docs: admin-guide: add kdump documentation into it

The Kdump documentation describes procedures with admins use
in order to solve issues on their systems.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

4 files changed, 0 insertions, 1307 deletions

diff --git a/Documentation/kdump/gdbmacros.txt b/Documentation/kdump/gdbmacros.txt
deleted file mode 100644
index 220d0a80ca2c..000000000000
--- a/Documentation/kdump/gdbmacros.txt
+++ /dev/null
@@ -1,264 +0,0 @@
-#
-# This file contains a few gdb macros (user defined commands) to extract
-# useful information from kernel crashdump (kdump) like stack traces of
-# all the processes or a particular process and trapinfo.
-#
-# These macros can be used by copying this file in .gdbinit (put in home
-# directory or current directory) or by invoking gdb command with
-# --command=<command-file-name> option
-#
-# Credits:
-# Alexander Nyberg <alexn@telia.com>
-# V Srivatsa <vatsa@in.ibm.com>
-# Maneesh Soni <maneesh@in.ibm.com>
-#
-
-define bttnobp
-	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
-	set $pid_off=((size_t)&((struct task_struct *)0)->thread_group.next)
-	set $init_t=&init_task
-	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
-	set var $stacksize = sizeof(union thread_union)
-	while ($next_t != $init_t)
-		set $next_t=(struct task_struct *)$next_t
-		printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
-		printf "===================\n"
-		set var $stackp = $next_t.thread.sp
-		set var $stack_top = ($stackp & ~($stacksize - 1)) + $stacksize
-
-		while ($stackp < $stack_top)
-			if (*($stackp) > _stext && *($stackp) < _sinittext)
-				info symbol *($stackp)
-			end
-			set $stackp += 4
-		end
-		set $next_th=(((char *)$next_t->thread_group.next) - $pid_off)
-		while ($next_th != $next_t)
-			set $next_th=(struct task_struct *)$next_th
-			printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
-			printf "===================\n"
-			set var $stackp = $next_t.thread.sp
-			set var $stack_top = ($stackp & ~($stacksize - 1)) + stacksize
-
-			while ($stackp < $stack_top)
-				if (*($stackp) > _stext && *($stackp) < _sinittext)
-					info symbol *($stackp)
-				end
-				set $stackp += 4
-			end
-			set $next_th=(((char *)$next_th->thread_group.next) - $pid_off)
-		end
-		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
-	end
-end
-document bttnobp
-	dump all thread stack traces on a kernel compiled with !CONFIG_FRAME_POINTER
-end
-
-define btthreadstack
-	set var $pid_task = $arg0
-
-	printf "\npid %d; comm %s:\n", $pid_task.pid, $pid_task.comm
-	printf "task struct: "
-	print $pid_task
-	printf "===================\n"
-	set var $stackp = $pid_task.thread.sp
-	set var $stacksize = sizeof(union thread_union)
-	set var $stack_top = ($stackp & ~($stacksize - 1)) + $stacksize
-	set var $stack_bot = ($stackp & ~($stacksize - 1))
-
-	set $stackp = *((unsigned long *) $stackp)
-	while (($stackp < $stack_top) && ($stackp > $stack_bot))
-		set var $addr = *(((unsigned long *) $stackp) + 1)
-		info symbol $addr
-		set $stackp = *((unsigned long *) $stackp)
-	end
-end
-document btthreadstack
-	 dump a thread stack using the given task structure pointer
-end
-
-
-define btt
-	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
-	set $pid_off=((size_t)&((struct task_struct *)0)->thread_group.next)
-	set $init_t=&init_task
-	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
-	while ($next_t != $init_t)
-		set $next_t=(struct task_struct *)$next_t
-		btthreadstack $next_t
-
-		set $next_th=(((char *)$next_t->thread_group.next) - $pid_off)
-		while ($next_th != $next_t)
-			set $next_th=(struct task_struct *)$next_th
-			btthreadstack $next_th
-			set $next_th=(((char *)$next_th->thread_group.next) - $pid_off)
-		end
-		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
-	end
-end
-document btt
-	dump all thread stack traces on a kernel compiled with CONFIG_FRAME_POINTER
-end
-
-define btpid
-	set var $pid = $arg0
-	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
-	set $pid_off=((size_t)&((struct task_struct *)0)->thread_group.next)
-	set $init_t=&init_task
-	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
-	set var $pid_task = 0
-
-	while ($next_t != $init_t)
-		set $next_t=(struct task_struct *)$next_t
-
-		if ($next_t.pid == $pid)
-			set $pid_task = $next_t
-		end
-
-		set $next_th=(((char *)$next_t->thread_group.next) - $pid_off)
-		while ($next_th != $next_t)
-			set $next_th=(struct task_struct *)$next_th
-			if ($next_th.pid == $pid)
-				set $pid_task = $next_th
-			end
-			set $next_th=(((char *)$next_th->thread_group.next) - $pid_off)
-		end
-		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
-	end
-
-	btthreadstack $pid_task
-end
-document btpid
-	backtrace of pid
-end
-
-
-define trapinfo
-	set var $pid = $arg0
-	set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
-	set $pid_off=((size_t)&((struct task_struct *)0)->thread_group.next)
-	set $init_t=&init_task
-	set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
-	set var $pid_task = 0
-
-	while ($next_t != $init_t)
-		set $next_t=(struct task_struct *)$next_t
-
-		if ($next_t.pid == $pid)
-			set $pid_task = $next_t
-		end
-
-		set $next_th=(((char *)$next_t->thread_group.next) - $pid_off)
-		while ($next_th != $next_t)
-			set $next_th=(struct task_struct *)$next_th
-			if ($next_th.pid == $pid)
-				set $pid_task = $next_th
-			end
-			set $next_th=(((char *)$next_th->thread_group.next) - $pid_off)
-		end
-		set $next_t=(char *)($next_t->tasks.next) - $tasks_off
-	end
-
-	printf "Trapno %ld, cr2 0x%lx, error_code %ld\n", $pid_task.thread.trap_no, \
-				$pid_task.thread.cr2, $pid_task.thread.error_code
-
-end
-document trapinfo
-	Run info threads and lookup pid of thread #1
-	'trapinfo <pid>' will tell you by which trap & possibly
-	address the kernel panicked.
-end
-
-define dump_log_idx
-	set $idx = $arg0
-	if ($argc > 1)
-		set $prev_flags = $arg1
-	else
-		set $prev_flags = 0
-	end
-	set $msg = ((struct printk_log *) (log_buf + $idx))
-	set $prefix = 1
-	set $newline = 1
-	set $log = log_buf + $idx + sizeof(*$msg)
-
-	# prev & LOG_CONT && !(msg->flags & LOG_PREIX)
-	if (($prev_flags & 8) && !($msg->flags & 4))
-		set $prefix = 0
-	end
-
-	# msg->flags & LOG_CONT
-	if ($msg->flags & 8)
-		# (prev & LOG_CONT && !(prev & LOG_NEWLINE))
-		if (($prev_flags & 8) && !($prev_flags & 2))
-			set $prefix = 0
-		end
-		# (!(msg->flags & LOG_NEWLINE))
-		if (!($msg->flags & 2))
-			set $newline = 0
-		end
-	end
-
-	if ($prefix)
-		printf "[%5lu.%06lu] ", $msg->ts_nsec / 1000000000, $msg->ts_nsec % 1000000000
-	end
-	if ($msg->text_len != 0)
-		eval "printf \"%%%d.%ds\", $log", $msg->text_len, $msg->text_len
-	end
-	if ($newline)
-		printf "\n"
-	end
-	if ($msg->dict_len > 0)
-		set $dict = $log + $msg->text_len
-		set $idx = 0
-		set $line = 1
-		while ($idx < $msg->dict_len)
-			if ($line)
-				printf " "
-				set $line = 0
-			end
-			set $c = $dict[$idx]
-			if ($c == '\0')
-				printf "\n"
-				set $line = 1
-			else
-				if ($c < ' ' || $c >= 127 || $c == '\\')
-					printf "\\x%02x", $c
-				else
-					printf "%c", $c
-				end
-			end
-			set $idx = $idx + 1
-		end
-		printf "\n"
-	end
-end
-document dump_log_idx
-	Dump a single log given its index in the log buffer.  The first
-	parameter is the index into log_buf, the second is optional and
-	specified the previous log buffer's flags, used for properly
-	formatting continued lines.
-end
-
-define dmesg
-	set $i = log_first_idx
-	set $end_idx = log_first_idx
-	set $prev_flags = 0
-
-	while (1)
-		set $msg = ((struct printk_log *) (log_buf + $i))
-		if ($msg->len == 0)
-			set $i = 0
-		else
-			dump_log_idx $i $prev_flags
-			set $i = $i + $msg->len
-			set $prev_flags = $msg->flags
-		end
-		if ($i == $end_idx)
-			loop_break
-		end
-	end
-end
-document dmesg
-	print the kernel ring buffer
-end
diff --git a/Documentation/kdump/index.rst b/Documentation/kdump/index.rst
deleted file mode 100644
index 2b17fcf6867a..000000000000
--- a/Documentation/kdump/index.rst
+++ /dev/null
@@ -1,21 +0,0 @@
-:orphan:
-
-================================================================
-Documentation for Kdump - The kexec-based Crash Dumping Solution
-================================================================
-
-This document includes overview, setup and installation, and analysis
-information.
-
-.. toctree::
-    :maxdepth: 1
-
-    kdump
-    vmcoreinfo
-
-.. only::  subproject and html
-
-   Indices
-   =======
-
-   * :ref:`genindex`
diff --git a/Documentation/kdump/kdump.rst b/Documentation/kdump/kdump.rst
deleted file mode 100644
index ac7e131d2935..000000000000
--- a/Documentation/kdump/kdump.rst
+++ /dev/null
@@ -1,534 +0,0 @@
-================================================================
-Documentation for Kdump - The kexec-based Crash Dumping Solution
-================================================================
-
-This document includes overview, setup and installation, and analysis
-information.
-
-Overview
-========
-
-Kdump uses kexec to quickly boot to a dump-capture kernel whenever a
-dump of the system kernel's memory needs to be taken (for example, when
-the system panics). The system kernel's memory image is preserved across
-the reboot and is accessible to the dump-capture kernel.
-
-You can use common commands, such as cp and scp, to copy the
-memory image to a dump file on the local disk, or across the network to
-a remote system.
-
-Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64,
-s390x, arm and arm64 architectures.
-
-When the system kernel boots, it reserves a small section of memory for
-the dump-capture kernel. This ensures that ongoing Direct Memory Access
-(DMA) from the system kernel does not corrupt the dump-capture kernel.
-The kexec -p command loads the dump-capture kernel into this reserved
-memory.
-
-On x86 machines, the first 640 KB of physical memory is needed to boot,
-regardless of where the kernel loads. Therefore, kexec backs up this
-region just before rebooting into the dump-capture kernel.
-
-Similarly on PPC64 machines first 32KB of physical memory is needed for
-booting regardless of where the kernel is loaded and to support 64K page
-size kexec backs up the first 64KB memory.
-
-For s390x, when kdump is triggered, the crashkernel region is exchanged
-with the region [0, crashkernel region size] and then the kdump kernel
-runs in [0, crashkernel region size]. Therefore no relocatable kernel is
-needed for s390x.
-
-All of the necessary information about the system kernel's core image is
-encoded in the ELF format, and stored in a reserved area of memory
-before a crash. The physical address of the start of the ELF header is
-passed to the dump-capture kernel through the elfcorehdr= boot
-parameter. Optionally the size of the ELF header can also be passed
-when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax.
-
-
-With the dump-capture kernel, you can access the memory image through
-/proc/vmcore. This exports the dump as an ELF-format file that you can
-write out using file copy commands such as cp or scp. Further, you can
-use analysis tools such as the GNU Debugger (GDB) and the Crash tool to
-debug the dump file. This method ensures that the dump pages are correctly
-ordered.
-
-
-Setup and Installation
-======================
-
-Install kexec-tools
--------------------
-
-1) Login as the root user.
-
-2) Download the kexec-tools user-space package from the following URL:
-
-http://kernel.org/pub/linux/utils/kernel/kexec/kexec-tools.tar.gz
-
-This is a symlink to the latest version.
-
-The latest kexec-tools git tree is available at:
-
-- git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
-- http://www.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
-
-There is also a gitweb interface available at
-http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git
-
-More information about kexec-tools can be found at
-http://horms.net/projects/kexec/
-
-3) Unpack the tarball with the tar command, as follows::
-
-	tar xvpzf kexec-tools.tar.gz
-
-4) Change to the kexec-tools directory, as follows::
-
-	cd kexec-tools-VERSION
-
-5) Configure the package, as follows::
-
-	./configure
-
-6) Compile the package, as follows::
-
-	make
-
-7) Install the package, as follows::
-
-	make install
-
-
-Build the system and dump-capture kernels
------------------------------------------
-There are two possible methods of using Kdump.
-
-1) Build a separate custom dump-capture kernel for capturing the
-   kernel core dump.
-
-2) Or use the system kernel binary itself as dump-capture kernel and there is
-   no need to build a separate dump-capture kernel. This is possible
-   only with the architectures which support a relocatable kernel. As
-   of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support
-   relocatable kernel.
-
-Building a relocatable kernel is advantageous from the point of view that
-one does not have to build a second kernel for capturing the dump. But
-at the same time one might want to build a custom dump capture kernel
-suitable to his needs.
-
-Following are the configuration setting required for system and
-dump-capture kernels for enabling kdump support.
-
-System kernel config options
-----------------------------
-
-1) Enable "kexec system call" in "Processor type and features."::
-
-	CONFIG_KEXEC=y
-
-2) Enable "sysfs file system support" in "Filesystem" -> "Pseudo
-   filesystems." This is usually enabled by default::
-
-	CONFIG_SYSFS=y
-
-   Note that "sysfs file system support" might not appear in the "Pseudo
-   filesystems" menu if "Configure standard kernel features (for small
-   systems)" is not enabled in "General Setup." In this case, check the
-   .config file itself to ensure that sysfs is turned on, as follows::
-
-	grep 'CONFIG_SYSFS' .config
-
-3) Enable "Compile the kernel with debug info" in "Kernel hacking."::
-
-	CONFIG_DEBUG_INFO=Y
-
-   This causes the kernel to be built with debug symbols. The dump
-   analysis tools require a vmlinux with debug symbols in order to read
-   and analyze a dump file.
-
-Dump-capture kernel config options (Arch Independent)
------------------------------------------------------
-
-1) Enable "kernel crash dumps" support under "Processor type and
-   features"::
-
-	CONFIG_CRASH_DUMP=y
-
-2) Enable "/proc/vmcore support" under "Filesystems" -> "Pseudo filesystems"::
-
-	CONFIG_PROC_VMCORE=y
-
-   (CONFIG_PROC_VMCORE is set by default when CONFIG_CRASH_DUMP is selected.)
-
-Dump-capture kernel config options (Arch Dependent, i386 and x86_64)
---------------------------------------------------------------------
-
-1) On i386, enable high memory support under "Processor type and
-   features"::
-
-	CONFIG_HIGHMEM64G=y
-
-   or::
-
-	CONFIG_HIGHMEM4G
-
-2) On i386 and x86_64, disable symmetric multi-processing support
-   under "Processor type and features"::
-
-	CONFIG_SMP=n
-
-   (If CONFIG_SMP=y, then specify maxcpus=1 on the kernel command line
-   when loading the dump-capture kernel, see section "Load the Dump-capture
-   Kernel".)
-
-3) If one wants to build and use a relocatable kernel,
-   Enable "Build a relocatable kernel" support under "Processor type and
-   features"::
-
-	CONFIG_RELOCATABLE=y
-
-4) Use a suitable value for "Physical address where the kernel is
-   loaded" (under "Processor type and features"). This only appears when
-   "kernel crash dumps" is enabled. A suitable value depends upon
-   whether kernel is relocatable or not.
-
-   If you are using a relocatable kernel use CONFIG_PHYSICAL_START=0x100000
-   This will compile the kernel for physical address 1MB, but given the fact
-   kernel is relocatable, it can be run from any physical address hence
-   kexec boot loader will load it in memory region reserved for dump-capture
-   kernel.
-
-   Otherwise it should be the start of memory region reserved for
-   second kernel using boot parameter "crashkernel=Y@X". Here X is
-   start of memory region reserved for dump-capture kernel.
-   Generally X is 16MB (0x1000000). So you can set
-   CONFIG_PHYSICAL_START=0x1000000
-
-5) Make and install the kernel and its modules. DO NOT add this kernel
-   to the boot loader configuration files.
-
-Dump-capture kernel config options (Arch Dependent, ppc64)
-----------------------------------------------------------
-
-1) Enable "Build a kdump crash kernel" support under "Kernel" options::
-
-	CONFIG_CRASH_DUMP=y
-
-2)   Enable "Build a relocatable kernel" support::
-
-	CONFIG_RELOCATABLE=y
-
-   Make and install the kernel and its modules.
-
-Dump-capture kernel config options (Arch Dependent, ia64)
-----------------------------------------------------------
-
-- No specific options are required to create a dump-capture kernel
-  for ia64, other than those specified in the arch independent section
-  above. This means that it is possible to use the system kernel
-  as a dump-capture kernel if desired.
-
-  The crashkernel region can be automatically placed by the system
-  kernel at run time. This is done by specifying the base address as 0,
-  or omitting it all together::
-
-	crashkernel=256M@0
-
-  or::
-
-	crashkernel=256M
-
-  If the start address is specified, note that the start address of the
-  kernel will be aligned to 64Mb, so if the start address is not then
-  any space below the alignment point will be wasted.
-
-Dump-capture kernel config options (Arch Dependent, arm)
-----------------------------------------------------------
-
--   To use a relocatable kernel,
-    Enable "AUTO_ZRELADDR" support under "Boot" options::
-
-	AUTO_ZRELADDR=y
-
-Dump-capture kernel config options (Arch Dependent, arm64)
-----------------------------------------------------------
-
-- Please note that kvm of the dump-capture kernel will not be enabled
-  on non-VHE systems even if it is configured. This is because the CPU
-  will not be reset to EL2 on panic.
-
-Extended crashkernel syntax
-===========================
-
-While the "crashkernel=size[@offset]" syntax is sufficient for most
-configurations, sometimes it's handy to have the reserved memory dependent
-on the value of System RAM -- that's mostly for distributors that pre-setup
-the kernel command line to avoid a unbootable system after some memory has
-been removed from the machine.
-
-The syntax is::
-
-    crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
-    range=start-[end]
-
-For example::
-
-    crashkernel=512M-2G:64M,2G-:128M
-
-This would mean:
-
-    1) if the RAM is smaller than 512M, then don't reserve anything
-       (this is the "rescue" case)
-    2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M
-    3) if the RAM size is larger than 2G, then reserve 128M
-
-
-
-Boot into System Kernel
-=======================
-
-1) Update the boot loader (such as grub, yaboot, or lilo) configuration
-   files as necessary.
-
-2) Boot the system kernel with the boot parameter "crashkernel=Y@X",
-   where Y specifies how much memory to reserve for the dump-capture kernel
-   and X specifies the beginning of this reserved memory. For example,
-   "crashkernel=64M@16M" tells the system kernel to reserve 64 MB of memory
-   starting at physical address 0x01000000 (16MB) for the dump-capture kernel.
-
-   On x86 and x86_64, use "crashkernel=64M@16M".
-
-   On ppc64, use "crashkernel=128M@32M".
-
-   On ia64, 256M@256M is a generous value that typically works.
-   The region may be automatically placed on ia64, see the
-   dump-capture kernel config option notes above.
-   If use sparse memory, the size should be rounded to GRANULE boundaries.
-
-   On s390x, typically use "crashkernel=xxM". The value of xx is dependent
-   on the memory consumption of the kdump system. In general this is not
-   dependent on the memory size of the production system.
-
-   On arm, the use of "crashkernel=Y@X" is no longer necessary; the
-   kernel will automatically locate the crash kernel image within the
-   first 512MB of RAM if X is not given.
-
-   On arm64, use "crashkernel=Y[@X]".  Note that the start address of
-   the kernel, X if explicitly specified, must be aligned to 2MiB (0x200000).
-
-Load the Dump-capture Kernel
-============================
-
-After booting to the system kernel, dump-capture kernel needs to be
-loaded.
-
-Based on the architecture and type of image (relocatable or not), one
-can choose to load the uncompressed vmlinux or compressed bzImage/vmlinuz
-of dump-capture kernel. Following is the summary.
-
-For i386 and x86_64:
-
-	- Use vmlinux if kernel is not relocatable.
-	- Use bzImage/vmlinuz if kernel is relocatable.
-
-For ppc64:
-
-	- Use vmlinux
-
-For ia64:
-
-	- Use vmlinux or vmlinuz.gz
-
-For s390x:
-
-	- Use image or bzImage
-
-For arm:
-
-	- Use zImage
-
-For arm64:
-
-	- Use vmlinux or Image
-
-If you are using an uncompressed vmlinux image then use following command
-to load dump-capture kernel::
-
-   kexec -p <dump-capture-kernel-vmlinux-image> \
-   --initrd=<initrd-for-dump-capture-kernel> --args-linux \
-   --append="root=<root-dev> <arch-specific-options>"
-
-If you are using a compressed bzImage/vmlinuz, then use following command
-to load dump-capture kernel::
-
-   kexec -p <dump-capture-kernel-bzImage> \
-   --initrd=<initrd-for-dump-capture-kernel> \
-   --append="root=<root-dev> <arch-specific-options>"
-
-If you are using a compressed zImage, then use following command
-to load dump-capture kernel::
-
-   kexec --type zImage -p <dump-capture-kernel-bzImage> \
-   --initrd=<initrd-for-dump-capture-kernel> \
-   --dtb=<dtb-for-dump-capture-kernel> \
-   --append="root=<root-dev> <arch-specific-options>"
-
-If you are using an uncompressed Image, then use following command
-to load dump-capture kernel::
-
-   kexec -p <dump-capture-kernel-Image> \
-   --initrd=<initrd-for-dump-capture-kernel> \
-   --append="root=<root-dev> <arch-specific-options>"
-
-Please note, that --args-linux does not need to be specified for ia64.
-It is planned to make this a no-op on that architecture, but for now
-it should be omitted
-
-Following are the arch specific command line options to be used while
-loading dump-capture kernel.
-
-For i386, x86_64 and ia64:
-
-	"1 irqpoll maxcpus=1 reset_devices"
-
-For ppc64:
-
-	"1 maxcpus=1 noirqdistrib reset_devices"
-
-For s390x:
-
-	"1 maxcpus=1 cgroup_disable=memory"
-
-For arm:
-
-	"1 maxcpus=1 reset_devices"
-
-For arm64:
-
-	"1 maxcpus=1 reset_devices"
-
-Notes on loading the dump-capture kernel:
-
-* By default, the ELF headers are stored in ELF64 format to support
-  systems with more than 4GB memory. On i386, kexec automatically checks if
-  the physical RAM size exceeds the 4 GB limit and if not, uses ELF32.
-  So, on non-PAE systems, ELF32 is always used.
-
-  The --elf32-core-headers option can be used to force the generation of ELF32
-  headers. This is necessary because GDB currently cannot open vmcore files
-  with ELF64 headers on 32-bit systems.
-
-* The "irqpoll" boot parameter reduces driver initialization failures
-  due to shared interrupts in the dump-capture kernel.
-
-* You must specify <root-dev> in the format corresponding to the root
-  device name in the output of mount command.
-
-* Boot parameter "1" boots the dump-capture kernel into single-user
-  mode without networking. If you want networking, use "3".
-
-* We generally don't have to bring up a SMP kernel just to capture the
-  dump. Hence generally it is useful either to build a UP dump-capture
-  kernel or specify maxcpus=1 option while loading dump-capture kernel.
-  Note, though maxcpus always works, you had better replace it with
-  nr_cpus to save memory if supported by the current ARCH, such as x86.
-
-* You should enable multi-cpu support in dump-capture kernel if you intend
-  to use multi-thread programs with it, such as parallel dump feature of
-  makedumpfile. Otherwise, the multi-thread program may have a great
-  performance degradation. To enable multi-cpu support, you should bring up an
-  SMP dump-capture kernel and specify maxcpus/nr_cpus, disable_cpu_apicid=[X]
-  options while loading it.
-
-* For s390x there are two kdump modes: If a ELF header is specified with
-  the elfcorehdr= kernel parameter, it is used by the kdump kernel as it
-  is done on all other architectures. If no elfcorehdr= kernel parameter is
-  specified, the s390x kdump kernel dynamically creates the header. The
-  second mode has the advantage that for CPU and memory hotplug, kdump has
-  not to be reloaded with kexec_load().
-
-* For s390x systems with many attached devices the "cio_ignore" kernel
-  parameter should be used for the kdump kernel in order to prevent allocation
-  of kernel memory for devices that are not relevant for kdump. The same
-  applies to systems that use SCSI/FCP devices. In that case the
-  "allow_lun_scan" zfcp module parameter should be set to zero before
-  setting FCP devices online.
-
-Kernel Panic
-============
-
-After successfully loading the dump-capture kernel as previously
-described, the system will reboot into the dump-capture kernel if a
-system crash is triggered.  Trigger points are located in panic(),
-die(), die_nmi() and in the sysrq handler (ALT-SysRq-c).
-
-The following conditions will execute a crash trigger point:
-
-If a hard lockup is detected and "NMI watchdog" is configured, the system
-will boot into the dump-capture kernel ( die_nmi() ).
-
-If die() is called, and it happens to be a thread with pid 0 or 1, or die()
-is called inside interrupt context or die() is called and panic_on_oops is set,
-the system will boot into the dump-capture kernel.
-
-On powerpc systems when a soft-reset is generated, die() is called by all cpus
-and the system will boot into the dump-capture kernel.
-
-For testing purposes, you can trigger a crash by using "ALT-SysRq-c",
-"echo c > /proc/sysrq-trigger" or write a module to force the panic.
-
-Write Out the Dump File
-=======================
-
-After the dump-capture kernel is booted, write out the dump file with
-the following command::
-
-   cp /proc/vmcore <dump-file>
-
-
-Analysis
-========
-
-Before analyzing the dump image, you should reboot into a stable kernel.
-
-You can do limited analysis using GDB on the dump file copied out of
-/proc/vmcore. Use the debug vmlinux built with -g and run the following
-command::
-
-   gdb vmlinux <dump-file>
-
-Stack trace for the task on processor 0, register display, and memory
-display work fine.
-
-Note: GDB cannot analyze core files generated in ELF64 format for x86.
-On systems with a maximum of 4GB of memory, you can generate
-ELF32-format headers using the --elf32-core-headers kernel option on the
-dump kernel.
-
-You can also use the Crash utility to analyze dump files in Kdump
-format. Crash is available on Dave Anderson's site at the following URL:
-
-   http://people.redhat.com/~anderson/
-
-Trigger Kdump on WARN()
-=======================
-
-The kernel parameter, panic_on_warn, calls panic() in all WARN() paths.  This
-will cause a kdump to occur at the panic() call.  In cases where a user wants
-to specify this during runtime, /proc/sys/kernel/panic_on_warn can be set to 1
-to achieve the same behaviour.
-
-Contact
-=======
-
-- Vivek Goyal (vgoyal@redhat.com)
-- Maneesh Soni (maneesh@in.ibm.com)
-
-GDB macros
-==========
-
-.. include:: gdbmacros.txt
-   :literal:
diff --git a/Documentation/kdump/vmcoreinfo.rst b/Documentation/kdump/vmcoreinfo.rst
deleted file mode 100644
index 007a6b86e0ee..000000000000
--- a/Documentation/kdump/vmcoreinfo.rst
+++ /dev/null
@@ -1,488 +0,0 @@
-==========
-VMCOREINFO
-==========
-
-What is it?
-===========
-
-VMCOREINFO is a special ELF note section. It contains various
-information from the kernel like structure size, page size, symbol
-values, field offsets, etc. These data are packed into an ELF note
-section and used by user-space tools like crash and makedumpfile to
-analyze a kernel's memory layout.
-
-Common variables
-================
-
-init_uts_ns.name.release
-------------------------
-
-The version of the Linux kernel. Used to find the corresponding source
-code from which the kernel has been built. For example, crash uses it to
-find the corresponding vmlinux in order to process vmcore.
-
-PAGE_SIZE
----------
-
-The size of a page. It is the smallest unit of data used by the memory
-management facilities. It is usually 4096 bytes of size and a page is
-aligned on 4096 bytes. Used for computing page addresses.
-
-init_uts_ns
------------
-
-The UTS namespace which is used to isolate two specific elements of the
-system that relate to the uname(2) system call. It is named after the
-data structure used to store information returned by the uname(2) system
-call.
-
-User-space tools can get the kernel name, host name, kernel release
-number, kernel version, architecture name and OS type from it.
-
-node_online_map
----------------
-
-An array node_states[N_ONLINE] which represents the set of online nodes
-in a system, one bit position per node number. Used to keep track of
-which nodes are in the system and online.
-
-swapper_pg_dir
---------------
-
-The global page directory pointer of the kernel. Used to translate
-virtual to physical addresses.
-
-_stext
-------
-
-Defines the beginning of the text section. In general, _stext indicates
-the kernel start address. Used to convert a virtual address from the
-direct kernel map to a physical address.
-
-vmap_area_list
---------------
-
-Stores the virtual area list. makedumpfile gets the vmalloc start value
-from this variable and its value is necessary for vmalloc translation.
-
-mem_map
--------
-
-Physical addresses are translated to struct pages by treating them as
-an index into the mem_map array. Right-shifting a physical address
-PAGE_SHIFT bits converts it into a page frame number which is an index
-into that mem_map array.
-
-Used to map an address to the corresponding struct page.
-
-contig_page_data
-----------------
-
-Makedumpfile gets the pglist_data structure from this symbol, which is
-used to describe the memory layout.
-
-User-space tools use this to exclude free pages when dumping memory.
-
-mem_section|(mem_section, NR_SECTION_ROOTS)|(mem_section, section_mem_map)
---------------------------------------------------------------------------
-
-The address of the mem_section array, its length, structure size, and
-the section_mem_map offset.
-
-It exists in the sparse memory mapping model, and it is also somewhat
-similar to the mem_map variable, both of them are used to translate an
-address.
-
-page
-----
-
-The size of a page structure. struct page is an important data structure
-and it is widely used to compute contiguous memory.
-
-pglist_data
------------
-
-The size of a pglist_data structure. This value is used to check if the
-pglist_data structure is valid. It is also used for checking the memory
-type.
-
-zone
-----
-
-The size of a zone structure. This value is used to check if the zone
-structure has been found. It is also used for excluding free pages.
-
-free_area
----------
-
-The size of a free_area structure. It indicates whether the free_area
-structure is valid or not. Useful when excluding free pages.
-
-list_head
----------
-
-The size of a list_head structure. Used when iterating lists in a
-post-mortem analysis session.
-
-nodemask_t
-----------
-
-The size of a nodemask_t type. Used to compute the number of online
-nodes.
-
-(page, flags|_refcount|mapping|lru|_mapcount|private|compound_dtor|compound_order|compound_head)
--------------------------------------------------------------------------------------------------
-
-User-space tools compute their values based on the offset of these
-variables. The variables are used when excluding unnecessary pages.
-
-(pglist_data, node_zones|nr_zones|node_mem_map|node_start_pfn|node_spanned_pages|node_id)
------------------------------------------------------------------------------------------
-
-On NUMA machines, each NUMA node has a pg_data_t to describe its memory
-layout. On UMA machines there is a single pglist_data which describes the
-whole memory.
-
-These values are used to check the memory type and to compute the
-virtual address for memory map.
-
-(zone, free_area|vm_stat|spanned_pages)
----------------------------------------
-
-Each node is divided into a number of blocks called zones which
-represent ranges within memory. A zone is described by a structure zone.
-
-User-space tools compute required values based on the offset of these
-variables.
-
-(free_area, free_list)
-----------------------
-
-Offset of the free_list's member. This value is used to compute the number
-of free pages.
-
-Each zone has a free_area structure array called free_area[MAX_ORDER].
-The free_list represents a linked list of free page blocks.
-
-(list_head, next|prev)
-----------------------
-
-Offsets of the list_head's members. list_head is used to define a
-circular linked list. User-space tools need these in order to traverse
-lists.
-
-(vmap_area, va_start|list)
---------------------------
-
-Offsets of the vmap_area's members. They carry vmalloc-specific
-information. Makedumpfile gets the start address of the vmalloc region
-from this.
-
-(zone.free_area, MAX_ORDER)
----------------------------
-
-Free areas descriptor. User-space tools use this value to iterate the
-free_area ranges. MAX_ORDER is used by the zone buddy allocator.
-
-log_first_idx
--------------
-
-Index of the first record stored in the buffer log_buf. Used by
-user-space tools to read the strings in the log_buf.
-
-log_buf
--------
-
-Console output is written to the ring buffer log_buf at index
-log_first_idx. Used to get the kernel log.
-
-log_buf_len
------------
-
-log_buf's length.
-
-clear_idx
----------
-
-The index that the next printk() record to read after the last clear
-command. It indicates the first record after the last SYSLOG_ACTION
-_CLEAR, like issued by 'dmesg -c'. Used by user-space tools to dump
-the dmesg log.
-
-log_next_idx
-------------
-
-The index of the next record to store in the buffer log_buf. Used to
-compute the index of the current buffer position.
-
-printk_log
-----------
-
-The size of a structure printk_log. Used to compute the size of
-messages, and extract dmesg log. It encapsulates header information for
-log_buf, such as timestamp, syslog level, etc.
-
-(printk_log, ts_nsec|len|text_len|dict_len)
--------------------------------------------
-
-It represents field offsets in struct printk_log. User space tools
-parse it and check whether the values of printk_log's members have been
-changed.
-
-(free_area.free_list, MIGRATE_TYPES)
-------------------------------------
-
-The number of migrate types for pages. The free_list is described by the
-array. Used by tools to compute the number of free pages.
-
-NR_FREE_PAGES
--------------
-
-On linux-2.6.21 or later, the number of free pages is in
-vm_stat[NR_FREE_PAGES]. Used to get the number of free pages.
-
-PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision|PG_head_mask
-------------------------------------------------------------------------------
-
-Page attributes. These flags are used to filter various unnecessary for
-dumping pages.
-
-PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy)|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline)
------------------------------------------------------------------------------
-
-More page attributes. These flags are used to filter various unnecessary for
-dumping pages.
-
-
-HUGETLB_PAGE_DTOR
------------------
-
-The HUGETLB_PAGE_DTOR flag denotes hugetlbfs pages. Makedumpfile
-excludes these pages.
-
-x86_64
-======
-
-phys_base
----------
-
-Used to convert the virtual address of an exported kernel symbol to its
-corresponding physical address.
-
-init_top_pgt
-------------
-
-Used to walk through the whole page table and convert virtual addresses
-to physical addresses. The init_top_pgt is somewhat similar to
-swapper_pg_dir, but it is only used in x86_64.
-
-pgtable_l5_enabled
-------------------
-
-User-space tools need to know whether the crash kernel was in 5-level
-paging mode.
-
-node_data
----------
-
-This is a struct pglist_data array and stores all NUMA nodes
-information. Makedumpfile gets the pglist_data structure from it.
-
-(node_data, MAX_NUMNODES)
--------------------------
-
-The maximum number of nodes in system.
-
-KERNELOFFSET
-------------
-
-The kernel randomization offset. Used to compute the page offset. If
-KASLR is disabled, this value is zero.
-
-KERNEL_IMAGE_SIZE
------------------
-
-Currently unused by Makedumpfile. Used to compute the module virtual
-address by Crash.
-
-sme_mask
---------
-
-AMD-specific with SME support: it indicates the secure memory encryption
-mask. Makedumpfile tools need to know whether the crash kernel was
-encrypted. If SME is enabled in the first kernel, the crash kernel's
-page table entries (pgd/pud/pmd/pte) contain the memory encryption
-mask. This is used to remove the SME mask and obtain the true physical
-address.
-
-Currently, sme_mask stores the value of the C-bit position. If needed,
-additional SME-relevant info can be placed in that variable.
-
-For example::
-
-  [ misc	        ][ enc bit  ][ other misc SME info       ]
-  0000_0000_0000_0000_1000_0000_0000_0000_0000_0000_..._0000
-  63   59   55   51   47   43   39   35   31   27   ... 3
-
-x86_32
-======
-
-X86_PAE
--------
-
-Denotes whether physical address extensions are enabled. It has the cost
-of a higher page table lookup overhead, and also consumes more page
-table space per process. Used to check whether PAE was enabled in the
-crash kernel when converting virtual addresses to physical addresses.
-
-ia64
-====
-
-pgdat_list|(pgdat_list, MAX_NUMNODES)
--------------------------------------
-
-pg_data_t array storing all NUMA nodes information. MAX_NUMNODES
-indicates the number of the nodes.
-
-node_memblk|(node_memblk, NR_NODE_MEMBLKS)
-------------------------------------------
-
-List of node memory chunks. Filled when parsing the SRAT table to obtain
-information about memory nodes. NR_NODE_MEMBLKS indicates the number of
-node memory chunks.
-
-These values are used to compute the number of nodes the crashed kernel used.
-
-node_memblk_s|(node_memblk_s, start_paddr)|(node_memblk_s, size)
-----------------------------------------------------------------
-
-The size of a struct node_memblk_s and the offsets of the
-node_memblk_s's members. Used to compute the number of nodes.
-
-PGTABLE_3|PGTABLE_4
--------------------
-
-User-space tools need to know whether the crash kernel was in 3-level or
-4-level paging mode. Used to distinguish the page table.
-
-ARM64
-=====
-
-VA_BITS
--------
-
-The maximum number of bits for virtual addresses. Used to compute the
-virtual memory ranges.
-
-kimage_voffset
---------------
-
-The offset between the kernel virtual and physical mappings. Used to
-translate virtual to physical addresses.
-
-PHYS_OFFSET
------------
-
-Indicates the physical address of the start of memory. Similar to
-kimage_voffset, which is used to translate virtual to physical
-addresses.
-
-KERNELOFFSET
-------------
-
-The kernel randomization offset. Used to compute the page offset. If
-KASLR is disabled, this value is zero.
-
-arm
-===
-
-ARM_LPAE
---------
-
-It indicates whether the crash kernel supports large physical address
-extensions. Used to translate virtual to physical addresses.
-
-s390
-====
-
-lowcore_ptr
------------
-
-An array with a pointer to the lowcore of every CPU. Used to print the
-psw and all registers information.
-
-high_memory
------------
-
-Used to get the vmalloc_start address from the high_memory symbol.
-
-(lowcore_ptr, NR_CPUS)
-----------------------
-
-The maximum number of CPUs.
-
-powerpc
-=======
-
-
-node_data|(node_data, MAX_NUMNODES)
------------------------------------
-
-See above.
-
-contig_page_data
-----------------
-
-See above.
-
-vmemmap_list
-------------
-
-The vmemmap_list maintains the entire vmemmap physical mapping. Used
-to get vmemmap list count and populated vmemmap regions info. If the
-vmemmap address translation information is stored in the crash kernel,
-it is used to translate vmemmap kernel virtual addresses.
-
-mmu_vmemmap_psize
------------------
-
-The size of a page. Used to translate virtual to physical addresses.
-
-mmu_psize_defs
---------------
-
-Page size definitions, i.e. 4k, 64k, or 16M.
-
-Used to make vtop translations.
-
-vmemmap_backing|(vmemmap_backing, list)|(vmemmap_backing, phys)|(vmemmap_backing, virt_addr)
---------------------------------------------------------------------------------------------
-
-The vmemmap virtual address space management does not have a traditional
-page table to track which virtual struct pages are backed by a physical
-mapping. The virtual to physical mappings are tracked in a simple linked
-list format.
-
-User-space tools need to know the offset of list, phys and virt_addr
-when computing the count of vmemmap regions.
-
-mmu_psize_def|(mmu_psize_def, shift)
-------------------------------------
-
-The size of a struct mmu_psize_def and the offset of mmu_psize_def's
-member.
-
-Used in vtop translations.
-
-sh
-==
-
-node_data|(node_data, MAX_NUMNODES)
------------------------------------
-
-See above.
-
-X2TLB
------
-
-Indicates whether the crashed kernel enabled SH extended mode.