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

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source code of linux/include/linux/posix-timers.h