'\" t

.\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de)

.\" and Copyright (c) 2002, 2006 by Michael Kerrisk <mtk.manpages@gmail.com>

.\" and Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk

.\"     <mtk.manpages@gmail.com>

.\"

.\" %%%LICENSE_START(VERBATIM)

.\" Permission is granted to make and distribute verbatim copies of this

.\" manual provided the copyright notice and this permission notice are

.\" preserved on all copies.

.\"

.\" Permission is granted to copy and distribute modified versions of this

.\" manual under the conditions for verbatim copying, provided that the

.\" entire resulting derived work is distributed under the terms of a

.\" permission notice identical to this one.

.\"

.\" Since the Linux kernel and libraries are constantly changing, this

.\" manual page may be incorrect or out-of-date.  The author(s) assume no

.\" responsibility for errors or omissions, or for damages resulting from

.\" the use of the information contained herein.  The author(s) may not

.\" have taken the same level of care in the production of this manual,

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.\" Formatted or processed versions of this manual, if unaccompanied by

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.\" %%%LICENSE_END

.\"

.\" Modified Sat Jul 24 17:34:08 1993 by Rik Faith (faith@cs.unc.edu)

.\" Modified Sun Jan  7 01:41:27 1996 by Andries Brouwer (aeb@cwi.nl)

.\" Modified Sun Apr 14 12:02:29 1996 by Andries Brouwer (aeb@cwi.nl)

.\" Modified Sat Nov 13 16:28:23 1999 by Andries Brouwer (aeb@cwi.nl)

.\" Modified 10 Apr 2002, by Michael Kerrisk <mtk.manpages@gmail.com>

.\" Modified  7 Jun 2002, by Michael Kerrisk <mtk.manpages@gmail.com>

.\"	Added information on real-time signals

.\" Modified 13 Jun 2002, by Michael Kerrisk <mtk.manpages@gmail.com>

.\"	Noted that SIGSTKFLT is in fact unused

.\" 2004-12-03, Modified mtk, added notes on RLIMIT_SIGPENDING

.\" 2006-04-24, mtk, Added text on changing signal dispositions,

.\"		signal mask, and pending signals.

.\" 2008-07-04, mtk:

.\"     Added section on system call restarting (SA_RESTART)

.\"     Added section on stop/cont signals interrupting syscalls.

.\" 2008-10-05, mtk: various additions

.\"

.TH SIGNAL 7  2017-09-15 "Linux" "Linux Programmer's Manual"

.SH NAME

signal \- overview of signals

.SH DESCRIPTION

Linux supports both POSIX reliable signals (hereinafter

"standard signals") and POSIX real-time signals.

.SS Signal dispositions

Each signal has a current

.IR disposition ,

which determines how the process behaves when it is delivered

the signal.

.PP

The entries in the "Action" column of the tables below specify

the default disposition for each signal, as follows:

.IP Term

Default action is to terminate the process.

.IP Ign

Default action is to ignore the signal.

.IP Core

Default action is to terminate the process and dump core (see

.BR core (5)).

.IP Stop

Default action is to stop the process.

.IP Cont

Default action is to continue the process if it is currently stopped.

.PP

A process can change the disposition of a signal using

.BR sigaction (2)

or

.BR signal (2).

(The latter is less portable when establishing a signal handler;

see

.BR signal (2)

for details.)

Using these system calls, a process can elect one of the

following behaviors to occur on delivery of the signal:

perform the default action; ignore the signal;

or catch the signal with a

.IR "signal handler" ,

a programmer-defined function that is automatically invoked

when the signal is delivered.

(By default, the signal handler is invoked on the

normal process stack.

It is possible to arrange that the signal handler

uses an alternate stack; see

.BR sigaltstack (2)

for a discussion of how to do this and when it might be useful.)

.PP

The signal disposition is a per-process attribute:

in a multithreaded application, the disposition of a

particular signal is the same for all threads.

.PP

A child created via

.BR fork (2)

inherits a copy of its parent's signal dispositions.

During an

.BR execve (2),

the dispositions of handled signals are reset to the default;

the dispositions of ignored signals are left unchanged.

.SS Sending a signal

The following system calls and library functions allow

the caller to send a signal:

.TP 16

.BR raise (3)

Sends a signal to the calling thread.

.TP

.BR kill (2)

Sends a signal to a specified process,

to all members of a specified process group,

or to all processes on the system.

.TP

.BR killpg (3)

Sends a signal to all of the members of a specified process group.

.TP

.BR pthread_kill (3)

Sends a signal to a specified POSIX thread in the same process as

the caller.

.TP

.BR tgkill (2)

Sends a signal to a specified thread within a specific process.

(This is the system call used to implement

.BR pthread_kill (3).)

.TP

.BR sigqueue (3)

Sends a real-time signal with accompanying data to a specified process.

.SS Waiting for a signal to be caught

The following system calls suspend execution of the calling process

or thread until a signal is caught

(or an unhandled signal terminates the process):

.TP 16

.BR pause (2)

Suspends execution until any signal is caught.

.TP

.BR sigsuspend (2)

Temporarily changes the signal mask (see below) and suspends

execution until one of the unmasked signals is caught.

.SS Synchronously accepting a signal

Rather than asynchronously catching a signal via a signal handler,

it is possible to synchronously accept the signal, that is,

to block execution until the signal is delivered,

at which point the kernel returns information about the

signal to the caller.

There are two general ways to do this:

.IP * 2

.BR sigwaitinfo (2),

.BR sigtimedwait (2),

and

.BR sigwait (3)

suspend execution until one of the signals in a specified

set is delivered.

Each of these calls returns information about the delivered signal.

.IP *

.BR signalfd (2)

returns a file descriptor that can be used to read information

about signals that are delivered to the caller.

Each

.BR read (2)

from this file descriptor blocks until one of the signals

in the set specified in the

.BR signalfd (2)

call is delivered to the caller.

The buffer returned by

.BR read (2)

contains a structure describing the signal.

.SS Signal mask and pending signals

A signal may be

.IR blocked ,

which means that it will not be delivered until it is later unblocked.

Between the time when it is generated and when it is delivered

a signal is said to be

.IR pending .

.PP

Each thread in a process has an independent

.IR "signal mask" ,

which indicates the set of signals that the thread is currently blocking.

A thread can manipulate its signal mask using

.BR pthread_sigmask (3).

In a traditional single-threaded application,

.BR sigprocmask (2)

can be used to manipulate the signal mask.

.PP

A child created via

.BR fork (2)

inherits a copy of its parent's signal mask;

the signal mask is preserved across

.BR execve (2).

.PP

A signal may be generated (and thus pending)

for a process as a whole (e.g., when sent using

.BR kill (2))

or for a specific thread (e.g., certain signals,

such as

.B SIGSEGV

and

.BR SIGFPE ,

generated as a

consequence of executing a specific machine-language instruction

are thread directed, as are signals targeted at a specific thread using

.BR pthread_kill (3)).

A process-directed signal may be delivered to any one of the

threads that does not currently have the signal blocked.

If more than one of the threads has the signal unblocked, then the

kernel chooses an arbitrary thread to which to deliver the signal.

.PP

A thread can obtain the set of signals that it currently has pending

using

.BR sigpending (2).

This set will consist of the union of the set of pending

process-directed signals and the set of signals pending for

the calling thread.

.PP

A child created via

.BR fork (2)

initially has an empty pending signal set;

the pending signal set is preserved across an

.BR execve (2).

.SS Standard signals

Linux supports the standard signals listed below.

Several signal numbers

are architecture-dependent, as indicated in the "Value" column.

(Where three values are given, the first one is usually valid for

alpha and sparc,

the middle one for x86, arm, and most other architectures,

and the last one for mips.

(Values for parisc are

.I not

shown; see the Linux kernel source for signal numbering on that architecture.)

A dash (\-) denotes that a signal is absent on the corresponding architecture.

.PP

First the signals described in the original POSIX.1-1990 standard.

.TS

l c c l

____

lB c c l.

Signal	Value	Action	Comment

SIGHUP	\01	Term	Hangup detected on controlling terminal

			or death of controlling process

SIGINT	\02	Term	Interrupt from keyboard

SIGQUIT	\03	Core	Quit from keyboard

SIGILL	\04	Core	Illegal Instruction

SIGABRT	\06	Core	Abort signal from \fBabort\fP(3)

SIGFPE	\08	Core	Floating-point exception

SIGKILL	\09	Term	Kill signal

SIGSEGV	11	Core	Invalid memory reference

SIGPIPE	13	Term	Broken pipe: write to pipe with no

			readers; see \fBpipe\fP(7)

SIGALRM	14	Term	Timer signal from \fBalarm\fP(2)

SIGTERM	15	Term	Termination signal

SIGUSR1	30,10,16	Term	User-defined signal 1

SIGUSR2	31,12,17	Term	User-defined signal 2

SIGCHLD	20,17,18	Ign	Child stopped or terminated

SIGCONT	19,18,25	Cont	Continue if stopped

SIGSTOP	17,19,23	Stop	Stop process

SIGTSTP	18,20,24	Stop	Stop typed at terminal

SIGTTIN	21,21,26	Stop	Terminal input for background process

SIGTTOU	22,22,27	Stop	Terminal output for background process

.TE

.sp 1

The signals

.B SIGKILL

and

.B SIGSTOP

cannot be caught, blocked, or ignored.

.PP

Next the signals not in the POSIX.1-1990 standard but described in

SUSv2 and POSIX.1-2001.

.TS

l c c l

____

lB c c l.

Signal	Value	Action	Comment

SIGBUS	10,7,10	Core	Bus error (bad memory access)

SIGPOLL		Term	Pollable event (Sys V).

			Synonym for \fBSIGIO\fP

SIGPROF	27,27,29	Term	Profiling timer expired

SIGSYS	12,31,12	Core	Bad system call (SVr4);

			see also \fBseccomp\fP(2)

SIGTRAP	5	Core	Trace/breakpoint trap

SIGURG	16,23,21	Ign	Urgent condition on socket (4.2BSD)

SIGVTALRM	26,26,28	Term	Virtual alarm clock (4.2BSD)

SIGXCPU	24,24,30	Core	CPU time limit exceeded (4.2BSD);

			see \fBsetrlimit\fP(2)

SIGXFSZ	25,25,31	Core	File size limit exceeded (4.2BSD);

			see \fBsetrlimit\fP(2)

.TE

.sp 1

Up to and including Linux 2.2, the default behavior for

.BR SIGSYS ", " SIGXCPU ", " SIGXFSZ ", "

and (on architectures other than SPARC and MIPS)

.B SIGBUS

was to terminate the process (without a core dump).

(On some other UNIX systems the default action for

.BR SIGXCPU " and " SIGXFSZ

is to terminate the process without a core dump.)

Linux 2.4 conforms to the POSIX.1-2001 requirements for these signals,

terminating the process with a core dump.

.PP

Next various other signals.

.TS

l c c l

____

lB c c l.

Signal	Value	Action	Comment

SIGIOT	6	Core	IOT trap. A synonym for \fBSIGABRT\fP

SIGEMT	7,\-,7	Term	Emulator trap

SIGSTKFLT	\-,16,\-	Term	Stack fault on coprocessor (unused)

SIGIO	23,29,22	Term	I/O now possible (4.2BSD)

SIGCLD	\-,\-,18	Ign	A synonym for \fBSIGCHLD\fP

SIGPWR	29,30,19	Term	Power failure (System V)

SIGINFO	29,\-,\-		A synonym for \fBSIGPWR\fP

SIGLOST	\-,\-,\-	Term	File lock lost (unused)

SIGWINCH	28,28,20	Ign	Window resize signal (4.3BSD, Sun)

SIGUNUSED	\-,31,\-	Core	Synonymous with \fBSIGSYS\fP

.TE

.sp 1

(Signal 29 is

.B SIGINFO

/

.B SIGPWR

on an alpha but

.B SIGLOST

on a sparc.)

.PP

.B SIGEMT

is not specified in POSIX.1-2001, but nevertheless appears

on most other UNIX systems,

where its default action is typically to terminate

the process with a core dump.

.PP

.B SIGPWR

(which is not specified in POSIX.1-2001) is typically ignored

by default on those other UNIX systems where it appears.

.PP

.B SIGIO

(which is not specified in POSIX.1-2001) is ignored by default

on several other UNIX systems.

.PP

Where defined,

.B SIGUNUSED

is synonymous with

.\" parisc is the only exception: SIGSYS is 12, SIGUNUSED is 31

.B SIGSYS

on most architectures.

Since glibc 2.26,

.B SIGUNUSED

is no longer defined on any architecture.

.SS Real-time signals

Starting with version 2.2,

Linux supports real-time signals as originally defined in the POSIX.1b

real-time extensions (and now included in POSIX.1-2001).

The range of supported real-time signals is defined by the macros

.B SIGRTMIN

and

.BR SIGRTMAX .

POSIX.1-2001 requires that an implementation support at least

.B _POSIX_RTSIG_MAX

(8) real-time signals.

.PP

The Linux kernel supports a range of 33 different real-time

signals, numbered 32 to 64.

However, the glibc POSIX threads implementation internally uses

two (for NPTL) or three (for LinuxThreads) real-time signals

(see

.BR pthreads (7)),

and adjusts the value of

.B SIGRTMIN

suitably (to 34 or 35).

Because the range of available real-time signals varies according

to the glibc threading implementation (and this variation can occur

at run time according to the available kernel and glibc),

and indeed the range of real-time signals varies across UNIX systems,

programs should

.IR "never refer to real-time signals using hard-coded numbers" ,

but instead should always refer to real-time signals using the notation

.BR SIGRTMIN +n,

and include suitable (run-time) checks that

.BR SIGRTMIN +n

does not exceed

.BR SIGRTMAX .

.PP

Unlike standard signals, real-time signals have no predefined meanings:

the entire set of real-time signals can be used for application-defined

purposes.

.PP

The default action for an unhandled real-time signal is to terminate the

receiving process.

.PP

Real-time signals are distinguished by the following:

.IP 1. 4

Multiple instances of real-time signals can be queued.

By contrast, if multiple instances of a standard signal are delivered

while that signal is currently blocked, then only one instance is queued.

.IP 2. 4

If the signal is sent using

.BR sigqueue (3),

an accompanying value (either an integer or a pointer) can be sent

with the signal.

If the receiving process establishes a handler for this signal using the

.B SA_SIGINFO

flag to

.BR sigaction (2),

then it can obtain this data via the

.I si_value

field of the

.I siginfo_t

structure passed as the second argument to the handler.

Furthermore, the

.I si_pid

and

.I si_uid

fields of this structure can be used to obtain the PID

and real user ID of the process sending the signal.

.IP 3. 4

Real-time signals are delivered in a guaranteed order.

Multiple real-time signals of the same type are delivered in the order

they were sent.

If different real-time signals are sent to a process, they are delivered

starting with the lowest-numbered signal.

(I.e., low-numbered signals have highest priority.)

By contrast, if multiple standard signals are pending for a process,

the order in which they are delivered is unspecified.

.PP

If both standard and real-time signals are pending for a process,

POSIX leaves it unspecified which is delivered first.

Linux, like many other implementations, gives priority

to standard signals in this case.

.PP

According to POSIX, an implementation should permit at least

.B _POSIX_SIGQUEUE_MAX

(32) real-time signals to be queued to

a process.

However, Linux does things differently.

In kernels up to and including 2.6.7, Linux imposes

a system-wide limit on the number of queued real-time signals

for all processes.

This limit can be viewed and (with privilege) changed via the

.I /proc/sys/kernel/rtsig-max

file.

A related file,

.IR /proc/sys/kernel/rtsig-nr ,

can be used to find out how many real-time signals are currently queued.

In Linux 2.6.8, these

.I /proc

interfaces were replaced by the

.B RLIMIT_SIGPENDING

resource limit, which specifies a per-user limit for queued

signals; see

.BR setrlimit (2)

for further details.

.PP

The addition of real-time signals required the widening

of the signal set structure

.RI ( sigset_t )

from 32 to 64 bits.

Consequently, various system calls were superseded by new system calls

that supported the larger signal sets.

The old and new system calls are as follows:

.TS

lb lb

l l.

Linux 2.0 and earlier	Linux 2.2 and later

\fBsigaction\fP(2)	\fBrt_sigaction\fP(2)

\fBsigpending\fP(2)	\fBrt_sigpending\fP(2)

\fBsigprocmask\fP(2)	\fBrt_sigprocmask\fP(2)

\fBsigreturn\fP(2)	\fBrt_sigreturn\fP(2)

\fBsigsuspend\fP(2)	\fBrt_sigsuspend\fP(2)

\fBsigtimedwait\fP(2)	\fBrt_sigtimedwait\fP(2)

.TE

.\"

.SS Interruption of system calls and library functions by signal handlers

If a signal handler is invoked while a system call or library

function call is blocked, then either:

.IP * 2

the call is automatically restarted after the signal handler returns; or

.IP *

the call fails with the error

.BR EINTR .

.PP

Which of these two behaviors occurs depends on the interface and

whether or not the signal handler was established using the

.BR SA_RESTART

flag (see

.BR sigaction (2)).

The details vary across UNIX systems;

below, the details for Linux.

.PP

If a blocked call to one of the following interfaces is interrupted

by a signal handler, then the call is automatically restarted

after the signal handler returns if the

.BR SA_RESTART

flag was used; otherwise the call fails with the error

.BR EINTR :

.\" The following system calls use ERESTARTSYS,

.\" so that they are restartable

.IP * 2

.BR read (2),

.BR readv (2),

.BR write (2),

.BR writev (2),

and

.BR ioctl (2)

calls on "slow" devices.

A "slow" device is one where the I/O call may block for an

indefinite time, for example, a terminal, pipe, or socket.

If an I/O call on a slow device has already transferred some

data by the time it is interrupted by a signal handler,

then the call will return a success status

(normally, the number of bytes transferred).

Note that a (local) disk is not a slow device according to this definition;

I/O operations on disk devices are not interrupted by signals.

.IP *

.BR open (2),

if it can block (e.g., when opening a FIFO; see

.BR fifo (7)).

.IP *

.BR wait (2),

.BR wait3 (2),

.BR wait4 (2),

.BR waitid (2),

and

.BR waitpid (2).

.IP *

Socket interfaces:

.\" If a timeout (setsockopt()) is in effect on the socket, then these

.\" system calls switch to using EINTR.  Consequently, they and are not

.\" automatically restarted, and they show the stop/cont behavior

.\" described below.  (Verified from 2.6.26 source, and by experiment; mtk)

.BR accept (2),

.BR connect (2),

.BR recv (2),

.BR recvfrom (2),

.BR recvmmsg (2),

.BR recvmsg (2),

.BR send (2),

.BR sendto (2),

and

.BR sendmsg (2),

.\" FIXME What about sendmmsg()?

unless a timeout has been set on the socket (see below).

.IP *

File locking interfaces:

.BR flock (2)

and

the

.BR F_SETLKW

and

.BR F_OFD_SETLKW

operations of

.BR fcntl (2)

.IP *

POSIX message queue interfaces:

.BR mq_receive (3),

.BR mq_timedreceive (3),

.BR mq_send (3),

and

.BR mq_timedsend (3).

.IP *

.BR futex (2)

.B FUTEX_WAIT

(since Linux 2.6.22;

.\" commit 72c1bbf308c75a136803d2d76d0e18258be14c7a

beforehand, always failed with

.BR EINTR ).

.IP *

.BR getrandom (2).

.IP *

.BR pthread_mutex_lock (3),

.BR pthread_cond_wait (3),

and related APIs.

.IP *

.BR futex (2)

.BR FUTEX_WAIT_BITSET .

.IP *

POSIX semaphore interfaces:

.BR sem_wait (3)

and

.BR sem_timedwait (3)

(since Linux 2.6.22;

.\" as a consequence of the 2.6.22 changes in the futex() implementation

beforehand, always failed with

.BR EINTR ).

.IP *

.BR read (2)

from an

.BR inotify (7)

file descriptor

(since Linux 3.8;

.\" commit 1ca39ab9d21ac93f94b9e3eb364ea9a5cf2aba06

beforehand, always failed with

.BR EINTR ).

.PP

The following interfaces are never restarted after

being interrupted by a signal handler,

regardless of the use of

.BR SA_RESTART ;

they always fail with the error

.B EINTR

when interrupted by a signal handler:

.\" These are the system calls that give EINTR or ERESTARTNOHAND

.\" on interruption by a signal handler.

.IP * 2

"Input" socket interfaces, when a timeout

.RB ( SO_RCVTIMEO )

has been set on the socket using

.BR setsockopt (2):

.BR accept (2),

.BR recv (2),

.BR recvfrom (2),

.BR recvmmsg (2)

(also with a non-NULL

.IR timeout

argument),

and

.BR recvmsg (2).

.IP *

"Output" socket interfaces, when a timeout

.RB ( SO_RCVTIMEO )

has been set on the socket using

.BR setsockopt (2):

.BR connect (2),

.BR send (2),

.BR sendto (2),

and

.BR sendmsg (2).

.\" FIXME What about sendmmsg()?

.IP *

Interfaces used to wait for signals:

.BR pause (2),

.BR sigsuspend (2),

.BR sigtimedwait (2),

and

.BR sigwaitinfo (2).

.IP *

File descriptor multiplexing interfaces:

.BR epoll_wait (2),

.BR epoll_pwait (2),

.BR poll (2),

.BR ppoll (2),

.BR select (2),

and

.BR pselect (2).

.IP *

System V IPC interfaces:

.\" On some other systems, SA_RESTART does restart these system calls

.BR msgrcv (2),

.BR msgsnd (2),

.BR semop (2),

and

.BR semtimedop (2).

.IP *

Sleep interfaces:

.BR clock_nanosleep (2),

.BR nanosleep (2),

and

.BR usleep (3).

.IP *

.BR io_getevents (2).

.PP

The

.BR sleep (3)

function is also never restarted if interrupted by a handler,

but gives a success return: the number of seconds remaining to sleep.

.SS Interruption of system calls and library functions by stop signals

On Linux, even in the absence of signal handlers,

certain blocking interfaces can fail with the error

.BR EINTR

after the process is stopped by one of the stop signals

and then resumed via

.BR SIGCONT .

This behavior is not sanctioned by POSIX.1, and doesn't occur

on other systems.

.PP

The Linux interfaces that display this behavior are:

.IP * 2

"Input" socket interfaces, when a timeout

.RB ( SO_RCVTIMEO )

has been set on the socket using

.BR setsockopt (2):

.BR accept (2),

.BR recv (2),

.BR recvfrom (2),

.BR recvmmsg (2)

(also with a non-NULL

.IR timeout

argument),

and

.BR recvmsg (2).

.IP *

"Output" socket interfaces, when a timeout

.RB ( SO_RCVTIMEO )

has been set on the socket using

.BR setsockopt (2):

.BR connect (2),

.BR send (2),

.BR sendto (2),

and

.\" FIXME What about sendmmsg()?

.BR sendmsg (2),

if a send timeout

.RB ( SO_SNDTIMEO )

has been set.

.IP * 2

.BR epoll_wait (2),

.BR epoll_pwait (2).

.IP *

.BR semop (2),

.BR semtimedop (2).

.IP *

.BR sigtimedwait (2),

.BR sigwaitinfo (2).

.IP *

Linux 3.7 and earlier:

.BR read (2)

from an

.BR inotify (7)

file descriptor

.\" commit 1ca39ab9d21ac93f94b9e3eb364ea9a5cf2aba06

.IP *

Linux 2.6.21 and earlier:

.BR futex (2)

.BR FUTEX_WAIT ,

.BR sem_timedwait (3),

.BR sem_wait (3).

.IP *

Linux 2.6.8 and earlier:

.BR msgrcv (2),

.BR msgsnd (2).

.IP *

Linux 2.4 and earlier:

.BR nanosleep (2).

.SH CONFORMING TO

POSIX.1, except as noted.

.\" It must be a *very* long time since this was true:

.\" .SH BUGS

.\" .B SIGIO

.\" and

.\" .B SIGLOST

.\" have the same value.

.\" The latter is commented out in the kernel source, but

.\" the build process of some software still thinks that

.\" signal 29 is

.\" .BR SIGLOST .

.SH NOTES

For a discussion of async-signal-safe functions, see

.BR signal-safety (7).

.SH SEE ALSO

.BR kill (1),

.BR getrlimit (2),

.BR kill (2),

.BR restart_syscall (2),

.BR rt_sigqueueinfo (2),

.BR setitimer (2),

.BR setrlimit (2),

.BR sgetmask (2),

.BR sigaction (2),

.BR sigaltstack (2),

.BR signal (2),

.BR signalfd (2),

.BR sigpending (2),

.BR sigprocmask (2),

.BR sigreturn (2),

.BR sigsuspend (2),

.BR sigwaitinfo (2),

.BR abort (3),

.BR bsd_signal (3),

.BR killpg (3),

.BR longjmp (3),

.BR pthread_sigqueue (3),

.BR raise (3),

.BR sigqueue (3),

.BR sigset (3),

.BR sigsetops (3),

.BR sigvec (3),

.BR sigwait (3),

.BR strsignal (3),

.BR sysv_signal (3),

.BR core (5),

.BR proc (5),

.BR nptl (7),

.BR pthreads (7),

.BR sigevent (7)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.