diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/libc/sys/sigaction.2 | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/lib/libc/sys/sigaction.2 b/lib/libc/sys/sigaction.2 index 64f534d..b9fe5ca 100644 --- a/lib/libc/sys/sigaction.2 +++ b/lib/libc/sys/sigaction.2 @@ -50,7 +50,7 @@ struct sigaction { .Sh DESCRIPTION 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 normally 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 @@ -68,7 +68,7 @@ of the process. This may be changed, on a per-handler basis, so that signals are taken on a special .Em "signal stack" . .Pp -Signal routines execute with the signal that caused their +Signal routines normally execute with the signal that caused their invocation .Em blocked , but other signals may yet occur. @@ -131,7 +131,7 @@ If is non-zero, the previous handling information for the signal is returned to the user. .Pp -Once a signal handler is installed, it remains installed +Once a signal handler is installed, it normally remains installed until another .Fn sigaction call is made, or an @@ -178,7 +178,16 @@ bit is set in the system will deliver the signal to the process on a .Em "signal stack" , specified with -.Xr sigstack 2 . +.Xr sigaltstack 2 . +If the +.Dv SA_NODEFER +bit is set, further occurrences of the delivered signal are not +masked during the execution of the handler. +If the +.Dv SA_RESETHAND +bit is set, the handler is reset back to +.Dv SIG_DFL +at the moment the signal is delivered. .Pp If a signal is caught during the system calls listed below, the call may be forced to terminate @@ -352,6 +361,11 @@ and Those signals are available on most .Tn BSD Ns \-derived systems. +The +.Dv SA_NODEFER +and +.Dv SA_RESETHAND +are intended for backwards compatability with other operating systems. .Sh SEE ALSO .Xr kill 1 , .Xr ptrace 2 , @@ -362,7 +376,7 @@ systems. .Xr sigblock 2 , .Xr sigsetmask 2 , .Xr sigpause 2 , -.Xr sigstack 2 , +.Xr sigaltstack 2 , .Xr sigvec 2 , .Xr setjmp 3 , .Xr siginterrupt 3 , |