#include <core/system.h>
#include <sys/proc.h>
#include <aquila/signal.h>

Macros
#define	SIG_MAX (NSIG - 1)
#define	SIGACT_ABORT 1
#define	SIGACT_TERMINATE 2
#define	SIGACT_IGNORE 3
#define	SIGACT_STOP 4
#define	SIGACT_CONTINUE 5
#define	SIG_DFL ((uintptr_t) 0)
#define	SIG_IGN ((uintptr_t) 1)
#define	SIG_ERR ((uintptr_t) -1)
#define	WAIT_STOPPED 1
#define	WAIT_CONTINUED 2
#define	ERESTARTSYS 512
#define	ERESTARTNOHAND 514
#define	SIG_UNMASKABLE ((1UL << SIGKILL) \| (1UL << SIGSTOP))

Functions
int	signal_send (int pid, int sig)
	Sends a signal as kill() does.
int	signal_proc_send (struct proc *proc, int signal)
	Sends a signal to a process.
int	signal_pgrp_send (struct pgroup *pg, int signal)
	Sends a signal to every process of a process group.
void	signal_action_set (struct proc *proc, int sig)
	Discards a pending signal that sigaction() just made ignored.
void	signal_force (struct proc *proc, int signal)
	Sends a signal that can't be blocked or ignored, such as the SIGSEGV of a fault: if the process blocks or ignores it, it is unblocked and its action reset to the default.
int	signal_interrupts (struct thread *thread)
	Says whether a thread has a signal to take, which ends a sleep that a signal may end.
int	signal_take (void)
	Takes the current process's pending signals, on the way back to user mode: ignored ones are dropped, and default actions are carried out (ending or stopping the process), until one with a handler is found.
void	signal_exit (int sig)
	Ends the current process because of a signal.
int	signal_stops (struct proc *proc, int sig)
	Says whether delivering a signal to a process would stop it: the signal isn't caught, and its default action is to stop.
void	signal_stop (int sig)
	Stops the current process, until SIGCONT or SIGKILL.

Variables
int	sig_default_action [SIG_MAX+1]

Macro Definition Documentation

◆ ERESTARTNOHAND

#define ERESTARTNOHAND 514

Definition at line 82 of file signal.h.

Referenced by aarch64_return_to_user(), sys_nanosleep(), sys_poll(), sys_select(), sys_sigsuspend(), and x86_return_to_user().

◆ ERESTARTSYS

#define ERESTARTSYS 512

Definition at line 81 of file signal.h.

Referenced by aarch64_return_to_user(), sys_thread_join(), sys_waitpid(), tty_background(), waitq_sleep(), and x86_return_to_user().

◆ SIG_DFL

#define SIG_DFL ((uintptr_t) 0)

Definition at line 26 of file signal.h.

Referenced by deliver(), deliver(), kproc_init(), proc_execve(), proc_new(), signal_force(), signal_ignored(), signal_stops(), signal_take(), and sys_sigaction().

◆ SIG_ERR

#define SIG_ERR ((uintptr_t) -1)

Definition at line 28 of file signal.h.

◆ SIG_IGN

#define SIG_IGN ((uintptr_t) 1)

Definition at line 27 of file signal.h.

Referenced by proc_execve(), proc_zombie_notify(), signal_force(), signal_ignored(), signal_take(), sys_sigaction(), and tty_background().

◆ SIG_MAX

#define SIG_MAX (NSIG - 1)

Definition at line 16 of file signal.h.

Referenced by kproc_init(), proc_execve(), proc_new(), signal_send(), signal_to(), and sys_sigaction().

◆ SIG_UNMASKABLE

#define SIG_UNMASKABLE ((1UL << SIGKILL) | (1UL << SIGSTOP))

Definition at line 85 of file signal.h.

Referenced by arch_sigreturn(), deliver(), deliver(), sys_select(), sys_sigmask(), and sys_sigsuspend().

◆ SIGACT_ABORT

#define SIGACT_ABORT 1

Definition at line 19 of file signal.h.

Referenced by signal_take().

◆ SIGACT_CONTINUE

#define SIGACT_CONTINUE 5

Definition at line 23 of file signal.h.

Referenced by signal_ignored().

◆ SIGACT_IGNORE

#define SIGACT_IGNORE 3

Definition at line 21 of file signal.h.

Referenced by signal_ignored().

◆ SIGACT_STOP

#define SIGACT_STOP 4

Definition at line 22 of file signal.h.

Referenced by signal_stops(), and signal_take().

◆ SIGACT_TERMINATE

#define SIGACT_TERMINATE 2

Definition at line 20 of file signal.h.

Referenced by signal_take().

◆ WAIT_CONTINUED

#define WAIT_CONTINUED 2

Definition at line 68 of file signal.h.

Referenced by signal_stop(), signal_to(), and sys_waitpid().

◆ WAIT_STOPPED

#define WAIT_STOPPED 1

Definition at line 67 of file signal.h.

Referenced by signal_stop(), signal_to(), and sys_waitpid().

Function Documentation

◆ signal_action_set()

void signal_action_set	(	struct proc *	proc,
		int	sig )

Discards a pending signal that sigaction() just made ignored.

Parameters

proc	the process
sig	the signal whose action changed

Definition at line 201 of file signal.c.

References proc::sig_pending, signal_action_set(), and signal_ignored().

Referenced by signal_action_set(), and sys_sigaction().

◆ signal_exit()

void signal_exit ( int sig )

Ends the current process because of a signal.

It doesn't return.

Parameters

sig	the signal, which its parent's wait() reports

Definition at line 245 of file signal.c.

References arch_sleep(), curproc, PROC_EXIT, proc_kill(), and signal_exit().

Referenced by deliver(), deliver(), signal_exit(), and signal_take().

◆ signal_force()

void signal_force	(	struct proc *	proc,
		int	signal )

Sends a signal that can't be blocked or ignored, such as the SIGSEGV of a fault: if the process blocks or ignores it, it is unblocked and its action reset to the default.

Parameters

proc	the process
signal	the signal

Definition at line 230 of file signal.c.

References SIG_DFL, SIG_IGN, proc::sigaction, proc::sigmask, signal_force(), and signal_to().

Referenced by abort(), arch_sigreturn(), isr_dispatch(), signal_force(), and sync_dispatch().

◆ signal_interrupts()

int signal_interrupts ( struct thread * thread )

Says whether a thread has a signal to take, which ends a sleep that a signal may end.

Parameters

thread the thread

Returns: 1 if its process has a pending signal that it doesn't block, 0 if not

Definition at line 215 of file signal.c.

References kproc, thread::owner, proc::sig_pending, proc::sigmask, and signal_interrupts().

Referenced by signal_interrupts(), and waitq_sleep().

◆ signal_pgrp_send()

int signal_pgrp_send	(	struct pgroup *	pg,
		int	signal )

Sends a signal to every process of a process group.

Parameters

pg	the process group
signal	the signal

Returns: 0

Definition at line 322 of file signal.c.

References pgroup::procs, queue_for, signal_pgrp_send(), and signal_to().

Referenced by pgrp_orphaned_hangup(), signal_pgrp_send(), tty_background(), tty_hangup(), and tty_signal().

◆ signal_proc_send()

int signal_proc_send	(	struct proc *	proc,
		int	signal )

Sends a signal to a process.

Parameters

proc	the process
signal	the signal (0 only checks that the process exists)

Returns: 0, -EINVAL for a bad signal, or -EPERM for process 0

Definition at line 310 of file signal.c.

References signal_proc_send(), and signal_to().

Referenced by kernel_ctrlaltdel(), mm_page_fault(), proc_zombie_notify(), sched_timer_tick(), signal_notify_parent(), signal_proc_send(), sys_send(), sys_write(), vt_signal(), and x86_fpu_trap().

◆ signal_send()

int signal_send	(	pid_t	pid,
		int	signal )

Sends a signal as kill() does.

Parameters

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

Returns: 0, -EINVAL for a bad signal, or -ESRCH if no such process or group exists

Definition at line 340 of file signal.c.

References curproc, kproc, pgroup::pgid, proc::pgrp, proc::pid, proc_pid_find(), procs, queue_for, proc::running, SIG_MAX, signal_send(), and signal_to().

Referenced by signal_send(), and sys_kill().

◆ signal_stop()

void signal_stop ( int sig )

Stops the current process, until SIGCONT or SIGKILL.

Its thread calls this on its way back to user mode (signal_take()), and sleeps here; other signals don't end the sleep, only continuing (or killing) the process does.

Parameters

sig	the signal that stops it

Definition at line 98 of file signal.c.

References curproc, signal_notify_parent(), signal_stop(), proc::stop_queue, proc::stopped, WAIT_CONTINUED, proc::wait_event, WAIT_STOPPED, and waitq_sleep_unint().

Referenced by signal_stop(), and signal_take().

◆ signal_stops()

int signal_stops	(	struct proc *	proc,
		int	sig )

Says whether delivering a signal to a process would stop it: the signal isn't caught, and its default action is to stop.

Parameters

proc	the process
sig	the signal

Returns: 1 if it would, 0 if not

Definition at line 69 of file signal.c.

References sig_default_action, SIG_DFL, SIGACT_STOP, proc::sigaction, and signal_stops().

Referenced by signal_stops().

◆ signal_take()

int signal_take ( void )

Takes the current process's pending signals, on the way back to user mode: ignored ones are dropped, and default actions are carried out (ending or stopping the process), until one with a handler is found.

Returns: a signal whose handler the architecture runs now, or 0 if there is none

Definition at line 262 of file signal.c.

References curproc, NULL, proc::pgrp, pgrp_orphaned(), ready, proc::running, sig_default_action, SIG_DFL, SIG_IGN, proc::sig_pending, SIGACT_ABORT, SIGACT_STOP, SIGACT_TERMINATE, proc::sigaction, proc::sigmask, signal_exit(), signal_stop(), and signal_take().

Referenced by aarch64_return_to_user(), signal_take(), and x86_return_to_user().

Variable Documentation

◆ sig_default_action

int sig_default_action[SIG_MAX+1]

extern

Definition at line 27 of file signal.c.

Referenced by signal_ignored(), signal_stops(), and signal_take().

Macros

Functions

Variables

Macro Definition Documentation

◆ ERESTARTNOHAND

◆ ERESTARTSYS

◆ SIG_DFL

◆ SIG_ERR

◆ SIG_IGN

◆ SIG_MAX

◆ SIG_UNMASKABLE

◆ SIGACT_ABORT

◆ SIGACT_CONTINUE

◆ SIGACT_IGNORE

◆ SIGACT_STOP

◆ SIGACT_TERMINATE

◆ WAIT_CONTINUED

◆ WAIT_STOPPED

Function Documentation

◆ signal_action_set()

◆ signal_exit()

◆ signal_force()

◆ signal_interrupts()

◆ signal_pgrp_send()

◆ signal_proc_send()

◆ signal_send()

◆ signal_stop()

◆ signal_stops()

◆ signal_take()

Variable Documentation

◆ sig_default_action