sigstack(2) [ultrix man page]

sigstack(2)							System Calls Manual						       sigstack(2)

Name
       sigstack - set or get signal stack context

Syntax
       #include <signal.h>

       struct sigstack {
       caddr_t	 ss_sp;
       int  ss_onstack;
       };

       sigstack(ss, oss)
       struct sigstack *ss, *oss;

Description
       The  system  call  allows users to define an alternate stack on which signals are to be processed.  If ss is nonzero, it specifies a signal
       stack on which to deliver signals and tells the system if the process is currently executing on that stack.  When a signal's  action  indi-
       cates  its handler should execute on the signal stack (specified with a call), the system checks to see if the process is currently execut-
       ing on that stack.  If the process is not currently executing on the signal stack, the system arranges a switch to the signal stack for the
       duration of the signal handler's execution.  If oss is nonzero, the current signal stack state is returned.

       Signal stacks are not grown'automatically, as is done for the normal stack.  If the stack overflows, unpredictable results may occur.

Return Values
       Upon successful completion, a value of zero (0) is returned.  Otherwise, a value of -1 is returned and errno is set to indicate the error.

Diagnostics
       The system call fails and the signal stack context remains unchanged, if one of the following occurs.

       [EFAULT]       Either ss or oss points to memory that is not a valid part of the process address space.

See Also
       sigvec(2), setjmp(3)

																       sigstack(2)

SIGSTACK(2)							System Calls Manual						       SIGSTACK(2)

NAME

       sigstack - set and/or get signal stack context

SYNOPSIS

       #include <signal.h>

       struct sigstack {
       caddr_t	 ss_sp;
       int  ss_onstack;
       };

       sigstack(ss, oss);
       struct sigstack *ss, *oss;

DESCRIPTION

       Sigstack allows users to define an alternate stack on which signals are to be processed.  If ss is non-zero, it specifies a signal stack on
       which to deliver signals and tells the system if the process is currently executing on that stack.  When a signal's  action  indicates  its
       handler	should execute on the signal stack (specified with a sigvec(2) call), the system checks to see if the process is currently execut-
       ing on that stack.  If the process is not currently executing on the signal stack, the system arranges a switch to the signal stack for the
       duration of the signal handler's execution.  If oss is non-zero, the current signal stack state is returned.

NOTES

       Signal stacks are not ``grown'' automatically, as is done for the normal stack.	If the stack overflows unpredictable results may occur.

RETURN VALUE

       Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS

       Sigstack will fail and the signal stack context will remain unchanged if one of the following occurs.

       [EFAULT]       Either ss or oss points to memory that is not a valid part of the process address space.

SEE ALSO

       sigvec(2), setjmp(3)

4.2 Berkeley Distribution					   June 30, 1985						       SIGSTACK(2)