sys_signal.c File Reference

System calls about signals, timers and the time: kill(), sigaction(), the signal mask, sigsuspend() and sigreturn(), setitimer(), nanosleep(), and the clocks. More...

#include "syscalls.h"

Go to the source code of this file.

Functions
long	sys_kill (pid_t pid, int sig)
	Implements kill(): sends a signal to a process or a process group.
long	sys_sigaction (int sig, const struct aquila_sigaction *act, struct aquila_sigaction *oact)
	Implements sigaction(): reads a signal's action, and sets a new one.
long	sys_gettimeofday (struct timeval *tv, struct timezone *tz)
	Implements gettimeofday(): the time of day.
long	sys_sigmask (int how, const sigset_t *set, sigset_t *oldset)
	Implements sigprocmask(): reads and changes the process's signal mask.
long	sys_sigsuspend (const sigset_t *set)
	Implements sigsuspend(): replaces the signal mask and waits for a signal.
long	sys_sigreturn (void)
	Implements sigreturn(): a signal handler returns, and the registers and signal mask that its frame saved are restored.
long	sys_setitimer (int which, const struct aquila_itimer *new, struct aquila_itimer *old)
	Implements setitimer(): sets the real time timer, which sends SIGALRM, and reads the old one.
long	sys_nanosleep (const struct aquila_timespec *req, struct aquila_timespec *rem)
	Implements nanosleep(): sleeps for a time.
long	sys_clock_gettime (int clock, struct aquila_timespec *ts)
	Implements clock_gettime(): reads a clock.

Detailed Description

System calls about signals, timers and the time: kill(), sigaction(), the signal mask, sigsuspend() and sigreturn(), setitimer(), nanosleep(), and the clocks.

Definition in file sys_signal.c.

Function Documentation

sys_clock_gettime()

long sys_clock_gettime	(	int	clock,
		struct aquila_timespec *	ts )

Implements clock_gettime(): reads a clock.

Parameters

clock	CLOCK_REALTIME or CLOCK_MONOTONIC
ts	where to put the time

Returns

0, -EINVAL for another clock, or -EFAULT

Definition at line 293 of file sys_signal.c.

References arch_rtime_ns(), clock, gettime(), LOG_DEBUG, sys_clock_gettime(), timespec::tv_nsec, and timespec::tv_sec.

Referenced by sys_clock_gettime().

sys_gettimeofday()

long sys_gettimeofday	(	struct timeval *	tv,
		struct timezone *	tz )

Implements gettimeofday(): the time of day.

Parameters

tv	where to put the time, or NULL
tz	where to put the time zone, or NULL

Returns

0, or -EFAULT

Definition at line 85 of file sys_signal.c.

References gettimeofday(), LOG_DEBUG, and sys_gettimeofday().

Referenced by sys_gettimeofday().

sys_kill()

long sys_kill	(	pid_t	pid,
		int	sig )

Implements kill(): sends a signal to a process or a process group.

Parameters

pid	whom to: a process if > 0, the caller's process group if 0, every process but init and the caller if -1, or process group -pid if < -1
sig	the signal, or 0 to only check that the target exists

Returns

0, -EINVAL for a bad signal, or -ESRCH if there is no such process or group

Definition at line 19 of file sys_signal.c.

References LOG_DEBUG, signal_send(), and sys_kill().

Referenced by sys_kill().

sys_nanosleep()

long sys_nanosleep	(	const struct aquila_timespec *	req,
		struct aquila_timespec *	rem )

Implements nanosleep(): sleeps for a time.

A stop doesn't change the deadline: the call is restarted until the same time.

Parameters

req	how long to sleep
rem	where to put the time left if a signal ends the sleep, or NULL

Returns

0, -EINTR if a handler ran, -EINVAL for a bad time, or -EFAULT

Definition at line 242 of file sys_signal.c.

References arch_rtime_ns(), curthread, ERESTARTNOHAND, LOG_DEBUG, sched_sleep(), and sys_nanosleep().

Referenced by sys_nanosleep().

sys_setitimer()

long sys_setitimer	(	int	which,
		const struct aquila_itimer *	new,
		struct aquila_itimer *	old )

Implements setitimer(): sets the real time timer, which sends SIGALRM, and reads the old one.

Parameters

which	AQUILA_ITIMER_REAL (the only timer supported)
new	the new timer, or NULL to only read the old one
old	where to put the old timer, or NULL

Returns

0, -EINVAL for another timer, or -EFAULT

Definition at line 201 of file sys_signal.c.

References curproc, LOG_DEBUG, sched_alarm(), sched_alarm_get(), and sys_setitimer().

Referenced by sys_setitimer().

sys_sigaction()

long sys_sigaction	(	int	sig,
		const struct aquila_sigaction *	act,
		struct aquila_sigaction *	oact )

Implements sigaction(): reads a signal's action, and sets a new one.

Parameters

sig	the signal
act	the new action, or NULL to leave it
oact	where to put the old action, or NULL

Returns

0, -EINVAL for a bad signal (or catching SIGKILL or SIGSTOP), or -EFAULT

Definition at line 37 of file sys_signal.c.

References curproc, LOG_DEBUG, SIG_DFL, SIG_IGN, SIG_MAX, signal_action_set(), sys_sigaction(), and uaccess_check().

Referenced by sys_sigaction().

sys_sigmask()

long sys_sigmask	(	int	how,
		const sigset_t *	set,
		sigset_t *	oldset )

Implements sigprocmask(): reads and changes the process's signal mask.

SIGKILL and SIGSTOP can't be blocked.

Parameters

how	SIG_BLOCK, SIG_UNBLOCK or SIG_SETMASK
set	the signals, or NULL to leave the mask
oldset	where to put the old mask, or NULL

Returns

0, -EINVAL for a bad how, or -EFAULT

Definition at line 108 of file sys_signal.c.

References curproc, LOG_DEBUG, SIG_UNMASKABLE, and sys_sigmask().

Referenced by sys_sigmask().

sys_sigreturn()

long sys_sigreturn

(

void

)

Implements sigreturn(): a signal handler returns, and the registers and signal mask that its frame saved are restored.

The kernel's signal code page calls it when a handler returns.

Returns

0, which syscall_dispatch() ignores: the registers are the frame's

Definition at line 182 of file sys_signal.c.

References arch_sigreturn(), LOG_DEBUG, and sys_sigreturn().

Referenced by sys_sigreturn().

sys_sigsuspend()

long sys_sigsuspend

(

const sigset_t *

set

)

Implements sigsuspend(): replaces the signal mask and waits for a signal.

The old mask comes back once a handler has run.

Parameters

set	the mask to wait with

Returns

-EINTR once a handler has run (it is restarted after a stop), or -EFAULT

Definition at line 146 of file sys_signal.c.

References curproc, curthread, ERESTARTNOHAND, LOG_DEBUG, thread::sig_oldmask, thread::sig_oldmask_set, SIG_UNMASKABLE, sys_sigsuspend(), and waitq_sleep().

Referenced by sys_sigsuspend().