SIGRETURN(2)		   Linux Programmers 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  upon
       return from the signal handler, sigreturn() will be called.

       This sigreturn() call undoes everything that was donechanging the pro
       cesss signal mask, switching stacks (see sigaltstack(2))in  order  to
       invoke  the  signal  handler:  it  restores  the processs signal mask,
       switches stacks, and restores the processs context (registers, proces
       sor flags), so that the process directly resumes execution at the point
       where it was interrupted by the signal.

RETURN VALUE
       sigreturn() never returns.

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

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

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

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

COLOPHON
       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2008-06-26			  SIGRETURN(2)