diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/compat-43/sigvec.3 | 232 |
1 files changed, 114 insertions, 118 deletions
diff --git a/lib/libc/compat-43/sigvec.3 b/lib/libc/compat-43/sigvec.3 index 4fb218b3254..255746f7e32 100644 --- a/lib/libc/compat-43/sigvec.3 +++ b/lib/libc/compat-43/sigvec.3 @@ -29,7 +29,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" $OpenBSD: sigvec.3,v 1.6 1997/11/05 19:25:43 deraadt Exp $ +.\" $OpenBSD: sigvec.3,v 1.7 1997/11/15 23:46:16 deraadt Exp $ .\" .Dd April 29, 1991 .Dt SIGVEC 3 @@ -56,15 +56,21 @@ This interface is made obsolete by sigaction(2). .Pp The system defines a set of signals that may be delivered to a process. Signal delivery resembles the occurrence of a hardware interrupt: -the signal is blocked from further occurrence, the current process +the signal is blocked from further occurrence, the current process context is saved, and a new one is built. A process may specify a .Em handler -to which a signal is delivered, or specify that a signal is to be +to which a signal is delivered, or specify that a signal is to be .Em blocked or .Em ignored . A process may also specify that a default action is to be taken by the system when a signal occurs. +A signal may also be +.Em blocked , +in which case its delivery is postponed until it is +.Em unblocked . +The action to be taken on delivery is determined at the time +of delivery. Normally, signal handlers execute on the current stack of the process. This may be changed, on a per-handler basis, so that signals are taken on a special @@ -76,7 +82,7 @@ Signal routines execute with the signal that caused their invocation .Em blocked , but other signals may yet occur. -A global +A global .Em "signal mask" defines the set of signals currently blocked from delivery to a process. The signal mask for a process is initialized @@ -91,9 +97,10 @@ When a signal condition arises for a process, the signal is added to a set of signals pending for the process. If the signal is not currently .Em blocked -by the process then it is delivered to the process. When a signal +by the process then it is delivered to the process. +When a caught signal is delivered, the current state of the process is saved, -a new signal mask is calculated (as described below), +a new signal mask is calculated (as described below), and the signal handler is invoked. The call to the handler is arranged so that if the signal handling routine returns normally the process will resume execution in the context @@ -108,76 +115,24 @@ installed for the duration of the process' signal handler or .Xr sigsetmask call is made). -This mask is formed by taking the current signal mask, -adding the signal to be delivered, and -.Em or Ns 'ing -in the signal mask associated with the handler to be invoked. +This mask is formed by taking the union of the current signal mask, +the signal to be delivered, and +the signal mask associated with the handler to be invoked. .Pp .Fn Sigvec assigns a handler for a specific signal. If .Fa vec is non-zero, it -specifies a handler routine and mask +specifies an action +.Pf ( Dv SIG_DFL , +.Dv SIG_IGN , +or a handler routine) and mask to be used when delivering the specified signal. -Further, if the -.Dv SV_ONSTACK -bit is set in -.Fa sv_flags , -the system will deliver the signal to the process on a -.Em "signal stack" , -specified with -.Xr sigstack 2 . -If +If .Fa ovec is non-zero, the previous handling information for the signal is returned to the user. .Pp -The following is a list of all signals -with names as in the include file -.Aq Pa signal.h : -.Bl -column SIGVTALARMXX "create core imagexxx" -.It Sy " NAME " " Default Action " " Description" -.It Dv SIGHUP No " terminate process" " terminal line hangup" -.It Dv SIGINT No " terminate process" " interrupt program" -.It Dv SIGQUIT No " create core image" " quit program" -.It Dv SIGILL No " create core image" " illegal instruction" -.It Dv SIGTRAP No " create core image" " trace trap" -.It Dv SIGABRT No " create core image" Xr abort 2 -call (formerly -.Dv SIGIOT ) -.It Dv SIGEMT No " create core image" " emulate instruction executed" -.It Dv SIGFPE No " create core image" " floating-point exception" -.It Dv SIGKILL No " terminate process" " kill program" -.It Dv SIGBUS No " create core image" " bus error" -.It Dv SIGSEGV No " create core image" " segmentation violation" -.It Dv SIGSYS No " create core image" " system call given invalid argument" -.It Dv SIGPIPE No " terminate process" " write on a pipe with no reader" -.It Dv SIGALRM No " terminate process" " real-time timer expired" -.It Dv SIGTERM No " terminate process" " software termination signal" -.It Dv SIGURG No " discard signal" " urgent condition present on socket" -.It Dv SIGSTOP No " stop process" " stop (cannot be caught or ignored)" -.It Dv SIGTSTP No " stop process" " stop signal generated from keyboard" -.It Dv SIGCONT No " discard signal" " continue after stop" -.It Dv SIGCHLD No " discard signal" " child status has changed" -.It Dv SIGTTIN No " stop process" " background read attempted from control terminal" -.It Dv SIGTTOU No " stop process" " background write attempted to control terminal" -.It Dv SIGIO No " discard signal" Tn " I/O" -is possible on a descriptor (see -.Xr fcntl 2 ) -.It Dv SIGXCPU No " terminate process" " cpu time limit exceeded (see" -.Xr setrlimit 2 ) -.It Dv SIGXFSZ No " terminate process" " file size limit exceeded (see" -.Xr setrlimit 2 ) -.It Dv SIGVTALRM No " terminate process" " virtual time alarm (see" -.Xr setitimer 2 ) -.It Dv SIGPROF No " terminate process" " profiling timer alarm (see" -.Xr setitimer 2 ) -.It Dv SIGWINCH No " discard signal" " Window size change" -.It Dv SIGINFO No " discard signal" " status request from keyboard" -.It Dv SIGUSR1 No " terminate process" " User defined signal 1" -.It Dv SIGUSR2 No " terminate process" " User defined signal 2" -.El -.Pp Once a signal handler is installed, it remains installed until another .Fn sigvec @@ -191,23 +146,45 @@ to .Dv SIG_DFL . The defaults are process termination, possibly with core dump; no action; stopping the process; or continuing the process. -See the above signal list for each signal's default action. +See the signal list below for each signal's default action. If .Fa sv_handler -is -.Dv SIG_IGN +is set to +.Dv SIG_IGN , +the default action for the signal is to discard the signal, +and if a signal is pending, +the pending signal is discarded even if the signal is masked. +If +.Fa sv_handler +is set to +.Dv SIG_IGN , current and pending instances of the signal are ignored and discarded. .Pp +Options may be specified by setting +.Em sv_flags . +If the +.Dv SV_ONSTACK +bit is set in +.Fa sv_flags , +the system will deliver the signal to the process on a +.Em "signal stack" , +specified with +.Xr sigstack 2 . +.Pp If a signal is caught during the system calls listed below, -the call is normally restarted. -The call can be forced to terminate prematurely with an -.Dv EINTR -error return by setting the +the call may be restarted, +the call may return with a data transfer shorter than requested, +or the call may forced to terminate +with the error +.Dv EINTR . +Interrupting of pending calls is requested +by setting the .Dv SV_INTERRUPT bit in -.Fa sv_flags . +.Ar sv_flags . The affected system calls include +.Xr open 2 , .Xr read 2 , .Xr write 2 , .Xr sendto 2 , @@ -229,7 +206,7 @@ After a or .Xr vfork 2 all signals, the signal mask, the signal stack, -and the restart/interrupt flags are inherited by the child. +and the interrupt/restart flags are inherited by the child. .Pp .Xr Execve 2 reinstates the default @@ -237,15 +214,61 @@ action for all signals which were caught and resets all signals to be caught on the user stack. Ignored signals remain ignored; the signal mask remains the same; -signals that interrupt system calls continue to do so. +signals that interrupt pending system calls continue to do so. +.Pp +The following is a list of all signals +with names as in the include file +.Aq Pa signal.h : +.Bl -column SIGVTALARMXX "create core imagexxx" +.It Sy " NAME " " Default Action " " Description" +.It Dv SIGHUP No " terminate process" " terminal line hangup" +.It Dv SIGINT No " terminate process" " interrupt program" +.It Dv SIGQUIT No " create core image" " quit program" +.It Dv SIGILL No " create core image" " illegal instruction" +.It Dv SIGTRAP No " create core image" " trace trap" +.It Dv SIGABRT No " create core image" Xr abort 2 +call (formerly +.Dv SIGIOT ) +.It Dv SIGEMT No " create core image" " emulate instruction executed" +.It Dv SIGFPE No " create core image" " floating-point exception" +.It Dv SIGKILL No " terminate process" " kill program (cannot be caught or ignored)" +.It Dv SIGBUS No " create core image" " bus error" +.It Dv SIGSEGV No " create core image" " segmentation violation" +.It Dv SIGSYS No " create core image" " system call given invalid argument" +.It Dv SIGPIPE No " terminate process" " write on a pipe with no reader" +.It Dv SIGALRM No " terminate process" " real-time timer expired" +.It Dv SIGTERM No " terminate process" " software termination signal" +.It Dv SIGURG No " discard signal" " urgent condition present on socket" +.It Dv SIGSTOP No " stop process" " stop (cannot be caught or ignored)" +.It Dv SIGTSTP No " stop process" " stop signal generated from keyboard" +.It Dv SIGCONT No " discard signal" " continue after stop" +.It Dv SIGCHLD No " discard signal" " child status has changed" +.It Dv SIGTTIN No " stop process" " background read attempted from control terminal" +.It Dv SIGTTOU No " stop process" " background write attempted to control terminal" +.It Dv SIGIO No " discard signal" Tn " I/O" +is possible on a descriptor (see +.Xr fcntl 2 ) +.It Dv SIGXCPU No " terminate process" " cpu time limit exceeded (see" +.Xr setrlimit 2 ) +.It Dv SIGXFSZ No " terminate process" " file size limit exceeded (see" +.Xr setrlimit 2 ) +.It Dv SIGVTALRM No " terminate process" " virtual time alarm (see" +.Xr setitimer 2 ) +.It Dv SIGPROF No " terminate process" " profiling timer alarm (see" +.Xr setitimer 2 ) +.It Dv SIGWINCH No " discard signal" " window size change" +.It Dv SIGINFO No " discard signal" " status request from keyboard" +.It Dv SIGUSR1 No " terminate process" " user-defined signal 1" +.It Dv SIGUSR2 No " terminate process" " user-defined signal 2" +.El .Sh NOTES -The mask specified in +The mask specified in .Fa vec is not allowed to block .Dv SIGKILL or .Dv SIGSTOP . -This is done silently by the system. +This is enforced silently by the system. .Pp The .Dv SV_INTERRUPT @@ -265,7 +288,7 @@ of the following occurs: .It Bq Er EFAULT Either .Fa vec -or +or .Fa ovec points to memory that is not a valid part of the process address space. @@ -278,50 +301,23 @@ An attempt is made to ignore or supply a handler for or .Dv SIGSTOP . .El +.Sh EXAMPLE +For an example of signal handler declerations, see +.Xr sigaction 2 . .Sh SEE ALSO -.Xr sigaction 2 , .Xr kill 1 , -.Xr ptrace 2 , .Xr kill 2 , -.Xr sigprocmask 2 , -.Xr sigsuspend 2 , +.Xr ptrace 2 , +.Xr setjmp 3 , +.Xr sigaction 2 , +.Xr sigaltstack 2 , .Xr sigblock 2 , -.Xr sigsetmask 2 , +.Xr siginterrupt 3 , .Xr sigpause 2 , +.Xr sigprocmask 2 , +.Xr sigsetmask 2 , +.Xr sigsetops 3 , .Xr sigstack 2 , +.Xr sigsuspend 2 , .Xr sigvec 2 , -.Xr sigsetops 3 , -.Xr setjmp 3 , -.Xr siginterrupt 3 , .Xr tty 4 -.Sh EXAMPLE -On the -.Tn VAX\-11 -The handler routine can be declared: -.Bd -literal -offset indent -void handler(sig, code, scp) -int sig, code; -struct sigcontext *scp; -.Ed -.Pp -Here -.Fa sig -is the signal number, into which the hardware faults and traps are -mapped as defined below. -.Fa Code -is a parameter that is either a constant -as given below or, for compatibility mode faults, the code provided by -the hardware (Compatibility mode faults are distinguished from the -other -.Dv SIGILL -traps by having -.Dv PSL_CM -set in the psl). -.Fa Scp -is a pointer to the -.Fa sigcontext -structure (defined in -.Aq Pa signal.h ) , -used to restore the context from before the signal. -.Sh BUGS -This manual page is still confusing. |