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 upon return from the signal handler, sigreturn() will be called.

       This sigreturn() call undoes everything that was done--changing the process's signal mask, switching stacks (see  sigalt-
       stack(2))--in  order  to  invoke the signal handler: it restores the process's signal mask, switches stacks, and restores
       the process's context (registers, processor 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 handlers.  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 3.25 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)