include/linux/posix-timers.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _linux_POSIX_TIMERS_H
   3 #define _linux_POSIX_TIMERS_H
   4
   5 #include <linux/spinlock.h>
   6 #include <linux/list.h>
   7 #include <linux/sched.h>
   8 #include <linux/timex.h>
   9 #include <linux/alarmtimer.h>
  10
  11 struct siginfo;
  12
  13 struct cpu_timer_list {
  14         struct list_head entry;
  15         u64 expires;
  16         struct task_struct *task;
  17         int firing;
  18 };
  19
  20 /*
  21  * Bit fields within a clockid:
  22  *
  23  * The most significant 29 bits hold either a pid or a file descriptor.
  24  *
  25  * Bit 2 indicates whether a cpu clock refers to a thread or a process.
  26  *
  27  * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
  28  *
  29  * A clockid is invalid if bits 2, 1, and 0 are all set.
  30  */
  31 #define CPUCLOCK_PID(clock)             ((pid_t) ~((clock) >> 3))
  32 #define CPUCLOCK_PERTHREAD(clock) \
  33         (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
  34
  35 #define CPUCLOCK_PERTHREAD_MASK 4
  36 #define CPUCLOCK_WHICH(clock)   ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
  37 #define CPUCLOCK_CLOCK_MASK     3
  38 #define CPUCLOCK_PROF           0
  39 #define CPUCLOCK_VIRT           1
  40 #define CPUCLOCK_SCHED          2
  41 #define CPUCLOCK_MAX            3
  42 #define CLOCKFD                 CPUCLOCK_MAX
  43 #define CLOCKFD_MASK            (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
  44
  45 static inline clockid_t make_process_cpuclock(const unsigned int pid,
  46                 const clockid_t clock)
  47 {
  48         return ((~pid) << 3) | clock;
  49 }
  50 static inline clockid_t make_thread_cpuclock(const unsigned int tid,
  51                 const clockid_t clock)
  52 {
  53         return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
  54 }
  55
  56 static inline clockid_t fd_to_clockid(const int fd)
  57 {
  58         return make_process_cpuclock((unsigned int) fd, CLOCKFD);
  59 }
  60
  61 static inline int clockid_to_fd(const clockid_t clk)
  62 {
  63         return ~(clk >> 3);
  64 }
  65
  66 #define REQUEUE_PENDING 1
  67
  68 /**
  69  * struct k_itimer - POSIX.1b interval timer structure.
  70  * @list:               List head for binding the timer to signals->posix_timers
  71  * @t_hash:             Entry in the posix timer hash table
  72  * @it_lock:            Lock protecting the timer
  73  * @kclock:             Pointer to the k_clock struct handling this timer
  74  * @it_clock:           The posix timer clock id
  75  * @it_id:              The posix timer id for identifying the timer
  76  * @it_active:          Marker that timer is active
  77  * @it_overrun:         The overrun counter for pending signals
  78  * @it_overrun_last:    The overrun at the time of the last delivered signal
  79  * @it_requeue_pending: Indicator that timer waits for being requeued on
  80  *                      signal delivery
  81  * @it_sigev_notify:    The notify word of sigevent struct for signal delivery
  82  * @it_interval:        The interval for periodic timers
  83  * @it_signal:          Pointer to the creators signal struct
  84  * @it_pid:             The pid of the process/task targeted by the signal
  85  * @it_process:         The task to wakeup on clock_nanosleep (CPU timers)
  86  * @sigq:               Pointer to preallocated sigqueue
  87  * @it:                 Union representing the various posix timer type
  88  *                      internals. Also used for rcu freeing the timer.
  89  */
  90 struct k_itimer {
  91         struct list_head        list;
  92         struct hlist_node       t_hash;
  93         spinlock_t              it_lock;
  94         const struct k_clock    *kclock;
  95         clockid_t               it_clock;
  96         timer_t                 it_id;
  97         int                     it_active;
  98         s64                     it_overrun;
  99         s64                     it_overrun_last;
 100         int                     it_requeue_pending;
 101         int                     it_sigev_notify;
 102         ktime_t                 it_interval;
 103         struct signal_struct    *it_signal;
 104         union {
 105                 struct pid              *it_pid;
 106                 struct task_struct      *it_process;
 107         };
 108         struct sigqueue         *sigq;
 109         union {
 110                 struct {
 111                         struct hrtimer  timer;
 112                 } real;
 113                 struct cpu_timer_list   cpu;
 114                 struct {
 115                         struct alarm    alarmtimer;
 116                 } alarm;
 117                 struct rcu_head         rcu;
 118         } it;
 119 };
 120
 121 void run_posix_cpu_timers(struct task_struct *task);
 122 void posix_cpu_timers_exit(struct task_struct *task);
 123 void posix_cpu_timers_exit_group(struct task_struct *task);
 124 void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
 125                            u64 *newval, u64 *oldval);
 126
 127 void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new);
 128
 129 void posixtimer_rearm(struct kernel_siginfo *info);
 130 #endif