linux/arch/openrisc
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
..
boot/dts openrisc: use new common dtc rule 2012-12-03 17:17:48 -06:00
configs openrisc: Refresh or1ksim_defconfig for v3.12 2013-11-15 10:37:32 +01:00
include all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
kernel all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
lib ARCH: drivers remove __dev* attributes. 2013-01-03 15:57:13 -08:00
mm vm: add VM_FAULT_SIGSEGV handling support 2015-01-29 10:51:32 -08:00
Kconfig openrisc: Convert handle_IRQ to use __handle_domain_irq 2014-09-03 13:10:19 +00:00
Makefile openrisc: Makefile: append "-D__linux__" to KBUILD_CFLAGS 2013-11-05 16:14:47 +01:00
README.openrisc OpenRISC: Miscellaneous 2011-07-22 18:46:41 +02:00
TODO.openrisc OpenRISC: Miscellaneous 2011-07-22 18:46:41 +02:00

README.openrisc

OpenRISC Linux
==============

This is a port of Linux to the OpenRISC class of microprocessors; the initial
target architecture, specifically, is the 32-bit OpenRISC 1000 family (or1k).

For information about OpenRISC processors and ongoing development:

	website		http://openrisc.net

For more information about Linux on OpenRISC, please contact South Pole AB.

	email:		info@southpole.se

	website:	http://southpole.se
			http://southpoleconsulting.com

---------------------------------------------------------------------

Build instructions for OpenRISC toolchain and Linux
===================================================

In order to build and run Linux for OpenRISC, you'll need at least a basic
toolchain and, perhaps, the architectural simulator.  Steps to get these bits
in place are outlined here.

1)  The toolchain can be obtained from openrisc.net.  Instructions for building
a toolchain can be found at:

http://openrisc.net/toolchain-build.html

2) or1ksim (optional)

or1ksim is the architectural simulator which will allow you to actually run
your OpenRISC Linux kernel if you don't have an OpenRISC processor at hand.

	git clone git://openrisc.net/jonas/or1ksim-svn

	cd or1ksim
	./configure --prefix=$OPENRISC_PREFIX
	make
	make install

3)  Linux kernel

Build the kernel as usual

	make ARCH=openrisc defconfig
	make ARCH=openrisc

4)  Run in architectural simulator

Grab the or1ksim platform configuration file (from the or1ksim source) and
together with your freshly built vmlinux, run your kernel with the following
incantation:

	sim -f arch/openrisc/or1ksim.cfg vmlinux

---------------------------------------------------------------------

Terminology
===========

In the code, the following particles are used on symbols to limit the scope
to more or less specific processor implementations:

openrisc: the OpenRISC class of processors
or1k:     the OpenRISC 1000 family of processors
or1200:   the OpenRISC 1200 processor

---------------------------------------------------------------------

History
========

18. 11. 2003	Matjaz Breskvar (phoenix@bsemi.com)
	initial port of linux to OpenRISC/or32 architecture.
        all the core stuff is implemented and seams usable.

08. 12. 2003	Matjaz Breskvar (phoenix@bsemi.com)
	complete change of TLB miss handling.
	rewrite of exceptions handling.
	fully functional sash-3.6 in default initrd.
	a much improved version with changes all around.

10. 04. 2004	Matjaz Breskvar (phoenix@bsemi.com)
	alot of bugfixes all over.
	ethernet support, functional http and telnet servers.
	running many standard linux apps.

26. 06. 2004	Matjaz Breskvar (phoenix@bsemi.com)
	port to 2.6.x

30. 11. 2004	Matjaz Breskvar (phoenix@bsemi.com)
	lots of bugfixes and enhancments.
	added opencores framebuffer driver.

09. 10. 2010    Jonas Bonn (jonas@southpole.se)
	major rewrite to bring up to par with upstream Linux 2.6.36