NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | FILES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON
SIGRETURN(2) Linux Programmer's Manual SIGRETURN(2)
sigreturn - return from signal handler and cleanup stack frame
int sigreturn(unsigned long __unused);
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.
sigreturn() never returns.
/usr/src/linux/arch/i386/kernel/signal.c
/usr/src/linux/arch/alpha/kernel/entry.S
sigreturn() is specific to Linux and should not be used in programs intended
to be portable.
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.
kill(2), sigaltstack(2), signal(2), signal(7)
This page is part of release 3.21 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)