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))\(emin 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
() 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.
This page is part of release 3.24 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/.
Copyright (C) 1995, Thomas K. Dyas <tdyaseden.rutgers.edu> Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. Created Sat Aug 21 1995 Thomas K. Dyas <tdyaseden.rutgers.edu> Modified Tue Oct 22 22:09:03 1996 by Eric S. Raymond <esrthyrsus.com> 2008-06-26, mtk, added some more detail on the work done by sigreturn() |