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-rw-r--r--include/linux/posix-timers.h257
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diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
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+++ b/include/linux/posix-timers.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _linux_POSIX_TIMERS_H
+#define _linux_POSIX_TIMERS_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/alarmtimer.h>
+#include <linux/timerqueue.h>
+#include <linux/task_work.h>
+
+struct kernel_siginfo;
+struct task_struct;
+
+/*
+ * Bit fields within a clockid:
+ *
+ * The most significant 29 bits hold either a pid or a file descriptor.
+ *
+ * Bit 2 indicates whether a cpu clock refers to a thread or a process.
+ *
+ * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
+ *
+ * A clockid is invalid if bits 2, 1, and 0 are all set.
+ */
+#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
+#define CPUCLOCK_PERTHREAD(clock) \
+ (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
+
+#define CPUCLOCK_PERTHREAD_MASK 4
+#define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
+#define CPUCLOCK_CLOCK_MASK 3
+#define CPUCLOCK_PROF 0
+#define CPUCLOCK_VIRT 1
+#define CPUCLOCK_SCHED 2
+#define CPUCLOCK_MAX 3
+#define CLOCKFD CPUCLOCK_MAX
+#define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
+
+static inline clockid_t make_process_cpuclock(const unsigned int pid,
+ const clockid_t clock)
+{
+ return ((~pid) << 3) | clock;
+}
+static inline clockid_t make_thread_cpuclock(const unsigned int tid,
+ const clockid_t clock)
+{
+ return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
+}
+
+static inline clockid_t fd_to_clockid(const int fd)
+{
+ return make_process_cpuclock((unsigned int) fd, CLOCKFD);
+}
+
+static inline int clockid_to_fd(const clockid_t clk)
+{
+ return ~(clk >> 3);
+}
+
+#ifdef CONFIG_POSIX_TIMERS
+
+/**
+ * cpu_timer - Posix CPU timer representation for k_itimer
+ * @node: timerqueue node to queue in the task/sig
+ * @head: timerqueue head on which this timer is queued
+ * @pid: Pointer to target task PID
+ * @elist: List head for the expiry list
+ * @firing: Timer is currently firing
+ * @handling: Pointer to the task which handles expiry
+ */
+struct cpu_timer {
+ struct timerqueue_node node;
+ struct timerqueue_head *head;
+ struct pid *pid;
+ struct list_head elist;
+ int firing;
+ struct task_struct __rcu *handling;
+};
+
+static inline bool cpu_timer_enqueue(struct timerqueue_head *head,
+ struct cpu_timer *ctmr)
+{
+ ctmr->head = head;
+ return timerqueue_add(head, &ctmr->node);
+}
+
+static inline void cpu_timer_dequeue(struct cpu_timer *ctmr)
+{
+ if (ctmr->head) {
+ timerqueue_del(ctmr->head, &ctmr->node);
+ ctmr->head = NULL;
+ }
+}
+
+static inline u64 cpu_timer_getexpires(struct cpu_timer *ctmr)
+{
+ return ctmr->node.expires;
+}
+
+static inline void cpu_timer_setexpires(struct cpu_timer *ctmr, u64 exp)
+{
+ ctmr->node.expires = exp;
+}
+
+/**
+ * posix_cputimer_base - Container per posix CPU clock
+ * @nextevt: Earliest-expiration cache
+ * @tqhead: timerqueue head for cpu_timers
+ */
+struct posix_cputimer_base {
+ u64 nextevt;
+ struct timerqueue_head tqhead;
+};
+
+/**
+ * posix_cputimers - Container for posix CPU timer related data
+ * @bases: Base container for posix CPU clocks
+ * @timers_active: Timers are queued.
+ * @expiry_active: Timer expiry is active. Used for
+ * process wide timers to avoid multiple
+ * task trying to handle expiry concurrently
+ *
+ * Used in task_struct and signal_struct
+ */
+struct posix_cputimers {
+ struct posix_cputimer_base bases[CPUCLOCK_MAX];
+ unsigned int timers_active;
+ unsigned int expiry_active;
+};
+
+/**
+ * posix_cputimers_work - Container for task work based posix CPU timer expiry
+ * @work: The task work to be scheduled
+ * @mutex: Mutex held around expiry in context of this task work
+ * @scheduled: @work has been scheduled already, no further processing
+ */
+struct posix_cputimers_work {
+ struct callback_head work;
+ struct mutex mutex;
+ unsigned int scheduled;
+};
+
+static inline void posix_cputimers_init(struct posix_cputimers *pct)
+{
+ memset(pct, 0, sizeof(*pct));
+ pct->bases[0].nextevt = U64_MAX;
+ pct->bases[1].nextevt = U64_MAX;
+ pct->bases[2].nextevt = U64_MAX;
+}
+
+void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit);
+
+static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
+ u64 runtime)
+{
+ pct->bases[CPUCLOCK_SCHED].nextevt = runtime;
+}
+
+/* Init task static initializer */
+#define INIT_CPU_TIMERBASE(b) { \
+ .nextevt = U64_MAX, \
+}
+
+#define INIT_CPU_TIMERBASES(b) { \
+ INIT_CPU_TIMERBASE(b[0]), \
+ INIT_CPU_TIMERBASE(b[1]), \
+ INIT_CPU_TIMERBASE(b[2]), \
+}
+
+#define INIT_CPU_TIMERS(s) \
+ .posix_cputimers = { \
+ .bases = INIT_CPU_TIMERBASES(s.posix_cputimers.bases), \
+ },
+#else
+struct posix_cputimers { };
+struct cpu_timer { };
+#define INIT_CPU_TIMERS(s)
+static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
+static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
+ u64 cpu_limit) { }
+#endif
+
+#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
+void clear_posix_cputimers_work(struct task_struct *p);
+void posix_cputimers_init_work(void);
+#else
+static inline void clear_posix_cputimers_work(struct task_struct *p) { }
+static inline void posix_cputimers_init_work(void) { }
+#endif
+
+#define REQUEUE_PENDING 1
+
+/**
+ * struct k_itimer - POSIX.1b interval timer structure.
+ * @list: List head for binding the timer to signals->posix_timers
+ * @t_hash: Entry in the posix timer hash table
+ * @it_lock: Lock protecting the timer
+ * @kclock: Pointer to the k_clock struct handling this timer
+ * @it_clock: The posix timer clock id
+ * @it_id: The posix timer id for identifying the timer
+ * @it_active: Marker that timer is active
+ * @it_overrun: The overrun counter for pending signals
+ * @it_overrun_last: The overrun at the time of the last delivered signal
+ * @it_requeue_pending: Indicator that timer waits for being requeued on
+ * signal delivery
+ * @it_sigev_notify: The notify word of sigevent struct for signal delivery
+ * @it_interval: The interval for periodic timers
+ * @it_signal: Pointer to the creators signal struct
+ * @it_pid: The pid of the process/task targeted by the signal
+ * @it_process: The task to wakeup on clock_nanosleep (CPU timers)
+ * @sigq: Pointer to preallocated sigqueue
+ * @it: Union representing the various posix timer type
+ * internals.
+ * @rcu: RCU head for freeing the timer.
+ */
+struct k_itimer {
+ struct list_head list;
+ struct hlist_node t_hash;
+ spinlock_t it_lock;
+ const struct k_clock *kclock;
+ clockid_t it_clock;
+ timer_t it_id;
+ int it_active;
+ s64 it_overrun;
+ s64 it_overrun_last;
+ int it_requeue_pending;
+ int it_sigev_notify;
+ ktime_t it_interval;
+ struct signal_struct *it_signal;
+ union {
+ struct pid *it_pid;
+ struct task_struct *it_process;
+ };
+ struct sigqueue *sigq;
+ union {
+ struct {
+ struct hrtimer timer;
+ } real;
+ struct cpu_timer cpu;
+ struct {
+ struct alarm alarmtimer;
+ } alarm;
+ } it;
+ struct rcu_head rcu;
+};
+
+void run_posix_cpu_timers(void);
+void posix_cpu_timers_exit(struct task_struct *task);
+void posix_cpu_timers_exit_group(struct task_struct *task);
+void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
+ u64 *newval, u64 *oldval);
+
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
+
+void posixtimer_rearm(struct kernel_siginfo *info);
+#endif