1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _linux_POSIX_TIMERS_H
3 #define _linux_POSIX_TIMERS_H
4
5 #include <linux/alarmtimer.h>
6 #include <linux/list.h>
7 #include <linux/mutex.h>
8 #include <linux/pid.h>
9 #include <linux/posix-timers_types.h>
10 #include <linux/rcuref.h>
11 #include <linux/spinlock.h>
12 #include <linux/timerqueue.h>
13
14 struct kernel_siginfo;
15 struct task_struct;
16 struct sigqueue;
17 struct k_itimer;
18
make_process_cpuclock(const unsigned int pid,const clockid_t clock)19 static inline clockid_t make_process_cpuclock(const unsigned int pid,
20 const clockid_t clock)
21 {
22 return ((~pid) << 3) | clock;
23 }
make_thread_cpuclock(const unsigned int tid,const clockid_t clock)24 static inline clockid_t make_thread_cpuclock(const unsigned int tid,
25 const clockid_t clock)
26 {
27 return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
28 }
29
fd_to_clockid(const int fd)30 static inline clockid_t fd_to_clockid(const int fd)
31 {
32 return make_process_cpuclock((unsigned int) fd, CLOCKFD);
33 }
34
clockid_to_fd(const clockid_t clk)35 static inline int clockid_to_fd(const clockid_t clk)
36 {
37 return ~(clk >> 3);
38 }
39
clockid_aux_valid(clockid_t id)40 static inline bool clockid_aux_valid(clockid_t id)
41 {
42 return IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS) && id >= CLOCK_AUX && id <= CLOCK_AUX_LAST;
43 }
44
45 #ifdef CONFIG_POSIX_TIMERS
46
47 #include <linux/signal_types.h>
48
49 /**
50 * cpu_timer - Posix CPU timer representation for k_itimer
51 * @node: timerqueue node to queue in the task/sig
52 * @head: timerqueue head on which this timer is queued
53 * @pid: Pointer to target task PID
54 * @elist: List head for the expiry list
55 * @firing: Timer is currently firing
56 * @nanosleep: Timer is used for nanosleep and is not a regular posix-timer
57 * @handling: Pointer to the task which handles expiry
58 */
59 struct cpu_timer {
60 struct timerqueue_node node;
61 struct timerqueue_head *head;
62 struct pid *pid;
63 struct list_head elist;
64 bool firing;
65 bool nanosleep;
66 struct task_struct __rcu *handling;
67 };
68
cpu_timer_enqueue(struct timerqueue_head * head,struct cpu_timer * ctmr)69 static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
70 struct cpu_timer *ctmr)
71 {
72 ctmr->head = head;
73 return timerqueue_add(head, &ctmr->node);
74 }
75
cpu_timer_queued(struct cpu_timer * ctmr)76 static inline bool cpu_timer_queued(struct cpu_timer *ctmr)
77 {
78 return !!ctmr->head;
79 }
80
cpu_timer_dequeue(struct cpu_timer * ctmr)81 static inline bool cpu_timer_dequeue(struct cpu_timer *ctmr)
82 {
83 if (cpu_timer_queued(ctmr)) {
84 timerqueue_del(ctmr->head, &ctmr->node);
85 ctmr->head = NULL;
86 return true;
87 }
88 return false;
89 }
90
cpu_timer_getexpires(struct cpu_timer * ctmr)91 static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
92 {
93 return ctmr->node.expires;
94 }
95
cpu_timer_setexpires(struct cpu_timer * ctmr,u64 exp)96 static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
97 {
98 ctmr->node.expires = exp;
99 }
100
posix_cputimers_init(struct posix_cputimers * pct)101 static inline void posix_cputimers_init(struct posix_cputimers *pct)
102 {
103 memset(pct, 0, sizeof(*pct));
104 pct->bases[0].nextevt = U64_MAX;
105 pct->bases[1].nextevt = U64_MAX;
106 pct->bases[2].nextevt = U64_MAX;
107 }
108
109 void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
110
posix_cputimers_rt_watchdog(struct posix_cputimers * pct,u64 runtime)111 static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
112 u64 runtime)
113 {
114 pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
115 }
116
117 void posixtimer_rearm_itimer(struct task_struct *p);
118 bool posixtimer_init_sigqueue(struct sigqueue *q);
119 void posixtimer_send_sigqueue(struct k_itimer *tmr);
120 bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq);
121 void posixtimer_free_timer(struct k_itimer *timer);
122 long posixtimer_create_prctl(unsigned long ctrl);
123
124 /* Init task static initializer */
125 #define INIT_CPU_TIMERBASE(b) { \
126 .nextevt = U64_MAX, \
127 }
128
129 #define INIT_CPU_TIMERBASES(b) { \
130 INIT_CPU_TIMERBASE(b[0]), \
131 INIT_CPU_TIMERBASE(b[1]), \
132 INIT_CPU_TIMERBASE(b[2]), \
133 }
134
135 #define INIT_CPU_TIMERS(s) \
136 .posix_cputimers = { \
137 .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \
138 },
139 #else
140 struct cpu_timer { };
141 #define INIT_CPU_TIMERS(s)
posix_cputimers_init(struct posix_cputimers * pct)142 static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
posix_cputimers_group_init(struct posix_cputimers * pct,u64 cpu_limit)143 static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
144 u64 cpu_limit) { }
posixtimer_rearm_itimer(struct task_struct * p)145 static inline void posixtimer_rearm_itimer(struct task_struct *p) { }
posixtimer_deliver_signal(struct kernel_siginfo * info,struct sigqueue * timer_sigq)146 static inline bool posixtimer_deliver_signal(struct kernel_siginfo *info,
147 struct sigqueue *timer_sigq) { return false; }
posixtimer_free_timer(struct k_itimer * timer)148 static inline void posixtimer_free_timer(struct k_itimer *timer) { }
posixtimer_create_prctl(unsigned long ctrl)149 static inline long posixtimer_create_prctl(unsigned long ctrl) { return -EINVAL; }
150 #endif
151
152 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
153 void clear_posix_cputimers_work(struct task_struct *p);
154 void posix_cputimers_init_work(void);
155 #else
clear_posix_cputimers_work(struct task_struct * p)156 static inline void clear_posix_cputimers_work(struct task_struct *p) { }
posix_cputimers_init_work(void)157 static inline void posix_cputimers_init_work(void) { }
158 #endif
159
160 /**
161 * struct k_itimer - POSIX.1b interval timer structure.
162 * @list: List node for binding the timer to tsk::signal::posix_timers
163 * @ignored_list: List node for tracking ignored timers in tsk::signal::ignored_posix_timers
164 * @t_hash: Entry in the posix timer hash table
165 * @it_lock: Lock protecting the timer
166 * @kclock: Pointer to the k_clock struct handling this timer
167 * @it_clock: The posix timer clock id
168 * @it_id: The posix timer id for identifying the timer
169 * @it_status: The status of the timer
170 * @it_sig_periodic: The periodic status at signal delivery
171 * @it_overrun: The overrun counter for pending signals
172 * @it_overrun_last: The overrun at the time of the last delivered signal
173 * @it_signal_seq: Sequence count to control signal delivery
174 * @it_sigqueue_seq: The sequence count at the point where the signal was queued
175 * @it_sigev_notify: The notify word of sigevent struct for signal delivery
176 * @it_interval: The interval for periodic timers
177 * @it_signal: Pointer to the creators signal struct
178 * @it_pid: The pid of the process/task targeted by the signal
179 * @it_process: The task to wakeup on clock_nanosleep (CPU timers)
180 * @rcuref: Reference count for life time management
181 * @sigq: Embedded sigqueue
182 * @it: Union representing the various posix timer type
183 * internals.
184 * @rcu: RCU head for freeing the timer.
185 */
186 struct k_itimer {
187 /* 1st cacheline contains read-mostly fields */
188 struct hlist_node t_hash;
189 struct hlist_node list;
190 timer_t it_id;
191 clockid_t it_clock;
192 int it_sigev_notify;
193 enum pid_type it_pid_type;
194 struct signal_struct *it_signal;
195 const struct k_clock *kclock;
196
197 /* 2nd cacheline and above contain fields which are modified regularly */
198 spinlock_t it_lock;
199 int it_status;
200 bool it_sig_periodic;
201 s64 it_overrun;
202 s64 it_overrun_last;
203 unsigned int it_signal_seq;
204 unsigned int it_sigqueue_seq;
205 ktime_t it_interval;
206 struct hlist_node ignored_list;
207 union {
208 struct pid *it_pid;
209 struct task_struct *it_process;
210 };
211 struct sigqueue sigq;
212 rcuref_t rcuref;
213 union {
214 struct {
215 struct hrtimer timer;
216 } real;
217 struct cpu_timer cpu;
218 struct {
219 struct alarm alarmtimer;
220 } alarm;
221 } it;
222 struct rcu_head rcu;
223 } ____cacheline_aligned_in_smp;
224
225 void run_posix_cpu_timers(void);
226 void posix_cpu_timers_exit(struct task_struct *task);
227 void posix_cpu_timers_exit_group(struct task_struct *task);
228 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
229 u64 *newval, u64 *oldval);
230
231 int update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
232
233 #ifdef CONFIG_POSIX_TIMERS
posixtimer_putref(struct k_itimer * tmr)234 static inline void posixtimer_putref(struct k_itimer *tmr)
235 {
236 if (rcuref_put(&tmr->rcuref))
237 posixtimer_free_timer(tmr);
238 }
239
posixtimer_sigqueue_getref(struct sigqueue * q)240 static inline void posixtimer_sigqueue_getref(struct sigqueue *q)
241 {
242 struct k_itimer *tmr = container_of(q, struct k_itimer, sigq);
243
244 WARN_ON_ONCE(!rcuref_get(&tmr->rcuref));
245 }
246
posixtimer_sigqueue_putref(struct sigqueue * q)247 static inline void posixtimer_sigqueue_putref(struct sigqueue *q)
248 {
249 struct k_itimer *tmr = container_of(q, struct k_itimer, sigq);
250
251 posixtimer_putref(tmr);
252 }
253
posixtimer_valid(const struct k_itimer * timer)254 static inline bool posixtimer_valid(const struct k_itimer *timer)
255 {
256 unsigned long val = (unsigned long)timer->it_signal;
257
258 return !(val & 0x1UL);
259 }
260 #else /* CONFIG_POSIX_TIMERS */
posixtimer_sigqueue_getref(struct sigqueue * q)261 static inline void posixtimer_sigqueue_getref(struct sigqueue *q) { }
posixtimer_sigqueue_putref(struct sigqueue * q)262 static inline void posixtimer_sigqueue_putref(struct sigqueue *q) { }
263 #endif /* !CONFIG_POSIX_TIMERS */
264
265 #endif
266