redhat man page for sigreturn

SIGRETURN(2)						     Linux Programmer's Manual						      SIGRETURN(2)

NAME
       sigreturn - return from signal handler and cleanup stack frame

SYNOPSIS
       int sigreturn(unsigned long __unused);

DESCRIPTION
       When  the  Linux  kernel creates the stack frame for a signal handler, a call to sigreturn is inserted into the stack frame so that the the
       signal handler will call sigreturn upon return. This inserted call to sigreturn cleans up the stack so that the process	can  restart  from
       where it was interrupted by the signal.

RETURN VALUE
       sigreturn never returns.

WARNING
       The  sigreturn call is used by the kernel to implement signal handlers. It should never be called directly. Better yet, the specific use of
       the __unused argument varies depending on the architecture.

CONFORMING TO
       sigreturn is specific to Linux and should not be used in programs intended to be portable.

FILES
       /usr/src/linux/arch/i386/kernel/signal.c
       /usr/src/linux/arch/alpha/kernel/entry.S

SEE ALSO
       kill(2), signal(2), signal(7)

Linux 1.3.20							    1995-08-21							      SIGRETURN(2)