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Konstantin Belousov 52f3c44efe Fix two issues with /dev/mem access on amd64, both causing kernel page
faults.

First, for accesses to direct map region should check for the limit by
which direct map is instantiated.

Second, for accesses to the kernel map, success returned from the
kernacc(9) does not guarantee that consequent attempt to read or write
to the checked address succeed, since other thread might invalidate
the address meantime.  Add a new thread private flag TDP_DEVMEMIO,
which instructs vm_fault() to return error when fault happens on the
MAP_ENTRY_NOFAULT entry, instead of panicing.  The trap handler would
then see a page fault from access, and recover in normal way, making
/dev/mem access safer.

Remove GIANT_REQUIRED from the amd64 memrw(), since it is not needed
and having Giant locked does not solve issues for amd64.

Note that at least the second issue exists on other architectures, and
requires similar patching for md code.

Reported and tested by:	clusteradm (gjb, sbruno)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2014-03-21 14:25:09 +00:00
bin sh: Don't overwrite old exit status if a PID is reused. 2014-03-20 22:38:13 +00:00
cddl MFV 263436-263438: 2014-03-21 01:32:25 +00:00
contrib - Update commit template to include 'Relnotes:' tag, to 2014-03-20 18:44:37 +00:00
crypto Update most userspace consumers of capability.h to use capsicum.h instead. 2014-03-16 11:04:44 +00:00
etc Add several ATF tests that deal with multiple fibs. They're described in 2014-03-20 20:39:41 +00:00
games Correct a typo in Malcolm MacDougall's name. 2014-02-15 22:15:24 +00:00
gnu Remove IPX support. 2014-03-14 02:58:48 +00:00
include Remove AppleTalk support. 2014-03-14 06:29:43 +00:00
kerberos5 Revert my commit in r261253; the real problem was tackled in r262209. 2014-02-20 20:53:29 +00:00
lib Update hwpmc to support core events for Atom Silvermont microarchitecture. 2014-03-20 20:51:08 +00:00
libexec Make bsd.test.mk the only public mk fragment for the building of tests. 2014-03-14 08:56:19 +00:00
release Remove IPX support. 2014-03-14 02:58:48 +00:00
rescue Remove IPX support. 2014-03-14 02:58:48 +00:00
sbin Add several ATF tests that deal with multiple fibs. They're described in 2014-03-20 20:39:41 +00:00
secure multiple: Remove 3rd clause from BSD license where approved by the 2014-03-14 03:07:51 +00:00
share cxgbe(4): man page updates. 2014-03-20 21:57:10 +00:00
sys Fix two issues with /dev/mem access on amd64, both causing kernel page 2014-03-21 14:25:09 +00:00
tests Add several ATF tests that deal with multiple fibs. They're described in 2014-03-20 20:39:41 +00:00
tools errx prepends the program name to the message; don't do it by hand. 2014-03-19 12:52:49 +00:00
usr.bin Mark multi_test as requiring /usr/share/dict/words. 2014-03-19 23:29:00 +00:00
usr.sbin Use 'cpuset_t' to represent the vcpus active in a virtual machine. 2014-03-20 18:15:37 +00:00
COPYRIGHT Bump copyright year. 2013-12-31 12:18:10 +00:00
LOCKS Explicitly require Security Officer's approval for kernel PRNG bits. 2013-09-17 14:19:05 +00:00
MAINTAINERS Since mlaier has been inactive for a long time, grab maintainership on pf. 2014-03-20 06:22:39 +00:00
Makefile Remove the armv6eb architecture as it is unused, and almost certainly 2013-09-22 07:30:17 +00:00
Makefile.inc1 Fix kern/187712: config(8) does not respect KERNCONFDIR. 2014-03-20 17:30:09 +00:00
ObsoleteFiles.inc Add more obsolete files 2014-03-16 20:31:05 +00:00
README
UPDATING Disable libwrap (TCP wrappers) support in rpcbind by default, introducing 2014-03-06 17:33:27 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
$FreeBSD$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel, the kernel-modules and the contents of /etc.  The ``world''
target should only be used in cases where the source tree has not
changed from the currently running version.  See:
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
for more information, including setting make(1) variables.

The ``buildkernel'' and ``installkernel'' targets build and install
the kernel and the modules (see below).  Please see the top of
the Makefile in this directory for more information on the
standard build targets and compile-time flags.

Building a kernel is a somewhat more involved process, documentation
for which can be found at:
   http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html
And in the config(8) man page.
Note: If you want to build and install the kernel with the
``buildkernel'' and ``installkernel'' targets, you might need to build
world before.  More information is available in the handbook.

The sample kernel configuration files reside in the sys/<arch>/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file NOTES contains entries and documentation for all possible
devices, not just those commonly used.  It is the successor of the ancient
LINT file, but in contrast to LINT, it is not buildable as a kernel but a
pure reference and documentation file.


Source Roadmap:
---------------
bin		System/user commands.

cddl		Various commands and libraries under the Common Development
		and Distribution License.

contrib		Packages contributed by 3rd parties.

crypto		Cryptography stuff (see crypto/README).

etc		Template files for /etc.

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

kerberos5	Kerberos5 (Heimdal) package.

lib		System libraries.

libexec		System daemons.

release		Release building Makefile & associated tools.

rescue		Build system for statically linked /rescue utilities.

sbin		System commands.

secure		Cryptographic libraries and commands.

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html