freebsd kernel with SKQ
Go to file
Svatopluk Kraus d18f8e22ec Take into account race conditions in case of accessed or modified bit
emulation in fast path of data/prefetch abort common routine. Process
these bits only if related page table entries are consistent with
provided abort info. In case of inconsistency, do nothing and let
processor to signal new abort if still needed.

The mapping related to an abort may be a subject of change concurrently.
The situation is more evident on multicore machines. Mapping may be
removed on one core while being used on another one before TLB flush
happened. Memory swapping process may be an example. Or, two or more
aborts may be signaled for the same page on more cores concurrently.
While an abort on one core may cause a promotion of related mapping,
an abort on another core may be inconsistent then as related mapping
was promoted. A question is how much real the issue may be on single
core machine. However, it's better to play safe even for these machines.

This change may solve some "PT2MAP abort" panics reported rarely.
The revision of pmap_fault() was initiated thanks to stack backtrace
provided by Bob Prohaska (fbsd at www.zefox.net).

While here, INVARIANTS block was changed. The previous check had iffy
value as only one entry from many was checked from L2 page table.

Reviewed by:	mmel
MFC after:	3 weeks
2017-11-02 14:08:38 +00:00
bin DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
cddl DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
contrib DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
crypto Upgrade to OpenSSH 7.5p1. 2017-08-04 12:57:24 +00:00
etc bluetooth: Default to discoverable off 2017-11-01 18:58:54 +00:00
gnu build-tools: De-special-case the gcc tools build. 2017-10-31 19:02:05 +00:00
include libc: Do not refer to _DefaultRuneLocale in ctype inlines 2017-10-22 20:01:07 +00:00
kerberos5 DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
lib Disconnect libpathconv tests since they require external perl and do not work with kyua. 2017-10-31 19:52:30 +00:00
libexec DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
release Add option UNIFIED_OBJDIR, on by default, which moves the default build OBJDIR. 2017-11-01 21:22:05 +00:00
rescue DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
sbin Add -c to the usage statements. 2017-10-31 03:39:36 +00:00
secure DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
share Actually add the dtsec(4) man page to the build 2017-11-02 04:17:10 +00:00
sys Take into account race conditions in case of accessed or modified bit 2017-11-02 14:08:38 +00:00
targets Disconnect libpathconv tests since they require external perl and do not work with kyua. 2017-10-31 19:52:30 +00:00
tests DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
tools Remove artificial limit for -i. 2017-11-02 12:16:50 +00:00
usr.bin DIRDEPS_BUILD: Update dependencies. 2017-10-31 00:07:04 +00:00
usr.sbin Remove 'adding_user.7' 2017-11-01 01:22:33 +00:00
.arcconfig callsign isn't required anymore 2016-09-29 06:19:45 +00:00
.arclint
COPYRIGHT Bump copyright year. 2016-12-31 12:41:42 +00:00
LOCKS
MAINTAINERS Add asomers as a pjdfstest co-maintainer per the project status change 2017-06-28 09:25:15 +00:00
Makefile Add a 'make cleanuniverse'. 2017-11-01 21:22:10 +00:00
Makefile.inc1 native-xtools/xdev: Store these in a location including both MACHINE/TARGET. 2017-11-01 21:22:13 +00:00
Makefile.libcompat Add option UNIFIED_OBJDIR, on by default, which moves the default build OBJDIR. 2017-11-01 21:22:05 +00:00
ObsoleteFiles.inc Remove 'adding_user.7' 2017-11-01 01:22:33 +00:00
README Correct the URLs for both READMEs for tracking src 2017-10-29 20:29:31 +00:00
README.md Correct the URLs for both READMEs for tracking src 2017-10-29 20:29:31 +00:00
UPDATING Add option UNIFIED_OBJDIR, on by default, which moves the default build OBJDIR. 2017-11-01 21:22:05 +00:00

FreeBSD Source:

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. See build(7) and https://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. See build(7), config(8), and https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html for more information.

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 kernel configuration files reside in the sys/<arch>/conf sub-directory. GENERIC is the default configuration used in release builds. NOTES contains entries and documentation for all possible devices, not just those commonly used.

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.

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.

tests			Regression tests which can be run by Kyua.  See tests/README
				for additional information.

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:

https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/current-stable.html