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diff --git a/share/man/man9/signal.9 b/share/man/man9/signal.9 new file mode 100644 index 000000000000..6f377eeb346b --- /dev/null +++ b/share/man/man9/signal.9 @@ -0,0 +1,446 @@ +.\" +.\" Copyright (C) 2002 Chad David <davidc@FreeBSD.org>. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice(s), this list of conditions and the following disclaimer as +.\" the first lines of this file unmodified other than the possible +.\" addition of one or more copyright notices. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice(s), this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY +.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY +.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH +.\" DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd November 20, 2004 +.Dt SIGNAL 9 +.Os +.Sh NAME +.Nm signal , +.Nm SIGADDSET , +.Nm SIGDELSET , +.Nm SETEMPTYSET , +.Nm SIGFILLSET , +.Nm SIGISMEMBER , +.Nm SIGISEMPTY , +.Nm SIGNOTEMPTY , +.Nm SIGSETEQ , +.Nm SIGSETNEQ , +.Nm SIGSETOR , +.Nm SIGSETAND , +.Nm SIGSETNAND , +.Nm SIGSETCANTMASK , +.Nm SIG_STOPSIGMASK , +.Nm SIG_CONTSIGMASK , +.Nm SIGPENDING , +.Nm cursig , +.Nm execsigs , +.Nm issignal , +.Nm killproc , +.Nm pgsigio , +.Nm postsig , +.Nm sigexit , +.Nm siginit , +.Nm signotify , +.Nm trapsignal +.Nd "kernel signal functions" +.Sh SYNOPSIS +.In sys/param.h +.In sys/proc.h +.In sys/signalvar.h +.Ft void +.Fn SIGADDSET "sigset_t set" "int signo" +.Ft void +.Fn SIGDELSET "sigset_t set" "int signo" +.Ft void +.Fn SIGEMPTYSET "sigset_t set" +.Ft void +.Fn SIGFILLSET "sigset_t set" +.Ft int +.Fn SIGISMEMBER "sigset_t set" "int signo" +.Ft int +.Fn SIGISEMPTY "sigset_t set" +.Ft int +.Fn SIGNOTEMPTY "sigset_t set" +.Ft int +.Fn SIGSETEQ "sigset_t set1" "sigset_t set2" +.Ft int +.Fn SIGSETNEQ "sigset_t set1" "sigset_t set2" +.Ft void +.Fn SIGSETOR "sigset_t set1" "sigset_t set2" +.Ft void +.Fn SIGSETAND "sigset_t set1" "sigset_t set2" +.Ft void +.Fn SIGSETNAND "sigset_t set1" "sigset_t set2" +.Ft void +.Fn SIG_CANTMASK "sigset_t set" +.Ft void +.Fn SIG_STOPSIGMASK "sigset_t set" +.Ft void +.Fn SIG_CONTSIGMASK "sigset_t set" +.Ft int +.Fn SIGPENDING "struct proc *p" +.Ft int +.Fn cursig "struct thread *td" +.Ft void +.Fn execsigs "struct proc *p" +.Ft int +.Fn issignal "struct thread *td" +.Ft void +.Fn killproc "struct proc *p" "char *why" +.Ft void +.Fn pgsigio "struct sigio **sigiop" "int sig" "int checkctty" +.Ft void +.Fn postsig "int sig" +.Ft void +.Fn sigexit "struct thread *td" "int signum" +.Ft void +.Fn siginit "struct proc *p" +.Ft void +.Fn signotify "struct thread *td" +.Ft void +.Fn trapsignal "struct thread *td" "int sig" "u_long code" +.Sh DESCRIPTION +The +.Fn SIGADDSET +macro adds +.Fa signo +to +.Fa set . +No effort is made to ensure that +.Fa signo +is a valid signal number. +.Pp +The +.Fn SIGDELSET +macro removes +.Fa signo +from +.Fa set . +No effort is made to ensure that +.Fa signo +is a valid signal number. +.Pp +The +.Fn SIGEMPTYSET +macro clears all signals in +.Fa set . +.Pp +The +.Fn SIGFILLSET +macro sets all signals in +.Fa set . +.Pp +The +.Fn SIGISMEMBER +macro determines if +.Fa signo +is set in +.Fa set . +.Pp +The +.Fn SIGISEMPTY +macro determines if +.Fa set +does not have any signals set. +.Pp +The +.Fn SIGNOTEMPTY +macro determines if +.Fa set +has any signals set. +.Pp +The +.Fn SIGSETEQ +macro determines if two signal sets are equal; that is, the same signals +are set in both. +.Pp +The +.Fn SIGSETNEQ +macro determines if two signal sets differ; that is, if any signal set in +one is not set in the other. +.Pp +The +.Fn SIGSETOR +macro ORs the signals set in +.Fa set2 +into +.Fa set1 . +.Pp +The +.Fn SIGSETAND +macro ANDs the signals set in +.Fa set2 +into +.Fa set1 . +.Pp +The +.Fn SIGSETNAND +macro NANDs the signals set in +.Fa set2 +into +.Fa set1 . +.Pp +The +.Fn SIG_CANTMASK +macro clears the +.Dv SIGKILL +and +.Dv SIGSTOP +signals from +.Fa set . +These two signals cannot be blocked or caught and +.Fn SIG_CANTMASK +is used in code where signals are manipulated to ensure this policy +is enforced. +.Pp +The +.Fn SIG_STOPSIGMASK +macro clears the +.Dv SIGSTOP , +.Dv SIGTSTP , +.Dv SIGTTIN , +and +.Dv SIGTTOU +signals from +.Fa set . +.Fn SIG_STOPSIGMASK +is used to clear stop signals when a process is waiting for a child to +exit or exec, and when a process is continuing after having been +suspended. +.Pp +The +.Fn SIG_CONTSIGMASK +macro clears the +.Dv SIGCONT +signal from +.Fa set . +.Fn SIG_CONTSIGMASK +is called when a process is stopped. +.Pp +The +.Fn SIGPENDING +macro determines if the given process has any pending signals that are +not masked. +If the process has a pending signal and the process is currently being +traced, +.Fn SIGPENDING +will return true even if the signal is masked. +.Pp +The +.Fn cursig +function returns the signal number that should be delivered to process +.Fa td->td_proc . +If there are no signals pending, zero is returned. +.Pp +The +.Fn execsigs +function resets the signal set and signal stack of a process in preparation +for an +.Xr execve 2 . +The lock for +.Fa p +must be held before +.Fn execsigs +is called. +.Pp +The +.Fn issignal +function determines if there are any pending signals for process +.Fa td->td_proc +that should be caught, or cause this process to terminate or interrupt its +current system call. +If process +.Fa td->td_proc +is currently being traced, ignored signals will be handled and the process +is always stopped. +Stop signals are handled and cleared right away by +.Fn issignal +unless the process is a member of an orphaned process group and the stop +signal originated from a TTY. +The +.Va sched_lock +lock may be acquired and released, and if +.Va Giant +is held, it may be released and reacquired. +The +.Vt sigacts +structure +.Fa td->td_proc->p_sigacts +must be locked before calling +.Fn issignal +and may be released and reacquired during the call. +The process lock for +.Fa td->td_proc +must be acquired before calling +.Fn issignal +and may be released and reacquired during the call. +The lock for the parent of +.Fa td->td_proc +may also be acquired and released. +Default signal actions are not taken for system processes and init. +.Pp +The +.Fn killproc +function delivers +.Dv SIGKILL +to +.Fa p . +.Fa why +is logged as the reason +.Em why +the process was killed. +.Pp +The +.Fn pgsigio +function sends the signal +.Fa sig +to the process or process group +.Fa sigiop->sio_pgid . +If +.Fa checkctty +is non-zero, the signal is only delivered to processes in the process group +that have a controlling terminal. +If +.Fa sigiop->sio_pgid +is for a process (> 0), the lock for +.Fa sigiop->sio_proc +is acquired and released. +If +.Fa sigiop->sio_pgid +is for a process group (< 0), the process group lock for +.Fa sigiop->sio_pgrp +is acquired and released. +The lock +.Va sigio_lock +is acquired and released. +.Pp +The +.Fn postsig +function handles the actual delivery of the signal +.Fa sig . +.Fn postsig +is called from +.Fn ast +after the kernel has been notified that a signal should be delivered +(via a call to +.Fn signotify , +which causes the flag +.Dv PS_NEEDSIGCHK +to be set). +The lock for process that owns +.Va curthread +must be held before +.Fn postsig +is called, and the current process cannot be 0. +The lock for the +.Va p_sigacts +field of the current process must be held before +.Fn postsig +is called, and may be released and reacquired. +.Pp +The +.Fn sigexit +function causes the process that owns +.Fa td +to exit with a return value of signal number +.Fa sig . +If required, the process will dump core. +The lock for the process that owns +.Fa td +must be held before +.Fn sigexit +is called. +.Pp +The +.Fn siginit +function is called during system initialization to cause every signal with +a default property of +.Dv SA_IGNORE +(except +.Dv SIGCONT ) +to be ignored by +.Fa p . +The process lock for +.Fa p +is acquired and released by +.Fn siginit . +The only process that +.Fn siginit +is ever called for +is +.Va proc0 . +.Pp +The +.Fn signotify +function flags that there are unmasked signals pending that +.Fn ast +should handle. +The lock for process +.Fa td->td_proc +must be held before +.Fn signotify +is called, and +.Va sched_lock +is acquired and released. +.Pp +The +.Fn trapsignal +function sends a signal that is the result of a trap to process +.Fa td->td_proc . +If the process is not being traced and the signal can be delivered +immediately, +.Fn trapsignal +will deliver it directly; otherwise, +.Fn trapsignal +will call +.Xr psignal 9 +to cause the signal to be delivered. +The +.Va sched_lock +lock is acquired and released, as is the lock for +.Fa td->td_proc . +The lock for the +.Va p_sigacts +field of +.Fa td->td_proc +is acquired and released. +.Sh RETURN VALUES +The +.Fn SIGISMEMBER , +.Fn SIGISEMPTY , +.Fn SIGNOTEMPTY , +.Fn SIGSETEQ , +.Fn SIGSETNEQ , +and +.Fn SIGPENDING +macros all return non-zero (true) if the condition they are checking +is found to be true; otherwise, zero (false) is returned. +.Pp +The +.Fn cursig +function returns either a valid signal number or zero. +.Pp +.Fn issignal +returns either a valid signal number or zero. +.Sh SEE ALSO +.Xr gsignal 9 , +.Xr pgsignal 9 , +.Xr psignal 9 +.Sh AUTHORS +This manual page was written by +.An Chad David Aq davidc@FreeBSD.org . |