osf1 man page for sigreturn

sigreturn(2)							System Calls Manual						      sigreturn(2)

NAME
       sigreturn - Returns from signal

SYNOPSIS
       #include <signal.h>
       int sigreturn(	   struct sigcontext *scp) ;

PARAMETERS
       Points  to a sigcontext structure whose members contain the processor state to be restored. The contents of the sigcontext structure should
       have been previously obtained by entry to a signal handler or by the setjmp() or sigsetjmp() function.

DESCRIPTION
       The sigreturn() function restores the processor state of the calling process from a sigcontext structure. The sigcontext structure contains
       the  state  of all application-visible registers as well as the signal mask. The specific members of the sigcontext structure depend on the
       machine architecture. Each machine-dependent structure member is defined in the signal.h include file.

       The sigreturn() function is used internally by the system software to restore the processor state on return from a signal handler and  from
       a longjmp() function, to restore the state saved by a previous setjmp() or sigsetjmp() function.

NOTES
       An application should only use sigreturn() with great caution.

RETURN VALUES
       Upon  successful  completion, the sigreturn() function does not return.	Otherwise, a value of -1 is returned and errno may be set to indi-
       cate the error.

ERRORS
       If the sigreturn() function fails, the process context remains unchanged and errno is set to one of the following values: The scp parameter
       points  to  memory  space  that is not a valid part of the process address space.  The sigcontext structure contains unsupported or illegal
       values.

RELATED INFORMATION
       Functions: setjmp(3), sigaction(2), sigvec(2) delim off

																      sigreturn(2)