the applications are designed correctly for real-time, you want to say + Y here. + + Enabling this monitor may have performance impact (due to select + TRACE_IRQFLAGS). Therefore, you probably should say N for + production kernel. diff --git a/kernel/trace/rv/monitors/sleep/sleep.c b/kernel/trace/rv/monitors/sleep/sleep.c new file mode 100644 index 000000000000..eea447b06907 --- /dev/null +++ b/kernel/trace/rv/monitors/sleep/sleep.c @@ -0,0 +1,237 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/ftrace.h> +#include <linux/tracepoint.h> +#include <linux/init.h> +#include <linux/irqflags.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rv.h> +#include <linux/sched/deadline.h> +#include <linux/sched/rt.h> +#include <rv/instrumentation.h> + +#define MODULE_NAME "sleep" + +#include <trace/events/syscalls.h> +#include <trace/events/sched.h> +#include <trace/events/lock.h> +#include <uapi/linux/futex.h> +#include <rv_trace.h> +#include <monitors/rtapp/rtapp.h> + +#include "sleep.h" +#include <rv/ltl_monitor.h> + +static void ltl_atoms_fetch(struct task_struct *task, struct ltl_monitor *mon) +{ + /* + * This includes "actual" real-time tasks and also PI-boosted + * tasks. A task being PI-boosted means it is blocking an "actual" + * real-task, therefore it should also obey the monitor's rule, + * otherwise the "actual" real-task may be delayed. + */ + ltl_atom_set(mon, LTL_RT, rt_or_dl_task(task)); +} + +static void ltl_atoms_init(struct task_struct *task, struct ltl_monitor *mon, bool task_creation) +{ + ltl_atom_set(mon, LTL_SLEEP, false); + ltl_atom_set(mon, LTL_WAKE, false); + ltl_atom_set(mon, LTL_ABORT_SLEEP, false); + ltl_atom_set(mon, LTL_WOKEN_BY_HARDIRQ, false); + ltl_atom_set(mon, LTL_WOKEN_BY_NMI, false); + ltl_atom_set(mon, LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, false); + + if (task_creation) { + ltl_atom_set(mon, LTL_KTHREAD_SHOULD_STOP, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false); + ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); + ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false); + ltl_atom_set(mon, LTL_FUTEX_WAIT, false); + ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false); + ltl_atom_set(mon, LTL_BLOCK_ON_RT_MUTEX, false); + } + + if (task->flags & PF_KTHREAD) { + ltl_atom_set(mon, LTL_KERNEL_THREAD, true); + + /* kernel tasks do not do syscall */ + ltl_atom_set(mon, LTL_FUTEX_WAIT, false); + ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false); + ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); + ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false); + + if (strstarts(task->comm, "migration/")) + ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, true); + else + ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, false); + + if (strstarts(task->comm, "rcu")) + ltl_atom_set(mon, LTL_TASK_IS_RCU, true); + else + ltl_atom_set(mon, LTL_TASK_IS_RCU, false); + } else { + ltl_atom_set(mon, LTL_KTHREAD_SHOULD_STOP, false); + ltl_atom_set(mon, LTL_KERNEL_THREAD, false); + ltl_atom_set(mon, LTL_TASK_IS_RCU, false); + ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, false); + } + +} + +static void handle_sched_set_state(void *data, struct task_struct *task, int state) +{ + if (state & TASK_INTERRUPTIBLE) + ltl_atom_pulse(task, LTL_SLEEP, true); + else if (state == TASK_RUNNING) + ltl_atom_pulse(task, LTL_ABORT_SLEEP, true); +} + +static void handle_sched_wakeup(void *data, struct task_struct *task) +{ + ltl_atom_pulse(task, LTL_WAKE, true); +} + +static void handle_sched_waking(void *data, struct task_struct *task) +{ + if (this_cpu_read(hardirq_context)) { + ltl_atom_pulse(task, LTL_WOKEN_BY_HARDIRQ, true); + } else if (in_task()) { + if (current->prio <= task->prio) + ltl_atom_pulse(task, LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, true); + } else if (in_nmi()) { + ltl_atom_pulse(task, LTL_WOKEN_BY_NMI, true); + } +} + +static void handle_contention_begin(void *data, void *lock, unsigned int flags) +{ + if (flags & LCB_F_RT) + ltl_atom_update(current, LTL_BLOCK_ON_RT_MUTEX, true); +} + +static void handle_contention_end(void *data, void *lock, int ret) +{ + ltl_atom_update(current, LTL_BLOCK_ON_RT_MUTEX, false); +} + +static void handle_sys_enter(void *data, struct pt_regs *regs, long id) +{ + struct ltl_monitor *mon; + unsigned long args[6]; + int op, cmd; + + mon = ltl_get_monitor(current); + + switch (id) { + case __NR_clock_nanosleep: +#ifdef __NR_clock_nanosleep_time64 + case __NR_clock_nanosleep_time64: +#endif + syscall_get_arguments(current, regs, args); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, args[0] == CLOCK_MONOTONIC); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, args[0] == CLOCK_TAI); + ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, args[1] == TIMER_ABSTIME); + ltl_atom_update(current, LTL_CLOCK_NANOSLEEP, true); + break; + + case __NR_futex: +#ifdef __NR_futex_time64 + case __NR_futex_time64: +#endif + syscall_get_arguments(current, regs, args); + op = args[1]; + cmd = op & FUTEX_CMD_MASK; + + switch (cmd) { + case FUTEX_LOCK_PI: + case FUTEX_LOCK_PI2: + ltl_atom_update(current, LTL_FUTEX_LOCK_PI, true); + break; + case FUTEX_WAIT: + case FUTEX_WAIT_BITSET: + case FUTEX_WAIT_REQUEUE_PI: + ltl_atom_update(current, LTL_FUTEX_WAIT, true); + break; + } + break; + } +} + +static void handle_sys_exit(void *data, struct pt_regs *regs, long ret) +{ + struct ltl_monitor *mon = ltl_get_monitor(current); + + ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false); + ltl_atom_set(mon, LTL_FUTEX_WAIT, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false); + ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false); + ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false); + ltl_atom_update(current, LTL_CLOCK_NANOSLEEP, false); +} + +static void handle_kthread_stop(void *data, struct task_struct *task) +{ + /* FIXME: this could race with other tracepoint handlers */ + ltl_atom_update(task, LTL_KTHREAD_SHOULD_STOP, true); +} + +static int enable_sleep(void) +{ + int retval; + + retval = ltl_monitor_init(); + if (retval) + return retval; + + rv_attach_trace_probe("rtapp_sleep", sched_waking, handle_sched_waking); + rv_attach_trace_probe("rtapp_sleep", sched_wakeup, handle_sched_wakeup); + rv_attach_trace_probe("rtapp_sleep", sched_set_state_tp, handle_sched_set_state); + rv_attach_trace_probe("rtapp_sleep", contention_begin, handle_contention_begin); + rv_attach_trace_probe("rtapp_sleep", contention_end, handle_contention_end); + rv_attach_trace_probe("rtapp_sleep", sched_kthread_stop, handle_kthread_stop); + rv_attach_trace_probe("rtapp_sleep", sys_enter, handle_sys_enter); + rv_attach_trace_probe("rtapp_sleep", sys_exit, handle_sys_exit); + return 0; +} + +static void disable_sleep(void) +{ + rv_detach_trace_probe("rtapp_sleep", sched_waking, handle_sched_waking); + rv_detach_trace_probe("rtapp_sleep", sched_wakeup, handle_sched_wakeup); + rv_detach_trace_probe("rtapp_sleep", sched_set_state_tp, handle_sched_set_state); + rv_detach_trace_probe("rtapp_sleep", contention_begin, handle_contention_begin); + rv_detach_trace_probe("rtapp_sleep", contention_end, handle_contention_end); + rv_detach_trace_probe("rtapp_sleep", sched_kthread_stop, handle_kthread_stop); + rv_detach_trace_probe("rtapp_sleep", sys_enter, handle_sys_enter); + rv_detach_trace_probe("rtapp_sleep", sys_exit, handle_sys_exit); + + ltl_monitor_destroy(); +} + +static struct rv_monitor rv_sleep = { + .name = "sleep", + .description = "Monitor that RT tasks do not undesirably sleep", + .enable = enable_sleep, + .disable = disable_sleep, +}; + +static int __init register_sleep(void) +{ + return rv_register_monitor(&rv_sleep, &rv_rtapp); +} + +static void __exit unregister_sleep(void) +{ + rv_unregister_monitor(&rv_sleep); +} + +module_init(register_sleep); +module_exit(unregister_sleep); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Nam Cao <namcao@linutronix.de>"); +MODULE_DESCRIPTION("sleep: Monitor that RT tasks do not undesirably sleep"); diff --git a/kernel/trace/rv/monitors/sleep/sleep.h b/kernel/trace/rv/monitors/sleep/sleep.h new file mode 100644 index 000000000000..2ab46fd218d2 --- /dev/null +++ b/kernel/trace/rv/monitors/sleep/sleep.h @@ -0,0 +1,257 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * C implementation of Buchi automaton, automatically generated by + * tools/verification/rvgen from the linear temporal logic specification. + * For further information, see kernel documentation: + * Documentation/trace/rv/linear_temporal_logic.rst + */ + +#include <linux/rv.h> + +#define MONITOR_NAME sleep + +enum ltl_atom { + LTL_ABORT_SLEEP, + LTL_BLOCK_ON_RT_MUTEX, + LTL_CLOCK_NANOSLEEP, + LTL_FUTEX_LOCK_PI, + LTL_FUTEX_WAIT, + LTL_KERNEL_THREAD, + LTL_KTHREAD_SHOULD_STOP, + LTL_NANOSLEEP_CLOCK_MONOTONIC, + LTL_NANOSLEEP_CLOCK_TAI, + LTL_NANOSLEEP_TIMER_ABSTIME, + LTL_RT, + LTL_SLEEP, + LTL_TASK_IS_MIGRATION, + LTL_TASK_IS_RCU, + LTL_WAKE, + LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, + LTL_WOKEN_BY_HARDIRQ, + LTL_WOKEN_BY_NMI, + LTL_NUM_ATOM +}; +static_assert(LTL_NUM_ATOM <= RV_MAX_LTL_ATOM); + +static const char *ltl_atom_str(enum ltl_atom atom) +{ + static const char *const names[] = { + "ab_sl", + "bl_on_rt_mu", + "cl_na", + "fu_lo_pi", + "fu_wa", + "ker_th", + "kth_sh_st", + "na_cl_mo", + "na_cl_ta", + "na_ti_ab", + "rt", + "sl", + "ta_mi", + "ta_rc", + "wak", + "wo_eq_hi_pr", + "wo_ha", + "wo_nm", + }; + + return names[atom]; +} + +enum ltl_buchi_state { + S0, + S1, + S2, + S3, + S4, + S5, + S6, + S7, + RV_NUM_BA_STATES +}; +static_assert(RV_NUM_BA_STATES <= RV_MAX_BA_STATES); + +static void ltl_start(struct task_struct *task, struct ltl_monitor *mon) +{ + bool task_is_migration = test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); + bool task_is_rcu = test_bit(LTL_TASK_IS_RCU, mon->atoms); + bool val40 = task_is_rcu || task_is_migration; + bool futex_lock_pi = test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); + bool val41 = futex_lock_pi || val40; + bool block_on_rt_mutex = test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); + bool val5 = block_on_rt_mutex || val41; + bool kthread_should_stop = test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms); + bool abort_sleep = test_bit(LTL_ABORT_SLEEP, mon->atoms); + bool val32 = abort_sleep || kthread_should_stop; + bool woken_by_nmi = test_bit(LTL_WOKEN_BY_NMI, mon->atoms); + bool val33 = woken_by_nmi || val32; + bool woken_by_hardirq = test_bit(LTL_WOKEN_BY_HARDIRQ, mon->atoms); + bool val34 = woken_by_hardirq || val33; + bool woken_by_equal_or_higher_prio = test_bit(LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, + mon->atoms); + bool val14 = woken_by_equal_or_higher_prio || val34; + bool wake = test_bit(LTL_WAKE, mon->atoms); + bool val13 = !wake; + bool kernel_thread = test_bit(LTL_KERNEL_THREAD, mon->atoms); + bool nanosleep_clock_tai = test_bit(LTL_NANOSLEEP_CLOCK_TAI, mon->atoms); + bool nanosleep_clock_monotonic = test_bit(LTL_NANOSLEEP_CLOCK_MONOTONIC, mon->atoms); + bool val24 = nanosleep_clock_monotonic || nanosleep_clock_tai; + bool nanosleep_timer_abstime = test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mon->atoms); + bool val25 = nanosleep_timer_abstime && val24; + bool clock_nanosleep = test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); + bool val18 = clock_nanosleep && val25; + bool futex_wait = test_bit(LTL_FUTEX_WAIT, mon->atoms); + bool val9 = futex_wait || val18; + bool val11 = val9 || kernel_thread; + bool sleep = test_bit(LTL_SLEEP, mon->atoms); + bool val2 = !sleep; + bool rt = test_bit(LTL_RT, mon->atoms); + bool val1 = !rt; + bool val3 = val1 || val2; + + if (val3) + __set_bit(S0, mon->states); + if (val11 && val13) + __set_bit(S1, mon->states); + if (val11 && val14) + __set_bit(S4, mon->states); + if (val5) + __set_bit(S5, mon->states); +} + +static void +ltl_possible_next_states(struct ltl_monitor *mon, unsigned int state, unsigned long *next) +{ + bool task_is_migration = test_bit(LTL_TASK_IS_MIGRATION, mon->atoms); + bool task_is_rcu = test_bit(LTL_TASK_IS_RCU, mon->atoms); + bool val40 = task_is_rcu || task_is_migration; + bool futex_lock_pi = test_bit(LTL_FUTEX_LOCK_PI, mon->atoms); + bool val41 = futex_lock_pi || val40; + bool block_on_rt_mutex = test_bit(LTL_BLOCK_ON_RT_MUTEX, mon->atoms); + bool val5 = block_on_rt_mutex || val41; + bool kthread_should_stop = test_bit(LTL_KTHREAD_SHOULD_STOP, mon->atoms); + bool abort_sleep = test_bit(LTL_ABORT_SLEEP, mon->atoms); + bool val32 = abort_sleep || kthread_should_stop; + bool woken_by_nmi = test_bit(LTL_WOKEN_BY_NMI, mon->atoms); + bool val33 = woken_by_nmi || val32; + bool woken_by_hardirq = test_bit(LTL_WOKEN_BY_HARDIRQ, mon->atoms); + bool val34 = woken_by_hardirq || val33; + bool woken_by_equal_or_higher_prio = test_bit(LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, + mon->atoms); + bool val14 = woken_by_equal_or_higher_prio || val34; + bool wake = test_bit(LTL_WAKE, mon->atoms); + bool val13 = !wake; + bool kernel_thread = test_bit(LTL_KERNEL_THREAD, mon->atoms); + bool nanosleep_clock_tai = test_bit(LTL_NANOSLEEP_CLOCK_TAI, mon->atoms); + bool nanosleep_clock_monotonic = test_bit(LTL_NANOSLEEP_CLOCK_MONOTONIC, mon->atoms); + bool val24 = nanosleep_clock_monotonic || nanosleep_clock_tai; + bool nanosleep_timer_abstime = test_bit(LTL_NANOSLEEP_TIMER_ABSTIME, mon->atoms); + bool val25 = nanosleep_timer_abstime && val24; + bool clock_nanosleep = test_bit(LTL_CLOCK_NANOSLEEP, mon->atoms); + bool val18 = clock_nanosleep && val25; + bool futex_wait = test_bit(LTL_FUTEX_WAIT, mon->atoms); + bool val9 = futex_wait || val18; + bool val11 = val9 || kernel_thread; + bool sleep = test_bit(LTL_SLEEP, mon->atoms); + bool val2 = !sleep; + bool rt = test_bit(LTL_RT, mon->atoms); + bool val1 = !rt; + bool val3 = val1 || val2; + + switch (state) { + case S0: + if (val3) + __set_bit(S0, next); + if (val11 && val13) + __set_bit(S1, next); + if (val11 && val14) + __set_bit(S4, next); + if (val5) + __set_bit(S5, next); + break; + case S1: + if (val11 && val13) + __set_bit(S1, next); + if (val13 && val3) + __set_bit(S2, next); + if (val14 && val3) + __set_bit(S3, next); + if (val11 && val14) + __set_bit(S4, next); + if (val13 && val5) + __set_bit(S6, next); + if (val14 && val5) + __set_bit(S7, next); + break; + case S2: + if (val11 && val13) + __set_bit(S1, next); + if (val13 && val3) + __set_bit(S2, next); + if (val14 && val3) + __set_bit(S3, next); + if (val11 && val14) + __set_bit(S4, next); + if (val13 && val5) + __set_bit(S6, next); + if (val14 && val5) + __set_bit(S7, next); + break; + case S3: + if (val3) + __set_bit(S0, next); + if (val11 && val13) + __set_bit(S1, next); + if (val11 && val14) + __set_bit(S4, next); + if (val5) + __set_bit(S5, next); + break; + case S4: + if (val3) + __set_bit(S0, next); + if (val11 && val13) + __set_bit(S1, next); + if (val11 && val14) + __set_bit(S4, next); + if (val5) + __set_bit(S5, next); + break; + case S5: + if (val3) + __set_bit(S0, next); + if (val11 && val13) + __set_bit(S1, next); + if (val11 && val14) + __set_bit(S4, next); + if (val5) + __set_bit(S5, next); + break; + case S6: + if (val11 && val13) + __set_bit(S1, next); + if (val13 && val3) + __set_bit(S2, next); + if (val14 && val3) + __set_bit(S3, next); + if (val11 && val14) + __set_bit(S4, next); + if (val13 && val5) + __set_bit(S6, next); + if (val14 && val5) + __set_bit(S7, next); + break; + case S7: + if (val3) + __set_bit(S0, next); + if (val11 && val13) + __set_bit(S1, next); + if (val11 && val14) + __set_bit(S4, next); + if (val5) + __set_bit(S5, next); + break; + } +} diff --git a/kernel/trace/rv/monitors/sleep/sleep_trace.h b/kernel/trace/rv/monitors/sleep/sleep_trace.h new file mode 100644 index 000000000000..22eaf31da987 --- /dev/null +++ b/kernel/trace/rv/monitors/sleep/sleep_trace.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * Snippet to be included in rv_trace.h + */ + +#ifdef CONFIG_RV_MON_SLEEP +DEFINE_EVENT(event_ltl_monitor_id, event_sleep, + TP_PROTO(struct task_struct *task, char *states, char *atoms, char *next), + TP_ARGS(task, states, atoms, next)); +DEFINE_EVENT(error_ltl_monitor_id, error_sleep, + TP_PROTO(struct task_struct *task), + TP_ARGS(task)); +#endif /* CONFIG_RV_MON_SLEEP */ |