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linux-next/include/linux/posix-timers.h
Oleg Nesterov 27af4245b6 posix-timers: use "struct pid*" instead of "struct task_struct*"
Impact: restructure, clean up code

k_itimer holds the ref to the ->it_process until sys_timer_delete(). This
allows to pin up to RLIMIT_SIGPENDING dead task_struct's. Change the code
to use "struct pid *" instead.

The patch doesn't kill ->it_process, it places ->it_pid into the union.
->it_process is still used by do_cpu_nanosleep() as before. It would be
trivial to change the nanosleep code as well, but since it uses it_process
in a special way I think it is better to keep this field for grep.

The patch bloats the kernel by 104 bytes and it also adds the new pointer,
->it_signal, to k_itimer. It is used by lock_timer() to verify that the
found timer was not created by another process. It is not clear why do we
use the global database (and thus the global idr_lock) for posix timers.
We still need the signal_struct->posix_timers which contains all useable
timers, perhaps it is better to use some form of per-process array
instead.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-12-12 17:00:07 +01:00

123 lines
4.2 KiB
C

#ifndef _linux_POSIX_TIMERS_H
#define _linux_POSIX_TIMERS_H
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sched.h>
union cpu_time_count {
cputime_t cpu;
unsigned long long sched;
};
struct cpu_timer_list {
struct list_head entry;
union cpu_time_count expires, incr;
struct task_struct *task;
int firing;
};
#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
#define CPUCLOCK_PERTHREAD(clock) \
(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
#define CPUCLOCK_PID_MASK 7
#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 MAKE_PROCESS_CPUCLOCK(pid, clock) \
((~(clockid_t) (pid) << 3) | (clockid_t) (clock))
#define MAKE_THREAD_CPUCLOCK(tid, clock) \
MAKE_PROCESS_CPUCLOCK((tid), (clock) | CPUCLOCK_PERTHREAD_MASK)
/* POSIX.1b interval timer structure. */
struct k_itimer {
struct list_head list; /* free/ allocate list */
spinlock_t it_lock;
clockid_t it_clock; /* which timer type */
timer_t it_id; /* timer id */
int it_overrun; /* overrun on pending signal */
int it_overrun_last; /* overrun on last delivered signal */
int it_requeue_pending; /* waiting to requeue this timer */
#define REQUEUE_PENDING 1
int it_sigev_notify; /* notify word of sigevent struct */
struct signal_struct *it_signal;
union {
struct pid *it_pid; /* pid of process to send signal to */
struct task_struct *it_process; /* for clock_nanosleep */
};
struct sigqueue *sigq; /* signal queue entry. */
union {
struct {
struct hrtimer timer;
ktime_t interval;
} real;
struct cpu_timer_list cpu;
struct {
unsigned int clock;
unsigned int node;
unsigned long incr;
unsigned long expires;
} mmtimer;
} it;
};
struct k_clock {
int res; /* in nanoseconds */
int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
int (*clock_set) (const clockid_t which_clock, struct timespec * tp);
int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
int (*timer_create) (struct k_itimer *timer);
int (*nsleep) (const clockid_t which_clock, int flags,
struct timespec *, struct timespec __user *);
long (*nsleep_restart) (struct restart_block *restart_block);
int (*timer_set) (struct k_itimer * timr, int flags,
struct itimerspec * new_setting,
struct itimerspec * old_setting);
int (*timer_del) (struct k_itimer * timr);
#define TIMER_RETRY 1
void (*timer_get) (struct k_itimer * timr,
struct itimerspec * cur_setting);
};
void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock);
/* error handlers for timer_create, nanosleep and settime */
int do_posix_clock_nonanosleep(const clockid_t, int flags, struct timespec *,
struct timespec __user *);
int do_posix_clock_nosettime(const clockid_t, struct timespec *tp);
/* function to call to trigger timer event */
int posix_timer_event(struct k_itimer *timr, int si_private);
int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts);
int posix_cpu_timer_create(struct k_itimer *timer);
int posix_cpu_nsleep(const clockid_t which_clock, int flags,
struct timespec *rqtp, struct timespec __user *rmtp);
long posix_cpu_nsleep_restart(struct restart_block *restart_block);
int posix_cpu_timer_set(struct k_itimer *timer, int flags,
struct itimerspec *new, struct itimerspec *old);
int posix_cpu_timer_del(struct k_itimer *timer);
void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp);
void posix_cpu_timer_schedule(struct k_itimer *timer);
void run_posix_cpu_timers(struct task_struct *task);
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,
cputime_t *newval, cputime_t *oldval);
long clock_nanosleep_restart(struct restart_block *restart_block);
void update_rlimit_cpu(unsigned long rlim_new);
#endif