Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 409 insertions, 0 deletions

diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst
new file mode 100644
index 000000000..15ea785b2
--- /dev/null
+++ b/Documentation/admin-guide/README.rst
@@ -0,0 +1,409 @@
+.. _readme:
+
+Linux kernel release 4.x <http://kernel.org/>
+=============================================
+
+These are the release notes for Linux version 4.  Read them carefully,
+as they tell you what this is all about, explain how to install the
+kernel, and what to do if something goes wrong.
+
+What is Linux?
+--------------
+
+  Linux is a clone of the operating system Unix, written from scratch by
+  Linus Torvalds with assistance from a loosely-knit team of hackers across
+  the Net. It aims towards POSIX and Single UNIX Specification compliance.
+
+  It has all the features you would expect in a modern fully-fledged Unix,
+  including true multitasking, virtual memory, shared libraries, demand
+  loading, shared copy-on-write executables, proper memory management,
+  and multistack networking including IPv4 and IPv6.
+
+  It is distributed under the GNU General Public License v2 - see the
+  accompanying COPYING file for more details.
+
+On what hardware does it run?
+-----------------------------
+
+  Although originally developed first for 32-bit x86-based PCs (386 or higher),
+  today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
+  UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
+  IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 Xtensa, and
+  ARC architectures.
+
+  Linux is easily portable to most general-purpose 32- or 64-bit architectures
+  as long as they have a paged memory management unit (PMMU) and a port of the
+  GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
+  also been ported to a number of architectures without a PMMU, although
+  functionality is then obviously somewhat limited.
+  Linux has also been ported to itself. You can now run the kernel as a
+  userspace application - this is called UserMode Linux (UML).
+
+Documentation
+-------------
+
+ - There is a lot of documentation available both in electronic form on
+   the Internet and in books, both Linux-specific and pertaining to
+   general UNIX questions.  I'd recommend looking into the documentation
+   subdirectories on any Linux FTP site for the LDP (Linux Documentation
+   Project) books.  This README is not meant to be documentation on the
+   system: there are much better sources available.
+
+ - There are various README files in the Documentation/ subdirectory:
+   these typically contain kernel-specific installation notes for some
+   drivers for example. See Documentation/00-INDEX for a list of what
+   is contained in each file.  Please read the
+   :ref:`Documentation/process/changes.rst <changes>` file, as it
+   contains information about the problems, which may result by upgrading
+   your kernel.
+
+Installing the kernel source
+----------------------------
+
+ - If you install the full sources, put the kernel tarball in a
+   directory where you have permissions (e.g. your home directory) and
+   unpack it::
+
+     xz -cd linux-4.X.tar.xz | tar xvf -
+
+   Replace "X" with the version number of the latest kernel.
+
+   Do NOT use the /usr/src/linux area! This area has a (usually
+   incomplete) set of kernel headers that are used by the library header
+   files.  They should match the library, and not get messed up by
+   whatever the kernel-du-jour happens to be.
+
+ - You can also upgrade between 4.x releases by patching.  Patches are
+   distributed in the xz format.  To install by patching, get all the
+   newer patch files, enter the top level directory of the kernel source
+   (linux-4.X) and execute::
+
+     xz -cd ../patch-4.x.xz | patch -p1
+
+   Replace "x" for all versions bigger than the version "X" of your current
+   source tree, **in_order**, and you should be ok.  You may want to remove
+   the backup files (some-file-name~ or some-file-name.orig), and make sure
+   that there are no failed patches (some-file-name# or some-file-name.rej).
+   If there are, either you or I have made a mistake.
+
+   Unlike patches for the 4.x kernels, patches for the 4.x.y kernels
+   (also known as the -stable kernels) are not incremental but instead apply
+   directly to the base 4.x kernel.  For example, if your base kernel is 4.0
+   and you want to apply the 4.0.3 patch, you must not first apply the 4.0.1
+   and 4.0.2 patches. Similarly, if you are running kernel version 4.0.2 and
+   want to jump to 4.0.3, you must first reverse the 4.0.2 patch (that is,
+   patch -R) **before** applying the 4.0.3 patch. You can read more on this in
+   :ref:`Documentation/process/applying-patches.rst <applying_patches>`.
+
+   Alternatively, the script patch-kernel can be used to automate this
+   process.  It determines the current kernel version and applies any
+   patches found::
+
+     linux/scripts/patch-kernel linux
+
+   The first argument in the command above is the location of the
+   kernel source.  Patches are applied from the current directory, but
+   an alternative directory can be specified as the second argument.
+
+ - Make sure you have no stale .o files and dependencies lying around::
+
+     cd linux
+     make mrproper
+
+   You should now have the sources correctly installed.
+
+Software requirements
+---------------------
+
+   Compiling and running the 4.x kernels requires up-to-date
+   versions of various software packages.  Consult
+   :ref:`Documentation/process/changes.rst <changes>` for the minimum version numbers
+   required and how to get updates for these packages.  Beware that using
+   excessively old versions of these packages can cause indirect
+   errors that are very difficult to track down, so don't assume that
+   you can just update packages when obvious problems arise during
+   build or operation.
+
+Build directory for the kernel
+------------------------------
+
+   When compiling the kernel, all output files will per default be
+   stored together with the kernel source code.
+   Using the option ``make O=output/dir`` allows you to specify an alternate
+   place for the output files (including .config).
+   Example::
+
+     kernel source code: /usr/src/linux-4.X
+     build directory:    /home/name/build/kernel
+
+   To configure and build the kernel, use::
+
+     cd /usr/src/linux-4.X
+     make O=/home/name/build/kernel menuconfig
+     make O=/home/name/build/kernel
+     sudo make O=/home/name/build/kernel modules_install install
+
+   Please note: If the ``O=output/dir`` option is used, then it must be
+   used for all invocations of make.
+
+Configuring the kernel
+----------------------
+
+   Do not skip this step even if you are only upgrading one minor
+   version.  New configuration options are added in each release, and
+   odd problems will turn up if the configuration files are not set up
+   as expected.  If you want to carry your existing configuration to a
+   new version with minimal work, use ``make oldconfig``, which will
+   only ask you for the answers to new questions.
+
+ - Alternative configuration commands are::
+
+     "make config"      Plain text interface.
+
+     "make menuconfig"  Text based color menus, radiolists & dialogs.
+
+     "make nconfig"     Enhanced text based color menus.
+
+     "make xconfig"     Qt based configuration tool.
+
+     "make gconfig"     GTK+ based configuration tool.
+
+     "make oldconfig"   Default all questions based on the contents of
+                        your existing ./.config file and asking about
+                        new config symbols.
+
+     "make olddefconfig"
+                        Like above, but sets new symbols to their default
+                        values without prompting.
+
+     "make defconfig"   Create a ./.config file by using the default
+                        symbol values from either arch/$ARCH/defconfig
+                        or arch/$ARCH/configs/${PLATFORM}_defconfig,
+                        depending on the architecture.
+
+     "make ${PLATFORM}_defconfig"
+                        Create a ./.config file by using the default
+                        symbol values from
+                        arch/$ARCH/configs/${PLATFORM}_defconfig.
+                        Use "make help" to get a list of all available
+                        platforms of your architecture.
+
+     "make allyesconfig"
+                        Create a ./.config file by setting symbol
+                        values to 'y' as much as possible.
+
+     "make allmodconfig"
+                        Create a ./.config file by setting symbol
+                        values to 'm' as much as possible.
+
+     "make allnoconfig" Create a ./.config file by setting symbol
+                        values to 'n' as much as possible.
+
+     "make randconfig"  Create a ./.config file by setting symbol
+                        values to random values.
+
+     "make localmodconfig" Create a config based on current config and
+                           loaded modules (lsmod). Disables any module
+                           option that is not needed for the loaded modules.
+
+                           To create a localmodconfig for another machine,
+                           store the lsmod of that machine into a file
+                           and pass it in as a LSMOD parameter.
+
+                   target$ lsmod > /tmp/mylsmod
+                   target$ scp /tmp/mylsmod host:/tmp
+
+                   host$ make LSMOD=/tmp/mylsmod localmodconfig
+
+                           The above also works when cross compiling.
+
+     "make localyesconfig" Similar to localmodconfig, except it will convert
+                           all module options to built in (=y) options.
+
+     "make kvmconfig"   Enable additional options for kvm guest kernel support.
+
+     "make xenconfig"   Enable additional options for xen dom0 guest kernel
+                        support.
+
+     "make tinyconfig"  Configure the tiniest possible kernel.
+
+   You can find more information on using the Linux kernel config tools
+   in Documentation/kbuild/kconfig.txt.
+
+ - NOTES on ``make config``:
+
+    - Having unnecessary drivers will make the kernel bigger, and can
+      under some circumstances lead to problems: probing for a
+      nonexistent controller card may confuse your other controllers.
+
+    - A kernel with math-emulation compiled in will still use the
+      coprocessor if one is present: the math emulation will just
+      never get used in that case.  The kernel will be slightly larger,
+      but will work on different machines regardless of whether they
+      have a math coprocessor or not.
+
+    - The "kernel hacking" configuration details usually result in a
+      bigger or slower kernel (or both), and can even make the kernel
+      less stable by configuring some routines to actively try to
+      break bad code to find kernel problems (kmalloc()).  Thus you
+      should probably answer 'n' to the questions for "development",
+      "experimental", or "debugging" features.
+
+Compiling the kernel
+--------------------
+
+ - Make sure you have at least gcc 3.2 available.
+   For more information, refer to :ref:`Documentation/process/changes.rst <changes>`.
+
+   Please note that you can still run a.out user programs with this kernel.
+
+ - Do a ``make`` to create a compressed kernel image. It is also
+   possible to do ``make install`` if you have lilo installed to suit the
+   kernel makefiles, but you may want to check your particular lilo setup first.
+
+   To do the actual install, you have to be root, but none of the normal
+   build should require that. Don't take the name of root in vain.
+
+ - If you configured any of the parts of the kernel as ``modules``, you
+   will also have to do ``make modules_install``.
+
+ - Verbose kernel compile/build output:
+
+   Normally, the kernel build system runs in a fairly quiet mode (but not
+   totally silent).  However, sometimes you or other kernel developers need
+   to see compile, link, or other commands exactly as they are executed.
+   For this, use "verbose" build mode.  This is done by passing
+   ``V=1`` to the ``make`` command, e.g.::
+
+     make V=1 all
+
+   To have the build system also tell the reason for the rebuild of each
+   target, use ``V=2``.  The default is ``V=0``.
+
+ - Keep a backup kernel handy in case something goes wrong.  This is
+   especially true for the development releases, since each new release
+   contains new code which has not been debugged.  Make sure you keep a
+   backup of the modules corresponding to that kernel, as well.  If you
+   are installing a new kernel with the same version number as your
+   working kernel, make a backup of your modules directory before you
+   do a ``make modules_install``.
+
+   Alternatively, before compiling, use the kernel config option
+   "LOCALVERSION" to append a unique suffix to the regular kernel version.
+   LOCALVERSION can be set in the "General Setup" menu.
+
+ - In order to boot your new kernel, you'll need to copy the kernel
+   image (e.g. .../linux/arch/x86/boot/bzImage after compilation)
+   to the place where your regular bootable kernel is found.
+
+ - Booting a kernel directly from a floppy without the assistance of a
+   bootloader such as LILO, is no longer supported.
+
+   If you boot Linux from the hard drive, chances are you use LILO, which
+   uses the kernel image as specified in the file /etc/lilo.conf.  The
+   kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
+   /boot/bzImage.  To use the new kernel, save a copy of the old image
+   and copy the new image over the old one.  Then, you MUST RERUN LILO
+   to update the loading map! If you don't, you won't be able to boot
+   the new kernel image.
+
+   Reinstalling LILO is usually a matter of running /sbin/lilo.
+   You may wish to edit /etc/lilo.conf to specify an entry for your
+   old kernel image (say, /vmlinux.old) in case the new one does not
+   work.  See the LILO docs for more information.
+
+   After reinstalling LILO, you should be all set.  Shutdown the system,
+   reboot, and enjoy!
+
+   If you ever need to change the default root device, video mode,
+   ramdisk size, etc.  in the kernel image, use the ``rdev`` program (or
+   alternatively the LILO boot options when appropriate).  No need to
+   recompile the kernel to change these parameters.
+
+ - Reboot with the new kernel and enjoy.
+
+If something goes wrong
+-----------------------
+
+ - If you have problems that seem to be due to kernel bugs, please check
+   the file MAINTAINERS to see if there is a particular person associated
+   with the part of the kernel that you are having trouble with. If there
+   isn't anyone listed there, then the second best thing is to mail
+   them to me (torvalds@linux-foundation.org), and possibly to any other
+   relevant mailing-list or to the newsgroup.
+
+ - In all bug-reports, *please* tell what kernel you are talking about,
+   how to duplicate the problem, and what your setup is (use your common
+   sense).  If the problem is new, tell me so, and if the problem is
+   old, please try to tell me when you first noticed it.
+
+ - If the bug results in a message like::
+
+     unable to handle kernel paging request at address C0000010
+     Oops: 0002
+     EIP:   0010:XXXXXXXX
+     eax: xxxxxxxx   ebx: xxxxxxxx   ecx: xxxxxxxx   edx: xxxxxxxx
+     esi: xxxxxxxx   edi: xxxxxxxx   ebp: xxxxxxxx
+     ds: xxxx  es: xxxx  fs: xxxx  gs: xxxx
+     Pid: xx, process nr: xx
+     xx xx xx xx xx xx xx xx xx xx
+
+   or similar kernel debugging information on your screen or in your
+   system log, please duplicate it *exactly*.  The dump may look
+   incomprehensible to you, but it does contain information that may
+   help debugging the problem.  The text above the dump is also
+   important: it tells something about why the kernel dumped code (in
+   the above example, it's due to a bad kernel pointer). More information
+   on making sense of the dump is in Documentation/admin-guide/bug-hunting.rst
+
+ - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
+   as is, otherwise you will have to use the ``ksymoops`` program to make
+   sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred).
+   This utility can be downloaded from
+   https://www.kernel.org/pub/linux/utils/kernel/ksymoops/ .
+   Alternatively, you can do the dump lookup by hand:
+
+ - In debugging dumps like the above, it helps enormously if you can
+   look up what the EIP value means.  The hex value as such doesn't help
+   me or anybody else very much: it will depend on your particular
+   kernel setup.  What you should do is take the hex value from the EIP
+   line (ignore the ``0010:``), and look it up in the kernel namelist to
+   see which kernel function contains the offending address.
+
+   To find out the kernel function name, you'll need to find the system
+   binary associated with the kernel that exhibited the symptom.  This is
+   the file 'linux/vmlinux'.  To extract the namelist and match it against
+   the EIP from the kernel crash, do::
+
+     nm vmlinux | sort | less
+
+   This will give you a list of kernel addresses sorted in ascending
+   order, from which it is simple to find the function that contains the
+   offending address.  Note that the address given by the kernel
+   debugging messages will not necessarily match exactly with the
+   function addresses (in fact, that is very unlikely), so you can't
+   just 'grep' the list: the list will, however, give you the starting
+   point of each kernel function, so by looking for the function that
+   has a starting address lower than the one you are searching for but
+   is followed by a function with a higher address you will find the one
+   you want.  In fact, it may be a good idea to include a bit of
+   "context" in your problem report, giving a few lines around the
+   interesting one.
+
+   If you for some reason cannot do the above (you have a pre-compiled
+   kernel image or similar), telling me as much about your setup as
+   possible will help.  Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>`
+   document for details.
+
+ - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
+   cannot change values or set break points.) To do this, first compile the
+   kernel with -g; edit arch/x86/Makefile appropriately, then do a ``make
+   clean``. You'll also need to enable CONFIG_PROC_FS (via ``make config``).
+
+   After you've rebooted with the new kernel, do ``gdb vmlinux /proc/kcore``.
+   You can now use all the usual gdb commands. The command to look up the
+   point where your system crashed is ``l *0xXXXXXXXX``. (Replace the XXXes
+   with the EIP value.)
+
+   gdb'ing a non-running kernel currently fails because ``gdb`` (wrongly)
+   disregards the starting offset for which the kernel is compiled.