virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

17 files changed, 7196 insertions, 0 deletions

diff --git a/init/.gitignore b/init/.gitignore
new file mode 100644
index 000000000..cbbe270ce
--- /dev/null
+++ b/init/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/utsversion-tmp.h
diff --git a/init/.kunitconfig b/init/.kunitconfig
new file mode 100644
index 000000000..acb906b1a
--- /dev/null
+++ b/init/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_INITRAMFS_TEST=y
diff --git a/init/Kconfig b/init/Kconfig
new file mode 100644
index 000000000..8583d9f06
--- /dev/null
+++ b/init/Kconfig
@@ -0,0 +1,2363 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CC_VERSION_TEXT
+	string
+	default "$(CC_VERSION_TEXT)"
+	help
+	  This is used in unclear ways:
+
+	  - Re-run Kconfig when the compiler is updated
+	    The 'default' property references the environment variable,
+	    CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd.
+	    When the compiler is updated, Kconfig will be invoked.
+
+	  - Ensure full rebuild when the compiler is updated
+	    include/linux/compiler-version.h contains this option in the comment
+	    line so fixdep adds include/config/CC_VERSION_TEXT into the
+	    auto-generated dependency. When the compiler is updated, syncconfig
+	    will touch it and then every file will be rebuilt.
+
+config CC_IS_GCC
+	def_bool $(success,test "$(cc-name)" = GCC)
+
+config GCC_VERSION
+	int
+	default $(cc-version) if CC_IS_GCC
+	default 0
+
+config CC_IS_CLANG
+	def_bool $(success,test "$(cc-name)" = Clang)
+
+config CLANG_VERSION
+	int
+	default $(cc-version) if CC_IS_CLANG
+	default 0
+
+config AS_IS_GNU
+	def_bool $(success,test "$(as-name)" = GNU)
+
+config AS_IS_LLVM
+	def_bool $(success,test "$(as-name)" = LLVM)
+
+config AS_VERSION
+	int
+	# Use clang version if this is the integrated assembler
+	default CLANG_VERSION if AS_IS_LLVM
+	default $(as-version)
+
+config LD_IS_BFD
+	def_bool $(success,test "$(ld-name)" = BFD)
+
+config LD_VERSION
+	int
+	default $(ld-version) if LD_IS_BFD
+	default 0
+
+config LD_IS_LLD
+	def_bool $(success,test "$(ld-name)" = LLD)
+
+config LLD_VERSION
+	int
+	default $(ld-version) if LD_IS_LLD
+	default 0
+
+config RUSTC_VERSION
+	int
+	default $(rustc-version)
+	help
+	  It does not depend on `RUST` since that one may need to use the version
+	  in a `depends on`.
+
+config RUST_IS_AVAILABLE
+	def_bool $(success,$(srctree)/scripts/rust_is_available.sh)
+	help
+	  This shows whether a suitable Rust toolchain is available (found).
+
+	  Please see Documentation/rust/quick-start.rst for instructions on how
+	  to satisfy the build requirements of Rust support.
+
+	  In particular, the Makefile target 'rustavailable' is useful to check
+	  why the Rust toolchain is not being detected.
+
+config RUSTC_LLVM_VERSION
+	int
+	default $(rustc-llvm-version)
+
+config RUSTC_LLVM_MAJOR_VERSION
+	int
+	default $(shell,expr $(rustc-llvm-version) / 10000)
+
+config RUSTC_CLANG_LLVM_COMPATIBLE
+	bool
+	default y if CC_IS_CLANG && RUSTC_LLVM_MAJOR_VERSION = $(shell,expr $(cc-version) / 10000)
+	help
+	  This indicates whether Rust and Clang use LLVM of the same major
+	  version.
+
+	  Operations involving handling LLVM IR or bitcode (e.g. cross-language
+	  LTO) require the same LLVM major version to work properly. For best
+	  compatibility it is recommended that the exact same LLVM is used.
+
+config ARCH_HAS_CC_CAN_LINK
+	bool
+
+config CC_CAN_LINK
+	bool
+	default ARCH_CC_CAN_LINK if ARCH_HAS_CC_CAN_LINK
+	default $(cc_can_link_user,$(m64-flag)) if 64BIT
+	default $(cc_can_link_user,$(m32-flag))
+
+# Fixed in GCC 14, 13.3, 12.4 and 11.5
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
+config GCC_ASM_GOTO_OUTPUT_BROKEN
+	bool
+	depends on CC_IS_GCC
+	default y if GCC_VERSION < 110500
+	default y if GCC_VERSION >= 120000 && GCC_VERSION < 120400
+	default y if GCC_VERSION >= 130000 && GCC_VERSION < 130300
+
+config CC_HAS_ASM_GOTO_OUTPUT
+	def_bool y
+	depends on !GCC_ASM_GOTO_OUTPUT_BROKEN
+	depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
+
+config CC_HAS_ASM_GOTO_TIED_OUTPUT
+	depends on CC_HAS_ASM_GOTO_OUTPUT
+	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
+	def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
+
+config TOOLS_SUPPORT_RELR
+	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
+
+config CC_HAS_ASM_INLINE
+	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
+
+config CC_HAS_ASSUME
+	bool
+	# clang needs to be at least 19.1.0 since the meaning of the assume
+	# attribute changed:
+	# https://github.com/llvm/llvm-project/commit/c44fa3e8a9a44c2e9a575768a3c185354b9f6c17
+	default y if CC_IS_CLANG && CLANG_VERSION >= 190100
+	# supported since gcc 13.1.0
+	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106654
+	default y if CC_IS_GCC && GCC_VERSION >= 130100
+
+config CC_HAS_NO_PROFILE_FN_ATTR
+	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
+
+config CC_HAS_COUNTED_BY
+	bool
+	# clang needs to be at least 20.1.0 to avoid potential crashes
+	# when building structures that contain __counted_by
+	# https://github.com/ClangBuiltLinux/linux/issues/2114
+	# https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489
+	default y if CC_IS_CLANG && CLANG_VERSION >= 200100
+	# supported since gcc 15.1.0
+	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
+	default y if CC_IS_GCC && GCC_VERSION >= 150100
+
+config CC_HAS_COUNTED_BY_PTR
+	bool
+	# supported since clang 22
+	default y if CC_IS_CLANG && CLANG_VERSION >= 220100
+	# supported since gcc 16.0.0
+	default y if CC_IS_GCC && GCC_VERSION >= 160000
+
+config CC_HAS_BROKEN_COUNTED_BY_REF
+	bool
+	# https://github.com/llvm/llvm-project/issues/182575
+	default y if CC_IS_CLANG && CLANG_VERSION < 220100
+
+config CC_HAS_ALLOC_TOKEN
+	def_bool $(cc-option,-falloc-token-max=123)
+
+config CC_HAS_MULTIDIMENSIONAL_NONSTRING
+	def_bool $(success,echo 'char tag[][4] __attribute__((__nonstring__)) = { };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
+
+config LD_CAN_USE_KEEP_IN_OVERLAY
+	# ld.lld prior to 21.0.0 did not support KEEP within an overlay description
+	# https://github.com/llvm/llvm-project/pull/130661
+	def_bool LD_IS_BFD || LLD_VERSION >= 210000
+
+config RUSTC_HAS_SPAN_FILE
+	def_bool RUSTC_VERSION >= 108800
+
+config RUSTC_HAS_UNNECESSARY_TRANSMUTES
+	def_bool RUSTC_VERSION >= 108800
+
+config RUSTC_HAS_FILE_WITH_NUL
+	def_bool RUSTC_VERSION >= 108900
+
+config RUSTC_HAS_FILE_AS_C_STR
+	def_bool RUSTC_VERSION >= 109100
+
+config RUSTC_HAS_SUSPICIOUS_RUNTIME_SYMBOL_DEFINITIONS
+	def_bool RUSTC_VERSION >= 109800
+
+config PAHOLE_VERSION
+	int
+	default "$(PAHOLE_VERSION)"
+
+config CONSTRUCTORS
+	bool
+
+config IRQ_WORK
+	def_bool y if SMP
+
+config BUILDTIME_TABLE_SORT
+	bool
+
+config THREAD_INFO_IN_TASK
+	bool
+	help
+	  Select this to move thread_info off the stack into task_struct.  To
+	  make this work, an arch will need to remove all thread_info fields
+	  except flags and fix any runtime bugs.
+
+	  One subtle change that will be needed is to use try_get_task_stack()
+	  and put_task_stack() in save_thread_stack_tsk() and get_wchan().
+
+menu "General setup"
+
+config BROKEN
+	bool
+	help
+	  This option allows you to choose whether you want to try to
+	  compile (and fix) old drivers that haven't been updated to
+	  new infrastructure.
+
+config BROKEN_ON_SMP
+	bool
+	depends on BROKEN || !SMP
+	default y
+
+config INIT_ENV_ARG_LIMIT
+	int
+	default 32 if !UML
+	default 128 if UML
+	help
+	  Maximum of each of the number of arguments and environment
+	  variables passed to init from the kernel command line.
+
+config COMPILE_TEST
+	bool "Compile also drivers which will not load"
+	depends on HAS_IOMEM
+	help
+	  Some drivers can be compiled on a different platform than they are
+	  intended to be run on. Despite they cannot be loaded there (or even
+	  when they load they cannot be used due to missing HW support),
+	  developers still, opposing to distributors, might want to build such
+	  drivers to compile-test them.
+
+	  If you are a developer and want to build everything available, say Y
+	  here. If you are a user/distributor, say N here to exclude useless
+	  drivers to be distributed.
+
+config WERROR
+	bool "Compile the kernel with warnings as errors"
+	default COMPILE_TEST
+	help
+	  A kernel build should not cause any compiler warnings, and this
+	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
+	  to enforce that rule by default. Certain warnings from other tools
+	  such as the linker may be upgraded to errors with this option as
+	  well.
+
+	  However, if you have a new (or very old) compiler or linker with odd
+	  and unusual warnings, or you have some architecture with problems,
+	  you may need to disable this config option in order to
+	  successfully build the kernel.
+
+	  If in doubt, say Y.
+
+config UAPI_HEADER_TEST
+	bool "Compile test UAPI headers"
+	depends on HEADERS_INSTALL
+	help
+	  Compile test headers exported to user-space to ensure they are
+	  self-contained, i.e. compilable as standalone units.
+
+	  If you are a developer or tester and want to ensure the exported
+	  headers are self-contained, say Y here. Otherwise, choose N.
+
+config LOCALVERSION
+	string "Local version - append to kernel release"
+	help
+	  Append an extra string to the end of your kernel version.
+	  This will show up when you type uname, for example.
+	  The string you set here will be appended after the contents of
+	  any files with a filename matching localversion* in your
+	  object and source tree, in that order.  Your total string can
+	  be a maximum of 64 characters.
+
+config LOCALVERSION_AUTO
+	bool "Automatically append version information to the version string"
+	default y
+	depends on !COMPILE_TEST
+	help
+	  This will try to automatically determine if the current tree is a
+	  release tree by looking for git tags that belong to the current
+	  top of tree revision.
+
+	  A string of the format -gxxxxxxxx will be added to the localversion
+	  if a git-based tree is found.  The string generated by this will be
+	  appended after any matching localversion* files, and after the value
+	  set in CONFIG_LOCALVERSION.
+
+	  (The actual string used here is the first 12 characters produced
+	  by running the command:
+
+	    $ git rev-parse --verify HEAD
+
+	  which is done within the script "scripts/setlocalversion".)
+
+config BUILD_SALT
+	string "Build ID Salt"
+	default ""
+	help
+	  The build ID is used to link binaries and their debug info. Setting
+	  this option will use the value in the calculation of the build id.
+	  This is mostly useful for distributions which want to ensure the
+	  build is unique between builds. It's safe to leave the default.
+
+config HAVE_KERNEL_GZIP
+	bool
+
+config HAVE_KERNEL_BZIP2
+	bool
+
+config HAVE_KERNEL_LZMA
+	bool
+
+config HAVE_KERNEL_XZ
+	bool
+
+config HAVE_KERNEL_LZO
+	bool
+
+config HAVE_KERNEL_LZ4
+	bool
+
+config HAVE_KERNEL_ZSTD
+	bool
+
+config HAVE_KERNEL_UNCOMPRESSED
+	bool
+
+choice
+	prompt "Kernel compression mode"
+	default KERNEL_GZIP
+	depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED
+	help
+	  The linux kernel is a kind of self-extracting executable.
+	  Several compression algorithms are available, which differ
+	  in efficiency, compression and decompression speed.
+	  Compression speed is only relevant when building a kernel.
+	  Decompression speed is relevant at each boot.
+
+	  If you have any problems with bzip2 or lzma compressed
+	  kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
+	  version of this functionality (bzip2 only), for 2.4, was
+	  supplied by Christian Ludwig)
+
+	  High compression options are mostly useful for users, who
+	  are low on disk space (embedded systems), but for whom ram
+	  size matters less.
+
+	  If in doubt, select 'gzip'
+
+config KERNEL_GZIP
+	bool "Gzip"
+	depends on HAVE_KERNEL_GZIP
+	help
+	  The old and tried gzip compression. It provides a good balance
+	  between compression ratio and decompression speed.
+
+config KERNEL_BZIP2
+	bool "Bzip2"
+	depends on HAVE_KERNEL_BZIP2
+	help
+	  Its compression ratio and speed is intermediate.
+	  Decompression speed is slowest among the choices.  The kernel
+	  size is about 10% smaller with bzip2, in comparison to gzip.
+	  Bzip2 uses a large amount of memory. For modern kernels you
+	  will need at least 8MB RAM or more for booting.
+
+config KERNEL_LZMA
+	bool "LZMA"
+	depends on HAVE_KERNEL_LZMA
+	help
+	  This compression algorithm's ratio is best.  Decompression speed
+	  is between gzip and bzip2.  Compression is slowest.
+	  The kernel size is about 33% smaller with LZMA in comparison to gzip.
+
+config KERNEL_XZ
+	bool "XZ"
+	depends on HAVE_KERNEL_XZ
+	help
+	  XZ uses the LZMA2 algorithm and instruction set specific
+	  BCJ filters which can improve compression ratio of executable
+	  code. The size of the kernel is about 30% smaller with XZ in
+	  comparison to gzip. On architectures for which there is a BCJ
+	  filter (i386, x86_64, ARM, ARM64, RISC-V, big endian PowerPC,
+	  and SPARC), XZ will create a few percent smaller kernel than
+	  plain LZMA.
+
+	  The speed is about the same as with LZMA: The decompression
+	  speed of XZ is better than that of bzip2 but worse than gzip
+	  and LZO. Compression is slow.
+
+config KERNEL_LZO
+	bool "LZO"
+	depends on HAVE_KERNEL_LZO
+	help
+	  Its compression ratio is the poorest among the choices. The kernel
+	  size is about 10% bigger than gzip; however its speed
+	  (both compression and decompression) is the fastest.
+
+config KERNEL_LZ4
+	bool "LZ4"
+	depends on HAVE_KERNEL_LZ4
+	help
+	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
+	  A preliminary version of LZ4 de/compression tool is available at
+	  <https://code.google.com/p/lz4/>.
+
+	  Its compression ratio is worse than LZO. The size of the kernel
+	  is about 8% bigger than LZO. But the decompression speed is
+	  faster than LZO.
+
+config KERNEL_ZSTD
+	bool "ZSTD"
+	depends on HAVE_KERNEL_ZSTD
+	help
+	  ZSTD is a compression algorithm targeting intermediate compression
+	  with fast decompression speed. It will compress better than GZIP and
+	  decompress around the same speed as LZO, but slower than LZ4. You
+	  will need at least 192 KB RAM or more for booting. The zstd command
+	  line tool is required for compression.
+
+config KERNEL_UNCOMPRESSED
+	bool "None"
+	depends on HAVE_KERNEL_UNCOMPRESSED
+	help
+	  Produce uncompressed kernel image. This option is usually not what
+	  you want. It is useful for debugging the kernel in slow simulation
+	  environments, where decompressing and moving the kernel is awfully
+	  slow. This option allows early boot code to skip the decompressor
+	  and jump right at uncompressed kernel image.
+
+endchoice
+
+config DEFAULT_INIT
+	string "Default init path"
+	default ""
+	help
+	  This option determines the default init for the system if no init=
+	  option is passed on the kernel command line. If the requested path is
+	  not present, we will still then move on to attempting further
+	  locations (e.g. /sbin/init, etc). If this is empty, we will just use
+	  the fallback list when init= is not passed.
+
+config DEFAULT_HOSTNAME
+	string "Default hostname"
+	default "(none)"
+	help
+	  This option determines the default system hostname before userspace
+	  calls sethostname(2). The kernel traditionally uses "(none)" here,
+	  but you may wish to use a different default here to make a minimal
+	  system more usable with less configuration.
+
+config SYSVIPC
+	bool "System V IPC"
+	help
+	  Inter Process Communication is a suite of library functions and
+	  system calls which let processes (running programs) synchronize and
+	  exchange information. It is generally considered to be a good thing,
+	  and some programs won't run unless you say Y here. In particular, if
+	  you want to run the DOS emulator dosemu under Linux (read the
+	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
+	  you'll need to say Y here.
+
+	  You can find documentation about IPC with "info ipc" and also in
+	  section 6.4 of the Linux Programmer's Guide, available from
+	  <http://www.tldp.org/guides.html>.
+
+config SYSVIPC_SYSCTL
+	bool
+	depends on SYSVIPC
+	depends on SYSCTL
+	default y
+
+config SYSVIPC_COMPAT
+	def_bool y
+	depends on COMPAT && SYSVIPC
+
+config POSIX_MQUEUE
+	bool "POSIX Message Queues"
+	depends on NET
+	help
+	  POSIX variant of message queues is a part of IPC. In POSIX message
+	  queues every message has a priority which decides about succession
+	  of receiving it by a process. If you want to compile and run
+	  programs written e.g. for Solaris with use of its POSIX message
+	  queues (functions mq_*) say Y here.
+
+	  POSIX message queues are visible as a filesystem called 'mqueue'
+	  and can be mounted somewhere if you want to do filesystem
+	  operations on message queues.
+
+	  If unsure, say Y.
+
+config POSIX_MQUEUE_SYSCTL
+	bool
+	depends on POSIX_MQUEUE
+	depends on SYSCTL
+	default y
+
+config WATCH_QUEUE
+	bool "General notification queue"
+	default n
+	help
+
+	  This is a general notification queue for the kernel to pass events to
+	  userspace by splicing them into pipes.  It can be used in conjunction
+	  with watches for key/keyring change notifications and device
+	  notifications.
+
+	  See Documentation/core-api/watch_queue.rst
+
+config CROSS_MEMORY_ATTACH
+	bool "Enable process_vm_readv/writev syscalls"
+	depends on MMU
+	default y
+	help
+	  Enabling this option adds the system calls process_vm_readv and
+	  process_vm_writev which allow a process with the correct privileges
+	  to directly read from or write to another process' address space.
+	  See the man page for more details.
+
+config AUDIT
+	bool "Auditing support"
+	depends on NET
+	help
+	  Enable auditing infrastructure that can be used with another
+	  kernel subsystem, such as SELinux (which requires this for
+	  logging of avc messages output).  System call auditing is included
+	  on architectures which support it.
+
+config HAVE_ARCH_AUDITSYSCALL
+	bool
+
+config AUDITSYSCALL
+	def_bool y
+	depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
+	select FSNOTIFY
+
+source "kernel/irq/Kconfig"
+source "kernel/time/Kconfig"
+source "kernel/bpf/Kconfig"
+source "kernel/Kconfig.preempt"
+
+menu "CPU/Task time and stats accounting"
+
+config VIRT_CPU_ACCOUNTING
+	bool
+
+choice
+	prompt "Cputime accounting"
+	default VIRT_CPU_ACCOUNTING_GEN if NO_HZ_FULL
+	default TICK_CPU_ACCOUNTING
+
+# Kind of a stub config for the pure tick based cputime accounting
+config TICK_CPU_ACCOUNTING
+	bool "Simple tick based cputime accounting"
+	depends on !S390 && !NO_HZ_FULL
+	help
+	  This is the basic tick based cputime accounting that maintains
+	  statistics about user, system and idle time spent on per jiffies
+	  granularity.
+
+	  If unsure, say Y.
+
+config VIRT_CPU_ACCOUNTING_NATIVE
+	bool "Deterministic task and CPU time accounting"
+	depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
+	select VIRT_CPU_ACCOUNTING
+	help
+	  Select this option to enable more accurate task and CPU time
+	  accounting.  This is done by reading a CPU counter on each
+	  kernel entry and exit and on transitions within the kernel
+	  between system, softirq and hardirq state, so there is a
+	  small performance impact.  In the case of s390 or IBM POWER > 5,
+	  this also enables accounting of stolen time on logically-partitioned
+	  systems.
+
+config VIRT_CPU_ACCOUNTING_GEN
+	bool "Full dynticks CPU time accounting"
+	depends on HAVE_CONTEXT_TRACKING_USER
+	depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
+	depends on GENERIC_CLOCKEVENTS
+	select VIRT_CPU_ACCOUNTING
+	select CONTEXT_TRACKING_USER
+	help
+	  Select this option to enable task and CPU time accounting on full
+	  dynticks systems. This accounting is implemented by watching every
+	  kernel-user boundaries using the context tracking subsystem.
+	  The accounting is thus performed at the expense of some significant
+	  overhead.
+
+	  For now this is only useful if you are working on the full
+	  dynticks subsystem development.
+
+	  If unsure, say N.
+
+endchoice
+
+config IRQ_TIME_ACCOUNTING
+	bool "Fine granularity task level IRQ time accounting"
+	depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
+	help
+	  Select this option to enable fine granularity task irq time
+	  accounting. This is done by reading a timestamp on each
+	  transitions between softirq and hardirq state, so there can be a
+	  small performance impact.
+
+	  If in doubt, say N here.
+
+config HAVE_SCHED_AVG_IRQ
+	def_bool y
+	depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
+	depends on SMP
+
+config SCHED_HW_PRESSURE
+	bool
+	default y if ARM && ARM_CPU_TOPOLOGY
+	default y if ARM64
+	depends on SMP
+	depends on CPU_FREQ_THERMAL
+	help
+	  Select this option to enable HW pressure accounting in the
+	  scheduler. HW pressure is the value conveyed to the scheduler
+	  that reflects the reduction in CPU compute capacity resulted from
+	  HW throttling. HW throttling occurs when the performance of
+	  a CPU is capped due to high operating temperatures as an example.
+
+	  If selected, the scheduler will be able to balance tasks accordingly,
+	  i.e. put less load on throttled CPUs than on non/less throttled ones.
+
+	  This requires the architecture to implement
+	  arch_update_hw_pressure() and arch_scale_thermal_pressure().
+
+config BSD_PROCESS_ACCT
+	bool "BSD Process Accounting (DEPRECATED)"
+	depends on MULTIUSER
+	default n
+	help
+	  If you say Y here, a user level program will be able to instruct the
+	  kernel (via a special system call) to write process accounting
+	  information to a file: whenever a process exits, information about
+	  that process will be appended to the file by the kernel.  The
+	  information includes things such as creation time, owning user,
+	  command name, memory usage, controlling terminal etc. (the complete
+	  list is in the struct acct in <file:include/linux/acct.h>).  It is
+	  up to the user level program to do useful things with this
+	  information.  This mechanism is antiquated and has significant
+	  scalability issues.  You probably want to use eBPF instead.  Say
+	  N unless you really need this.
+
+config BSD_PROCESS_ACCT_V3
+	bool "BSD Process Accounting version 3 file format"
+	depends on BSD_PROCESS_ACCT
+	default n
+	help
+	  If you say Y here, the process accounting information is written
+	  in a new file format that also logs the process IDs of each
+	  process and its parent. Note that this file format is incompatible
+	  with previous v0/v1/v2 file formats, so you will need updated tools
+	  for processing it. A preliminary version of these tools is available
+	  at <http://www.gnu.org/software/acct/>.
+
+config TASKSTATS
+	bool "Export task/process statistics through netlink"
+	depends on NET
+	depends on MULTIUSER
+	default n
+	help
+	  Export selected statistics for tasks/processes through the
+	  generic netlink interface. Unlike BSD process accounting, the
+	  statistics are available during the lifetime of tasks/processes as
+	  responses to commands. Like BSD accounting, they are sent to user
+	  space on task exit.
+
+	  Say N if unsure.
+
+config TASK_DELAY_ACCT
+	bool "Enable per-task delay accounting"
+	depends on TASKSTATS
+	select SCHED_INFO
+	help
+	  Collect information on time spent by a task waiting for system
+	  resources like cpu, synchronous block I/O completion and swapping
+	  in pages. Such statistics can help in setting a task's priorities
+	  relative to other tasks for cpu, io, rss limits etc.
+
+	  Say N if unsure.
+
+config TASK_XACCT
+	bool "Enable extended accounting over taskstats"
+	depends on TASKSTATS
+	help
+	  Collect extended task accounting data and send the data
+	  to userland for processing over the taskstats interface.
+
+	  Say N if unsure.
+
+config TASK_IO_ACCOUNTING
+	bool "Enable per-task storage I/O accounting"
+	depends on TASK_XACCT
+	help
+	  Collect information on the number of bytes of storage I/O which this
+	  task has caused.
+
+	  Say N if unsure.
+
+config PSI
+	bool "Pressure stall information tracking"
+	select KERNFS
+	help
+	  Collect metrics that indicate how overcommitted the CPU, memory,
+	  and IO capacity are in the system.
+
+	  If you say Y here, the kernel will create /proc/pressure/ with the
+	  pressure statistics files cpu, memory, and io. These will indicate
+	  the share of walltime in which some or all tasks in the system are
+	  delayed due to contention of the respective resource.
+
+	  In kernels with cgroup support, cgroups (cgroup2 only) will
+	  have cpu.pressure, memory.pressure, and io.pressure files,
+	  which aggregate pressure stalls for the grouped tasks only.
+
+	  For more details see Documentation/accounting/psi.rst.
+
+	  Say N if unsure.
+
+config PSI_DEFAULT_DISABLED
+	bool "Require boot parameter to enable pressure stall information tracking"
+	default n
+	depends on PSI
+	help
+	  If set, pressure stall information tracking will be disabled
+	  per default but can be enabled through passing psi=1 on the
+	  kernel commandline during boot.
+
+	  This feature adds some code to the task wakeup and sleep
+	  paths of the scheduler. The overhead is too low to affect
+	  common scheduling-intense workloads in practice (such as
+	  webservers, memcache), but it does show up in artificial
+	  scheduler stress tests, such as hackbench.
+
+	  If you are paranoid and not sure what the kernel will be
+	  used for, say Y.
+
+	  Say N if unsure.
+
+endmenu # "CPU/Task time and stats accounting"
+
+config CPU_ISOLATION
+	bool "CPU isolation"
+	depends on SMP
+	default y
+	help
+	  Make sure that CPUs running critical tasks are not disturbed by
+	  any source of "noise" such as unbound workqueues, timers, kthreads...
+	  Unbound jobs get offloaded to housekeeping CPUs. This is driven by
+	  the "isolcpus=" boot parameter.
+
+	  Say Y if unsure.
+
+source "kernel/rcu/Kconfig"
+
+config IKCONFIG
+	tristate "Kernel .config support"
+	help
+	  This option enables the complete Linux kernel ".config" file
+	  contents to be saved in the kernel. It provides documentation
+	  of which kernel options are used in a running kernel or in an
+	  on-disk kernel.  This information can be extracted from the kernel
+	  image file with the script scripts/extract-ikconfig and used as
+	  input to rebuild the current kernel or to build another kernel.
+	  It can also be extracted from a running kernel by reading
+	  /proc/config.gz if enabled (below).
+
+config IKCONFIG_PROC
+	bool "Enable access to .config through /proc/config.gz"
+	depends on IKCONFIG && PROC_FS
+	help
+	  This option enables access to the kernel configuration file
+	  through /proc/config.gz.
+
+config IKHEADERS
+	tristate "Enable kernel headers through /sys/kernel/kheaders.tar.xz"
+	depends on SYSFS
+	help
+	  This option enables access to the in-kernel headers that are generated during
+	  the build process. These can be used to build eBPF tracing programs,
+	  or similar programs.  If you build the headers as a module, a module called
+	  kheaders.ko is built which can be loaded on-demand to get access to headers.
+
+config LOG_BUF_SHIFT
+	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
+	range 12 25
+	default 17
+	depends on PRINTK
+	help
+	  Select the minimal kernel log buffer size as a power of 2.
+	  The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
+	  parameter, see below. Any higher size also might be forced
+	  by "log_buf_len" boot parameter.
+
+	  Examples:
+		     17 => 128 KB
+		     16 => 64 KB
+		     15 => 32 KB
+		     14 => 16 KB
+		     13 =>  8 KB
+		     12 =>  4 KB
+
+config LOG_CPU_MAX_BUF_SHIFT
+	int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
+	depends on SMP
+	range 0 21
+	default 0 if BASE_SMALL
+	default 12
+	depends on PRINTK
+	help
+	  This option allows to increase the default ring buffer size
+	  according to the number of CPUs. The value defines the contribution
+	  of each CPU as a power of 2. The used space is typically only few
+	  lines however it might be much more when problems are reported,
+	  e.g. backtraces.
+
+	  The increased size means that a new buffer has to be allocated and
+	  the original static one is unused. It makes sense only on systems
+	  with more CPUs. Therefore this value is used only when the sum of
+	  contributions is greater than the half of the default kernel ring
+	  buffer as defined by LOG_BUF_SHIFT. The default values are set
+	  so that more than 16 CPUs are needed to trigger the allocation.
+
+	  Also this option is ignored when "log_buf_len" kernel parameter is
+	  used as it forces an exact (power of two) size of the ring buffer.
+
+	  The number of possible CPUs is used for this computation ignoring
+	  hotplugging making the computation optimal for the worst case
+	  scenario while allowing a simple algorithm to be used from bootup.
+
+	  Examples shift values and their meaning:
+		     17 => 128 KB for each CPU
+		     16 =>  64 KB for each CPU
+		     15 =>  32 KB for each CPU
+		     14 =>  16 KB for each CPU
+		     13 =>   8 KB for each CPU
+		     12 =>   4 KB for each CPU
+
+config PRINTK_INDEX
+	bool "Printk indexing debugfs interface"
+	depends on PRINTK && DEBUG_FS
+	help
+	  Add support for indexing of all printk formats known at compile time
+	  at <debugfs>/printk/index/<module>.
+
+	  This can be used as part of maintaining daemons which monitor
+	  /dev/kmsg, as it permits auditing the printk formats present in a
+	  kernel, allowing detection of cases where monitored printks are
+	  changed or no longer present.
+
+	  There is no additional runtime cost to printk with this enabled.
+
+#
+# Architectures with an unreliable sched_clock() should select this:
+#
+config HAVE_UNSTABLE_SCHED_CLOCK
+	bool
+
+config GENERIC_SCHED_CLOCK
+	bool
+
+menu "Scheduler features"
+
+config UCLAMP_TASK
+	bool "Enable utilization clamping for RT/FAIR tasks"
+	depends on CPU_FREQ_GOV_SCHEDUTIL
+	help
+	  This feature enables the scheduler to track the clamped utilization
+	  of each CPU based on RUNNABLE tasks scheduled on that CPU.
+
+	  With this option, the user can specify the min and max CPU
+	  utilization allowed for RUNNABLE tasks. The max utilization defines
+	  the maximum frequency a task should use while the min utilization
+	  defines the minimum frequency it should use.
+
+	  Both min and max utilization clamp values are hints to the scheduler,
+	  aiming at improving its frequency selection policy, but they do not
+	  enforce or grant any specific bandwidth for tasks.
+
+	  If in doubt, say N.
+
+config UCLAMP_BUCKETS_COUNT
+	int "Number of supported utilization clamp buckets"
+	range 5 20
+	default 5
+	depends on UCLAMP_TASK
+	help
+	  Defines the number of clamp buckets to use. The range of each bucket
+	  will be SCHED_CAPACITY_SCALE/UCLAMP_BUCKETS_COUNT. The higher the
+	  number of clamp buckets the finer their granularity and the higher
+	  the precision of clamping aggregation and tracking at run-time.
+
+	  For example, with the minimum configuration value we will have 5
+	  clamp buckets tracking 20% utilization each. A 25% boosted tasks will
+	  be refcounted in the [20..39]% bucket and will set the bucket clamp
+	  effective value to 25%.
+	  If a second 30% boosted task should be co-scheduled on the same CPU,
+	  that task will be refcounted in the same bucket of the first task and
+	  it will boost the bucket clamp effective value to 30%.
+	  The clamp effective value of a bucket is reset to its nominal value
+	  (20% in the example above) when there are no more tasks refcounted in
+	  that bucket.
+
+	  An additional boost/capping margin can be added to some tasks. In the
+	  example above the 25% task will be boosted to 30% until it exits the
+	  CPU. If that should be considered not acceptable on certain systems,
+	  it's always possible to reduce the margin by increasing the number of
+	  clamp buckets to trade off used memory for run-time tracking
+	  precision.
+
+	  If in doubt, use the default value.
+
+config SCHED_PROXY_EXEC
+	bool "Proxy Execution"
+	# Avoid some build failures w/ PREEMPT_RT until it can be fixed
+	depends on !PREEMPT_RT
+	# Need to investigate how to inform sched_ext of split contexts
+	depends on !SCHED_CLASS_EXT
+	# Not particularly useful until we get to multi-rq proxying
+	depends on EXPERT
+	help
+	  This option enables proxy execution, a mechanism for mutex-owning
+	  tasks to inherit the scheduling context of higher priority waiters.
+
+endmenu
+
+#
+# For architectures that support present-but-inaccessible (PROT_NONE) page
+# table entries detectable via pte_protnone() / pmd_protnone():
+#
+config ARCH_HAS_PTE_PROTNONE
+	bool
+
+#
+# For architectures that want to enable the support for NUMA-affine scheduler
+# balancing logic:
+#
+config ARCH_SUPPORTS_NUMA_BALANCING
+	bool
+
+#
+# For architectures that prefer to flush all TLBs after a number of pages
+# are unmapped instead of sending one IPI per page to flush. The architecture
+# must provide guarantees on what happens if a clean TLB cache entry is
+# written after the unmap. Details are in mm/rmap.c near the check for
+# should_defer_flush. The architecture should also consider if the full flush
+# and the refill costs are offset by the savings of sending fewer IPIs.
+config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+	bool
+
+config CC_HAS_INT128
+	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
+
+config CC_IMPLICIT_FALLTHROUGH
+	string
+	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
+	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
+
+config CC_MS_EXTENSIONS
+	string
+	default "-fms-anonymous-structs" if $(cc-option,-fms-anonymous-structs)
+	default "-fms-extensions"
+
+# Currently, disable gcc-10+ array-bounds globally.
+# It's still broken in gcc-13, so no upper bound yet.
+config GCC10_NO_ARRAY_BOUNDS
+	def_bool y
+
+config CC_NO_ARRAY_BOUNDS
+	bool
+	default y if CC_IS_GCC && GCC_VERSION >= 90000 && GCC10_NO_ARRAY_BOUNDS
+
+# Currently, disable -Wstringop-overflow for GCC globally.
+config GCC_NO_STRINGOP_OVERFLOW
+	def_bool y
+
+config CC_NO_STRINGOP_OVERFLOW
+	bool
+	default y if CC_IS_GCC && GCC_NO_STRINGOP_OVERFLOW
+
+config CC_STRINGOP_OVERFLOW
+	bool
+	default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW
+
+#
+# For architectures that know their GCC __int128 support is sound
+#
+config ARCH_SUPPORTS_INT128
+	bool
+
+# For architectures that (ab)use NUMA to represent different memory regions
+# all cpu-local but of different latencies, such as SuperH.
+#
+config ARCH_WANT_NUMA_VARIABLE_LOCALITY
+	bool
+
+config NUMA_BALANCING
+	bool "Memory placement aware NUMA scheduler"
+	depends on ARCH_SUPPORTS_NUMA_BALANCING
+	depends on ARCH_HAS_PTE_PROTNONE
+	depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
+	depends on SMP && NUMA_MIGRATION && !PREEMPT_RT
+	help
+	  This option adds support for automatic NUMA aware memory/task placement.
+	  The mechanism is quite primitive and is based on migrating memory when
+	  it has references to the node the task is running on.
+
+	  This system will be inactive on UMA systems.
+
+config SCHED_CACHE
+	bool "Cache aware load balance"
+	default y
+	depends on SMP
+	help
+	  When enabled, the scheduler will attempt to aggregate tasks from
+	  the same process onto a single Last Level Cache (LLC) domain when
+	  possible. This improves cache locality by keeping tasks that share
+	  resources within the same cache domain, reducing cache misses and
+	  lowering data access latency.
+
+config NUMA_BALANCING_DEFAULT_ENABLED
+	bool "Automatically enable NUMA aware memory/task placement"
+	default y
+	depends on NUMA_BALANCING
+	help
+	  If set, automatic NUMA balancing will be enabled if running on a NUMA
+	  machine.
+
+config SLAB_OBJ_EXT
+	bool
+
+menuconfig CGROUPS
+	bool "Control Group support"
+	select KERNFS
+	help
+	  This option adds support for grouping sets of processes together, for
+	  use with process control subsystems such as Cpusets, CFS, memory
+	  controls or device isolation.
+	  See
+		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
+		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
+					  and resource control)
+
+	  Say N if unsure.
+
+if CGROUPS
+
+config PAGE_COUNTER
+	bool
+
+config CGROUP_FAVOR_DYNMODS
+	bool "Favor dynamic modification latency reduction by default"
+	help
+	  This option enables the "favordynmods" mount option by default
+	  which reduces the latencies of dynamic cgroup modifications such
+	  as task migrations and controller on/offs at the cost of making
+	  hot path operations such as forks and exits more expensive.
+
+	  Say N if unsure.
+
+config MEMCG
+	bool "Memory controller"
+	select PAGE_COUNTER
+	select EVENTFD
+	select SLAB_OBJ_EXT
+	select VM_EVENT_COUNTERS
+	help
+	  Provides control over the memory footprint of tasks in a cgroup.
+
+config MEMCG_NMI_UNSAFE
+	bool
+	depends on MEMCG
+	depends on HAVE_NMI
+	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !ARCH_HAVE_NMI_SAFE_CMPXCHG
+	default y
+
+config MEMCG_NMI_SAFETY_REQUIRES_ATOMIC
+	bool
+	depends on MEMCG
+	depends on HAVE_NMI
+	depends on !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && ARCH_HAVE_NMI_SAFE_CMPXCHG
+	default y
+
+config MEMCG_V1
+	bool "Legacy cgroup v1 memory controller"
+	depends on MEMCG
+	default n
+	help
+	  Legacy cgroup v1 memory controller which has been deprecated by
+	  cgroup v2 implementation. The v1 is there for legacy applications
+	  which haven't migrated to the new cgroup v2 interface yet. If you
+	  do not have any such application then you are completely fine leaving
+	  this option disabled.
+
+	  Please note that feature set of the legacy memory controller is likely
+	  going to shrink due to deprecation process. New deployments with v1
+	  controller are highly discouraged.
+
+	  Say N if unsure.
+
+config BLK_CGROUP
+	bool "IO controller"
+	depends on BLOCK
+	default n
+	help
+	Generic block IO controller cgroup interface. This is the common
+	cgroup interface which should be used by various IO controlling
+	policies.
+
+	Currently, CFQ IO scheduler uses it to recognize task groups and
+	control disk bandwidth allocation (proportional time slice allocation)
+	to such task groups. It is also used by bio throttling logic in
+	block layer to implement upper limit in IO rates on a device.
+
+	This option only enables generic Block IO controller infrastructure.
+	One needs to also enable actual IO controlling logic/policy. For
+	enabling proportional weight division of disk bandwidth in CFQ, set
+	CONFIG_BFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
+	CONFIG_BLK_DEV_THROTTLING=y.
+
+	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
+
+config CGROUP_WRITEBACK
+	bool
+	depends on MEMCG && BLK_CGROUP
+	default y
+
+menuconfig CGROUP_SCHED
+	bool "CPU controller"
+	default n
+	help
+	  This feature lets CPU scheduler recognize task groups and control CPU
+	  bandwidth allocation to such task groups. It uses cgroups to group
+	  tasks.
+
+if CGROUP_SCHED
+config GROUP_SCHED_WEIGHT
+	def_bool n
+
+config GROUP_SCHED_BANDWIDTH
+	def_bool n
+
+config FAIR_GROUP_SCHED
+	bool "Group scheduling for SCHED_OTHER"
+	depends on CGROUP_SCHED
+	select GROUP_SCHED_WEIGHT
+	default CGROUP_SCHED
+
+config CFS_BANDWIDTH
+	bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
+	depends on FAIR_GROUP_SCHED
+	select GROUP_SCHED_BANDWIDTH
+	default n
+	help
+	  This option allows users to define CPU bandwidth rates (limits) for
+	  tasks running within the fair group scheduler.  Groups with no limit
+	  set are considered to be unconstrained and will run with no
+	  restriction.
+	  See Documentation/scheduler/sched-bwc.rst for more information.
+
+config RT_GROUP_SCHED
+	bool "Group scheduling for SCHED_RR/FIFO"
+	depends on CGROUP_SCHED
+	default n
+	help
+	  This feature lets you explicitly allocate real CPU bandwidth
+	  to task groups. If enabled, it will also make it impossible to
+	  schedule realtime tasks for non-root users until you allocate
+	  realtime bandwidth for them.
+	  See Documentation/scheduler/sched-rt-group.rst for more information.
+
+config RT_GROUP_SCHED_DEFAULT_DISABLED
+	bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO"
+	depends on RT_GROUP_SCHED
+	default n
+	help
+	  When set, the RT group scheduling is disabled by default. The option
+	  is in inverted form so that mere RT_GROUP_SCHED enables the group
+	  scheduling.
+
+	  Say N if unsure.
+
+config EXT_GROUP_SCHED
+	bool
+	depends on SCHED_CLASS_EXT && CGROUP_SCHED
+	select GROUP_SCHED_WEIGHT
+	select GROUP_SCHED_BANDWIDTH
+	default y
+
+endif #CGROUP_SCHED
+
+config EXT_SUB_SCHED
+        def_bool y
+        depends on SCHED_CLASS_EXT && CGROUPS
+
+config SCHED_MM_CID
+	def_bool y
+	depends on SMP && RSEQ
+
+config UCLAMP_TASK_GROUP
+	bool "Utilization clamping per group of tasks"
+	depends on CGROUP_SCHED
+	depends on UCLAMP_TASK
+	default n
+	help
+	  This feature enables the scheduler to track the clamped utilization
+	  of each CPU based on RUNNABLE tasks currently scheduled on that CPU.
+
+	  When this option is enabled, the user can specify a min and max
+	  CPU bandwidth which is allowed for each single task in a group.
+	  The max bandwidth allows to clamp the maximum frequency a task
+	  can use, while the min bandwidth allows to define a minimum
+	  frequency a task will always use.
+
+	  When task group based utilization clamping is enabled, an eventually
+	  specified task-specific clamp value is constrained by the cgroup
+	  specified clamp value. Both minimum and maximum task clamping cannot
+	  be bigger than the corresponding clamping defined at task group level.
+
+	  If in doubt, say N.
+
+config CGROUP_PIDS
+	bool "PIDs controller"
+	help
+	  Provides enforcement of process number limits in the scope of a
+	  cgroup. Any attempt to fork more processes than is allowed in the
+	  cgroup will fail. PIDs are fundamentally a global resource because it
+	  is fairly trivial to reach PID exhaustion before you reach even a
+	  conservative kmemcg limit. As a result, it is possible to grind a
+	  system to halt without being limited by other cgroup policies. The
+	  PIDs controller is designed to stop this from happening.
+
+	  It should be noted that organisational operations (such as attaching
+	  to a cgroup hierarchy) will *not* be blocked by the PIDs controller,
+	  since the PIDs limit only affects a process's ability to fork, not to
+	  attach to a cgroup.
+
+config CGROUP_RDMA
+	bool "RDMA controller"
+	help
+	  Provides enforcement of RDMA resources defined by IB stack.
+	  It is fairly easy for consumers to exhaust RDMA resources, which
+	  can result into resource unavailability to other consumers.
+	  RDMA controller is designed to stop this from happening.
+	  Attaching processes with active RDMA resources to the cgroup
+	  hierarchy is allowed even if can cross the hierarchy's limit.
+
+config CGROUP_DMEM
+	bool "Device memory controller (DMEM)"
+	select PAGE_COUNTER
+	help
+	  The DMEM controller allows compatible devices to restrict device
+	  memory usage based on the cgroup hierarchy.
+
+	  As an example, it allows you to restrict VRAM usage for applications
+	  in the DRM subsystem.
+
+config CGROUP_FREEZER
+	bool "Freezer controller"
+	help
+	  Provides a way to freeze and unfreeze all tasks in a
+	  cgroup.
+
+	  This option affects the ORIGINAL cgroup interface. The cgroup2 memory
+	  controller includes important in-kernel memory consumers per default.
+
+	  If you're using cgroup2, say N.
+
+config CGROUP_HUGETLB
+	bool "HugeTLB controller"
+	depends on HUGETLB_PAGE
+	select PAGE_COUNTER
+	default n
+	help
+	  Provides a cgroup controller for HugeTLB pages.
+	  When you enable this, you can put a per cgroup limit on HugeTLB usage.
+	  The limit is enforced during page fault. Since HugeTLB doesn't
+	  support page reclaim, enforcing the limit at page fault time implies
+	  that, the application will get SIGBUS signal if it tries to access
+	  HugeTLB pages beyond its limit. This requires the application to know
+	  beforehand how much HugeTLB pages it would require for its use. The
+	  control group is tracked in the third page lru pointer. This means
+	  that we cannot use the controller with huge page less than 3 pages.
+
+config CPUSETS
+	bool "Cpuset controller"
+	depends on SMP
+	select UNION_FIND
+	select CPU_ISOLATION
+	help
+	  This option will let you create and manage CPUSETs which
+	  allow dynamically partitioning a system into sets of CPUs and
+	  Memory Nodes and assigning tasks to run only within those sets.
+	  This is primarily useful on large SMP or NUMA systems.
+
+	  Say N if unsure.
+
+config CPUSETS_V1
+	bool "Legacy cgroup v1 cpusets controller"
+	depends on CPUSETS
+	default n
+	help
+	  Legacy cgroup v1 cpusets controller which has been deprecated by
+	  cgroup v2 implementation. The v1 is there for legacy applications
+	  which haven't migrated to the new cgroup v2 interface yet. Legacy
+	  interface includes cpuset filesystem and /proc/<pid>/cpuset. If you
+	  do not have any such application then you are completely fine leaving
+	  this option disabled.
+
+	  Say N if unsure.
+
+config PROC_PID_CPUSET
+	bool "Include legacy /proc/<pid>/cpuset file"
+	depends on CPUSETS_V1
+	default y
+
+config CGROUP_DEVICE
+	bool "Device controller"
+	help
+	  Provides a cgroup controller implementing whitelists for
+	  devices which a process in the cgroup can mknod or open.
+
+config CGROUP_CPUACCT
+	bool "Simple CPU accounting controller"
+	help
+	  Provides a simple controller for monitoring the
+	  total CPU consumed by the tasks in a cgroup.
+
+config CGROUP_PERF
+	bool "Perf controller"
+	depends on PERF_EVENTS
+	help
+	  This option extends the perf per-cpu mode to restrict monitoring
+	  to threads which belong to the cgroup specified and run on the
+	  designated cpu.  Or this can be used to have cgroup ID in samples
+	  so that it can monitor performance events among cgroups.
+
+	  Say N if unsure.
+
+config CGROUP_BPF
+	bool "Support for eBPF programs attached to cgroups"
+	depends on BPF_SYSCALL
+	select SOCK_CGROUP_DATA
+	help
+	  Allow attaching eBPF programs to a cgroup using the bpf(2)
+	  syscall command BPF_PROG_ATTACH.
+
+	  In which context these programs are accessed depends on the type
+	  of attachment. For instance, programs that are attached using
+	  BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
+	  inet sockets.
+
+config CGROUP_MISC
+	bool "Misc resource controller"
+	default n
+	help
+	  Provides a controller for miscellaneous resources on a host.
+
+	  Miscellaneous scalar resources are the resources on the host system
+	  which cannot be abstracted like the other cgroups. This controller
+	  tracks and limits the miscellaneous resources used by a process
+	  attached to a cgroup hierarchy.
+
+	  For more information, please check misc cgroup section in
+	  /Documentation/admin-guide/cgroup-v2.rst.
+
+config CGROUP_DEBUG
+	bool "Debug controller"
+	default n
+	depends on DEBUG_KERNEL
+	help
+	  This option enables a simple controller that exports
+	  debugging information about the cgroups framework. This
+	  controller is for control cgroup debugging only. Its
+	  interfaces are not stable.
+
+	  Say N.
+
+config SOCK_CGROUP_DATA
+	bool
+	default n
+
+endif # CGROUPS
+
+menuconfig NAMESPACES
+	bool "Namespaces support" if EXPERT
+	depends on MULTIUSER
+	default !EXPERT
+	help
+	  Provides the way to make tasks work with different objects using
+	  the same id. For example same IPC id may refer to different objects
+	  or same user id or pid may refer to different tasks when used in
+	  different namespaces.
+
+if NAMESPACES
+
+config UTS_NS
+	bool "UTS namespace"
+	default y
+	help
+	  In this namespace tasks see different info provided with the
+	  uname() system call
+
+config TIME_NS
+	bool "TIME namespace"
+	default y
+	help
+	  In this namespace boottime and monotonic clocks can be set.
+	  The time will keep going with the same pace.
+
+config TIME_NS_VDSO
+	def_bool TIME_NS && GENERIC_GETTIMEOFDAY
+
+config IPC_NS
+	bool "IPC namespace"
+	depends on (SYSVIPC || POSIX_MQUEUE)
+	default y
+	help
+	  In this namespace tasks work with IPC ids which correspond to
+	  different IPC objects in different namespaces.
+
+config USER_NS
+	bool "User namespace"
+	default n
+	help
+	  This allows containers, i.e. vservers, to use user namespaces
+	  to provide different user info for different servers.
+
+	  When user namespaces are enabled in the kernel it is
+	  recommended that the MEMCG option also be enabled and that
+	  user-space use the memory control groups to limit the amount
+	  of memory a memory unprivileged users can use.
+
+	  If unsure, say N.
+
+config PID_NS
+	bool "PID Namespaces"
+	default y
+	help
+	  Support process id namespaces.  This allows having multiple
+	  processes with the same pid as long as they are in different
+	  pid namespaces.  This is a building block of containers.
+
+config NET_NS
+	bool "Network namespace"
+	depends on NET
+	default y
+	help
+	  Allow user space to create what appear to be multiple instances
+	  of the network stack.
+
+endif # NAMESPACES
+
+config CHECKPOINT_RESTORE
+	bool "Checkpoint/restore support"
+	depends on PROC_FS
+	select PROC_CHILDREN
+	select KCMP
+	default n
+	help
+	  Enables additional kernel features in a sake of checkpoint/restore.
+	  In particular it adds auxiliary prctl codes to setup process text,
+	  data and heap segment sizes, and a few additional /proc filesystem
+	  entries.
+
+	  If unsure, say N here.
+
+config SCHED_AUTOGROUP
+	bool "Automatic process group scheduling"
+	select CGROUPS
+	select CGROUP_SCHED
+	select FAIR_GROUP_SCHED
+	help
+	  This option optimizes the scheduler for common desktop workloads by
+	  automatically creating and populating task groups.  This separation
+	  of workloads isolates aggressive CPU burners (like build jobs) from
+	  desktop applications.  Task group autogeneration is currently based
+	  upon task session.
+
+config RELAY
+	bool "Kernel->user space relay support (formerly relayfs)"
+	select IRQ_WORK
+	help
+	  This option enables support for relay interface support in
+	  certain file systems (such as debugfs).
+	  It is designed to provide an efficient mechanism for tools and
+	  facilities to relay large amounts of data from kernel space to
+	  user space.
+
+	  If unsure, say N.
+
+config BLK_DEV_INITRD
+	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
+	help
+	  The initial RAM filesystem is a ramfs which is loaded by the
+	  boot loader (loadlin or lilo) and that is mounted as root
+	  before the normal boot procedure. It is typically used to
+	  load modules needed to mount the "real" root file system,
+	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
+
+	  If RAM disk support (BLK_DEV_RAM) is also included, this
+	  also enables initial RAM disk (initrd) support and adds
+	  15 Kbytes (more on some other architectures) to the kernel size.
+
+	  If unsure say Y.
+
+if BLK_DEV_INITRD
+
+source "usr/Kconfig"
+
+endif
+
+config BOOT_CONFIG
+	bool "Boot config support"
+	select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED
+	help
+	  Extra boot config allows system admin to pass a config file as
+	  complemental extension of kernel cmdline when booting.
+	  The boot config file must be attached at the end of initramfs
+	  with checksum, size and magic word.
+	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
+
+	  If unsure, say Y.
+
+config BOOT_CONFIG_FORCE
+	bool "Force unconditional bootconfig processing"
+	depends on BOOT_CONFIG
+	default y if BOOT_CONFIG_EMBED
+	help
+	  With this Kconfig option set, BOOT_CONFIG processing is carried
+	  out even when the "bootconfig" kernel-boot parameter is omitted.
+	  In fact, with this Kconfig option set, there is no way to
+	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
+	  parameters.
+
+	  If unsure, say N.
+
+config BOOT_CONFIG_EMBED
+	bool "Embed bootconfig file in the kernel"
+	depends on BOOT_CONFIG
+	help
+	  Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the
+	  kernel. Usually, the bootconfig file is loaded with the initrd
+	  image. But if the system doesn't support initrd, this option will
+	  help you by embedding a bootconfig file while building the kernel.
+
+	  If unsure, say N.
+
+config BOOT_CONFIG_EMBED_FILE
+	string "Embedded bootconfig file path"
+	depends on BOOT_CONFIG_EMBED
+	help
+	  Specify a bootconfig file which will be embedded to the kernel.
+	  This bootconfig will be used if there is no initrd or no other
+	  bootconfig in the initrd.
+
+config ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG
+	bool
+	help
+	  Silent symbol; no C code reads it directly. Architectures
+	  select it once their setup_arch() calls
+	  xbc_prepend_embedded_cmdline() before parse_early_param().
+	  Its only role is to gate the user-visible
+	  CMDLINE_FROM_BOOTCONFIG option per-arch, the same
+	  ARCH_SUPPORTS_* idiom used by ARCH_SUPPORTS_CFI, etc.
+
+config CMDLINE_FROM_BOOTCONFIG
+	bool "Render embedded bootconfig as kernel cmdline at build time"
+	depends on BOOT_CONFIG_EMBED_FILE != ""
+	depends on ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG
+	depends on CMDLINE = ""
+	default n
+	help
+	  Render the "kernel" subtree of the embedded bootconfig file into a
+	  flat cmdline string at kernel build time and prepend it to
+	  boot_command_line during early architecture setup. This makes
+	  early_param() handlers (e.g. mem=, earlycon=, loglevel=) see the
+	  values supplied via the embedded bootconfig.
+
+	  The runtime bootconfig parser is unaffected, so tree-structured
+	  consumers such as ftrace boot-time tracing keep working.
+
+	  Note: when an initrd also carries a bootconfig, its "kernel"
+	  subtree is still parsed at runtime, but the embedded "kernel"
+	  keys remain in boot_command_line for parse_early_param() and
+	  end up later than the initrd keys in saved_command_line, so
+	  parse_args() last-wins favors the embedded values. If you need
+	  initrd to override embedded kernel.* keys, leave this option
+	  off.
+
+	  If unsure, say N.
+
+config CMDLINE_LOG_WRAP_IDEAL_LEN
+	int "Length to try to wrap the cmdline when logged at boot"
+	default 1021
+	range 0 1021
+	help
+	  At boot time, the kernel command line is logged to the console.
+	  The log message will start with the prefix "Kernel command line: ".
+	  The log message will attempt to be wrapped (split into multiple log
+	  messages) at spaces based on CMDLINE_LOG_WRAP_IDEAL_LEN characters.
+	  If wrapping happens, each log message will start with the prefix and
+	  all but the last message will end with " \". Messages may exceed the
+	  ideal length if a place to wrap isn't found before the specified
+	  number of characters.
+
+	  A value of 0 disables wrapping, though be warned that the maximum
+	  length of a log message (1021 characters) may cause the cmdline to
+	  be truncated.
+
+config INITRAMFS_PRESERVE_MTIME
+	bool "Preserve cpio archive mtimes in initramfs"
+	depends on BLK_DEV_INITRD
+	default y
+	help
+	  Each entry in an initramfs cpio archive carries an mtime value. When
+	  enabled, extracted cpio items take this mtime, with directory mtime
+	  setting deferred until after creation of any child entries.
+
+	  If unsure, say Y.
+
+config INITRAMFS_TEST
+	bool "Test initramfs cpio archive extraction" if !KUNIT_ALL_TESTS
+	depends on BLK_DEV_INITRD && KUNIT=y
+	default KUNIT_ALL_TESTS
+	help
+	  Build KUnit tests for initramfs. See Documentation/dev-tools/kunit
+
+choice
+	prompt "Compiler optimization level"
+	default CC_OPTIMIZE_FOR_PERFORMANCE
+
+config CC_OPTIMIZE_FOR_PERFORMANCE
+	bool "Optimize for performance (-O2)"
+	help
+	  This is the default optimization level for the kernel, building
+	  with the "-O2" compiler flag for best performance and most
+	  helpful compile-time warnings.
+
+config CC_OPTIMIZE_FOR_SIZE
+	bool "Optimize for size (-Os)"
+	help
+	  Choosing this option will pass "-Os" to your compiler resulting
+	  in a smaller kernel.
+
+endchoice
+
+config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	bool
+	help
+	  This requires that the arch annotates or otherwise protects
+	  its external entry points from being discarded. Linker scripts
+	  must also merge .text.*, .data.*, and .bss.* correctly into
+	  output sections. Care must be taken not to pull in unrelated
+	  sections (e.g., '.text.init'). Typically '.' in section names
+	  is used to distinguish them from label names / C identifiers.
+
+config LD_DEAD_CODE_DATA_ELIMINATION
+	bool "Dead code and data elimination (EXPERIMENTAL)"
+	depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	depends on EXPERT
+	depends on $(cc-option,-ffunction-sections -fdata-sections)
+	depends on $(ld-option,--gc-sections)
+	help
+	  Enable this if you want to do dead code and data elimination with
+	  the linker by compiling with -ffunction-sections -fdata-sections,
+	  and linking with --gc-sections.
+
+	  This can reduce on disk and in-memory size of the kernel
+	  code and static data, particularly for small configs and
+	  on small systems. This has the possibility of introducing
+	  silently broken kernel if the required annotations are not
+	  present. This option is not well tested yet, so use at your
+	  own risk.
+
+config LD_ORPHAN_WARN
+	def_bool y
+	depends on ARCH_WANT_LD_ORPHAN_WARN
+	depends on $(ld-option,--orphan-handling=warn)
+	depends on $(ld-option,--orphan-handling=error)
+
+config LD_ORPHAN_WARN_LEVEL
+	string
+	depends on LD_ORPHAN_WARN
+	default "error" if WERROR
+	default "warn"
+
+config HAVE_UID16
+	bool
+
+config SYSCTL_EXCEPTION_TRACE
+	bool
+	help
+	  Enable support for /proc/sys/debug/exception-trace.
+
+config SYSCTL_ARCH_UNALIGN_NO_WARN
+	bool
+	help
+	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
+	  Allows arch to define/use @no_unaligned_warning to possibly warn
+	  about unaligned access emulation going on under the hood.
+
+config SYSCTL_ARCH_UNALIGN_ALLOW
+	bool
+	help
+	  Enable support for /proc/sys/kernel/unaligned-trap
+	  Allows arches to define/use @unaligned_enabled to runtime toggle
+	  the unaligned access emulation.
+	  see arch/parisc/kernel/unaligned.c for reference
+
+config SYSFS_SYSCALL
+	bool "Sysfs syscall support"
+	default n
+	help
+	  sys_sysfs is an obsolete system call no longer supported in libc.
+	  Note that disabling this option is more secure but might break
+	  compatibility with some systems.
+
+	  If unsure say N here.
+
+config HAVE_PCSPKR_PLATFORM
+	bool
+
+menuconfig EXPERT
+	bool "Configure standard kernel features (expert users)"
+	# Unhide debug options, to make the on-by-default options visible
+	select DEBUG_KERNEL
+	help
+	  This option allows certain base kernel options and settings
+	  to be disabled or tweaked. This is for specialized
+	  environments which can tolerate a "non-standard" kernel.
+	  Only use this if you really know what you are doing.
+
+config UID16
+	bool "Enable 16-bit UID system calls" if EXPERT
+	depends on HAVE_UID16 && MULTIUSER
+	default y
+	help
+	  This enables the legacy 16-bit UID syscall wrappers.
+
+config MULTIUSER
+	bool "Multiple users, groups and capabilities support" if EXPERT
+	default y
+	help
+	  This option enables support for non-root users, groups and
+	  capabilities.
+
+	  If you say N here, all processes will run with UID 0, GID 0, and all
+	  possible capabilities.  Saying N here also compiles out support for
+	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
+	  setgid, and capset.
+
+	  If unsure, say Y here.
+
+config SGETMASK_SYSCALL
+	bool "sgetmask/ssetmask syscalls support" if EXPERT
+	default PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
+	help
+	  sys_sgetmask and sys_ssetmask are obsolete system calls
+	  no longer supported in libc but still enabled by default in some
+	  architectures.
+
+	  If unsure, leave the default option here.
+
+config FHANDLE
+	bool "open by fhandle syscalls" if EXPERT
+	select EXPORTFS
+	default y
+	help
+	  If you say Y here, a user level program will be able to map
+	  file names to handle and then later use the handle for
+	  different file system operations. This is useful in implementing
+	  userspace file servers, which now track files using handles instead
+	  of names. The handle would remain the same even if file names
+	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
+	  syscalls.
+
+config POSIX_TIMERS
+	bool "Posix Clocks & timers" if EXPERT
+	default y
+	help
+	  This includes native support for POSIX timers to the kernel.
+	  Some embedded systems have no use for them and therefore they
+	  can be configured out to reduce the size of the kernel image.
+
+	  When this option is disabled, the following syscalls won't be
+	  available: timer_create, timer_gettime: timer_getoverrun,
+	  timer_settime, timer_delete, clock_adjtime, getitimer,
+	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
+	  clock_getres and clock_nanosleep syscalls will be limited to
+	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
+
+	  If unsure say y.
+
+config PRINTK
+	default y
+	bool "Enable support for printk" if EXPERT
+	select IRQ_WORK
+	help
+	  This option enables normal printk support. Removing it
+	  eliminates most of the message strings from the kernel image
+	  and makes the kernel more or less silent. As this makes it
+	  very difficult to diagnose system problems, saying N here is
+	  strongly discouraged.
+
+config PRINTK_RINGBUFFER_KUNIT_TEST
+	tristate "KUnit Test for the printk ringbuffer" if !KUNIT_ALL_TESTS
+	depends on PRINTK && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the printk ringbuffer KUnit test suite.
+
+	  For more information on KUnit and unit tests in general, please refer
+	  to the KUnit documentation.
+
+	  If unsure, say N.
+
+config BUG
+	bool "BUG() support" if EXPERT
+	default y
+	help
+	  Disabling this option eliminates support for BUG and WARN, reducing
+	  the size of your kernel image and potentially quietly ignoring
+	  numerous fatal conditions. You should only consider disabling this
+	  option for embedded systems with no facilities for reporting errors.
+	  Just say Y.
+
+config ELF_CORE
+	depends on COREDUMP
+	default y
+	bool "Enable ELF core dumps" if EXPERT
+	help
+	  Enable support for generating core dumps. Disabling saves about 4k.
+
+
+config PCSPKR_PLATFORM
+	bool "Enable PC-Speaker support" if EXPERT
+	depends on HAVE_PCSPKR_PLATFORM
+	select I8253_LOCK
+	default y
+	help
+	  This option allows to disable the internal PC-Speaker
+	  support, saving some memory.
+
+config BASE_SMALL
+	bool "Enable smaller-sized data structures for core" if EXPERT
+	help
+	  Enabling this option reduces the size of miscellaneous core
+	  kernel data structures. This saves memory on small machines,
+	  but may reduce performance.
+
+config FUTEX
+	bool "Enable futex support" if EXPERT
+	depends on !(SPARC32 && SMP)
+	default y
+	imply RT_MUTEXES
+	help
+	  Disabling this option will cause the kernel to be built without
+	  support for "fast userspace mutexes".  The resulting kernel may not
+	  run glibc-based applications correctly.
+
+config FUTEX_PI
+	bool
+	depends on FUTEX && RT_MUTEXES
+	default y
+
+config FUTEX_PRIVATE_HASH
+	bool
+	depends on FUTEX && !BASE_SMALL && MMU
+	default y
+
+config FUTEX_MPOL
+	bool
+	depends on FUTEX && NUMA
+	default y
+
+config HAVE_FUTEX_ROBUST_UNLOCK
+	bool
+
+config FUTEX_ROBUST_UNLOCK
+	def_bool FUTEX && GENERIC_IRQ_ENTRY && RSEQ && HAVE_FUTEX_ROBUST_UNLOCK
+
+config EPOLL
+	bool "Enable eventpoll support" if EXPERT
+	default y
+	help
+	  Disabling this option will cause the kernel to be built without
+	  support for epoll family of system calls.
+
+config SIGNALFD
+	bool "Enable signalfd() system call" if EXPERT
+	default y
+	help
+	  Enable the signalfd() system call that allows to receive signals
+	  on a file descriptor.
+
+	  If unsure, say Y.
+
+config TIMERFD
+	bool "Enable timerfd() system call" if EXPERT
+	default y
+	help
+	  Enable the timerfd() system call that allows to receive timer
+	  events on a file descriptor.
+
+	  If unsure, say Y.
+
+config EVENTFD
+	bool "Enable eventfd() system call" if EXPERT
+	default y
+	help
+	  Enable the eventfd() system call that allows to receive both
+	  kernel notification (ie. KAIO) or userspace notifications.
+
+	  If unsure, say Y.
+
+config SHMEM
+	bool "Use full shmem filesystem" if EXPERT
+	default y
+	depends on MMU
+	help
+	  The shmem is an internal filesystem used to manage shared memory.
+	  It is backed by swap and manages resource limits. It is also exported
+	  to userspace as tmpfs if TMPFS is enabled. Disabling this
+	  option replaces shmem and tmpfs with the much simpler ramfs code,
+	  which may be appropriate on small systems without swap.
+
+config AIO
+	bool "Enable AIO support" if EXPERT
+	default y
+	help
+	  This option enables POSIX asynchronous I/O which may by used
+	  by some high performance threaded applications. Disabling
+	  this option saves about 7k.
+
+config IO_URING
+	bool "Enable IO uring support" if EXPERT
+	select IO_WQ
+	default y
+	help
+	  This option enables support for the io_uring interface, enabling
+	  applications to submit and complete IO through submission and
+	  completion rings that are shared between the kernel and application.
+
+config GCOV_PROFILE_URING
+	bool "Enable GCOV profiling on the io_uring subsystem"
+	depends on IO_URING && GCOV_KERNEL
+	help
+	  Enable GCOV profiling on the io_uring subsystem, to facilitate
+	  code coverage testing.
+
+	  If unsure, say N.
+
+	  Note that this will have a negative impact on the performance of
+	  the io_uring subsystem, hence this should only be enabled for
+	  specific test purposes.
+
+config IO_URING_MOCK_FILE
+	tristate "Enable io_uring mock files (Experimental)" if EXPERT
+	default n
+	depends on IO_URING
+	help
+	  Enable mock files for io_uring subsystem testing. The ABI might
+	  still change, so it's still experimental and should only be enabled
+	  for specific test purposes.
+
+	  If unsure, say N.
+
+config ADVISE_SYSCALLS
+	bool "Enable madvise/fadvise syscalls" if EXPERT
+	default y
+	help
+	  This option enables the madvise and fadvise syscalls, used by
+	  applications to advise the kernel about their future memory or file
+	  usage, improving performance. If building an embedded system where no
+	  applications use these syscalls, you can disable this option to save
+	  space.
+
+config MEMBARRIER
+	bool "Enable membarrier() system call" if EXPERT
+	default y
+	help
+	  Enable the membarrier() system call that allows issuing memory
+	  barriers across all running threads, which can be used to distribute
+	  the cost of user-space memory barriers asymmetrically by transforming
+	  pairs of memory barriers into pairs consisting of membarrier() and a
+	  compiler barrier.
+
+	  If unsure, say Y.
+
+config KCMP
+	bool "Enable kcmp() system call" if EXPERT
+	help
+	  Enable the kernel resource comparison system call. It provides
+	  user-space with the ability to compare two processes to see if they
+	  share a common resource, such as a file descriptor or even virtual
+	  memory space.
+
+	  If unsure, say N.
+
+config RSEQ
+	bool "Enable rseq() system call" if EXPERT
+	default y
+	depends on HAVE_RSEQ
+	select MEMBARRIER
+	help
+	  Enable the restartable sequences system call. It provides a
+	  user-space cache for the current CPU number value, which
+	  speeds up getting the current CPU number from user-space,
+	  as well as an ABI to speed up user-space operations on
+	  per-CPU data.
+
+	  If unsure, say Y.
+
+config RSEQ_SLICE_EXTENSION
+	bool "Enable rseq-based time slice extension mechanism"
+	depends on RSEQ && HIGH_RES_TIMERS && GENERIC_ENTRY && HAVE_GENERIC_TIF_BITS
+	help
+	  Allows userspace to request a limited time slice extension when
+	  returning from an interrupt to user space via the RSEQ shared
+	  data ABI. If granted, that allows to complete a critical section,
+	  so that other threads are not stuck on a conflicted resource,
+	  while the task is scheduled out.
+
+	  If unsure, say N.
+
+config RSEQ_STATS
+	default n
+	bool "Enable lightweight statistics of restartable sequences" if EXPERT
+	depends on RSEQ && DEBUG_FS
+	help
+	  Enable lightweight counters which expose information about the
+	  frequency of RSEQ operations via debugfs. Mostly interesting for
+	  kernel debugging or performance analysis. While lightweight it's
+	  still adding code into the user/kernel mode transitions.
+
+	  If unsure, say N.
+
+config RSEQ_DEBUG_DEFAULT_ENABLE
+	default n
+	bool "Enable restartable sequences debug mode by default" if EXPERT
+	depends on RSEQ
+	help
+	  This enables the static branch for debug mode of restartable
+	  sequences.
+
+	  This also can be controlled on the kernel command line via the
+	  command line parameter "rseq_debug=0/1" and through debugfs.
+
+	  If unsure, say N.
+
+config DEBUG_RSEQ
+	default n
+	bool "Enable debugging of rseq() system call" if EXPERT
+	depends on RSEQ && DEBUG_KERNEL && !GENERIC_ENTRY
+	select RSEQ_DEBUG_DEFAULT_ENABLE
+	help
+	  Enable extra debugging checks for the rseq system call.
+
+	  If unsure, say N.
+
+config CACHESTAT_SYSCALL
+	bool "Enable cachestat() system call" if EXPERT
+	default y
+	help
+	  Enable the cachestat system call, which queries the page cache
+	  statistics of a file (number of cached pages, dirty pages,
+	  pages marked for writeback, (recently) evicted pages).
+
+	  If unsure say Y here.
+
+config KALLSYMS
+	bool "Load all symbols for debugging/ksymoops" if EXPERT
+	default y
+	help
+	  Say Y here to let the kernel print out symbolic crash information and
+	  symbolic stack backtraces. This increases the size of the kernel
+	  somewhat, as all symbols have to be loaded into the kernel image.
+
+config KALLSYMS_SELFTEST
+	bool "Test the basic functions and performance of kallsyms"
+	depends on KALLSYMS
+	default n
+	help
+	  Test the basic functions and performance of some interfaces, such as
+	  kallsyms_lookup_name. It also calculates the compression rate of the
+	  kallsyms compression algorithm for the current symbol set.
+
+	  Start self-test automatically after system startup. Suggest executing
+	  "dmesg | grep kallsyms_selftest" to collect test results. "finish" is
+	  displayed in the last line, indicating that the test is complete.
+
+config KALLSYMS_ALL
+	bool "Include all symbols in kallsyms"
+	depends on DEBUG_KERNEL && KALLSYMS
+	help
+	  Normally kallsyms only contains the symbols of functions for nicer
+	  OOPS messages and backtraces (i.e., symbols from the text and inittext
+	  sections). This is sufficient for most cases. And only if you want to
+	  enable kernel live patching, or other less common use cases (e.g.,
+	  when a debugger is used) all symbols are required (i.e., names of
+	  variables from the data sections, etc).
+
+	  This option makes sure that all symbols are loaded into the kernel
+	  image (i.e., symbols from all sections) in cost of increased kernel
+	  size (depending on the kernel configuration, it may be 300KiB or
+	  something like this).
+
+	  Say N unless you really need all symbols, or kernel live patching.
+
+# end of the "standard kernel features (expert users)" menu
+
+config ARCH_HAS_MEMBARRIER_CALLBACKS
+	bool
+
+config ARCH_HAS_MEMBARRIER_SYNC_CORE
+	bool
+
+config ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
+	bool
+	help
+	  Control MSEAL_SYSTEM_MAPPINGS access based on architecture.
+
+	  A 64-bit kernel is required for the memory sealing feature.
+	  No specific hardware features from the CPU are needed.
+
+	  To enable this feature, the architecture needs to update their
+	  special mappings calls to include the sealing flag and confirm
+	  that it doesn't unmap/remap system mappings during the life
+	  time of the process. The existence of this flag for an architecture
+	  implies that it does not require the remapping of the system
+	  mappings during process lifetime, so sealing these mappings is safe
+	  from a kernel perspective.
+
+	  After the architecture enables this, a distribution can set
+	  CONFIG_MSEAL_SYSTEM_MAPPINGS to manage access to the feature.
+
+	  For complete descriptions of memory sealing, please see
+	  Documentation/userspace-api/mseal.rst
+
+config HAVE_PERF_EVENTS
+	bool
+	help
+	  See tools/perf/design.txt for details.
+
+config GUEST_PERF_EVENTS
+	bool
+	depends on HAVE_PERF_EVENTS
+
+config PERF_GUEST_MEDIATED_PMU
+	bool
+	depends on GUEST_PERF_EVENTS
+
+config PERF_USE_VMALLOC
+	bool
+	help
+	  See tools/perf/design.txt for details
+
+menu "Kernel Performance Events And Counters"
+
+config PERF_EVENTS
+	bool "Kernel performance events and counters"
+	default y if PROFILING
+	depends on HAVE_PERF_EVENTS
+	select IRQ_WORK
+	help
+	  Enable kernel support for various performance events provided
+	  by software and hardware.
+
+	  Software events are supported either built-in or via the
+	  use of generic tracepoints.
+
+	  Most modern CPUs support performance events via performance
+	  counter registers. These registers count the number of certain
+	  types of hw events: such as instructions executed, cachemisses
+	  suffered, or branches mis-predicted - without slowing down the
+	  kernel or applications. These registers can also trigger interrupts
+	  when a threshold number of events have passed - and can thus be
+	  used to profile the code that runs on that CPU.
+
+	  The Linux Performance Event subsystem provides an abstraction of
+	  these software and hardware event capabilities, available via a
+	  system call and used by the "perf" utility in tools/perf/. It
+	  provides per task and per CPU counters, and it provides event
+	  capabilities on top of those.
+
+	  Say Y if unsure.
+
+config DEBUG_PERF_USE_VMALLOC
+	default n
+	bool "Debug: use vmalloc to back perf mmap() buffers"
+	depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
+	select PERF_USE_VMALLOC
+	help
+	  Use vmalloc memory to back perf mmap() buffers.
+
+	  Mostly useful for debugging the vmalloc code on platforms
+	  that don't require it.
+
+	  Say N if unsure.
+
+endmenu
+
+config SYSTEM_DATA_VERIFICATION
+	def_bool n
+	select SYSTEM_TRUSTED_KEYRING
+	select KEYS
+	select CRYPTO
+	select CRYPTO_RSA
+	select ASYMMETRIC_KEY_TYPE
+	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	select ASN1
+	select OID_REGISTRY
+	select X509_CERTIFICATE_PARSER
+	select PKCS7_MESSAGE_PARSER
+	help
+	  Provide PKCS#7 message verification using the contents of the system
+	  trusted keyring to provide public keys.  This then can be used for
+	  module verification, kexec image verification and firmware blob
+	  verification.
+
+config PROFILING
+	bool "Profiling support"
+	help
+	  Say Y here to enable the extended profiling support mechanisms used
+	  by profilers.
+
+config RUST
+	bool "Rust support"
+	depends on HAVE_RUST
+	depends on RUST_IS_AVAILABLE
+	select EXTENDED_MODVERSIONS if MODVERSIONS
+	depends on !MODVERSIONS || GENDWARFKSYMS
+	depends on !GCC_PLUGIN_RANDSTRUCT
+	depends on !RANDSTRUCT
+	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
+	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
+	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
+	depends on !KASAN || CC_IS_CLANG
+	depends on !KASAN_SW_TAGS || RUSTC_VERSION >= 109600
+	help
+	  Enables Rust support in the kernel.
+
+	  This allows other Rust-related options, like drivers written in Rust,
+	  to be selected.
+
+	  It is also required to be able to load external kernel modules
+	  written in Rust.
+
+	  See Documentation/rust/ for more information.
+
+	  If unsure, say N.
+
+source "rust/kernel/Kconfig.test"
+
+config RUSTC_VERSION_TEXT
+	string
+	depends on RUST
+	default "$(RUSTC_VERSION_TEXT)"
+	help
+	  See `CC_VERSION_TEXT`.
+
+config BINDGEN_VERSION_TEXT
+	string
+	depends on RUST
+	default "$(shell,$(BINDGEN) --version 2>/dev/null)"
+
+#
+# Place an empty function call at each tracepoint site. Can be
+# dynamically changed for a probe function.
+#
+config TRACEPOINTS
+	bool
+	select TASKS_TRACE_RCU
+
+source "kernel/Kconfig.kexec"
+
+source "kernel/liveupdate/Kconfig"
+
+endmenu		# General setup
+
+source "arch/Kconfig"
+
+config RT_MUTEXES
+	bool
+	default y if PREEMPT_RT
+
+config MODULE_SIG_FORMAT
+	def_bool n
+	select SYSTEM_DATA_VERIFICATION
+
+source "kernel/module/Kconfig"
+
+config INIT_ALL_POSSIBLE
+	bool
+	help
+	  Back when each arch used to define their own cpu_online_mask and
+	  cpu_possible_mask, some of them chose to initialize cpu_possible_mask
+	  with all 1s, and others with all 0s.  When they were centralised,
+	  it was better to provide this option than to break all the archs
+	  and have several arch maintainers pursuing me down dark alleys.
+
+source "block/Kconfig"
+
+config PREEMPT_NOTIFIERS
+	bool
+
+config PADATA
+	depends on SMP
+	bool
+
+config ASN1
+	tristate
+	help
+	  Build a simple ASN.1 grammar compiler that produces a bytecode output
+	  that can be interpreted by the ASN.1 stream decoder and used to
+	  inform it as to what tags are to be expected in a stream and what
+	  functions to call on what tags.
+
+source "kernel/Kconfig.locks"
+
+config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	bool
+
+config ARCH_HAS_PREPARE_SYNC_CORE_CMD
+	bool
+
+config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
+	bool
+
+# It may be useful for an architecture to override the definitions of the
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
+# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
+# different calling convention for syscalls. They can also override the
+# macros for not-implemented syscalls in kernel/sys_ni.c and
+# kernel/time/posix-stubs.c. All these overrides need to be available in
+# <asm/syscall_wrapper.h>.
+config ARCH_HAS_SYSCALL_WRAPPER
+	def_bool n
diff --git a/init/Makefile b/init/Makefile
new file mode 100644
index 000000000..d6f75d890
--- /dev/null
+++ b/init/Makefile
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+ccflags-y := -fno-function-sections -fno-data-sections
+
+obj-y                          := main.o version.o mounts.o
+ifneq ($(CONFIG_BLK_DEV_INITRD),y)
+obj-y                          += noinitramfs.o
+else
+obj-$(CONFIG_BLK_DEV_INITRD)   += initramfs.o
+endif
+obj-$(CONFIG_GENERIC_CALIBRATE_DELAY) += calibrate.o
+obj-$(CONFIG_INITRAMFS_TEST)   += initramfs_test.o
+
+obj-y                          += init_task.o
+
+mounts-y			:= do_mounts.o
+mounts-$(CONFIG_BLK_DEV_RAM)	+= do_mounts_rd.o
+mounts-$(CONFIG_BLK_DEV_INITRD)	+= do_mounts_initrd.o
+
+#
+# UTS_VERSION
+#
+
+smp-flag-$(CONFIG_SMP)			:= SMP
+preempt-flag-$(CONFIG_PREEMPT_BUILD)	:= PREEMPT
+preempt-flag-$(CONFIG_PREEMPT_DYNAMIC)	:= PREEMPT_DYNAMIC
+preempt-flag-$(CONFIG_PREEMPT_RT)	:= PREEMPT_RT
+
+build-version = $(or $(KBUILD_BUILD_VERSION), $(build-version-auto))
+build-timestamp = $(or $(KBUILD_BUILD_TIMESTAMP), $(build-timestamp-auto))
+
+# Maximum length of UTS_VERSION is 64 chars
+filechk_uts_version = \
+	utsver=$$(echo '$(pound)'"$(build-version)" $(smp-flag-y) $(preempt-flag-y) "$(build-timestamp)" | cut -b -64); \
+	echo '$(pound)'define UTS_VERSION \""$${utsver}"\"
+
+#
+# Build version.c with temporary UTS_VERSION
+#
+
+$(obj)/utsversion-tmp.h: FORCE
+	$(call filechk,uts_version)
+
+clean-files += utsversion-tmp.h
+
+$(obj)/version.o: $(obj)/utsversion-tmp.h
+CFLAGS_version.o := -include $(obj)/utsversion-tmp.h
+
+#
+# Build version-timestamp.c with final UTS_VERSION
+#
+
+include/generated/utsversion.h: build-version-auto = $(shell $(srctree)/scripts/build-version)
+include/generated/utsversion.h: build-timestamp-auto = $(shell LC_ALL=C date)
+include/generated/utsversion.h: FORCE
+	$(call filechk,uts_version)
+
+$(obj)/version-timestamp.o: include/generated/utsversion.h
+CFLAGS_version-timestamp.o := -include include/generated/utsversion.h
diff --git a/init/calibrate.c b/init/calibrate.c
new file mode 100644
index 000000000..2bfe97034
--- /dev/null
+++ b/init/calibrate.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+/* calibrate.c: default delay calibration
+ *
+ * Excised from init/main.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kstrtox.h>
+#include <linux/percpu.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+
+unsigned long lpj_fine;
+unsigned long preset_lpj;
+
+static int __init lpj_setup(char *str)
+{
+	return kstrtoul(str, 0, &preset_lpj) == 0;
+}
+
+__setup("lpj=", lpj_setup);
+
+#ifdef CONFIG_ARCH_HAS_DELAY_TIMER
+
+/* This routine uses the delay_read_timer() routine and gets the
+ * loops per jiffy directly, instead of guessing it using delay().
+ * Also, this code tries to handle non-maskable asynchronous events
+ * (like SMIs)
+ */
+#define DELAY_CALIBRATION_TICKS			((HZ < 100) ? 1 : (HZ/100))
+#define MAX_DIRECT_CALIBRATION_RETRIES		5
+
+static unsigned long calibrate_delay_direct(void)
+{
+	unsigned long pre_start, start, post_start;
+	unsigned long pre_end, end, post_end;
+	unsigned long start_jiffies;
+	unsigned long timer_rate_min, timer_rate_max;
+	unsigned long good_timer_sum = 0;
+	unsigned long good_timer_count = 0;
+	unsigned long measured_times[MAX_DIRECT_CALIBRATION_RETRIES];
+	int max = -1; /* index of measured_times with max/min values or not set */
+	int min = -1;
+	int i;
+
+	if (!delay_read_timer(&pre_start))
+		return 0;
+
+	/*
+	 * A simple loop like
+	 *	while ( jiffies < start_jiffies+1)
+	 *		start = delay_read_timer();
+	 * will not do. As we don't really know whether jiffy switch
+	 * happened first or timer_value was read first. And some asynchronous
+	 * event can happen between these two events introducing errors in lpj.
+	 *
+	 * So, we do
+	 * 1. pre_start <- When we are sure that jiffy switch hasn't happened
+	 * 2. check jiffy switch
+	 * 3. start <- timer value before or after jiffy switch
+	 * 4. post_start <- When we are sure that jiffy switch has happened
+	 *
+	 * Note, we don't know anything about order of 2 and 3.
+	 * Now, by looking at post_start and pre_start difference, we can
+	 * check whether any asynchronous event happened or not
+	 */
+
+	for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
+		pre_start = 0;
+		delay_read_timer(&start);
+		start_jiffies = jiffies;
+		while (time_before_eq(jiffies, start_jiffies + 1)) {
+			pre_start = start;
+			delay_read_timer(&start);
+		}
+		delay_read_timer(&post_start);
+
+		pre_end = 0;
+		end = post_start;
+		while (time_before_eq(jiffies, start_jiffies + 1 +
+					       DELAY_CALIBRATION_TICKS)) {
+			pre_end = end;
+			delay_read_timer(&end);
+		}
+		delay_read_timer(&post_end);
+
+		timer_rate_max = (post_end - pre_start) /
+					DELAY_CALIBRATION_TICKS;
+		timer_rate_min = (pre_end - post_start) /
+					DELAY_CALIBRATION_TICKS;
+
+		/*
+		 * If the upper limit and lower limit of the timer_rate is
+		 * >= 12.5% apart, redo calibration.
+		 */
+		if (start >= post_end)
+			printk(KERN_NOTICE "calibrate_delay_direct() ignoring "
+					"timer_rate as we had a TSC wrap around"
+					" start=%lu >=post_end=%lu\n",
+				start, post_end);
+		if (start < post_end && pre_start != 0 && pre_end != 0 &&
+		    (timer_rate_max - timer_rate_min) < (timer_rate_max >> 3)) {
+			good_timer_count++;
+			good_timer_sum += timer_rate_max;
+			measured_times[i] = timer_rate_max;
+			if (max < 0 || timer_rate_max > measured_times[max])
+				max = i;
+			if (min < 0 || timer_rate_max < measured_times[min])
+				min = i;
+		} else
+			measured_times[i] = 0;
+
+	}
+
+	/*
+	 * Find the maximum & minimum - if they differ too much throw out the
+	 * one with the largest difference from the mean and try again...
+	 */
+	while (good_timer_count > 1) {
+		unsigned long estimate;
+		unsigned long maxdiff;
+
+		/* compute the estimate */
+		estimate = (good_timer_sum/good_timer_count);
+		maxdiff = estimate >> 3;
+
+		/* if range is within 12% let's take it */
+		if ((measured_times[max] - measured_times[min]) < maxdiff)
+			return estimate;
+
+		/* ok - drop the worse value and try again... */
+		good_timer_sum = 0;
+		good_timer_count = 0;
+		if ((measured_times[max] - estimate) <
+				(estimate - measured_times[min])) {
+			printk(KERN_NOTICE "calibrate_delay_direct() dropping "
+					"min bogoMips estimate %d = %lu\n",
+				min, measured_times[min]);
+			measured_times[min] = 0;
+			min = max;
+		} else {
+			printk(KERN_NOTICE "calibrate_delay_direct() dropping "
+					"max bogoMips estimate %d = %lu\n",
+				max, measured_times[max]);
+			measured_times[max] = 0;
+			max = min;
+		}
+
+		for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
+			if (measured_times[i] == 0)
+				continue;
+			good_timer_count++;
+			good_timer_sum += measured_times[i];
+			if (measured_times[i] < measured_times[min])
+				min = i;
+			if (measured_times[i] > measured_times[max])
+				max = i;
+		}
+
+	}
+
+	printk(KERN_NOTICE "calibrate_delay_direct() failed to get a good "
+	       "estimate for loops_per_jiffy.\nProbably due to long platform "
+		"interrupts. Consider using \"lpj=\" boot option.\n");
+	return 0;
+}
+#else
+static unsigned long calibrate_delay_direct(void)
+{
+	return 0;
+}
+#endif
+
+/*
+ * This is the number of bits of precision for the loops_per_jiffy.  Each
+ * time we refine our estimate after the first takes 1.5/HZ seconds, so try
+ * to start with a good estimate.
+ * For the boot cpu we can skip the delay calibration and assign it a value
+ * calculated based on the timer frequency.
+ * For the rest of the CPUs we cannot assume that the timer frequency is same as
+ * the cpu frequency, hence do the calibration for those.
+ */
+#define LPS_PREC 8
+
+static unsigned long calibrate_delay_converge(void)
+{
+	/* First stage - slowly accelerate to find initial bounds */
+	unsigned long lpj, lpj_base, ticks, loopadd, loopadd_base, chop_limit;
+	int trials = 0, band = 0, trial_in_band = 0;
+
+	lpj = (1<<12);
+
+	/* wait for "start of" clock tick */
+	ticks = jiffies;
+	while (ticks == jiffies)
+		; /* nothing */
+	/* Go .. */
+	ticks = jiffies;
+	do {
+		if (++trial_in_band == (1<<band)) {
+			++band;
+			trial_in_band = 0;
+		}
+		__delay(lpj * band);
+		trials += band;
+	} while (ticks == jiffies);
+	/*
+	 * We overshot, so retreat to a clear underestimate. Then estimate
+	 * the largest likely undershoot. This defines our chop bounds.
+	 */
+	trials -= band;
+	loopadd_base = lpj * band;
+	lpj_base = lpj * trials;
+
+recalibrate:
+	lpj = lpj_base;
+	loopadd = loopadd_base;
+
+	/*
+	 * Do a binary approximation to get lpj set to
+	 * equal one clock (up to LPS_PREC bits)
+	 */
+	chop_limit = lpj >> LPS_PREC;
+	while (loopadd > chop_limit) {
+		lpj += loopadd;
+		ticks = jiffies;
+		while (ticks == jiffies)
+			; /* nothing */
+		ticks = jiffies;
+		__delay(lpj);
+		if (jiffies != ticks)	/* longer than 1 tick */
+			lpj -= loopadd;
+		loopadd >>= 1;
+	}
+	/*
+	 * If we incremented every single time possible, presume we've
+	 * massively underestimated initially, and retry with a higher
+	 * start, and larger range. (Only seen on x86_64, due to SMIs)
+	 */
+	if (lpj + loopadd * 2 == lpj_base + loopadd_base * 2) {
+		lpj_base = lpj;
+		loopadd_base <<= 2;
+		goto recalibrate;
+	}
+
+	return lpj;
+}
+
+static DEFINE_PER_CPU(unsigned long, cpu_loops_per_jiffy) = { 0 };
+
+/*
+ * Check if cpu calibration delay is already known. For example,
+ * some processors with multi-core sockets may have all cores
+ * with the same calibration delay.
+ *
+ * Architectures should override this function if a faster calibration
+ * method is available.
+ */
+unsigned long __attribute__((weak)) calibrate_delay_is_known(void)
+{
+	return 0;
+}
+
+/*
+ * Indicate the cpu delay calibration is done. This can be used by
+ * architectures to stop accepting delay timer registrations after this point.
+ */
+
+void __attribute__((weak)) calibration_delay_done(void)
+{
+}
+
+void calibrate_delay(void)
+{
+	unsigned long lpj;
+	static bool printed;
+	int this_cpu = smp_processor_id();
+
+	if (per_cpu(cpu_loops_per_jiffy, this_cpu)) {
+		lpj = per_cpu(cpu_loops_per_jiffy, this_cpu);
+		if (!printed)
+			pr_info("Calibrating delay loop (skipped) "
+				"already calibrated this CPU");
+	} else if (preset_lpj) {
+		lpj = preset_lpj;
+		if (!printed)
+			pr_info("Calibrating delay loop (skipped) "
+				"preset value.. ");
+	} else if ((!printed) && lpj_fine) {
+		lpj = lpj_fine;
+		pr_info("Calibrating delay loop (skipped), "
+			"value calculated using timer frequency.. ");
+	} else if ((lpj = calibrate_delay_is_known())) {
+		;
+	} else if ((lpj = calibrate_delay_direct()) != 0) {
+		if (!printed)
+			pr_info("Calibrating delay using timer "
+				"specific routine.. ");
+	} else {
+		if (!printed)
+			pr_info("Calibrating delay loop... ");
+		lpj = calibrate_delay_converge();
+	}
+	per_cpu(cpu_loops_per_jiffy, this_cpu) = lpj;
+	if (!printed)
+		pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
+			lpj/(500000/HZ),
+			(lpj/(5000/HZ)) % 100, lpj);
+
+	loops_per_jiffy = lpj;
+	printed = true;
+
+	calibration_delay_done();
+}
diff --git a/init/do_mounts.c b/init/do_mounts.c
new file mode 100644
index 000000000..95e0b3a0f
--- /dev/null
+++ b/init/do_mounts.c
@@ -0,0 +1,520 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/ctype.h>
+#include <linux/fd.h>
+#include <linux/tty.h>
+#include <linux/suspend.h>
+#include <linux/root_dev.h>
+#include <linux/security.h>
+#include <linux/delay.h>
+#include <linux/mount.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/initrd.h>
+#include <linux/async.h>
+#include <linux/fs_struct.h>
+#include <linux/slab.h>
+#include <linux/ramfs.h>
+#include <linux/shmem_fs.h>
+#include <linux/ktime.h>
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/nfs_mount.h>
+#include <linux/raid/detect.h>
+#include <uapi/linux/mount.h>
+
+#include "do_mounts.h"
+
+int root_mountflags = MS_RDONLY | MS_SILENT;
+static char __initdata saved_root_name[64];
+static int root_wait;
+
+dev_t ROOT_DEV;
+
+static int __init readonly(char *str)
+{
+	if (*str)
+		return 0;
+	root_mountflags |= MS_RDONLY;
+	return 1;
+}
+
+static int __init readwrite(char *str)
+{
+	if (*str)
+		return 0;
+	root_mountflags &= ~MS_RDONLY;
+	return 1;
+}
+
+__setup("ro", readonly);
+__setup("rw", readwrite);
+
+static int __init root_dev_setup(char *line)
+{
+	strscpy(saved_root_name, line, sizeof(saved_root_name));
+	return 1;
+}
+
+__setup("root=", root_dev_setup);
+
+static int __init rootwait_setup(char *str)
+{
+	if (*str)
+		return 0;
+	root_wait = -1;
+	return 1;
+}
+
+__setup("rootwait", rootwait_setup);
+
+static int __init rootwait_timeout_setup(char *str)
+{
+	int sec;
+
+	if (kstrtoint(str, 0, &sec) || sec < 0) {
+		pr_warn("ignoring invalid rootwait value\n");
+		goto ignore;
+	}
+
+	if (check_mul_overflow(sec, MSEC_PER_SEC, &root_wait)) {
+		pr_warn("ignoring excessive rootwait value\n");
+		goto ignore;
+	}
+
+	return 1;
+
+ignore:
+	/* Fallback to indefinite wait */
+	root_wait = -1;
+
+	return 1;
+}
+
+__setup("rootwait=", rootwait_timeout_setup);
+
+static char * __initdata root_mount_data;
+static int __init root_data_setup(char *str)
+{
+	root_mount_data = str;
+	return 1;
+}
+
+static char * __initdata root_fs_names;
+static int __init fs_names_setup(char *str)
+{
+	root_fs_names = str;
+	return 1;
+}
+
+static unsigned int __initdata root_delay;
+static int __init root_delay_setup(char *str)
+{
+	if (kstrtouint(str, 0, &root_delay))
+		return 0;
+	return 1;
+}
+
+__setup("rootflags=", root_data_setup);
+__setup("rootfstype=", fs_names_setup);
+__setup("rootdelay=", root_delay_setup);
+
+/* This can return zero length strings. Caller should check */
+static int __init split_fs_names(char *page, size_t size)
+{
+	int count = 1;
+	char *p = page;
+
+	strscpy(p, root_fs_names, size);
+	while (*p++) {
+		if (p[-1] == ',') {
+			p[-1] = '\0';
+			count++;
+		}
+	}
+
+	return count;
+}
+
+static int __init do_mount_root(const char *name, const char *fs,
+				 const int flags, const void *data)
+{
+	struct super_block *s;
+	char *data_page = NULL;
+	int ret;
+
+	if (data) {
+		/* init_mount() requires a full page as fifth argument */
+		data_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!data_page)
+			return -ENOMEM;
+		strscpy_pad(data_page, data, PAGE_SIZE);
+	}
+
+	ret = init_mount(name, "/root", fs, flags, data_page);
+	if (ret)
+		goto out;
+
+	init_chdir("/root");
+	s = current->fs->pwd.dentry->d_sb;
+	ROOT_DEV = s->s_dev;
+	printk(KERN_INFO
+	       "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
+	       s->s_type->name,
+	       sb_rdonly(s) ? " readonly" : "",
+	       MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
+
+out:
+	kfree(data_page);
+	return ret;
+}
+
+void __init mount_root_generic(char *name, char *pretty_name, int flags)
+{
+	char *fs_names = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	char *p;
+	char b[BDEVNAME_SIZE];
+	int num_fs, i;
+
+	if (!fs_names)
+		panic("VFS: Unable to mount root fs: not enough memory");
+
+	scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
+		  MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
+	if (root_fs_names)
+		num_fs = split_fs_names(fs_names, PAGE_SIZE);
+	else
+		num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
+retry:
+	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
+		int err;
+
+		if (!*p)
+			continue;
+		err = do_mount_root(name, p, flags, root_mount_data);
+		switch (err) {
+			case 0:
+				goto out;
+			case -EACCES:
+			case -EINVAL:
+#ifdef CONFIG_BLOCK
+				init_flush_fput();
+#endif
+				continue;
+		}
+	        /*
+		 * Allow the user to distinguish between failed sys_open
+		 * and bad superblock on root device.
+		 * and give them a list of the available devices
+		 */
+		printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
+				pretty_name, b, err);
+		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
+		printk_all_partitions();
+
+		if (root_fs_names)
+			num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
+		if (!num_fs)
+			pr_err("Can't find any bdev filesystem to be used for mount!\n");
+		else {
+			pr_err("List of all bdev filesystems:\n");
+			for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
+				pr_err(" %s", p);
+			pr_err("\n");
+		}
+
+		panic("VFS: Unable to mount root fs on %s", b);
+	}
+	if (!(flags & SB_RDONLY)) {
+		flags |= SB_RDONLY;
+		goto retry;
+	}
+
+	printk("List of all partitions:\n");
+	printk_all_partitions();
+	printk("No filesystem could mount root, tried: ");
+	for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
+		printk(" %s", p);
+	printk("\n");
+	panic("VFS: Unable to mount root fs on \"%s\" or %s", pretty_name, b);
+out:
+	kfree(fs_names);
+}
+ 
+#ifdef CONFIG_ROOT_NFS
+
+#define NFSROOT_TIMEOUT_MIN	5
+#define NFSROOT_TIMEOUT_MAX	30
+#define NFSROOT_RETRY_MAX	5
+
+static void __init mount_nfs_root(void)
+{
+	char *root_dev, *root_data;
+	unsigned int timeout;
+	int try;
+
+	if (nfs_root_data(&root_dev, &root_data))
+		goto fail;
+
+	/*
+	 * The server or network may not be ready, so try several
+	 * times.  Stop after a few tries in case the client wants
+	 * to fall back to other boot methods.
+	 */
+	timeout = NFSROOT_TIMEOUT_MIN;
+	for (try = 1; ; try++) {
+		if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data))
+			return;
+		if (try > NFSROOT_RETRY_MAX)
+			break;
+
+		/* Wait, in case the server refused us immediately */
+		ssleep(timeout);
+		timeout <<= 1;
+		if (timeout > NFSROOT_TIMEOUT_MAX)
+			timeout = NFSROOT_TIMEOUT_MAX;
+	}
+fail:
+	pr_err("VFS: Unable to mount root fs via NFS.\n");
+}
+#else
+static inline void mount_nfs_root(void)
+{
+}
+#endif /* CONFIG_ROOT_NFS */
+
+#ifdef CONFIG_CIFS_ROOT
+
+#define CIFSROOT_TIMEOUT_MIN	5
+#define CIFSROOT_TIMEOUT_MAX	30
+#define CIFSROOT_RETRY_MAX	5
+
+static void __init mount_cifs_root(void)
+{
+	char *root_dev, *root_data;
+	unsigned int timeout;
+	int try;
+
+	if (cifs_root_data(&root_dev, &root_data))
+		goto fail;
+
+	timeout = CIFSROOT_TIMEOUT_MIN;
+	for (try = 1; ; try++) {
+		if (!do_mount_root(root_dev, "cifs", root_mountflags,
+				   root_data))
+			return;
+		if (try > CIFSROOT_RETRY_MAX)
+			break;
+
+		ssleep(timeout);
+		timeout <<= 1;
+		if (timeout > CIFSROOT_TIMEOUT_MAX)
+			timeout = CIFSROOT_TIMEOUT_MAX;
+	}
+fail:
+	pr_err("VFS: Unable to mount root fs via SMB.\n");
+}
+#else
+static inline void mount_cifs_root(void)
+{
+}
+#endif /* CONFIG_CIFS_ROOT */
+
+static bool __init fs_is_nodev(char *fstype)
+{
+	struct file_system_type *fs = get_fs_type(fstype);
+	bool ret = false;
+
+	if (fs) {
+		ret = !(fs->fs_flags & FS_REQUIRES_DEV);
+		put_filesystem(fs);
+	}
+
+	return ret;
+}
+
+static int __init mount_nodev_root(char *root_device_name)
+{
+	char *fs_names, *fstype;
+	int err = -EINVAL;
+	int num_fs, i;
+
+	fs_names = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!fs_names)
+		return -EINVAL;
+	num_fs = split_fs_names(fs_names, PAGE_SIZE);
+
+	for (i = 0, fstype = fs_names; i < num_fs;
+	     i++, fstype += strlen(fstype) + 1) {
+		if (!*fstype)
+			continue;
+		if (!fs_is_nodev(fstype))
+			continue;
+		err = do_mount_root(root_device_name, fstype, root_mountflags,
+				    root_mount_data);
+		if (!err)
+			break;
+	}
+
+	kfree(fs_names);
+	return err;
+}
+
+#ifdef CONFIG_BLOCK
+static void __init mount_block_root(char *root_device_name)
+{
+	int err = create_dev("/dev/root", ROOT_DEV);
+
+	if (err < 0)
+		pr_emerg("Failed to create /dev/root: %d\n", err);
+	mount_root_generic("/dev/root", root_device_name, root_mountflags);
+}
+#else
+static inline void mount_block_root(char *root_device_name)
+{
+}
+#endif /* CONFIG_BLOCK */
+
+void __init mount_root(char *root_device_name)
+{
+	switch (ROOT_DEV) {
+	case Root_NFS:
+		mount_nfs_root();
+		break;
+	case Root_CIFS:
+		mount_cifs_root();
+		break;
+	case Root_Generic:
+		mount_root_generic(root_device_name, root_device_name,
+				   root_mountflags);
+		break;
+	case 0:
+		if (root_device_name && root_fs_names &&
+		    mount_nodev_root(root_device_name) == 0)
+			break;
+		fallthrough;
+	default:
+		mount_block_root(root_device_name);
+		break;
+	}
+}
+
+/* wait for any asynchronous scanning to complete */
+static void __init wait_for_root(char *root_device_name)
+{
+	ktime_t end;
+
+	if (ROOT_DEV != 0)
+		return;
+
+	pr_info("Waiting for root device %s...\n", root_device_name);
+
+	end = ktime_add_ms(ktime_get_raw(), root_wait);
+
+	while (!driver_probe_done() ||
+	       early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
+		msleep(5);
+		if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
+			break;
+	}
+
+	async_synchronize_full();
+
+}
+
+static dev_t __init parse_root_device(char *root_device_name)
+{
+	int error;
+	dev_t dev;
+
+	if (!strncmp(root_device_name, "mtd", 3) ||
+	    !strncmp(root_device_name, "ubi", 3))
+		return Root_Generic;
+	if (strcmp(root_device_name, "/dev/nfs") == 0)
+		return Root_NFS;
+	if (strcmp(root_device_name, "/dev/cifs") == 0)
+		return Root_CIFS;
+	if (strcmp(root_device_name, "/dev/ram") == 0)
+		return Root_RAM0;
+
+	error = early_lookup_bdev(root_device_name, &dev);
+	if (error) {
+		if (error == -EINVAL && root_wait) {
+			pr_err("Disabling rootwait; root= is invalid.\n");
+			root_wait = 0;
+		}
+		return 0;
+	}
+	return dev;
+}
+
+/*
+ * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
+ */
+void __init prepare_namespace(void)
+{
+	if (root_delay) {
+		printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
+		       root_delay);
+		ssleep(root_delay);
+	}
+
+	/*
+	 * wait for the known devices to complete their probing
+	 *
+	 * Note: this is a potential source of long boot delays.
+	 * For example, it is not atypical to wait 5 seconds here
+	 * for the touchpad of a laptop to initialize.
+	 */
+	wait_for_device_probe();
+
+	md_run_setup();
+
+	if (saved_root_name[0])
+		ROOT_DEV = parse_root_device(saved_root_name);
+
+	initrd_load();
+
+	if (root_wait)
+		wait_for_root(saved_root_name);
+	mount_root(saved_root_name);
+	devtmpfs_mount();
+
+	if (init_pivot_root(".", ".")) {
+		pr_err("VFS: Failed to pivot into new rootfs\n");
+		return;
+	}
+	if (init_umount(".", MNT_DETACH)) {
+		pr_err("VFS: Failed to unmount old rootfs\n");
+		return;
+	}
+	pr_info("VFS: Pivoted into new rootfs\n");
+}
+
+static bool is_tmpfs;
+static int rootfs_init_fs_context(struct fs_context *fc)
+{
+	if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
+		return shmem_init_fs_context(fc);
+
+	return ramfs_init_fs_context(fc);
+}
+
+struct file_system_type rootfs_fs_type = {
+	.name		= "rootfs",
+	.init_fs_context = rootfs_init_fs_context,
+	.kill_sb	= kill_anon_super,
+};
+
+void __init init_rootfs(void)
+{
+	if (IS_ENABLED(CONFIG_TMPFS)) {
+		if (!saved_root_name[0] && !root_fs_names)
+			is_tmpfs = true;
+		else if (root_fs_names && !!strstr(root_fs_names, "tmpfs"))
+			is_tmpfs = true;
+	}
+}
diff --git a/init/do_mounts.h b/init/do_mounts.h
new file mode 100644
index 000000000..a386ee531
--- /dev/null
+++ b/init/do_mounts.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/syscalls.h>
+#include <linux/unistd.h>
+#include <linux/slab.h>
+#include <linux/mount.h>
+#include <linux/major.h>
+#include <linux/root_dev.h>
+#include <linux/init_syscalls.h>
+#include <linux/task_work.h>
+#include <linux/file.h>
+
+void  mount_root_generic(char *name, char *pretty_name, int flags);
+void  mount_root(char *root_device_name);
+extern int root_mountflags;
+
+static inline __init int create_dev(char *name, dev_t dev)
+{
+	init_unlink(name);
+	return init_mknod(name, S_IFBLK | 0600, new_encode_dev(dev));
+}
+
+#ifdef CONFIG_BLK_DEV_RAM
+int __init rd_load_image(void);
+#else
+static inline int rd_load_image(void) { return 0; }
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init initrd_load(void);
+#else
+static inline void initrd_load(void) { }
+#endif
+
+/* Ensure that async file closing finished to prevent spurious errors. */
+static inline void init_flush_fput(void)
+{
+	flush_delayed_fput();
+	task_work_run();
+}
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
new file mode 100644
index 000000000..892e69ab4
--- /dev/null
+++ b/init/do_mounts_initrd.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/unistd.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/initrd.h>
+
+#include "do_mounts.h"
+
+unsigned long initrd_start, initrd_end;
+int initrd_below_start_ok;
+static int __initdata mount_initrd = 1;
+
+phys_addr_t phys_initrd_start __initdata;
+unsigned long phys_initrd_size __initdata;
+
+static int __init no_initrd(char *str)
+{
+	pr_warn("noinitrd option is deprecated and will be removed soon\n");
+	mount_initrd = 0;
+	return 1;
+}
+
+__setup("noinitrd", no_initrd);
+
+static int __init early_initrdmem(char *p)
+{
+	phys_addr_t start;
+	unsigned long size;
+	char *endp;
+
+	start = memparse(p, &endp);
+	if (*endp == ',') {
+		size = memparse(endp + 1, NULL);
+
+		phys_initrd_start = start;
+		phys_initrd_size = size;
+	}
+	return 0;
+}
+early_param("initrdmem", early_initrdmem);
+
+static int __init early_initrd(char *p)
+{
+	return early_initrdmem(p);
+}
+early_param("initrd", early_initrd);
+
+void __init initrd_load(void)
+{
+	if (mount_initrd) {
+		create_dev("/dev/ram", Root_RAM0);
+		/*
+		 * Load the initrd data into /dev/ram0.
+		 */
+		if (rd_load_image()) {
+			pr_warn("using deprecated initrd support, will be removed in January 2027; "
+				"use initramfs instead or (as a last resort) /sys/firmware/initrd; "
+				"see section \"Workaround\" in "
+				"https://lore.kernel.org/lkml/20251010094047.3111495-1-safinaskar@gmail.com\n");
+		}
+	}
+	init_unlink("/initrd.image");
+}
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
new file mode 100644
index 000000000..48bfab2fc
--- /dev/null
+++ b/init/do_mounts_rd.c
@@ -0,0 +1,315 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/minix_fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/romfs_fs.h>
+#include <uapi/linux/cramfs_fs.h>
+#include <linux/initrd.h>
+#include <linux/string.h>
+#include <linux/string_choices.h>
+#include <linux/slab.h>
+
+#include "do_mounts.h"
+#include "../fs/squashfs/squashfs_fs.h"
+
+#include <linux/decompress/generic.h>
+
+static struct file *in_file, *out_file;
+static loff_t in_pos, out_pos;
+
+int __initdata rd_image_start;		/* starting block # of image */
+
+static int __init ramdisk_start_setup(char *str)
+{
+	pr_warn("ramdisk_start= option is deprecated and will be removed soon\n");
+	return kstrtoint(str, 0, &rd_image_start) == 0;
+}
+__setup("ramdisk_start=", ramdisk_start_setup);
+
+static int __init crd_load(decompress_fn deco);
+
+/*
+ * This routine tries to find a RAM disk image to load, and returns the
+ * number of blocks to read for a non-compressed image, 0 if the image
+ * is a compressed image, and -1 if an image with the right magic
+ * numbers could not be found.
+ *
+ * We currently check for the following magic numbers:
+ *	minix
+ *	ext2
+ *	romfs
+ *	cramfs
+ *	squashfs
+ *	gzip
+ *	bzip2
+ *	lzma
+ *	xz
+ *	lzo
+ *	lz4
+ */
+static int __init
+identify_ramdisk_image(struct file *file, loff_t pos,
+		decompress_fn *decompressor)
+{
+	const int size = 512;
+	struct minix_super_block *minixsb;
+	struct romfs_super_block *romfsb;
+	struct cramfs_super *cramfsb;
+	struct squashfs_super_block *squashfsb;
+	int nblocks = -1;
+	unsigned char *buf;
+	const char *compress_name;
+	unsigned long n;
+	int start_block = rd_image_start;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	minixsb = (struct minix_super_block *) buf;
+	romfsb = (struct romfs_super_block *) buf;
+	cramfsb = (struct cramfs_super *) buf;
+	squashfsb = (struct squashfs_super_block *) buf;
+	memset(buf, 0xe5, size);
+
+	/*
+	 * Read block 0 to test for compressed kernel
+	 */
+	pos = start_block * BLOCK_SIZE;
+	kernel_read(file, buf, size, &pos);
+
+	*decompressor = decompress_method(buf, size, &compress_name);
+	if (compress_name) {
+		printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
+		       compress_name, start_block);
+		if (!*decompressor)
+			printk(KERN_EMERG
+			       "RAMDISK: %s decompressor not configured!\n",
+			       compress_name);
+		nblocks = 0;
+		goto done;
+	}
+
+	/* romfs is at block zero too */
+	if (romfsb->word0 == ROMSB_WORD0 &&
+	    romfsb->word1 == ROMSB_WORD1) {
+		printk(KERN_NOTICE
+		       "RAMDISK: romfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	if (cramfsb->magic == CRAMFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: cramfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/* squashfs is at block zero too */
+	if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: squashfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
+			 >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/*
+	 * Read 512 bytes further to check if cramfs is padded
+	 */
+	pos = start_block * BLOCK_SIZE + 0x200;
+	kernel_read(file, buf, size, &pos);
+
+	if (cramfsb->magic == CRAMFS_MAGIC) {
+		printk(KERN_NOTICE
+		       "RAMDISK: cramfs filesystem found at block %d\n",
+		       start_block);
+		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
+		goto done;
+	}
+
+	/*
+	 * Read block 1 to test for minix and ext2 superblock
+	 */
+	pos = (start_block + 1) * BLOCK_SIZE;
+	kernel_read(file, buf, size, &pos);
+
+	/* Try minix */
+	if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
+	    minixsb->s_magic == MINIX_SUPER_MAGIC2) {
+		printk(KERN_NOTICE
+		       "RAMDISK: Minix filesystem found at block %d\n",
+		       start_block);
+		nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
+		goto done;
+	}
+
+	/* Try ext2 */
+	n = ext2_image_size(buf);
+	if (n) {
+		printk(KERN_NOTICE
+		       "RAMDISK: ext2 filesystem found at block %d\n",
+		       start_block);
+		nblocks = n;
+		goto done;
+	}
+
+	printk(KERN_NOTICE
+	       "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
+	       start_block);
+
+done:
+	kfree(buf);
+	return nblocks;
+}
+
+static unsigned long nr_blocks(struct file *file)
+{
+	struct inode *inode = file->f_mapping->host;
+
+	if (!S_ISBLK(inode->i_mode))
+		return 0;
+	return i_size_read(inode) >> 10;
+}
+
+int __init rd_load_image(void)
+{
+	int res = 0;
+	unsigned long rd_blocks, devblocks, nr_disks;
+	int nblocks, i;
+	char *buf = NULL;
+	unsigned short rotate = 0;
+	decompress_fn decompressor = NULL;
+	char rotator[4] = { '|' , '/' , '-' , '\\' };
+
+	out_file = filp_open("/dev/ram", O_RDWR, 0);
+	if (IS_ERR(out_file))
+		goto out;
+
+	in_file = filp_open("/initrd.image", O_RDONLY, 0);
+	if (IS_ERR(in_file))
+		goto noclose_input;
+
+	in_pos = rd_image_start * BLOCK_SIZE;
+	nblocks = identify_ramdisk_image(in_file, in_pos, &decompressor);
+	if (nblocks < 0)
+		goto done;
+
+	if (nblocks == 0) {
+		if (crd_load(decompressor) == 0)
+			goto successful_load;
+		goto done;
+	}
+
+	/*
+	 * NOTE NOTE: nblocks is not actually blocks but
+	 * the number of kibibytes of data to load into a ramdisk.
+	 */
+	rd_blocks = nr_blocks(out_file);
+	if (nblocks > rd_blocks) {
+		printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
+		       nblocks, rd_blocks);
+		goto done;
+	}
+
+	/*
+	 * OK, time to copy in the data
+	 */
+	devblocks = nblocks;
+
+	if (devblocks == 0) {
+		printk(KERN_ERR "RAMDISK: could not determine device size\n");
+		goto done;
+	}
+
+	buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
+	if (!buf) {
+		printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
+		goto done;
+	}
+
+	nr_disks = (nblocks - 1) / devblocks + 1;
+	pr_notice("RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
+		  nblocks, nr_disks, str_plural(nr_disks));
+	for (i = 0; i < nblocks; i++) {
+		if (i && (i % devblocks == 0)) {
+			pr_cont("done disk #1.\n");
+			rotate = 0;
+			fput(in_file);
+			break;
+		}
+		kernel_read(in_file, buf, BLOCK_SIZE, &in_pos);
+		kernel_write(out_file, buf, BLOCK_SIZE, &out_pos);
+		if (!IS_ENABLED(CONFIG_S390) && !(i % 16)) {
+			pr_cont("%c\b", rotator[rotate & 0x3]);
+			rotate++;
+		}
+	}
+	pr_cont("done.\n");
+
+successful_load:
+	res = 1;
+done:
+	fput(in_file);
+noclose_input:
+	fput(out_file);
+out:
+	kfree(buf);
+	init_unlink("/dev/ram");
+	return res;
+}
+
+static int exit_code;
+static int decompress_error;
+
+static long __init compr_fill(void *buf, unsigned long len)
+{
+	long r = kernel_read(in_file, buf, len, &in_pos);
+	if (r < 0)
+		printk(KERN_ERR "RAMDISK: error while reading compressed data");
+	else if (r == 0)
+		printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
+	return r;
+}
+
+static long __init compr_flush(void *window, unsigned long outcnt)
+{
+	long written = kernel_write(out_file, window, outcnt, &out_pos);
+	if (written != outcnt) {
+		if (decompress_error == 0)
+			printk(KERN_ERR
+			       "RAMDISK: incomplete write (%ld != %ld)\n",
+			       written, outcnt);
+		decompress_error = 1;
+		return -1;
+	}
+	return outcnt;
+}
+
+static void __init error(char *x)
+{
+	printk(KERN_ERR "%s\n", x);
+	exit_code = 1;
+	decompress_error = 1;
+}
+
+static int __init crd_load(decompress_fn deco)
+{
+	int result;
+
+	if (!deco) {
+		pr_emerg("Invalid ramdisk decompression routine.  "
+			 "Select appropriate config option.\n");
+		panic("Could not decompress initial ramdisk image.");
+	}
+
+	result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
+	if (decompress_error)
+		result = 1;
+	return result;
+}
diff --git a/init/init_task.c b/init/init_task.c
new file mode 100644
index 000000000..adb207cd9
--- /dev/null
+++ b/init/init_task.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init_task.h>
+#include <linux/export.h>
+#include <linux/mqueue.h>
+#include <linux/sched.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/rt.h>
+#include <linux/sched/task.h>
+#include <linux/sched/ext.h>
+#include <linux/sched/exec_state.h>
+#include <linux/user_namespace.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/audit.h>
+#include <linux/numa.h>
+#include <linux/scs.h>
+#include <linux/plist.h>
+
+#include <linux/uaccess.h>
+
+static struct signal_struct init_signals = {
+	.nr_threads	= 1,
+	.thread_head	= LIST_HEAD_INIT(init_task.thread_node),
+	.wait_chldexit	= __WAIT_QUEUE_HEAD_INITIALIZER(init_signals.wait_chldexit),
+	.shared_pending	= {
+		.list = LIST_HEAD_INIT(init_signals.shared_pending.list),
+		.signal =  {{0}}
+	},
+	.multiprocess	= HLIST_HEAD_INIT,
+	.rlim		= INIT_RLIMITS,
+#ifdef CONFIG_CGROUPS
+	.cgroup_threadgroup_rwsem	= __RWSEM_INITIALIZER(init_signals.cgroup_threadgroup_rwsem),
+#endif
+	.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
+	.exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
+#ifdef CONFIG_POSIX_TIMERS
+	.posix_timers		= HLIST_HEAD_INIT,
+	.ignored_posix_timers	= HLIST_HEAD_INIT,
+	.cputimer		= {
+		.cputime_atomic	= INIT_CPUTIME_ATOMIC,
+	},
+#endif
+	INIT_CPU_TIMERS(init_signals)
+	.pids = {
+		[PIDTYPE_PID]	= &init_struct_pid,
+		[PIDTYPE_TGID]	= &init_struct_pid,
+		[PIDTYPE_PGID]	= &init_struct_pid,
+		[PIDTYPE_SID]	= &init_struct_pid,
+	},
+	INIT_PREV_CPUTIME(init_signals)
+};
+
+static struct sighand_struct init_sighand = {
+	.count		= REFCOUNT_INIT(1),
+	.action		= { { { .sa_handler = SIG_DFL, } }, },
+	.siglock	= __SPIN_LOCK_UNLOCKED(init_sighand.siglock),
+	.signalfd_wqh	= __WAIT_QUEUE_HEAD_INITIALIZER(init_sighand.signalfd_wqh),
+};
+
+/* init to 2 - one for init_task, one to ensure it is never freed */
+struct task_exec_state init_task_exec_state = {
+	.count		= REFCOUNT_INIT(2),
+	.dumpable	= TASK_DUMPABLE_OWNER,
+	.user_ns	= &init_user_ns,
+};
+
+#ifdef CONFIG_SHADOW_CALL_STACK
+unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = {
+	[(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC
+};
+#endif
+
+/* init to 2 - one for init_task, one to ensure it is never freed */
+static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) };
+
+/*
+ * The initial credentials for the initial task
+ */
+static struct cred init_cred = {
+	.usage			= ATOMIC_INIT(4),
+	.uid			= GLOBAL_ROOT_UID,
+	.gid			= GLOBAL_ROOT_GID,
+	.suid			= GLOBAL_ROOT_UID,
+	.sgid			= GLOBAL_ROOT_GID,
+	.euid			= GLOBAL_ROOT_UID,
+	.egid			= GLOBAL_ROOT_GID,
+	.fsuid			= GLOBAL_ROOT_UID,
+	.fsgid			= GLOBAL_ROOT_GID,
+	.securebits		= SECUREBITS_DEFAULT,
+	.cap_inheritable	= CAP_EMPTY_SET,
+	.cap_permitted		= CAP_FULL_SET,
+	.cap_effective		= CAP_FULL_SET,
+	.cap_bset		= CAP_FULL_SET,
+	.user			= INIT_USER,
+	.user_ns		= &init_user_ns,
+	.group_info		= &init_groups,
+	.ucounts		= &init_ucounts,
+};
+
+/*
+ * Set up the first task table, touch at your own risk!. Base=0,
+ * limit=0x1fffff (=2MB)
+ */
+struct task_struct init_task __aligned(L1_CACHE_BYTES) = {
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	.thread_info	= INIT_THREAD_INFO(init_task),
+	.stack_refcount	= REFCOUNT_INIT(1),
+#endif
+	.__state	= 0,
+	.stack		= init_stack,
+	.usage		= REFCOUNT_INIT(2),
+	.flags		= PF_KTHREAD,
+	.prio		= MAX_PRIO - 20,
+	.static_prio	= MAX_PRIO - 20,
+	.normal_prio	= MAX_PRIO - 20,
+	.policy		= SCHED_NORMAL,
+	.cpus_ptr	= &init_task.cpus_mask,
+	.user_cpus_ptr	= NULL,
+	.cpus_mask	= CPU_MASK_ALL,
+	.max_allowed_capacity	= SCHED_CAPACITY_SCALE,
+	.nr_cpus_allowed= NR_CPUS,
+	.mm		= NULL,
+	.active_mm	= &init_mm,
+	.exec_state	= &init_task_exec_state,
+	.restart_block	= {
+		.fn = do_no_restart_syscall,
+	},
+	.se		= {
+		.group_node 	= LIST_HEAD_INIT(init_task.se.group_node),
+	},
+	.rt		= {
+		.run_list	= LIST_HEAD_INIT(init_task.rt.run_list),
+		.time_slice	= RR_TIMESLICE,
+	},
+	.tasks		= LIST_HEAD_INIT(init_task.tasks),
+#ifdef CONFIG_SMP
+	.pushable_tasks	= PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO),
+#endif
+#ifdef CONFIG_CGROUP_SCHED
+	.sched_task_group = &root_task_group,
+#endif
+#ifdef CONFIG_SCHED_CLASS_EXT
+	.scx		= {
+		.dsq_list.node	= LIST_HEAD_INIT(init_task.scx.dsq_list.node),
+		.sticky_cpu	= -1,
+		.holding_cpu	= -1,
+		.runnable_cpu	= -1,
+		.runnable_node	= LIST_HEAD_INIT(init_task.scx.runnable_node),
+		.runnable_at	= INITIAL_JIFFIES,
+		.ddsp_dsq_id	= SCX_DSQ_INVALID,
+		.slice		= SCX_SLICE_DFL,
+	},
+#endif
+	.ptraced	= LIST_HEAD_INIT(init_task.ptraced),
+	.ptrace_entry	= LIST_HEAD_INIT(init_task.ptrace_entry),
+	.real_parent	= &init_task,
+	.parent		= &init_task,
+	.children	= LIST_HEAD_INIT(init_task.children),
+	.sibling	= LIST_HEAD_INIT(init_task.sibling),
+	.group_leader	= &init_task,
+	RCU_POINTER_INITIALIZER(real_cred, &init_cred),
+	RCU_POINTER_INITIALIZER(cred, &init_cred),
+	.comm		= INIT_TASK_COMM,
+	.thread		= INIT_THREAD,
+	.real_fs	= &init_fs,
+	.fs		= &init_fs,
+	.files		= &init_files,
+#ifdef CONFIG_IO_URING
+	.io_uring	= NULL,
+#endif
+	.signal		= &init_signals,
+	.sighand	= &init_sighand,
+	.nsproxy	= &init_nsproxy,
+	.pending	= {
+		.list = LIST_HEAD_INIT(init_task.pending.list),
+		.signal = {{0}}
+	},
+	.blocked	= {{0}},
+	.alloc_lock	= __SPIN_LOCK_UNLOCKED(init_task.alloc_lock),
+	.journal_info	= NULL,
+	INIT_CPU_TIMERS(init_task)
+	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.pi_lock),
+	.blocked_lock	= __RAW_SPIN_LOCK_UNLOCKED(init_task.blocked_lock),
+	.timer_slack_ns = 50000, /* 50 usec default slack */
+	.thread_pid	= &init_struct_pid,
+	.thread_node	= LIST_HEAD_INIT(init_signals.thread_head),
+#ifdef CONFIG_AUDIT
+	.loginuid	= INVALID_UID,
+	.sessionid	= AUDIT_SID_UNSET,
+#endif
+#ifdef CONFIG_PERF_EVENTS
+	.perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
+	.perf_event_list = LIST_HEAD_INIT(init_task.perf_event_list),
+#endif
+#ifdef CONFIG_PREEMPT_RCU
+	.rcu_read_lock_nesting = 0,
+	.rcu_read_unlock_special.s = 0,
+	.rcu_node_entry = LIST_HEAD_INIT(init_task.rcu_node_entry),
+	.rcu_blocked_node = NULL,
+#endif
+#ifdef CONFIG_TASKS_RCU
+	.rcu_tasks_holdout = false,
+	.rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list),
+	.rcu_tasks_idle_cpu = -1,
+	.rcu_tasks_exit_list = LIST_HEAD_INIT(init_task.rcu_tasks_exit_list),
+#endif
+#ifdef CONFIG_TASKS_TRACE_RCU
+	.trc_reader_nesting = 0,
+#endif
+#ifdef CONFIG_CPUSETS
+	.mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
+						 &init_task.alloc_lock),
+#endif
+	.blocked_donor = NULL,
+#ifdef CONFIG_RT_MUTEXES
+	.pi_waiters	= RB_ROOT_CACHED,
+	.pi_top_task	= NULL,
+#endif
+	INIT_PREV_CPUTIME(init_task)
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+	.vtime.seqcount	= SEQCNT_ZERO(init_task.vtime_seqcount),
+	.vtime.starttime = 0,
+	.vtime.state	= VTIME_SYS,
+#endif
+#ifdef CONFIG_NUMA_BALANCING
+	.numa_preferred_nid = NUMA_NO_NODE,
+	.numa_group	= NULL,
+	.numa_faults	= NULL,
+#endif
+#ifdef CONFIG_SCHED_CACHE
+	.preferred_llc  = -1,
+	.pref_llc_queued  = 0,
+#endif
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+	.kasan_depth	= 1,
+#endif
+#ifdef CONFIG_KCSAN
+	.kcsan_ctx = {
+		.scoped_accesses	= {LIST_POISON1, NULL},
+	},
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+	.softirqs_enabled = 1,
+#endif
+#ifdef CONFIG_LOCKDEP
+	.lockdep_depth = 0, /* no locks held yet */
+	.curr_chain_key = INITIAL_CHAIN_KEY,
+	.lockdep_recursion = 0,
+#endif
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	.ret_stack		= NULL,
+	.tracing_graph_pause	= ATOMIC_INIT(0),
+#endif
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
+	.trace_recursion = 0,
+#endif
+#ifdef CONFIG_LIVEPATCH
+	.patch_state	= KLP_TRANSITION_IDLE,
+#endif
+#ifdef CONFIG_SECURITY
+	.security	= NULL,
+#endif
+#ifdef CONFIG_SECCOMP_FILTER
+	.seccomp	= { .filter_count = ATOMIC_INIT(0) },
+#endif
+#ifdef CONFIG_SCHED_MM_CID
+	.mm_cid		= { .cid = MM_CID_UNSET, },
+#endif
+};
+EXPORT_SYMBOL(init_task);
+
+/*
+ * Initial thread structure. Alignment of this is handled by a special
+ * linker map entry.
+ */
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+struct thread_info init_thread_info __init_thread_info = INIT_THREAD_INFO(init_task);
+#endif
diff --git a/init/initramfs.c b/init/initramfs.c
new file mode 100644
index 000000000..3cee8b50a
--- /dev/null
+++ b/init/initramfs.c
@@ -0,0 +1,798 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/async.h>
+#include <linux/delay.h>
+#include <linux/dirent.h>
+#include <linux/export.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/fs_struct.h>
+#include <linux/hex.h>
+#include <linux/init.h>
+#include <linux/init_syscalls.h>
+#include <linux/kstrtox.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/namei.h>
+#include <linux/overflow.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/umh.h>
+#include <linux/utime.h>
+
+#include <asm/byteorder.h>
+
+#include "do_mounts.h"
+#include "initramfs_internal.h"
+
+static __initdata bool csum_present;
+static __initdata u32 io_csum;
+
+static ssize_t __init xwrite(struct file *file, const unsigned char *p,
+		size_t count, loff_t *pos)
+{
+	ssize_t out = 0;
+
+	/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
+	while (count) {
+		ssize_t rv = kernel_write(file, p, count, pos);
+
+		if (rv < 0) {
+			if (rv == -EINTR || rv == -EAGAIN)
+				continue;
+			return out ? out : rv;
+		} else if (rv == 0)
+			break;
+
+		if (csum_present) {
+			ssize_t i;
+
+			for (i = 0; i < rv; i++)
+				io_csum += p[i];
+		}
+
+		p += rv;
+		out += rv;
+		count -= rv;
+	}
+
+	return out;
+}
+
+static __initdata char *message;
+static void __init error(char *x)
+{
+	if (!message)
+		message = x;
+}
+
+#define panic_show_mem(fmt, ...) \
+	({ show_mem(); panic(fmt, ##__VA_ARGS__); })
+
+/* link hash */
+
+#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
+
+static __initdata struct hash {
+	int ino, minor, major;
+	umode_t mode;
+	struct hash *next;
+	char name[N_ALIGN(PATH_MAX)];
+} *head[32];
+static __initdata bool hardlink_seen;
+
+static inline int hash(int major, int minor, int ino)
+{
+	unsigned long tmp = ino + minor + (major << 3);
+	tmp += tmp >> 5;
+	return tmp & 31;
+}
+
+static char __init *find_link(int major, int minor, int ino,
+			      umode_t mode, char *name)
+{
+	struct hash **p, *q;
+	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
+		if ((*p)->ino != ino)
+			continue;
+		if ((*p)->minor != minor)
+			continue;
+		if ((*p)->major != major)
+			continue;
+		if (((*p)->mode ^ mode) & S_IFMT)
+			continue;
+		return (*p)->name;
+	}
+	q = kmalloc_obj(struct hash);
+	if (!q)
+		panic_show_mem("can't allocate link hash entry");
+	q->major = major;
+	q->minor = minor;
+	q->ino = ino;
+	q->mode = mode;
+	strscpy(q->name, name);
+	q->next = NULL;
+	*p = q;
+	hardlink_seen = true;
+	return NULL;
+}
+
+static void __init free_hash(void)
+{
+	struct hash **p, *q;
+	for (p = head; hardlink_seen && p < head + 32; p++) {
+		while (*p) {
+			q = *p;
+			*p = q->next;
+			kfree(q);
+		}
+	}
+	hardlink_seen = false;
+}
+
+#ifdef CONFIG_INITRAMFS_PRESERVE_MTIME
+static void __init do_utime(char *filename, time64_t mtime)
+{
+	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
+	init_utimes(filename, t);
+}
+
+static void __init do_utime_path(const struct path *path, time64_t mtime)
+{
+	struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } };
+	vfs_utimes(path, t);
+}
+
+static __initdata LIST_HEAD(dir_list);
+struct dir_entry {
+	struct list_head list;
+	time64_t mtime;
+	char name[];
+};
+
+static void __init dir_add(const char *name, size_t nlen, time64_t mtime)
+{
+	struct dir_entry *de;
+
+	de = kmalloc_flex(*de, name, nlen);
+	if (!de)
+		panic_show_mem("can't allocate dir_entry buffer");
+	INIT_LIST_HEAD(&de->list);
+	strscpy(de->name, name, nlen);
+	de->mtime = mtime;
+	list_add(&de->list, &dir_list);
+}
+
+static void __init dir_utime(void)
+{
+	struct dir_entry *de, *tmp;
+	list_for_each_entry_safe(de, tmp, &dir_list, list) {
+		list_del(&de->list);
+		do_utime(de->name, de->mtime);
+		kfree(de);
+	}
+}
+#else
+static void __init do_utime(char *filename, time64_t mtime) {}
+static void __init do_utime_path(const struct path *path, time64_t mtime) {}
+static void __init dir_add(const char *name, size_t nlen, time64_t mtime) {}
+static void __init dir_utime(void) {}
+#endif
+
+static __initdata time64_t mtime;
+
+/* cpio header parsing */
+
+static __initdata unsigned long ino, major, minor, nlink;
+static __initdata umode_t mode;
+static __initdata unsigned long body_len, name_len;
+static __initdata uid_t uid;
+static __initdata gid_t gid;
+static __initdata unsigned rdev;
+static __initdata u32 hdr_csum;
+
+static int __init parse_header(char *s)
+{
+	__be32 header[13];
+	int ret;
+
+	ret = hex2bin((u8 *)header, s + 6, sizeof(header));
+	if (ret) {
+		error("damaged header");
+		return ret;
+	}
+
+	ino = be32_to_cpu(header[0]);
+	mode = be32_to_cpu(header[1]);
+	uid = be32_to_cpu(header[2]);
+	gid = be32_to_cpu(header[3]);
+	nlink = be32_to_cpu(header[4]);
+	mtime = be32_to_cpu(header[5]); /* breaks in y2106 */
+	body_len = be32_to_cpu(header[6]);
+	major = be32_to_cpu(header[7]);
+	minor = be32_to_cpu(header[8]);
+	rdev = new_encode_dev(MKDEV(be32_to_cpu(header[9]), be32_to_cpu(header[10])));
+	name_len = be32_to_cpu(header[11]);
+	hdr_csum = be32_to_cpu(header[12]);
+	return 0;
+}
+
+/* Finite-state machine */
+
+static __initdata enum state {
+	Start,
+	Collect,
+	GotHeader,
+	SkipIt,
+	GotName,
+	CopyFile,
+	GotSymlink,
+	Reset
+} state, next_state;
+
+static __initdata char *victim;
+static unsigned long byte_count __initdata;
+static __initdata loff_t this_header, next_header;
+
+static inline void __init eat(unsigned n)
+{
+	victim += n;
+	this_header += n;
+	byte_count -= n;
+}
+
+static __initdata char *collected;
+static long remains __initdata;
+static __initdata char *collect;
+
+static void __init read_into(char *buf, unsigned size, enum state next)
+{
+	if (byte_count >= size) {
+		collected = victim;
+		eat(size);
+		state = next;
+	} else {
+		collect = collected = buf;
+		remains = size;
+		next_state = next;
+		state = Collect;
+	}
+}
+
+static __initdata char *header_buf, *symlink_buf, *name_buf;
+
+static int __init do_start(void)
+{
+	read_into(header_buf, CPIO_HDRLEN, GotHeader);
+	return 0;
+}
+
+static int __init do_collect(void)
+{
+	unsigned long n = remains;
+	if (byte_count < n)
+		n = byte_count;
+	memcpy(collect, victim, n);
+	eat(n);
+	collect += n;
+	if ((remains -= n) != 0)
+		return 1;
+	state = next_state;
+	return 0;
+}
+
+static int __init do_header(void)
+{
+	if (!memcmp(collected, "070701", 6)) {
+		csum_present = false;
+	} else if (!memcmp(collected, "070702", 6)) {
+		csum_present = true;
+	} else {
+		if (memcmp(collected, "070707", 6) == 0)
+			error("incorrect cpio method used: use -H newc option");
+		else
+			error("no cpio magic");
+		return 1;
+	}
+	if (parse_header(collected))
+		return 1;
+	next_header = this_header + N_ALIGN(name_len) + body_len;
+	next_header = (next_header + 3) & ~3;
+	state = SkipIt;
+	if (name_len <= 0 || name_len > PATH_MAX)
+		return 0;
+	if (S_ISLNK(mode)) {
+		if (body_len > PATH_MAX)
+			return 0;
+		collect = collected = symlink_buf;
+		remains = N_ALIGN(name_len) + body_len;
+		next_state = GotSymlink;
+		state = Collect;
+		return 0;
+	}
+	if (S_ISREG(mode) || !body_len)
+		read_into(name_buf, N_ALIGN(name_len), GotName);
+	return 0;
+}
+
+static int __init do_skip(void)
+{
+	if (this_header + byte_count < next_header) {
+		eat(byte_count);
+		return 1;
+	} else {
+		eat(next_header - this_header);
+		state = next_state;
+		return 0;
+	}
+}
+
+static int __init do_reset(void)
+{
+	while (byte_count && *victim == '\0')
+		eat(1);
+	if (byte_count && (this_header & 3))
+		error("broken padding");
+	return 1;
+}
+
+static void __init clean_path(char *path, umode_t fmode)
+{
+	struct kstat st;
+
+	if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
+	    (st.mode ^ fmode) & S_IFMT) {
+		if (S_ISDIR(st.mode))
+			init_rmdir(path);
+		else
+			init_unlink(path);
+	}
+}
+
+static int __init maybe_link(void)
+{
+	if (nlink >= 2) {
+		char *old = find_link(major, minor, ino, mode, collected);
+		if (old) {
+			clean_path(collected, 0);
+			return (init_link(old, collected) < 0) ? -1 : 1;
+		}
+	}
+	return 0;
+}
+
+static __initdata struct file *wfile;
+static __initdata loff_t wfile_pos;
+
+static int __init do_name(void)
+{
+	state = SkipIt;
+	next_state = Reset;
+
+	/* name_len > 0 && name_len <= PATH_MAX checked in do_header */
+	if (collected[name_len - 1] != '\0') {
+		pr_err("initramfs name without nulterm: %.*s\n",
+		       (int)name_len, collected);
+		error("malformed archive");
+		return 1;
+	}
+
+	if (strcmp(collected, "TRAILER!!!") == 0) {
+		free_hash();
+		return 0;
+	}
+	clean_path(collected, mode);
+	if (S_ISREG(mode)) {
+		int ml = maybe_link();
+		if (ml >= 0) {
+			int openflags = O_WRONLY|O_CREAT|O_LARGEFILE;
+			if (ml != 1)
+				openflags |= O_TRUNC;
+			wfile = filp_open(collected, openflags, mode);
+			if (IS_ERR(wfile))
+				return 0;
+			wfile_pos = 0;
+			io_csum = 0;
+
+			vfs_fchown(wfile, uid, gid);
+			vfs_fchmod(wfile, mode);
+			if (body_len)
+				vfs_truncate(&wfile->f_path, body_len);
+			state = CopyFile;
+		}
+	} else if (S_ISDIR(mode)) {
+		init_mkdir(collected, mode);
+		init_chown(collected, uid, gid, 0);
+		init_chmod(collected, mode);
+		dir_add(collected, name_len, mtime);
+	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
+		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
+		if (maybe_link() == 0) {
+			init_mknod(collected, mode, rdev);
+			init_chown(collected, uid, gid, 0);
+			init_chmod(collected, mode);
+			do_utime(collected, mtime);
+		}
+	}
+	return 0;
+}
+
+static int __init do_copy(void)
+{
+	if (byte_count >= body_len) {
+		if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len)
+			error("write error");
+
+		do_utime_path(&wfile->f_path, mtime);
+		fput(wfile);
+		if (csum_present && io_csum != hdr_csum)
+			error("bad data checksum");
+		eat(body_len);
+		state = SkipIt;
+		return 0;
+	} else {
+		if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count)
+			error("write error");
+		body_len -= byte_count;
+		eat(byte_count);
+		return 1;
+	}
+}
+
+static int __init do_symlink(void)
+{
+	if (collected[name_len - 1] != '\0') {
+		pr_err("initramfs symlink without nulterm: %.*s\n",
+		       (int)name_len, collected);
+		error("malformed archive");
+		return 1;
+	}
+	collected[N_ALIGN(name_len) + body_len] = '\0';
+	clean_path(collected, 0);
+	init_symlink(collected + N_ALIGN(name_len), collected);
+	init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW);
+	do_utime(collected, mtime);
+	state = SkipIt;
+	next_state = Reset;
+	return 0;
+}
+
+static __initdata int (*actions[])(void) = {
+	[Start]		= do_start,
+	[Collect]	= do_collect,
+	[GotHeader]	= do_header,
+	[SkipIt]	= do_skip,
+	[GotName]	= do_name,
+	[CopyFile]	= do_copy,
+	[GotSymlink]	= do_symlink,
+	[Reset]		= do_reset,
+};
+
+static long __init write_buffer(char *buf, unsigned long len)
+{
+	byte_count = len;
+	victim = buf;
+
+	while (!actions[state]())
+		;
+	return len - byte_count;
+}
+
+static long __init flush_buffer(void *bufv, unsigned long len)
+{
+	char *buf = bufv;
+	long written;
+	long origLen = len;
+	if (message)
+		return -1;
+	while ((written = write_buffer(buf, len)) < len && !message) {
+		char c = buf[written];
+		if (c == '0') {
+			buf += written;
+			len -= written;
+			state = Start;
+		} else if (c == 0) {
+			buf += written;
+			len -= written;
+			state = Reset;
+		} else
+			error("junk within compressed archive");
+	}
+	return origLen;
+}
+
+static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */
+
+#include <linux/decompress/generic.h>
+
+/**
+ * unpack_to_rootfs - decompress and extract an initramfs archive
+ * @buf: input initramfs archive to extract
+ * @len: length of initramfs data to process
+ *
+ * Returns: NULL for success or an error message string
+ *
+ * This symbol shouldn't be used externally. It's available for unit tests.
+ */
+char * __init unpack_to_rootfs(char *buf, unsigned long len)
+{
+	long written;
+	decompress_fn decompress;
+	const char *compress_name;
+	struct {
+		char header[CPIO_HDRLEN];
+		char symlink[PATH_MAX + N_ALIGN(PATH_MAX) + 1];
+		char name[N_ALIGN(PATH_MAX)];
+	} *bufs = kmalloc_obj(*bufs);
+
+	if (!bufs)
+		panic_show_mem("can't allocate buffers");
+
+	header_buf = bufs->header;
+	symlink_buf = bufs->symlink;
+	name_buf = bufs->name;
+
+	state = Start;
+	this_header = 0;
+	message = NULL;
+	while (!message && len) {
+		loff_t saved_offset = this_header;
+		if (*buf == '0' && !(this_header & 3)) {
+			state = Start;
+			written = write_buffer(buf, len);
+			buf += written;
+			len -= written;
+			continue;
+		}
+		if (!*buf) {
+			buf++;
+			len--;
+			this_header++;
+			continue;
+		}
+		this_header = 0;
+		decompress = decompress_method(buf, len, &compress_name);
+		pr_debug("Detected %s compressed data\n", compress_name);
+		if (decompress) {
+			int res = decompress(buf, len, NULL, flush_buffer, NULL,
+				   &my_inptr, error);
+			if (res)
+				error("decompressor failed");
+		} else if (compress_name) {
+			pr_err("compression method %s not configured\n",
+			       compress_name);
+			error("decompressor failed");
+		} else
+			error("invalid magic at start of compressed archive");
+		if (state != Reset)
+			error("junk at the end of compressed archive");
+		this_header = saved_offset + my_inptr;
+		buf += my_inptr;
+		len -= my_inptr;
+	}
+	dir_utime();
+	/* free any hardlink state collected without optional TRAILER!!! */
+	free_hash();
+	kfree(bufs);
+	return message;
+}
+
+static int __initdata do_retain_initrd;
+
+static int __init retain_initrd_param(char *str)
+{
+	if (*str)
+		return 0;
+	do_retain_initrd = 1;
+	return 1;
+}
+__setup("retain_initrd", retain_initrd_param);
+
+#ifdef CONFIG_ARCH_HAS_KEEPINITRD
+static int __init keepinitrd_setup(char *__unused)
+{
+	do_retain_initrd = 1;
+	return 1;
+}
+__setup("keepinitrd", keepinitrd_setup);
+#endif
+
+static bool __initdata initramfs_async = true;
+static int __init initramfs_async_setup(char *str)
+{
+	return kstrtobool(str, &initramfs_async) == 0;
+}
+__setup("initramfs_async=", initramfs_async_setup);
+
+extern char __initramfs_start[];
+extern unsigned long __initramfs_size;
+#include <linux/initrd.h>
+#include <linux/kexec.h>
+
+static BIN_ATTR(initrd, 0440, sysfs_bin_attr_simple_read, NULL, 0);
+
+void __init reserve_initrd_mem(void)
+{
+	phys_addr_t start;
+	unsigned long size;
+
+	/* Ignore the virtual address computed during device tree parsing */
+	initrd_start = initrd_end = 0;
+
+	if (!phys_initrd_size)
+		return;
+	/*
+	 * Round the memory region to page boundaries as per free_initrd_mem()
+	 * This allows us to detect whether the pages overlapping the initrd
+	 * are in use, but more importantly, reserves the entire set of pages
+	 * as we don't want these pages allocated for other purposes.
+	 */
+	start = round_down(phys_initrd_start, PAGE_SIZE);
+	size = phys_initrd_size + (phys_initrd_start - start);
+	size = round_up(size, PAGE_SIZE);
+
+	if (!memblock_is_region_memory(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
+		       (u64)start, size);
+		goto disable;
+	}
+
+	if (memblock_is_region_reserved(start, size)) {
+		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
+		       (u64)start, size);
+		goto disable;
+	}
+
+	memblock_reserve(start, size);
+	/* Now convert initrd to virtual addresses */
+	initrd_start = (unsigned long)__va(phys_initrd_start);
+	initrd_end = initrd_start + phys_initrd_size;
+	initrd_below_start_ok = 1;
+
+	return;
+disable:
+	pr_cont(" - disabling initrd\n");
+	initrd_start = 0;
+	initrd_end = 0;
+}
+
+void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
+			"initrd");
+}
+
+#ifdef CONFIG_CRASH_RESERVE
+static bool __init kexec_free_initrd(void)
+{
+	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
+	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
+
+	/*
+	 * If the initrd region is overlapped with crashkernel reserved region,
+	 * free only memory that is not part of crashkernel region.
+	 */
+	if (initrd_start >= crashk_end || initrd_end <= crashk_start)
+		return false;
+
+	/*
+	 * Initialize initrd memory region since the kexec boot does not do.
+	 */
+	memset((void *)initrd_start, 0, initrd_end - initrd_start);
+	if (initrd_start < crashk_start)
+		free_initrd_mem(initrd_start, crashk_start);
+	if (initrd_end > crashk_end)
+		free_initrd_mem(crashk_end, initrd_end);
+	return true;
+}
+#else
+static inline bool kexec_free_initrd(void)
+{
+	return false;
+}
+#endif /* CONFIG_KEXEC_CORE */
+
+#ifdef CONFIG_BLK_DEV_RAM
+static void __init populate_initrd_image(char *err)
+{
+	ssize_t written;
+	struct file *file;
+	loff_t pos = 0;
+
+	printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
+			err);
+	file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700);
+	if (IS_ERR(file))
+		return;
+
+	written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start,
+			&pos);
+	if (written != initrd_end - initrd_start)
+		pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
+		       written, initrd_end - initrd_start);
+	fput(file);
+}
+#endif /* CONFIG_BLK_DEV_RAM */
+
+static void __init unpack_initramfs(async_cookie_t cookie)
+{
+	/* Load the built in initramfs */
+	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
+	if (err)
+		panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */
+
+	if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
+		return;
+
+	if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
+		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
+	else
+		printk(KERN_INFO "Unpacking initramfs...\n");
+
+	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
+	if (err) {
+#ifdef CONFIG_BLK_DEV_RAM
+		populate_initrd_image(err);
+#else
+		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
+#endif
+	}
+}
+
+static void __init do_populate_rootfs(void *unused, async_cookie_t cookie)
+{
+	scoped_with_init_fs() {
+		unpack_initramfs(cookie);
+		security_initramfs_populated();
+	}
+
+	/*
+	 * If the initrd region is overlapped with crashkernel reserved region,
+	 * free only memory that is not part of crashkernel region.
+	 */
+	if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) {
+		free_initrd_mem(initrd_start, initrd_end);
+	} else if (do_retain_initrd && initrd_start) {
+		bin_attr_initrd.size = initrd_end - initrd_start;
+		bin_attr_initrd.private = (void *)initrd_start;
+		if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd))
+			pr_err("Failed to create initrd sysfs file");
+	}
+	initrd_start = 0;
+	initrd_end = 0;
+
+	init_flush_fput();
+}
+
+static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain);
+static async_cookie_t initramfs_cookie;
+
+void wait_for_initramfs(void)
+{
+	if (!initramfs_cookie) {
+		/*
+		 * Something before rootfs_initcall wants to access
+		 * the filesystem/initramfs. Probably a bug. Make a
+		 * note, avoid deadlocking the machine, and let the
+		 * caller's access fail as it used to.
+		 */
+		pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n");
+		return;
+	}
+	async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain);
+}
+EXPORT_SYMBOL_GPL(wait_for_initramfs);
+
+static int __init populate_rootfs(void)
+{
+	initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL,
+						 &initramfs_domain);
+	usermodehelper_enable();
+	if (!initramfs_async)
+		wait_for_initramfs();
+	return 0;
+}
+rootfs_initcall(populate_rootfs);
diff --git a/init/initramfs_internal.h b/init/initramfs_internal.h
new file mode 100644
index 000000000..233dad16b
--- /dev/null
+++ b/init/initramfs_internal.h
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef __INITRAMFS_INTERNAL_H__
+#define __INITRAMFS_INTERNAL_H__
+
+char *unpack_to_rootfs(char *buf, unsigned long len);
+#define CPIO_HDRLEN 110
+
+#endif
diff --git a/init/initramfs_test.c b/init/initramfs_test.c
new file mode 100644
index 000000000..9cf316c13
--- /dev/null
+++ b/init/initramfs_test.c
@@ -0,0 +1,600 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <kunit/test.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/fs_struct.h>
+#include <linux/init.h>
+#include <linux/init_syscalls.h>
+#include <linux/initrd.h>
+#include <linux/stringify.h>
+#include <linux/timekeeping.h>
+#include "initramfs_internal.h"
+
+struct initramfs_test_cpio {
+	char *magic;
+	unsigned int ino;
+	unsigned int mode;
+	unsigned int uid;
+	unsigned int gid;
+	unsigned int nlink;
+	unsigned int mtime;
+	unsigned int filesize;
+	unsigned int devmajor;
+	unsigned int devminor;
+	unsigned int rdevmajor;
+	unsigned int rdevminor;
+	unsigned int namesize;
+	unsigned int csum;
+	char *fname;
+	char *data;
+};
+
+/* regular newc header format */
+#define CPIO_HDR_FMT "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s"
+/*
+ * Bogus newc header with "0x" prefixes on the uid, gid, and namesize values.
+ * parse_header()/simple_str[n]toul() accepted this, contrary to the initramfs
+ * specification. hex2bin() now fails.
+ */
+#define CPIO_HDR_OX_INJECT \
+	"%s%08x%08x0x%06x0X%06x%08x%08x%08x%08x%08x%08x%08x0x%06x%08x%s"
+
+static size_t fill_cpio(struct initramfs_test_cpio *cs, size_t csz,
+			bool inject_ox, char *out)
+{
+	int i;
+	size_t off = 0;
+
+	for (i = 0; i < csz; i++) {
+		char *pos = &out[off];
+		struct initramfs_test_cpio *c = &cs[i];
+		size_t thislen;
+
+		/* +1 to account for nulterm */
+		thislen = sprintf(pos,
+			inject_ox ? CPIO_HDR_OX_INJECT : CPIO_HDR_FMT,
+			c->magic, c->ino, c->mode, c->uid, c->gid, c->nlink,
+			c->mtime, c->filesize, c->devmajor, c->devminor,
+			c->rdevmajor, c->rdevminor, c->namesize, c->csum,
+			c->fname) + 1;
+
+		pr_debug("packing (%zu): %.*s\n", thislen, (int)thislen, pos);
+		if (thislen != CPIO_HDRLEN + c->namesize)
+			pr_debug("padded to: %u\n", CPIO_HDRLEN + c->namesize);
+		off += CPIO_HDRLEN + c->namesize;
+		while (off & 3)
+			out[off++] = '\0';
+
+		memcpy(&out[off], c->data, c->filesize);
+		off += c->filesize;
+		while (off & 3)
+			out[off++] = '\0';
+	}
+
+	return off;
+}
+
+static void __init initramfs_test_extract(struct kunit *test)
+{
+	char *err, *cpio_srcbuf;
+	size_t len;
+	struct timespec64 ts_before, ts_after;
+	struct kstat st = {};
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.uid = 12,
+		.gid = 34,
+		.nlink = 1,
+		.mtime = 56,
+		.filesize = 0,
+		.devmajor = 0,
+		.devminor = 1,
+		.rdevmajor = 0,
+		.rdevminor = 0,
+		.namesize = sizeof("initramfs_test_extract"),
+		.csum = 0,
+		.fname = "initramfs_test_extract",
+	}, {
+		.magic = "070701",
+		.ino = 2,
+		.mode = S_IFDIR | 0777,
+		.nlink = 1,
+		.mtime = 57,
+		.devminor = 1,
+		.namesize = sizeof("initramfs_test_extract_dir"),
+		.fname = "initramfs_test_extract_dir",
+	}, {
+		.magic = "070701",
+		.namesize = sizeof("TRAILER!!!"),
+		.fname = "TRAILER!!!",
+	} };
+
+	/* +3 to cater for any 4-byte end-alignment */
+	cpio_srcbuf = kzalloc(ARRAY_SIZE(c) * (CPIO_HDRLEN + PATH_MAX + 3),
+			      GFP_KERNEL);
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+
+	ktime_get_real_ts64(&ts_before);
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	ktime_get_real_ts64(&ts_after);
+	if (err) {
+		KUNIT_FAIL(test, "unpack failed %s", err);
+		goto out;
+	}
+
+	KUNIT_EXPECT_EQ(test, init_stat(c[0].fname, &st, 0), 0);
+	KUNIT_EXPECT_TRUE(test, S_ISREG(st.mode));
+	KUNIT_EXPECT_TRUE(test, uid_eq(st.uid, KUIDT_INIT(c[0].uid)));
+	KUNIT_EXPECT_TRUE(test, gid_eq(st.gid, KGIDT_INIT(c[0].gid)));
+	KUNIT_EXPECT_EQ(test, st.nlink, 1);
+	if (IS_ENABLED(CONFIG_INITRAMFS_PRESERVE_MTIME)) {
+		KUNIT_EXPECT_EQ(test, st.mtime.tv_sec, c[0].mtime);
+	} else {
+		KUNIT_EXPECT_GE(test, st.mtime.tv_sec, ts_before.tv_sec);
+		KUNIT_EXPECT_LE(test, st.mtime.tv_sec, ts_after.tv_sec);
+	}
+	KUNIT_EXPECT_EQ(test, st.blocks, c[0].filesize);
+
+	KUNIT_EXPECT_EQ(test, init_stat(c[1].fname, &st, 0), 0);
+	KUNIT_EXPECT_TRUE(test, S_ISDIR(st.mode));
+	if (IS_ENABLED(CONFIG_INITRAMFS_PRESERVE_MTIME)) {
+		KUNIT_EXPECT_EQ(test, st.mtime.tv_sec, c[1].mtime);
+	} else {
+		KUNIT_EXPECT_GE(test, st.mtime.tv_sec, ts_before.tv_sec);
+		KUNIT_EXPECT_LE(test, st.mtime.tv_sec, ts_after.tv_sec);
+	}
+
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+	KUNIT_EXPECT_EQ(test, init_rmdir(c[1].fname), 0);
+out:
+	kfree(cpio_srcbuf);
+}
+
+/*
+ * Don't terminate filename. Previously, the cpio filename field was passed
+ * directly to filp_open(collected, O_CREAT|..) without nulterm checks. See
+ * https://lore.kernel.org/linux-fsdevel/20241030035509.20194-2-ddiss@suse.de
+ */
+static void __init initramfs_test_fname_overrun(struct kunit *test)
+{
+	char *err, *cpio_srcbuf;
+	size_t len, suffix_off;
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.uid = 0,
+		.gid = 0,
+		.nlink = 1,
+		.mtime = 1,
+		.filesize = 0,
+		.devmajor = 0,
+		.devminor = 1,
+		.rdevmajor = 0,
+		.rdevminor = 0,
+		.namesize = sizeof("initramfs_test_fname_overrun"),
+		.csum = 0,
+		.fname = "initramfs_test_fname_overrun",
+	} };
+
+	/*
+	 * poison cpio source buffer, so we can detect overrun. source
+	 * buffer is used by read_into() when hdr or fname
+	 * are already available (e.g. no compression).
+	 */
+	cpio_srcbuf = kmalloc(CPIO_HDRLEN + PATH_MAX + 3, GFP_KERNEL);
+	memset(cpio_srcbuf, 'B', CPIO_HDRLEN + PATH_MAX + 3);
+	/* limit overrun to avoid crashes / filp_open() ENAMETOOLONG */
+	cpio_srcbuf[CPIO_HDRLEN + strlen(c[0].fname) + 20] = '\0';
+
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+	/* overwrite trailing fname terminator and padding */
+	suffix_off = len - 1;
+	while (cpio_srcbuf[suffix_off] == '\0') {
+		cpio_srcbuf[suffix_off] = 'P';
+		suffix_off--;
+	}
+
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NOT_NULL(test, err);
+
+	kfree(cpio_srcbuf);
+}
+
+static void __init initramfs_test_data(struct kunit *test)
+{
+	char *err, *cpio_srcbuf;
+	size_t len;
+	struct file *file;
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.uid = 0,
+		.gid = 0,
+		.nlink = 1,
+		.mtime = 1,
+		.filesize = sizeof("ASDF") - 1,
+		.devmajor = 0,
+		.devminor = 1,
+		.rdevmajor = 0,
+		.rdevminor = 0,
+		.namesize = sizeof("initramfs_test_data"),
+		.csum = 0,
+		.fname = "initramfs_test_data",
+		.data = "ASDF",
+	} };
+
+	/* +6 for max name and data 4-byte padding */
+	cpio_srcbuf = kmalloc(CPIO_HDRLEN + c[0].namesize + c[0].filesize + 6,
+			      GFP_KERNEL);
+
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	file = filp_open(c[0].fname, O_RDONLY, 0);
+	if (IS_ERR(file)) {
+		KUNIT_FAIL(test, "open failed");
+		goto out;
+	}
+
+	/* read back file contents into @cpio_srcbuf and confirm match */
+	len = kernel_read(file, cpio_srcbuf, c[0].filesize, NULL);
+	KUNIT_EXPECT_EQ(test, len, c[0].filesize);
+	KUNIT_EXPECT_MEMEQ(test, cpio_srcbuf, c[0].data, len);
+
+	fput(file);
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+out:
+	kfree(cpio_srcbuf);
+}
+
+static void __init initramfs_test_csum(struct kunit *test)
+{
+	char *err, *cpio_srcbuf;
+	size_t len;
+	struct initramfs_test_cpio c[] = { {
+		/* 070702 magic indicates a valid csum is present */
+		.magic = "070702",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.nlink = 1,
+		.filesize = sizeof("ASDF") - 1,
+		.devminor = 1,
+		.namesize = sizeof("initramfs_test_csum"),
+		.csum = 'A' + 'S' + 'D' + 'F',
+		.fname = "initramfs_test_csum",
+		.data = "ASDF",
+	}, {
+		/* mix csum entry above with no-csum entry below */
+		.magic = "070701",
+		.ino = 2,
+		.mode = S_IFREG | 0777,
+		.nlink = 1,
+		.filesize = sizeof("ASDF") - 1,
+		.devminor = 1,
+		.namesize = sizeof("initramfs_test_csum_not_here"),
+		/* csum ignored */
+		.csum = 5555,
+		.fname = "initramfs_test_csum_not_here",
+		.data = "ASDF",
+	} };
+
+	cpio_srcbuf = kmalloc(8192, GFP_KERNEL);
+
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+	KUNIT_EXPECT_EQ(test, init_unlink(c[1].fname), 0);
+
+	/* mess up the csum and confirm that unpack fails */
+	c[0].csum--;
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NOT_NULL(test, err);
+
+	/*
+	 * file (with content) is still retained in case of bad-csum abort.
+	 * Perhaps we should change this.
+	 */
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+	KUNIT_EXPECT_EQ(test, init_unlink(c[1].fname), -ENOENT);
+	kfree(cpio_srcbuf);
+}
+
+/*
+ * hardlink hashtable may leak when the archive omits a trailer:
+ * https://lore.kernel.org/r/20241107002044.16477-10-ddiss@suse.de/
+ */
+static void __init initramfs_test_hardlink(struct kunit *test)
+{
+	char *err, *cpio_srcbuf;
+	size_t len;
+	struct kstat st0 = {}, st1 = {};
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.nlink = 2,
+		.devminor = 1,
+		.namesize = sizeof("initramfs_test_hardlink"),
+		.fname = "initramfs_test_hardlink",
+	}, {
+		/* hardlink data is present in last archive entry */
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.nlink = 2,
+		.filesize = sizeof("ASDF") - 1,
+		.devminor = 1,
+		.namesize = sizeof("initramfs_test_hardlink_link"),
+		.fname = "initramfs_test_hardlink_link",
+		.data = "ASDF",
+	} };
+
+	cpio_srcbuf = kmalloc(8192, GFP_KERNEL);
+
+	len = fill_cpio(c, ARRAY_SIZE(c), false, cpio_srcbuf);
+
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	KUNIT_EXPECT_EQ(test, init_stat(c[0].fname, &st0, 0), 0);
+	KUNIT_EXPECT_EQ(test, init_stat(c[1].fname, &st1, 0), 0);
+	KUNIT_EXPECT_EQ(test, st0.ino, st1.ino);
+	KUNIT_EXPECT_EQ(test, st0.nlink, 2);
+	KUNIT_EXPECT_EQ(test, st1.nlink, 2);
+
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+	KUNIT_EXPECT_EQ(test, init_unlink(c[1].fname), 0);
+
+	kfree(cpio_srcbuf);
+}
+
+#define INITRAMFS_TEST_MANY_LIMIT 1000
+#define INITRAMFS_TEST_MANY_PATH_MAX (sizeof("initramfs_test_many-") \
+			+ sizeof(__stringify(INITRAMFS_TEST_MANY_LIMIT)))
+static void __init initramfs_test_many(struct kunit *test)
+{
+	char *err, *cpio_srcbuf, *p;
+	size_t len = INITRAMFS_TEST_MANY_LIMIT *
+		     (CPIO_HDRLEN + INITRAMFS_TEST_MANY_PATH_MAX + 3);
+	char thispath[INITRAMFS_TEST_MANY_PATH_MAX];
+	int i;
+
+	p = cpio_srcbuf = kmalloc(len, GFP_KERNEL);
+
+	for (i = 0; i < INITRAMFS_TEST_MANY_LIMIT; i++) {
+		struct initramfs_test_cpio c = {
+			.magic = "070701",
+			.ino = i,
+			.mode = S_IFREG | 0777,
+			.nlink = 1,
+			.devminor = 1,
+			.fname = thispath,
+		};
+
+		c.namesize = 1 + sprintf(thispath, "initramfs_test_many-%d", i);
+		p += fill_cpio(&c, 1, false, p);
+	}
+
+	len = p - cpio_srcbuf;
+	err = unpack_to_rootfs(cpio_srcbuf, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	for (i = 0; i < INITRAMFS_TEST_MANY_LIMIT; i++) {
+		sprintf(thispath, "initramfs_test_many-%d", i);
+		KUNIT_EXPECT_EQ(test, init_unlink(thispath), 0);
+	}
+
+	kfree(cpio_srcbuf);
+}
+
+/*
+ * An initramfs filename is namesize in length, including the zero-terminator.
+ * A filename can be zero-terminated prior to namesize, with the remainder used
+ * as padding. This can be useful for e.g. alignment of file data segments with
+ * a 4KB filesystem block, allowing for extent sharing (reflinks) between cpio
+ * source and destination. This hack works with both GNU cpio and initramfs, as
+ * long as PATH_MAX isn't exceeded.
+ */
+static void __init initramfs_test_fname_pad(struct kunit *test)
+{
+	char *err;
+	size_t len;
+	struct file *file;
+	char fdata[] = "this file data is aligned at 4K in the archive";
+	struct test_fname_pad {
+		char padded_fname[4096 - CPIO_HDRLEN];
+		char cpio_srcbuf[CPIO_HDRLEN + PATH_MAX + 3 + sizeof(fdata)];
+	} *tbufs = kzalloc_obj(struct test_fname_pad);
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.uid = 0,
+		.gid = 0,
+		.nlink = 1,
+		.mtime = 1,
+		.filesize = sizeof(fdata),
+		.devmajor = 0,
+		.devminor = 1,
+		.rdevmajor = 0,
+		.rdevminor = 0,
+		/* align file data at 4K archive offset via padded fname */
+		.namesize = 4096 - CPIO_HDRLEN,
+		.csum = 0,
+		.fname = tbufs->padded_fname,
+		.data = fdata,
+	} };
+
+	memcpy(tbufs->padded_fname, "padded_fname", sizeof("padded_fname"));
+	len = fill_cpio(c, ARRAY_SIZE(c), false, tbufs->cpio_srcbuf);
+
+	err = unpack_to_rootfs(tbufs->cpio_srcbuf, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	file = filp_open(c[0].fname, O_RDONLY, 0);
+	if (IS_ERR(file)) {
+		KUNIT_FAIL(test, "open failed");
+		goto out;
+	}
+
+	/* read back file contents into @cpio_srcbuf and confirm match */
+	len = kernel_read(file, tbufs->cpio_srcbuf, c[0].filesize, NULL);
+	KUNIT_EXPECT_EQ(test, len, c[0].filesize);
+	KUNIT_EXPECT_MEMEQ(test, tbufs->cpio_srcbuf, c[0].data, len);
+
+	fput(file);
+	KUNIT_EXPECT_EQ(test, init_unlink(c[0].fname), 0);
+out:
+	kfree(tbufs);
+}
+
+static void __init initramfs_test_fname_path_max(struct kunit *test)
+{
+	char *err;
+	size_t len;
+	struct kstat st0 = {}, st1 = {};
+	char fdata[] = "this file data will not be unpacked";
+	struct test_fname_path_max {
+		char fname_oversize[PATH_MAX + 1];
+		char fname_ok[PATH_MAX];
+		char cpio_src[(CPIO_HDRLEN + PATH_MAX + 3 + sizeof(fdata)) * 2];
+	} *tbufs = kzalloc_obj(struct test_fname_path_max);
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFDIR | 0777,
+		.nlink = 1,
+		.namesize = sizeof(tbufs->fname_oversize),
+		.fname = tbufs->fname_oversize,
+		.filesize = sizeof(fdata),
+		.data = fdata,
+	}, {
+		.magic = "070701",
+		.ino = 2,
+		.mode = S_IFDIR | 0777,
+		.nlink = 1,
+		.namesize = sizeof(tbufs->fname_ok),
+		.fname = tbufs->fname_ok,
+	} };
+
+	memset(tbufs->fname_oversize, '/', sizeof(tbufs->fname_oversize) - 1);
+	memset(tbufs->fname_ok, '/', sizeof(tbufs->fname_ok) - 1);
+	memcpy(tbufs->fname_oversize, "fname_oversize",
+	       sizeof("fname_oversize") - 1);
+	memcpy(tbufs->fname_ok, "fname_ok", sizeof("fname_ok") - 1);
+	len = fill_cpio(c, ARRAY_SIZE(c), false, tbufs->cpio_src);
+
+	/* unpack skips over fname_oversize instead of returning an error */
+	err = unpack_to_rootfs(tbufs->cpio_src, len);
+	KUNIT_EXPECT_NULL(test, err);
+
+	KUNIT_EXPECT_EQ(test, init_stat("fname_oversize", &st0, 0), -ENOENT);
+	KUNIT_EXPECT_EQ(test, init_stat("fname_ok", &st1, 0), 0);
+	KUNIT_EXPECT_EQ(test, init_rmdir("fname_ok"), 0);
+
+	kfree(tbufs);
+}
+
+static void __init initramfs_test_hdr_hex(struct kunit *test)
+{
+	char *err;
+	size_t len;
+	char fdata[] = "this file data will not be unpacked";
+	struct initramfs_test_bufs {
+		char cpio_src[(CPIO_HDRLEN + PATH_MAX + 3 + sizeof(fdata)) * 2];
+	} *tbufs = kzalloc(sizeof(struct initramfs_test_bufs), GFP_KERNEL);
+	struct initramfs_test_cpio c[] = { {
+		.magic = "070701",
+		.ino = 1,
+		.mode = S_IFREG | 0777,
+		.uid = 0x123456,
+		.gid = 0x123457,
+		.nlink = 1,
+		.namesize = sizeof("initramfs_test_hdr_hex_0"),
+		.fname = "initramfs_test_hdr_hex_0",
+		.filesize = sizeof(fdata),
+		.data = fdata,
+	}, {
+		.magic = "070701",
+		.ino = 2,
+		.mode = S_IFDIR | 0777,
+		.uid = 0x000056,
+		.gid = 0x000057,
+		.nlink = 1,
+		.namesize = sizeof("initramfs_test_hdr_hex_1"),
+		.fname = "initramfs_test_hdr_hex_1",
+	} };
+
+	/* inject_ox=true to add "0x" cpio field prefixes */
+	len = fill_cpio(c, ARRAY_SIZE(c), true, tbufs->cpio_src);
+
+	err = unpack_to_rootfs(tbufs->cpio_src, len);
+	KUNIT_EXPECT_NOT_NULL(test, err);
+
+	kfree(tbufs);
+}
+
+/*
+ * The kunit_case/_suite struct cannot be marked as __initdata as this will be
+ * used in debugfs to retrieve results after test has run.
+ */
+static struct kunit_case __refdata initramfs_test_cases[] = {
+	KUNIT_CASE(initramfs_test_extract),
+	KUNIT_CASE(initramfs_test_fname_overrun),
+	KUNIT_CASE(initramfs_test_data),
+	KUNIT_CASE(initramfs_test_csum),
+	KUNIT_CASE(initramfs_test_hardlink),
+	KUNIT_CASE(initramfs_test_many),
+	KUNIT_CASE(initramfs_test_fname_pad),
+	KUNIT_CASE(initramfs_test_fname_path_max),
+	KUNIT_CASE(initramfs_test_hdr_hex),
+	{},
+};
+
+static int __init initramfs_suite_init(struct kunit_suite *suite)
+{
+	/*
+	 * unpack_to_rootfs() uses module-static state (victim, byte_count,
+	 * state, ...). The boot-time async do_populate_rootfs() may still be
+	 * running, so wait for it to finish before we call unpack_to_rootfs()
+	 * from the test thread, otherwise the two writers race and crash.
+	 */
+	wait_for_initramfs();
+	return 0;
+}
+
+/* Tests run in a nullfs kthread; always use the init fs for path resolution. */
+static int __init initramfs_test_init(struct kunit *test)
+{
+	test->priv = __override_init_fs();
+	return 0;
+}
+
+static void __init initramfs_test_exit(struct kunit *test)
+{
+	__revert_init_fs(test->priv);
+}
+
+static struct kunit_suite __refdata initramfs_test_suite = {
+	.name = "initramfs",
+	.suite_init = initramfs_suite_init,
+	.init = initramfs_test_init,
+	.exit = initramfs_test_exit,
+	.test_cases = initramfs_test_cases,
+};
+kunit_test_init_section_suites(&initramfs_test_suite);
+
+MODULE_DESCRIPTION("Initramfs KUnit test suite");
+MODULE_LICENSE("GPL v2");
diff --git a/init/main.c b/init/main.c
new file mode 100644
index 000000000..2613d3f9b
--- /dev/null
+++ b/init/main.c
@@ -0,0 +1,1701 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/main.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  GK 2/5/95  -  Changed to support mounting root fs via NFS
+ *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
+ *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
+ *  Simplified starting of init:  Michael A. Griffith <grif@acm.org>
+ */
+
+#define DEBUG		/* Enable initcall_debug */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/extable.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/binfmts.h>
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/stackprotector.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/memblock.h>
+#include <linux/acpi.h>
+#include <linux/bootconfig.h>
+#include <linux/console.h>
+#include <linux/nmi.h>
+#include <linux/percpu.h>
+#include <linux/kmod.h>
+#include <linux/kprobes.h>
+#include <linux/kmsan.h>
+#include <linux/ksysfs.h>
+#include <linux/vmalloc.h>
+#include <linux/kernel_stat.h>
+#include <linux/start_kernel.h>
+#include <linux/security.h>
+#include <linux/smp.h>
+#include <linux/profile.h>
+#include <linux/kfence.h>
+#include <linux/rcupdate.h>
+#include <linux/srcu.h>
+#include <linux/moduleparam.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/writeback.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/memcontrol.h>
+#include <linux/cgroup.h>
+#include <linux/tick.h>
+#include <linux/sched/isolation.h>
+#include <linux/interrupt.h>
+#include <linux/taskstats_kern.h>
+#include <linux/delayacct.h>
+#include <linux/unistd.h>
+#include <linux/utsname.h>
+#include <linux/rmap.h>
+#include <linux/mempolicy.h>
+#include <linux/key.h>
+#include <linux/debug_locks.h>
+#include <linux/debugobjects.h>
+#include <linux/lockdep.h>
+#include <linux/kmemleak.h>
+#include <linux/padata.h>
+#include <linux/pid_namespace.h>
+#include <linux/device/driver.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/sched/init.h>
+#include <linux/signal.h>
+#include <linux/idr.h>
+#include <linux/kgdb.h>
+#include <linux/ftrace.h>
+#include <linux/async.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/pti.h>
+#include <linux/blkdev.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/context_tracking.h>
+#include <linux/random.h>
+#include <linux/moduleloader.h>
+#include <linux/list.h>
+#include <linux/integrity.h>
+#include <linux/proc_ns.h>
+#include <linux/io.h>
+#include <linux/cache.h>
+#include <linux/rodata_test.h>
+#include <linux/jump_label.h>
+#include <linux/kcsan.h>
+#include <linux/init_syscalls.h>
+#include <linux/stackdepot.h>
+#include <linux/randomize_kstack.h>
+#include <linux/pidfs.h>
+#include <linux/fs_struct.h>
+#include <linux/ptdump.h>
+#include <linux/time_namespace.h>
+#include <linux/unaligned.h>
+#include <linux/vdso_datastore.h>
+#include <net/net_namespace.h>
+
+#include <asm/io.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cacheflush.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/initcall.h>
+
+#include <kunit/test.h>
+
+static int kernel_init(void *);
+
+/*
+ * Debug helper: via this flag we know that we are in 'early bootup code'
+ * where only the boot processor is running with IRQ disabled.  This means
+ * two things - IRQ must not be enabled before the flag is cleared and some
+ * operations which are not allowed with IRQ disabled are allowed while the
+ * flag is set.
+ */
+bool early_boot_irqs_disabled __read_mostly;
+
+enum system_states system_state __read_mostly;
+EXPORT_SYMBOL(system_state);
+
+/*
+ * Boot command-line arguments
+ */
+#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
+#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
+
+/* Default late time init is NULL. archs can override this later. */
+void (*__initdata late_time_init)(void);
+
+/* Untouched command line saved by arch-specific code. */
+char __initdata boot_command_line[COMMAND_LINE_SIZE];
+/* Untouched saved command line (eg. for /proc) */
+char *saved_command_line __ro_after_init;
+unsigned int saved_command_line_len __ro_after_init;
+/* Command line for parameter parsing */
+static char *static_command_line;
+/* Untouched extra command line */
+static char *extra_command_line;
+/* Extra init arguments */
+static char *extra_init_args;
+
+#ifdef CONFIG_BOOT_CONFIG
+/* Is bootconfig on command line? */
+static bool bootconfig_found;
+static size_t initargs_offs;
+#else
+# define bootconfig_found false
+# define initargs_offs 0
+#endif
+
+static char *execute_command;
+static char *ramdisk_execute_command = "/init";
+static bool __initdata ramdisk_execute_command_set;
+
+/*
+ * Used to generate warnings if static_key manipulation functions are used
+ * before jump_label_init is called.
+ */
+bool static_key_initialized __read_mostly;
+EXPORT_SYMBOL_GPL(static_key_initialized);
+
+/*
+ * If set, this is an indication to the drivers that reset the underlying
+ * device before going ahead with the initialization otherwise driver might
+ * rely on the BIOS and skip the reset operation.
+ *
+ * This is useful if kernel is booting in an unreliable environment.
+ * For ex. kdump situation where previous kernel has crashed, BIOS has been
+ * skipped and devices will be in unknown state.
+ */
+unsigned int reset_devices;
+EXPORT_SYMBOL(reset_devices);
+
+static int __init set_reset_devices(char *str)
+{
+	reset_devices = 1;
+	return 1;
+}
+
+__setup("reset_devices", set_reset_devices);
+
+static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
+const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
+static const char *panic_later, *panic_param;
+
+static bool __init obsolete_checksetup(char *line)
+{
+	const struct obs_kernel_param *p;
+	bool had_early_param = false;
+
+	p = __setup_start;
+	do {
+		int n = strlen(p->str);
+		if (parameqn(line, p->str, n)) {
+			if (p->early) {
+				/* Already done in parse_early_param?
+				 * (Needs exact match on param part).
+				 * Keep iterating, as we can have early
+				 * params and __setups of same names 8( */
+				if (line[n] == '\0' || line[n] == '=')
+					had_early_param = true;
+			} else if (!p->setup_func) {
+				pr_warn("Parameter %s is obsolete, ignored\n",
+					p->str);
+				return true;
+			} else if (p->setup_func(line + n))
+				return true;
+		}
+		p++;
+	} while (p < __setup_end);
+
+	return had_early_param;
+}
+
+/*
+ * This should be approx 2 Bo*oMips to start (note initial shift), and will
+ * still work even if initially too large, it will just take slightly longer
+ */
+unsigned long loops_per_jiffy = (1<<12);
+EXPORT_SYMBOL(loops_per_jiffy);
+
+static int __init debug_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
+	return 0;
+}
+
+static int __init quiet_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
+	return 0;
+}
+
+early_param("debug", debug_kernel);
+early_param("quiet", quiet_kernel);
+
+static int __init loglevel(char *str)
+{
+	int newlevel;
+
+	/*
+	 * Only update loglevel value when a correct setting was passed,
+	 * to prevent blind crashes (when loglevel being set to 0) that
+	 * are quite hard to debug
+	 */
+	if (get_option(&str, &newlevel)) {
+		console_loglevel = newlevel;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+early_param("loglevel", loglevel);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	u32 size, csum;
+	char *data;
+	u8 *hdr;
+	int i;
+
+	if (!initrd_end)
+		return NULL;
+
+	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
+	/*
+	 * Since Grub may align the size of initrd to 4, we must
+	 * check the preceding 3 bytes as well.
+	 */
+	for (i = 0; i < 4; i++) {
+		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
+			goto found;
+		data--;
+	}
+	return NULL;
+
+found:
+	hdr = (u8 *)(data - 8);
+	size = get_unaligned_le32(hdr);
+	csum = get_unaligned_le32(hdr + 4);
+
+	data = ((void *)hdr) - size;
+	if ((unsigned long)data < initrd_start) {
+		pr_err("bootconfig size %d is greater than initrd size %ld\n",
+			size, initrd_end - initrd_start);
+		return NULL;
+	}
+
+	if (xbc_calc_checksum(data, size) != csum) {
+		pr_err("bootconfig checksum failed\n");
+		return NULL;
+	}
+
+	/* Remove bootconfig from initramfs/initrd */
+	initrd_end = (unsigned long)data;
+	if (_size)
+		*_size = size;
+
+	return data;
+}
+#else
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_BOOT_CONFIG
+
+/* Make an extra command line under given key word */
+static char * __init xbc_make_cmdline(const char *key)
+{
+	struct xbc_node *root;
+	char *new_cmdline;
+	int ret, len = 0;
+
+	root = xbc_find_node(key);
+	if (!root)
+		return NULL;
+
+	/* Count required buffer size */
+	len = xbc_snprint_cmdline(NULL, 0, root);
+	if (len <= 0)
+		return NULL;
+
+	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
+	if (!new_cmdline) {
+		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
+		return NULL;
+	}
+
+	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
+	if (ret < 0 || ret > len) {
+		pr_err("Failed to print extra kernel cmdline.\n");
+		memblock_free(new_cmdline, len + 1);
+		return NULL;
+	}
+
+	return new_cmdline;
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	/* The 'bootconfig' option is handled by setup_boot_config(). */
+	return 0;
+}
+
+static void __init setup_boot_config(void)
+{
+	const char *msg, *data;
+	int pos, ret, offs;
+	size_t size;
+	bool from_embedded = false;
+
+	/* Cut out the bootconfig data even if we have no bootconfig option */
+	data = get_boot_config_from_initrd(&size);
+	/* If there is no bootconfig in initrd, try embedded one. */
+	if (!data) {
+		data = xbc_get_embedded_bootconfig(&size);
+		from_embedded = true;
+	}
+
+	bootconfig_found = bootconfig_cmdline_requested(boot_command_line, &offs);
+	if (!(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
+		return;
+
+	/* Offset of the init arguments after a "--", located by the helper. */
+	initargs_offs = offs;
+
+	if (!data) {
+		/* If user intended to use bootconfig, show an error level message */
+		if (bootconfig_found)
+			pr_err("'bootconfig' found on command line, but no bootconfig found\n");
+		else
+			pr_info("No bootconfig data provided, so skipping bootconfig");
+		return;
+	}
+
+	if (size >= XBC_DATA_MAX) {
+		pr_err("bootconfig size %ld greater than max size %d\n",
+			(long)size, XBC_DATA_MAX);
+		return;
+	}
+
+	ret = xbc_init(data, size, &msg, &pos);
+	if (ret < 0) {
+		if (pos < 0)
+			pr_err("Failed to init bootconfig: %s.\n", msg);
+		else
+			pr_err("Failed to parse bootconfig: %s at %d.\n",
+				msg, pos);
+	} else {
+		xbc_get_info(&ret, NULL);
+		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
+		/*
+		 * keys starting with "kernel." are passed via cmdline. When
+		 * this bootconfig came from the embedded source and
+		 * setup_arch() already prepended the rendered "kernel" subtree
+		 * to boot_command_line, rendering again here would duplicate
+		 * the keys in saved_command_line and make accumulating handlers
+		 * (console=, earlycon=, ...) re-register the same value. Skip
+		 * only when the prepend really happened.
+		 *
+		 * On arches that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG,
+		 * CONFIG_CMDLINE_FROM_BOOTCONFIG is unselectable and
+		 * xbc_embedded_cmdline_applied() collapses to a stub returning
+		 * false, so this path still runs and the embedded "kernel"
+		 * keys reach the cmdline via the runtime parser exactly as
+		 * before this series.
+		 */
+		if (!from_embedded || !xbc_embedded_cmdline_applied())
+			extra_command_line = xbc_make_cmdline("kernel");
+		/* Also, "init." keys are init arguments */
+		extra_init_args = xbc_make_cmdline("init");
+	}
+	return;
+}
+
+static void __init exit_boot_config(void)
+{
+	xbc_exit();
+}
+
+#else	/* !CONFIG_BOOT_CONFIG */
+
+static void __init setup_boot_config(void)
+{
+	/* Remove bootconfig data from initrd */
+	get_boot_config_from_initrd(NULL);
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
+	return 0;
+}
+
+#define exit_boot_config()	do {} while (0)
+
+#endif	/* CONFIG_BOOT_CONFIG */
+
+early_param("bootconfig", warn_bootconfig);
+
+bool __init cmdline_has_extra_options(void)
+{
+	return extra_command_line || extra_init_args;
+}
+
+/* Change NUL term back to "=", to make "param" the whole string. */
+static void __init repair_env_string(char *param, char *val)
+{
+	if (val) {
+		/* param=val or param="val"? */
+		if (val == param+strlen(param)+1)
+			val[-1] = '=';
+		else if (val == param+strlen(param)+2) {
+			val[-2] = '=';
+			memmove(val-1, val, strlen(val)+1);
+		} else
+			BUG();
+	}
+}
+
+/* Anything after -- gets handed straight to init. */
+static int __init set_init_arg(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	unsigned int i;
+
+	if (panic_later)
+		return 0;
+
+	repair_env_string(param, val);
+
+	for (i = 0; argv_init[i]; i++) {
+		if (i == MAX_INIT_ARGS) {
+			panic_later = "init";
+			panic_param = param;
+			return 0;
+		}
+	}
+	argv_init[i] = param;
+	return 0;
+}
+
+/*
+ * Unknown boot options get handed to init, unless they look like
+ * unused parameters (modprobe will find them in /proc/cmdline).
+ */
+static int __init unknown_bootoption(char *param, char *val,
+				     const char *unused, void *arg)
+{
+	size_t len = strlen(param);
+	/*
+	 * Well-known bootloader identifiers:
+	 * 1. LILO/Grub pass "BOOT_IMAGE=...";
+	 * 2. kexec/kdump (kexec-tools) pass "kexec".
+	 */
+	const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL };
+
+	/* Handle params aliased to sysctls */
+	if (sysctl_is_alias(param))
+		return 0;
+
+	repair_env_string(param, val);
+
+	/* Handle bootloader identifier */
+	for (int i = 0; bootloader[i]; i++) {
+		if (strstarts(param, bootloader[i]))
+			return 0;
+	}
+
+	/* Handle obsolete-style parameters */
+	if (obsolete_checksetup(param))
+		return 0;
+
+	/* Unused module parameter. */
+	if (strnchr(param, len, '.'))
+		return 0;
+
+	if (panic_later)
+		return 0;
+
+	if (val) {
+		/* Environment option */
+		unsigned int i;
+		for (i = 0; envp_init[i]; i++) {
+			if (i == MAX_INIT_ENVS) {
+				panic_later = "env";
+				panic_param = param;
+			}
+			if (!strncmp(param, envp_init[i], len+1))
+				break;
+		}
+		envp_init[i] = param;
+	} else {
+		/* Command line option */
+		unsigned int i;
+		for (i = 0; argv_init[i]; i++) {
+			if (i == MAX_INIT_ARGS) {
+				panic_later = "init";
+				panic_param = param;
+			}
+		}
+		argv_init[i] = param;
+	}
+	return 0;
+}
+
+static int __init init_setup(char *str)
+{
+	unsigned int i;
+
+	execute_command = str;
+	/*
+	 * In case LILO is going to boot us with default command line,
+	 * it prepends "auto" before the whole cmdline which makes
+	 * the shell think it should execute a script with such name.
+	 * So we ignore all arguments entered _before_ init=... [MJ]
+	 */
+	for (i = 1; i < MAX_INIT_ARGS; i++)
+		argv_init[i] = NULL;
+	return 1;
+}
+__setup("init=", init_setup);
+
+static int __init rdinit_setup(char *str)
+{
+	unsigned int i;
+
+	ramdisk_execute_command = str;
+	ramdisk_execute_command_set = true;
+	/* See "auto" comment in init_setup */
+	for (i = 1; i < MAX_INIT_ARGS; i++)
+		argv_init[i] = NULL;
+	return 1;
+}
+__setup("rdinit=", rdinit_setup);
+
+#ifndef CONFIG_SMP
+static inline void setup_nr_cpu_ids(void) { }
+static inline void smp_prepare_cpus(unsigned int maxcpus) { }
+#endif
+
+/*
+ * We need to store the untouched command line for future reference.
+ * We also need to store the touched command line since the parameter
+ * parsing is performed in place, and we should allow a component to
+ * store reference of name/value for future reference.
+ */
+static void __init setup_command_line(char *command_line)
+{
+	size_t len, xlen = 0, ilen = 0;
+
+	if (extra_command_line)
+		xlen = strlen(extra_command_line);
+	if (extra_init_args) {
+		extra_init_args = strim(extra_init_args); /* remove trailing space */
+		ilen = strlen(extra_init_args) + 4; /* for " -- " */
+	}
+
+	len = xlen + strlen(boot_command_line) + ilen + 1;
+
+	saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
+
+	len = xlen + strlen(command_line) + 1;
+
+	static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
+
+	if (xlen) {
+		/*
+		 * We have to put extra_command_line before boot command
+		 * lines because there could be dashes (separator of init
+		 * command line) in the command lines.
+		 */
+		strcpy(saved_command_line, extra_command_line);
+		strcpy(static_command_line, extra_command_line);
+	}
+	strcpy(saved_command_line + xlen, boot_command_line);
+	strcpy(static_command_line + xlen, command_line);
+
+	if (ilen) {
+		/*
+		 * Append supplemental init boot args to saved_command_line
+		 * so that user can check what command line options passed
+		 * to init.
+		 * The order should always be
+		 * " -- "[bootconfig init-param][cmdline init-param]
+		 */
+		if (initargs_offs) {
+			len = xlen + initargs_offs;
+			strcpy(saved_command_line + len, extra_init_args);
+			len += ilen - 4;	/* strlen(extra_init_args) */
+			strcpy(saved_command_line + len,
+				boot_command_line + initargs_offs - 1);
+		} else {
+			len = strlen(saved_command_line);
+			strcpy(saved_command_line + len, " -- ");
+			len += 4;
+			strcpy(saved_command_line + len, extra_init_args);
+		}
+	}
+
+	saved_command_line_len = strlen(saved_command_line);
+}
+
+/*
+ * We need to finalize in a non-__init function or else race conditions
+ * between the root thread and the init thread may cause start_kernel to
+ * be reaped by free_initmem before the root thread has proceeded to
+ * cpu_idle.
+ *
+ * gcc-3.4 accidentally inlines this function, so use noinline.
+ */
+
+static __initdata DECLARE_COMPLETION(kthreadd_done);
+
+static noinline void __ref __noreturn rest_init(void)
+{
+	struct kernel_clone_args init_args = {
+		.flags		= (CLONE_VM | CLONE_UNTRACED),
+		.fn		= kernel_init,
+		.fn_arg		= NULL,
+	};
+	struct task_struct *tsk;
+	int pid;
+
+	rcu_scheduler_starting();
+	/*
+	 * We need to spawn init first so that it obtains pid 1, however
+	 * the init task will end up wanting to create kthreads, which, if
+	 * we schedule it before we create kthreadd, will OOPS.
+	 */
+	pid = kernel_clone(&init_args);
+	/*
+	 * Pin init on the boot CPU. Task migration is not properly working
+	 * until sched_init_smp() has been run. It will set the allowed
+	 * CPUs for init to the non isolated CPUs.
+	 */
+	rcu_read_lock();
+	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
+	tsk->flags |= PF_NO_SETAFFINITY;
+	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
+	rcu_read_unlock();
+
+	numa_default_policy();
+	pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
+	rcu_read_lock();
+	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
+	rcu_read_unlock();
+
+	/*
+	 * Enable might_sleep() and smp_processor_id() checks.
+	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
+	 * kernel_thread() would trigger might_sleep() splats. With
+	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
+	 * already, but it's stuck on the kthreadd_done completion.
+	 */
+	system_state = SYSTEM_SCHEDULING;
+
+	complete(&kthreadd_done);
+
+	/*
+	 * The boot idle thread must execute schedule()
+	 * at least once to get things moving:
+	 */
+	schedule_preempt_disabled();
+	/* Call into cpu_idle with preempt disabled */
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+/* Check for early params. */
+static int __init do_early_param(char *param, char *val,
+				 const char *unused, void *arg)
+{
+	const struct obs_kernel_param *p;
+
+	for (p = __setup_start; p < __setup_end; p++) {
+		if (p->early && parameq(param, p->str)) {
+			if (p->setup_func(val) != 0)
+				pr_warn("Malformed early option '%s'\n", param);
+		}
+	}
+	/* We accept everything at this stage. */
+	return 0;
+}
+
+void __init parse_early_options(char *cmdline)
+{
+	parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
+		   do_early_param);
+}
+
+/* Arch code calls this early on, or if not, just before other parsing. */
+void __init parse_early_param(void)
+{
+	static int done __initdata;
+	static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
+
+	if (done)
+		return;
+
+	/* All fall through to do_early_param. */
+	strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+	parse_early_options(tmp_cmdline);
+	done = 1;
+}
+
+void __init __weak arch_post_acpi_subsys_init(void) { }
+
+void __init __weak smp_setup_processor_id(void)
+{
+}
+
+void __init __weak smp_prepare_boot_cpu(void)
+{
+}
+
+# if THREAD_SIZE >= PAGE_SIZE
+void __init __weak thread_stack_cache_init(void)
+{
+}
+#endif
+
+void __init __weak poking_init(void) { }
+
+void __init __weak pgtable_cache_init(void) { }
+
+void __init __weak trap_init(void) { }
+
+bool initcall_debug;
+core_param(initcall_debug, initcall_debug, bool, 0644);
+
+#ifdef TRACEPOINTS_ENABLED
+static void __init initcall_debug_enable(void);
+#else
+static inline void initcall_debug_enable(void)
+{
+}
+#endif
+
+#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
+DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
+			   randomize_kstack_offset);
+DEFINE_PER_CPU(struct rnd_state, kstack_rnd_state);
+
+static int __init random_kstack_init(void)
+{
+	prandom_seed_full_state(&kstack_rnd_state);
+	return 0;
+}
+late_initcall(random_kstack_init);
+
+static int __init early_randomize_kstack_offset(char *buf)
+{
+	int ret;
+	bool bool_result;
+
+	ret = kstrtobool(buf, &bool_result);
+	if (ret)
+		return ret;
+
+	if (bool_result)
+		static_branch_enable(&randomize_kstack_offset);
+	else
+		static_branch_disable(&randomize_kstack_offset);
+	return 0;
+}
+early_param("randomize_kstack_offset", early_randomize_kstack_offset);
+#endif
+
+static void __init print_unknown_bootoptions(void)
+{
+	char *unknown_options;
+	char *end;
+	const char *const *p;
+	size_t len;
+
+	if (panic_later || (!argv_init[1] && !envp_init[2]))
+		return;
+
+	/*
+	 * Determine how many options we have to print out, plus a space
+	 * before each
+	 */
+	len = 1; /* null terminator */
+	for (p = &argv_init[1]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+	for (p = &envp_init[2]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+
+	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!unknown_options) {
+		pr_err("%s: Failed to allocate %zu bytes\n",
+			__func__, len);
+		return;
+	}
+	end = unknown_options;
+
+	for (p = &argv_init[1]; *p; p++)
+		end += sprintf(end, " %s", *p);
+	for (p = &envp_init[2]; *p; p++)
+		end += sprintf(end, " %s", *p);
+
+	/* Start at unknown_options[1] to skip the initial space */
+	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
+		&unknown_options[1]);
+	memblock_free(unknown_options, len);
+}
+
+static void __init early_numa_node_init(void)
+{
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+#ifndef cpu_to_node
+	int cpu;
+
+	/* The early_cpu_to_node() should be ready here. */
+	for_each_possible_cpu(cpu)
+		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
+#endif
+#endif
+}
+
+#define KERNEL_CMDLINE_PREFIX		"Kernel command line: "
+#define KERNEL_CMDLINE_PREFIX_LEN	(sizeof(KERNEL_CMDLINE_PREFIX) - 1)
+#define KERNEL_CMDLINE_CONTINUATION	" \\"
+#define KERNEL_CMDLINE_CONTINUATION_LEN	(sizeof(KERNEL_CMDLINE_CONTINUATION) - 1)
+
+#define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN	(KERNEL_CMDLINE_PREFIX_LEN + \
+					 KERNEL_CMDLINE_CONTINUATION_LEN)
+#define CMDLINE_LOG_WRAP_IDEAL_LEN	(CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \
+					 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \
+					 CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \
+					 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN)
+
+#define IDEAL_CMDLINE_LEN		(CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN)
+#define IDEAL_CMDLINE_SPLIT_LEN		(IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN)
+
+/**
+ * print_kernel_cmdline() - Print the kernel cmdline with wrapping.
+ * @cmdline: The cmdline to print.
+ *
+ * Print the kernel command line, trying to wrap based on the Kconfig knob
+ * CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN.
+ *
+ * Wrapping is based on spaces, ignoring quotes. All lines are prefixed
+ * with "Kernel command line: " and lines that are not the last line have
+ * a " \" suffix added to them. The prefix and suffix count towards the
+ * line length for wrapping purposes. The ideal length will be exceeded
+ * if no appropriate place to wrap is found.
+ *
+ * Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40:
+ *   Kernel command line: loglevel=7 \
+ *   Kernel command line: init=/sbin/init \
+ *   Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \
+ *   Kernel command line: rootwait ro \
+ *   Kernel command line: my_quoted_arg="The \
+ *   Kernel command line: quick brown fox \
+ *   Kernel command line: jumps over the \
+ *   Kernel command line: lazy dog."
+ */
+static void __init print_kernel_cmdline(const char *cmdline)
+{
+	size_t len;
+
+	/* Config option of 0 or anything longer than the max disables wrapping */
+	if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 ||
+	    IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) {
+		pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
+		return;
+	}
+
+	len = strlen(cmdline);
+	while (len > IDEAL_CMDLINE_LEN) {
+		const char *first_space;
+		const char *prev_cutoff;
+		const char *cutoff;
+		int to_print;
+		size_t used;
+
+		/* Find the last ' ' that wouldn't make the line too long */
+		prev_cutoff = NULL;
+		cutoff = cmdline;
+		while (true) {
+			cutoff = strchr(cutoff + 1, ' ');
+			if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN)
+				break;
+			prev_cutoff = cutoff;
+		}
+		if (prev_cutoff)
+			cutoff = prev_cutoff;
+		else if (!cutoff)
+			break;
+
+		/* Find the beginning and end of the string of spaces */
+		first_space = cutoff;
+		while (first_space > cmdline && first_space[-1] == ' ')
+			first_space--;
+		to_print = first_space - cmdline;
+		while (*cutoff == ' ')
+			cutoff++;
+		used = cutoff - cmdline;
+
+		/* If the whole string is used, break and do the final printout */
+		if (len == used)
+			break;
+
+		if (to_print)
+			pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX,
+				  to_print, cmdline, KERNEL_CMDLINE_CONTINUATION);
+
+		len -= used;
+		cmdline += used;
+	}
+	if (len)
+		pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
+}
+
+asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
+void start_kernel(void)
+{
+	char *command_line;
+	char *after_dashes;
+
+	set_task_stack_end_magic(&init_task);
+	smp_setup_processor_id();
+	debug_objects_early_init();
+	init_vmlinux_build_id();
+
+	cgroup_init_early();
+
+	local_irq_disable();
+	early_boot_irqs_disabled = true;
+
+	/*
+	 * Interrupts are still disabled. Do necessary setups, then
+	 * enable them.
+	 */
+	boot_cpu_init();
+	page_address_init();
+	pr_notice("%s", linux_banner);
+	setup_arch(&command_line);
+	mm_core_init_early();
+	/* Static keys and static calls are needed by LSMs */
+	jump_label_init();
+	static_call_init();
+	early_security_init();
+	setup_boot_config();
+	setup_command_line(command_line);
+	setup_nr_cpu_ids();
+	setup_per_cpu_areas();
+	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
+	early_numa_node_init();
+	boot_cpu_hotplug_init();
+
+	print_kernel_cmdline(saved_command_line);
+	/* parameters may set static keys */
+	parse_early_param();
+	after_dashes = parse_args("Booting kernel",
+				  static_command_line, __start___param,
+				  __stop___param - __start___param,
+				  -1, -1, NULL, &unknown_bootoption);
+	print_unknown_bootoptions();
+	if (!IS_ERR_OR_NULL(after_dashes))
+		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
+			   NULL, set_init_arg);
+	if (extra_init_args)
+		parse_args("Setting extra init args", extra_init_args,
+			   NULL, 0, -1, -1, NULL, set_init_arg);
+
+	/* Architectural and non-timekeeping rng init, before allocator init */
+	random_init_early(command_line);
+
+	/*
+	 * These use large bootmem allocations and must precede
+	 * initalization of page allocator
+	 */
+	setup_log_buf(0);
+	vfs_caches_init_early();
+	sort_main_extable();
+	trap_init();
+	mm_core_init();
+	maple_tree_init();
+	poking_init();
+	ftrace_init();
+
+	/* trace_printk can be enabled here */
+	early_trace_init();
+
+	/*
+	 * Set up the scheduler prior starting any interrupts (such as the
+	 * timer interrupt). Full topology setup happens at smp_init()
+	 * time - but meanwhile we still have a functioning scheduler.
+	 */
+	sched_init();
+
+	if (WARN(!irqs_disabled(),
+		 "Interrupts were enabled *very* early, fixing it\n"))
+		local_irq_disable();
+	radix_tree_init();
+
+	/*
+	 * Set up housekeeping before setting up workqueues to allow the unbound
+	 * workqueue to take non-housekeeping into account.
+	 */
+	housekeeping_init();
+
+	/*
+	 * Allow workqueue creation and work item queueing/cancelling
+	 * early.  Work item execution depends on kthreads and starts after
+	 * workqueue_init().
+	 */
+	workqueue_init_early();
+
+	rcu_init();
+	kvfree_rcu_init();
+
+	/* Trace events are available after this */
+	trace_init();
+
+	if (initcall_debug)
+		initcall_debug_enable();
+
+	context_tracking_init();
+	/* init some links before init_ISA_irqs() */
+	early_irq_init();
+	init_IRQ();
+	tick_init();
+	rcu_init_nohz();
+	timers_init();
+	srcu_init();
+	hrtimers_init();
+	softirq_init();
+	vdso_setup_data_pages();
+	timekeeping_init();
+	time_init();
+
+	/* This must be after timekeeping is initialized */
+	random_init();
+
+	/* These make use of the fully initialized rng */
+	kfence_init();
+	boot_init_stack_canary();
+
+	perf_event_init();
+	profile_init();
+	call_function_init();
+	WARN(!irqs_disabled(), "Interrupts were enabled early\n");
+
+	early_boot_irqs_disabled = false;
+	local_irq_enable();
+
+	kmem_cache_init_late();
+
+	/*
+	 * HACK ALERT! This is early. We're enabling the console before
+	 * we've done PCI setups etc, and console_init() must be aware of
+	 * this. But we do want output early, in case something goes wrong.
+	 */
+	console_init();
+	if (panic_later)
+		panic("Too many boot %s vars at `%s'", panic_later,
+		      panic_param);
+
+	lockdep_init();
+
+	/*
+	 * Need to run this when irqs are enabled, because it wants
+	 * to self-test [hard/soft]-irqs on/off lock inversion bugs
+	 * too:
+	 */
+	locking_selftest();
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start && !initrd_below_start_ok &&
+	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
+		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
+		    page_to_pfn(virt_to_page((void *)initrd_start)),
+		    min_low_pfn);
+		initrd_start = 0;
+	}
+#endif
+	setup_per_cpu_pageset();
+	numa_policy_init();
+	acpi_early_init();
+	if (late_time_init)
+		late_time_init();
+	sched_clock_init();
+	calibrate_delay();
+
+	arch_cpu_finalize_init();
+
+	pid_idr_init();
+	anon_vma_init();
+	thread_stack_cache_init();
+	cred_init();
+	fork_init();
+	proc_caches_init();
+	uts_ns_init();
+	time_ns_init();
+	key_init();
+	security_init();
+	dbg_late_init();
+	net_ns_init();
+	vfs_caches_init();
+	pagecache_init();
+	signals_init();
+	seq_file_init();
+	proc_root_init();
+	nsfs_init();
+	pidfs_init();
+	cpuset_init();
+	mem_cgroup_init();
+	cgroup_init();
+	taskstats_init_early();
+	delayacct_init();
+
+	acpi_subsystem_init();
+	arch_post_acpi_subsys_init();
+	kcsan_init();
+
+	/* Do the rest non-__init'ed, we're now alive */
+	rest_init();
+
+	/*
+	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
+	 * and older.
+	 */
+#if !__has_attribute(__no_stack_protector__)
+	prevent_tail_call_optimization();
+#endif
+}
+
+/* Call all constructor functions linked into the kernel. */
+static void __init do_ctors(void)
+{
+/*
+ * For UML, the constructors have already been called by the
+ * normal setup code as it's just a normal ELF binary, so we
+ * cannot do it again - but we do need CONFIG_CONSTRUCTORS
+ * even on UML for modules.
+ */
+#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
+	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
+
+	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
+		(*fn)();
+#endif
+}
+
+#ifdef CONFIG_KALLSYMS
+struct blacklist_entry {
+	struct list_head next;
+	char *buf;
+};
+
+static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
+
+static int __init initcall_blacklist(char *str)
+{
+	char *str_entry;
+	struct blacklist_entry *entry;
+
+	/* str argument is a comma-separated list of functions */
+	do {
+		str_entry = strsep(&str, ",");
+		if (str_entry) {
+			pr_debug("blacklisting initcall %s\n", str_entry);
+			entry = memblock_alloc_or_panic(sizeof(*entry),
+					       SMP_CACHE_BYTES);
+			entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1,
+						    SMP_CACHE_BYTES);
+			strcpy(entry->buf, str_entry);
+			list_add(&entry->next, &blacklisted_initcalls);
+		}
+	} while (str_entry);
+
+	return 1;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+	struct blacklist_entry *entry;
+	char fn_name[KSYM_SYMBOL_LEN];
+	unsigned long addr;
+
+	if (list_empty(&blacklisted_initcalls))
+		return false;
+
+	addr = (unsigned long) dereference_function_descriptor(fn);
+	sprint_symbol_no_offset(fn_name, addr);
+
+	/*
+	 * fn will be "function_name [module_name]" where [module_name] is not
+	 * displayed for built-in init functions.  Strip off the [module_name].
+	 */
+	strreplace(fn_name, ' ', '\0');
+
+	list_for_each_entry(entry, &blacklisted_initcalls, next) {
+		if (!strcmp(fn_name, entry->buf)) {
+			pr_debug("initcall %s blacklisted\n", fn_name);
+			return true;
+		}
+	}
+
+	return false;
+}
+#else
+static int __init initcall_blacklist(char *str)
+{
+	pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
+	return 0;
+}
+
+static bool __init_or_module initcall_blacklisted(initcall_t fn)
+{
+	return false;
+}
+#endif
+__setup("initcall_blacklist=", initcall_blacklist);
+
+static __init_or_module void
+trace_initcall_start_cb(void *data, initcall_t fn)
+{
+	ktime_t *calltime = data;
+
+	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
+	*calltime = ktime_get();
+}
+
+static __init_or_module void
+trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
+{
+	ktime_t rettime, *calltime = data;
+
+	rettime = ktime_get();
+	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
+		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
+}
+
+static __init_or_module void
+trace_initcall_level_cb(void *data, const char *level)
+{
+	printk(KERN_DEBUG "entering initcall level: %s\n", level);
+}
+
+static ktime_t initcall_calltime;
+
+#ifdef TRACEPOINTS_ENABLED
+static void __init initcall_debug_enable(void)
+{
+	int ret;
+
+	ret = register_trace_initcall_start(trace_initcall_start_cb,
+					    &initcall_calltime);
+	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
+					      &initcall_calltime);
+	ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL);
+	WARN(ret, "Failed to register initcall tracepoints\n");
+}
+# define do_trace_initcall_start	trace_initcall_start
+# define do_trace_initcall_finish	trace_initcall_finish
+# define do_trace_initcall_level	trace_initcall_level
+#else
+static inline void do_trace_initcall_start(initcall_t fn)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_start_cb(&initcall_calltime, fn);
+}
+static inline void do_trace_initcall_finish(initcall_t fn, int ret)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_finish_cb(&initcall_calltime, fn, ret);
+}
+static inline void do_trace_initcall_level(const char *level)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_level_cb(NULL, level);
+}
+#endif /* !TRACEPOINTS_ENABLED */
+
+int __init_or_module do_one_initcall(initcall_t fn)
+{
+	int count = preempt_count();
+	char msgbuf[64];
+	int ret;
+
+	if (initcall_blacklisted(fn))
+		return -EPERM;
+
+	do_trace_initcall_start(fn);
+	ret = fn();
+	do_trace_initcall_finish(fn, ret);
+
+	msgbuf[0] = 0;
+
+	if (preempt_count() != count) {
+		sprintf(msgbuf, "preemption imbalance ");
+		preempt_count_set(count);
+	}
+	if (irqs_disabled()) {
+		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
+		local_irq_enable();
+	}
+	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
+
+	add_latent_entropy();
+	return ret;
+}
+
+
+static initcall_entry_t *initcall_levels[] __initdata = {
+	__initcall0_start,
+	__initcall1_start,
+	__initcall2_start,
+	__initcall3_start,
+	__initcall4_start,
+	__initcall5_start,
+	__initcall6_start,
+	__initcall7_start,
+	__initcall_end,
+};
+
+/* Keep these in sync with initcalls in include/linux/init.h */
+static const char *initcall_level_names[] __initdata = {
+	"pure",
+	"core",
+	"postcore",
+	"arch",
+	"subsys",
+	"fs",
+	"device",
+	"late",
+};
+
+static int __init ignore_unknown_bootoption(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	return 0;
+}
+
+static void __init do_initcall_level(int level, char *command_line)
+{
+	initcall_entry_t *fn;
+
+	parse_args(initcall_level_names[level],
+		   command_line, __start___param,
+		   __stop___param - __start___param,
+		   level, level,
+		   NULL, ignore_unknown_bootoption);
+
+	do_trace_initcall_level(initcall_level_names[level]);
+	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static void __init do_initcalls(void)
+{
+	int level;
+	size_t len = saved_command_line_len + 1;
+	char *command_line;
+
+	command_line = kzalloc(len, GFP_KERNEL);
+	if (!command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
+		/* Parser modifies command_line, restore it each time */
+		strcpy(command_line, saved_command_line);
+		do_initcall_level(level, command_line);
+	}
+
+	kfree(command_line);
+}
+
+/*
+ * Ok, the machine is now initialized. None of the devices
+ * have been touched yet, but the CPU subsystem is up and
+ * running, and memory and process management works.
+ *
+ * Now we can finally start doing some real work..
+ */
+static void __init do_basic_setup(void)
+{
+	cpuset_init_smp();
+	ksysfs_init();
+	driver_init();
+	init_irq_proc();
+	do_ctors();
+	do_initcalls();
+}
+
+static void __init do_pre_smp_initcalls(void)
+{
+	initcall_entry_t *fn;
+
+	do_trace_initcall_level("early");
+	for (fn = __initcall_start; fn < __initcall0_start; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static int run_init_process(const char *init_filename)
+{
+	const char *const *p;
+
+	argv_init[0] = init_filename;
+	pr_info("Run %s as init process\n", init_filename);
+	pr_debug("  with arguments:\n");
+	for (p = argv_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	pr_debug("  with environment:\n");
+	for (p = envp_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	return kernel_execve(init_filename, argv_init, envp_init);
+}
+
+static int try_to_run_init_process(const char *init_filename)
+{
+	int ret;
+
+	ret = run_init_process(init_filename);
+
+	if (ret && ret != -ENOENT) {
+		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
+		       init_filename, ret);
+	}
+
+	return ret;
+}
+
+static noinline void __init kernel_init_freeable(void);
+
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
+bool rodata_enabled __ro_after_init = true;
+
+#ifndef arch_parse_debug_rodata
+static inline bool arch_parse_debug_rodata(char *str) { return false; }
+#endif
+
+static int __init set_debug_rodata(char *str)
+{
+	if (arch_parse_debug_rodata(str))
+		return 0;
+
+	if (str && !strcmp(str, "on"))
+		rodata_enabled = true;
+	else if (str && !strcmp(str, "off"))
+		rodata_enabled = false;
+	else
+		pr_warn("Invalid option string for rodata: '%s'\n", str);
+	return 0;
+}
+early_param("rodata", set_debug_rodata);
+#endif
+
+static void mark_readonly(void)
+{
+	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) {
+		/*
+		 * load_module() results in W+X mappings, which are cleaned
+		 * up with init_free_wq. Let's make sure that queued work is
+		 * flushed so that we don't hit false positives looking for
+		 * insecure pages which are W+X.
+		 */
+		flush_module_init_free_work();
+		jump_label_init_ro();
+		mark_rodata_ro();
+		debug_checkwx();
+		rodata_test();
+	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
+		pr_info("Kernel memory protection disabled.\n");
+	} else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) {
+		pr_warn("Kernel memory protection not selected by kernel config.\n");
+	} else {
+		pr_warn("This architecture does not have kernel memory protection.\n");
+	}
+}
+
+void __weak free_initmem(void)
+{
+	free_initmem_default(POISON_FREE_INITMEM);
+}
+
+static int __ref kernel_init(void *unused)
+{
+	int ret;
+
+	init_userspace_fs();
+
+	/*
+	 * Wait until kthreadd is all set-up.
+	 */
+	wait_for_completion(&kthreadd_done);
+
+	kernel_init_freeable();
+	/* need to finish all async __init code before freeing the memory */
+	async_synchronize_full();
+
+	system_state = SYSTEM_FREEING_INITMEM;
+	kprobe_free_init_mem();
+	ftrace_free_init_mem();
+	kgdb_free_init_mem();
+	exit_boot_config();
+	free_initmem();
+	mark_readonly();
+
+	/*
+	 * Kernel mappings are now finalized - update the userspace page-table
+	 * to finalize PTI.
+	 */
+	pti_finalize();
+
+	system_state = SYSTEM_RUNNING;
+	numa_default_policy();
+
+	rcu_end_inkernel_boot();
+
+	do_sysctl_args();
+
+	if (ramdisk_execute_command) {
+		ret = run_init_process(ramdisk_execute_command);
+		if (!ret)
+			return 0;
+		pr_err("Failed to execute %s (error %d)\n",
+		       ramdisk_execute_command, ret);
+	}
+
+	/*
+	 * We try each of these until one succeeds.
+	 *
+	 * The Bourne shell can be used instead of init if we are
+	 * trying to recover a really broken machine.
+	 */
+	if (execute_command) {
+		ret = run_init_process(execute_command);
+		if (!ret)
+			return 0;
+		panic("Requested init %s failed (error %d).",
+		      execute_command, ret);
+	}
+
+	if (CONFIG_DEFAULT_INIT[0] != '\0') {
+		ret = run_init_process(CONFIG_DEFAULT_INIT);
+		if (ret)
+			pr_err("Default init %s failed (error %d)\n",
+			       CONFIG_DEFAULT_INIT, ret);
+		else
+			return 0;
+	}
+
+	if (!try_to_run_init_process("/sbin/init") ||
+	    !try_to_run_init_process("/etc/init") ||
+	    !try_to_run_init_process("/bin/init") ||
+	    !try_to_run_init_process("/bin/sh"))
+		return 0;
+
+	panic("No working init found.  Try passing init= option to kernel. "
+	      "See Linux Documentation/admin-guide/init.rst for guidance.");
+}
+
+/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
+void __init console_on_rootfs(void)
+{
+	struct file *file = filp_open("/dev/console", O_RDWR, 0);
+
+	if (IS_ERR(file)) {
+		pr_err("Warning: unable to open an initial console.\n");
+		return;
+	}
+	init_dup(file);
+	init_dup(file);
+	init_dup(file);
+	fput(file);
+}
+
+static noinline void __init kernel_init_freeable(void)
+{
+	/* Now the scheduler is fully set up and can do blocking allocations */
+	gfp_allowed_mask = __GFP_BITS_MASK;
+
+	/*
+	 * init can allocate pages on any node
+	 */
+	set_mems_allowed(node_states[N_MEMORY]);
+
+	cad_pid = get_pid(task_pid(current));
+
+	smp_prepare_cpus(setup_max_cpus);
+
+	workqueue_init();
+
+	init_mm_internals();
+
+	do_pre_smp_initcalls();
+	lockup_detector_init();
+
+	smp_init();
+	sched_init_smp();
+
+	workqueue_init_topology();
+	async_init();
+	padata_init();
+	page_alloc_init_late();
+
+	do_basic_setup();
+
+	kunit_run_all_tests();
+
+	wait_for_initramfs();
+	console_on_rootfs();
+
+	/*
+	 * check if there is an early userspace init.  If yes, let it do all
+	 * the work
+	 */
+	int ramdisk_command_access;
+	ramdisk_command_access = init_eaccess(ramdisk_execute_command);
+	if (ramdisk_command_access != 0) {
+		if (ramdisk_execute_command_set)
+			pr_warn("check access for rdinit=%s failed: %i, ignoring\n",
+				ramdisk_execute_command, ramdisk_command_access);
+		ramdisk_execute_command = NULL;
+		prepare_namespace();
+	}
+
+	/*
+	 * Ok, we have completed the initial bootup, and
+	 * we're essentially up and running. Get rid of the
+	 * initmem segments and start the user-mode stuff..
+	 *
+	 * rootfs is available now, try loading the public keys
+	 * and default modules
+	 */
+
+	integrity_load_keys();
+}
diff --git a/init/noinitramfs.c b/init/noinitramfs.c
new file mode 100644
index 000000000..d1d26b93d
--- /dev/null
+++ b/init/noinitramfs.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * init/noinitramfs.c
+ *
+ * Copyright (C) 2006, NXP Semiconductors, All Rights Reserved
+ * Author: Jean-Paul Saman <jean-paul.saman@nxp.com>
+ */
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/kdev_t.h>
+#include <linux/syscalls.h>
+#include <linux/init_syscalls.h>
+#include <linux/umh.h>
+
+/*
+ * Create a simple rootfs that is similar to the default initramfs
+ */
+static int __init default_rootfs(void)
+{
+	int err;
+
+	usermodehelper_enable();
+	err = init_mkdir("/dev", 0755);
+	if (err < 0)
+		goto out;
+
+	err = init_mknod("/dev/console", S_IFCHR | S_IRUSR | S_IWUSR,
+			new_encode_dev(MKDEV(5, 1)));
+	if (err < 0)
+		goto out;
+
+	err = init_mkdir("/root", 0700);
+	if (err < 0)
+		goto out;
+
+	return 0;
+
+out:
+	printk(KERN_WARNING "Failed to create a rootfs\n");
+	return err;
+}
+rootfs_initcall(default_rootfs);
diff --git a/init/version-timestamp.c b/init/version-timestamp.c
new file mode 100644
index 000000000..375726e05
--- /dev/null
+++ b/init/version-timestamp.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <generated/compile.h>
+#include <generated/utsrelease.h>
+#include <linux/proc_ns.h>
+#include <linux/refcount.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+
+struct uts_namespace init_uts_ns = {
+	.ns = NS_COMMON_INIT(init_uts_ns),
+	.name = {
+		.sysname	= UTS_SYSNAME,
+		.nodename	= UTS_NODENAME,
+		.release	= UTS_RELEASE,
+		.version	= UTS_VERSION,
+		.machine	= UTS_MACHINE,
+		.domainname	= UTS_DOMAINNAME,
+	},
+	.user_ns = &init_user_ns,
+};
+
+/* FIXED STRINGS! Don't touch! */
+const char linux_banner[] =
+	"Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
+	LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";
diff --git a/init/version.c b/init/version.c
new file mode 100644
index 000000000..94c96f6fb
--- /dev/null
+++ b/init/version.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/version.c
+ *
+ *  Copyright (C) 1992  Theodore Ts'o
+ *
+ *  May be freely distributed as part of Linux.
+ */
+
+#include <generated/compile.h>
+#include <linux/build-salt.h>
+#include <linux/elfnote-lto.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/uts.h>
+#include <linux/utsname.h>
+#include <linux/proc_ns.h>
+
+static int __init early_hostname(char *arg)
+{
+	size_t bufsize = sizeof(init_uts_ns.name.nodename);
+	size_t maxlen  = bufsize - 1;
+	ssize_t arglen;
+
+	arglen = strscpy(init_uts_ns.name.nodename, arg, bufsize);
+	if (arglen < 0) {
+		pr_warn("hostname parameter exceeds %zd characters and will be truncated",
+			maxlen);
+	}
+	return 0;
+}
+early_param("hostname", early_hostname);
+
+const char linux_proc_banner[] =
+	"%s version %s"
+	" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
+	" (" LINUX_COMPILER ") %s\n";
+
+BUILD_SALT;
+BUILD_LTO_INFO;
+
+/*
+ * init_uts_ns and linux_banner contain the build version and timestamp,
+ * which are really fixed at the very last step of build process.
+ * They are compiled with __weak first, and without __weak later.
+ */
+
+struct uts_namespace init_uts_ns __weak;
+const char linux_banner[] __weak;
+
+#include "version-timestamp.c"
+
+EXPORT_SYMBOL_GPL(init_uts_ns);