1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ftrace.h>
3 #include <linux/tracepoint.h>
4 #include <linux/init.h>
5 #include <linux/irqflags.h>
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/rv.h>
9 #include <linux/sched/deadline.h>
10 #include <linux/sched/rt.h>
11 #include <rv/instrumentation.h>
12
13 #define MODULE_NAME "sleep"
14
15 #include <trace/events/syscalls.h>
16 #include <trace/events/sched.h>
17 #include <trace/events/lock.h>
18 #include <uapi/linux/futex.h>
19 #include <rv_trace.h>
20 #include <monitors/rtapp/rtapp.h>
21
22 #include "sleep.h"
23 #include <rv/ltl_monitor.h>
24
ltl_atoms_fetch(struct task_struct * task,struct ltl_monitor * mon)25 static void ltl_atoms_fetch(struct task_struct *task, struct ltl_monitor *mon)
26 {
27 /*
28 * This includes "actual" real-time tasks and also PI-boosted
29 * tasks. A task being PI-boosted means it is blocking an "actual"
30 * real-task, therefore it should also obey the monitor's rule,
31 * otherwise the "actual" real-task may be delayed.
32 */
33 ltl_atom_set(mon, LTL_RT, rt_or_dl_task(task));
34 }
35
ltl_atoms_init(struct task_struct * task,struct ltl_monitor * mon,bool task_creation)36 static void ltl_atoms_init(struct task_struct *task, struct ltl_monitor *mon, bool task_creation)
37 {
38 ltl_atom_set(mon, LTL_SLEEP, false);
39 ltl_atom_set(mon, LTL_WAKE, false);
40 ltl_atom_set(mon, LTL_ABORT_SLEEP, false);
41 ltl_atom_set(mon, LTL_WOKEN_BY_HARDIRQ, false);
42 ltl_atom_set(mon, LTL_WOKEN_BY_NMI, false);
43 ltl_atom_set(mon, LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, false);
44
45 if (task_creation) {
46 ltl_atom_set(mon, LTL_KTHREAD_SHOULD_STOP, false);
47 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false);
48 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false);
49 ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false);
50 ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false);
51 ltl_atom_set(mon, LTL_FUTEX_WAIT, false);
52 ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false);
53 ltl_atom_set(mon, LTL_BLOCK_ON_RT_MUTEX, false);
54 }
55
56 if (task->flags & PF_KTHREAD) {
57 ltl_atom_set(mon, LTL_KERNEL_THREAD, true);
58
59 /* kernel tasks do not do syscall */
60 ltl_atom_set(mon, LTL_FUTEX_WAIT, false);
61 ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false);
62 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false);
63 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false);
64 ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false);
65 ltl_atom_set(mon, LTL_CLOCK_NANOSLEEP, false);
66
67 if (strstarts(task->comm, "migration/"))
68 ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, true);
69 else
70 ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, false);
71
72 if (strstarts(task->comm, "rcu"))
73 ltl_atom_set(mon, LTL_TASK_IS_RCU, true);
74 else
75 ltl_atom_set(mon, LTL_TASK_IS_RCU, false);
76 } else {
77 ltl_atom_set(mon, LTL_KTHREAD_SHOULD_STOP, false);
78 ltl_atom_set(mon, LTL_KERNEL_THREAD, false);
79 ltl_atom_set(mon, LTL_TASK_IS_RCU, false);
80 ltl_atom_set(mon, LTL_TASK_IS_MIGRATION, false);
81 }
82
83 }
84
handle_sched_set_state(void * data,struct task_struct * task,int state)85 static void handle_sched_set_state(void *data, struct task_struct *task, int state)
86 {
87 if (state & TASK_INTERRUPTIBLE)
88 ltl_atom_pulse(task, LTL_SLEEP, true);
89 else if (state == TASK_RUNNING)
90 ltl_atom_pulse(task, LTL_ABORT_SLEEP, true);
91 }
92
handle_sched_wakeup(void * data,struct task_struct * task)93 static void handle_sched_wakeup(void *data, struct task_struct *task)
94 {
95 ltl_atom_pulse(task, LTL_WAKE, true);
96 }
97
handle_sched_waking(void * data,struct task_struct * task)98 static void handle_sched_waking(void *data, struct task_struct *task)
99 {
100 if (this_cpu_read(hardirq_context)) {
101 ltl_atom_pulse(task, LTL_WOKEN_BY_HARDIRQ, true);
102 } else if (in_task()) {
103 if (current->prio <= task->prio)
104 ltl_atom_pulse(task, LTL_WOKEN_BY_EQUAL_OR_HIGHER_PRIO, true);
105 } else if (in_nmi()) {
106 ltl_atom_pulse(task, LTL_WOKEN_BY_NMI, true);
107 }
108 }
109
handle_contention_begin(void * data,void * lock,unsigned int flags)110 static void handle_contention_begin(void *data, void *lock, unsigned int flags)
111 {
112 if (flags & LCB_F_RT)
113 ltl_atom_update(current, LTL_BLOCK_ON_RT_MUTEX, true);
114 }
115
handle_contention_end(void * data,void * lock,int ret)116 static void handle_contention_end(void *data, void *lock, int ret)
117 {
118 ltl_atom_update(current, LTL_BLOCK_ON_RT_MUTEX, false);
119 }
120
handle_sys_enter(void * data,struct pt_regs * regs,long id)121 static void handle_sys_enter(void *data, struct pt_regs *regs, long id)
122 {
123 struct ltl_monitor *mon;
124 unsigned long args[6];
125 int op, cmd;
126
127 mon = ltl_get_monitor(current);
128
129 switch (id) {
130 case __NR_clock_nanosleep:
131 #ifdef __NR_clock_nanosleep_time64
132 case __NR_clock_nanosleep_time64:
133 #endif
134 syscall_get_arguments(current, regs, args);
135 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, args[0] == CLOCK_MONOTONIC);
136 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, args[0] == CLOCK_TAI);
137 ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, args[1] == TIMER_ABSTIME);
138 ltl_atom_update(current, LTL_CLOCK_NANOSLEEP, true);
139 break;
140
141 case __NR_futex:
142 #ifdef __NR_futex_time64
143 case __NR_futex_time64:
144 #endif
145 syscall_get_arguments(current, regs, args);
146 op = args[1];
147 cmd = op & FUTEX_CMD_MASK;
148
149 switch (cmd) {
150 case FUTEX_LOCK_PI:
151 case FUTEX_LOCK_PI2:
152 ltl_atom_update(current, LTL_FUTEX_LOCK_PI, true);
153 break;
154 case FUTEX_WAIT:
155 case FUTEX_WAIT_BITSET:
156 case FUTEX_WAIT_REQUEUE_PI:
157 ltl_atom_update(current, LTL_FUTEX_WAIT, true);
158 break;
159 }
160 break;
161 }
162 }
163
handle_sys_exit(void * data,struct pt_regs * regs,long ret)164 static void handle_sys_exit(void *data, struct pt_regs *regs, long ret)
165 {
166 struct ltl_monitor *mon = ltl_get_monitor(current);
167
168 ltl_atom_set(mon, LTL_FUTEX_LOCK_PI, false);
169 ltl_atom_set(mon, LTL_FUTEX_WAIT, false);
170 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_MONOTONIC, false);
171 ltl_atom_set(mon, LTL_NANOSLEEP_CLOCK_TAI, false);
172 ltl_atom_set(mon, LTL_NANOSLEEP_TIMER_ABSTIME, false);
173 ltl_atom_update(current, LTL_CLOCK_NANOSLEEP, false);
174 }
175
handle_kthread_stop(void * data,struct task_struct * task)176 static void handle_kthread_stop(void *data, struct task_struct *task)
177 {
178 /* FIXME: this could race with other tracepoint handlers */
179 ltl_atom_update(task, LTL_KTHREAD_SHOULD_STOP, true);
180 }
181
enable_sleep(void)182 static int enable_sleep(void)
183 {
184 int retval;
185
186 retval = ltl_monitor_init();
187 if (retval)
188 return retval;
189
190 rv_attach_trace_probe("rtapp_sleep", sched_waking, handle_sched_waking);
191 rv_attach_trace_probe("rtapp_sleep", sched_wakeup, handle_sched_wakeup);
192 rv_attach_trace_probe("rtapp_sleep", sched_set_state_tp, handle_sched_set_state);
193 rv_attach_trace_probe("rtapp_sleep", contention_begin, handle_contention_begin);
194 rv_attach_trace_probe("rtapp_sleep", contention_end, handle_contention_end);
195 rv_attach_trace_probe("rtapp_sleep", sched_kthread_stop, handle_kthread_stop);
196 rv_attach_trace_probe("rtapp_sleep", sys_enter, handle_sys_enter);
197 rv_attach_trace_probe("rtapp_sleep", sys_exit, handle_sys_exit);
198 return 0;
199 }
200
disable_sleep(void)201 static void disable_sleep(void)
202 {
203 rv_detach_trace_probe("rtapp_sleep", sched_waking, handle_sched_waking);
204 rv_detach_trace_probe("rtapp_sleep", sched_wakeup, handle_sched_wakeup);
205 rv_detach_trace_probe("rtapp_sleep", sched_set_state_tp, handle_sched_set_state);
206 rv_detach_trace_probe("rtapp_sleep", contention_begin, handle_contention_begin);
207 rv_detach_trace_probe("rtapp_sleep", contention_end, handle_contention_end);
208 rv_detach_trace_probe("rtapp_sleep", sched_kthread_stop, handle_kthread_stop);
209 rv_detach_trace_probe("rtapp_sleep", sys_enter, handle_sys_enter);
210 rv_detach_trace_probe("rtapp_sleep", sys_exit, handle_sys_exit);
211
212 ltl_monitor_destroy();
213 }
214
215 static struct rv_monitor rv_sleep = {
216 .name = "sleep",
217 .description = "Monitor that RT tasks do not undesirably sleep",
218 .enable = enable_sleep,
219 .disable = disable_sleep,
220 };
221
register_sleep(void)222 static int __init register_sleep(void)
223 {
224 return rv_register_monitor(&rv_sleep, &rv_rtapp);
225 }
226
unregister_sleep(void)227 static void __exit unregister_sleep(void)
228 {
229 rv_unregister_monitor(&rv_sleep);
230 }
231
232 module_init(register_sleep);
233 module_exit(unregister_sleep);
234
235 MODULE_LICENSE("GPL");
236 MODULE_AUTHOR("Nam Cao <namcao@linutronix.de>");
237 MODULE_DESCRIPTION("sleep: Monitor that RT tasks do not undesirably sleep");
238