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 sigaltstack(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), restart_syscall(2), sigaltstack(2), signal(2), signal(7)

COLOPHON

       This  page  is  part  of  release 3.54 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                                              2013-07-30                                       SIGRETURN(2)