Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 515 insertions, 0 deletions

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
new file mode 100644
index 000000000..0a4fdd8bd
--- /dev/null
+++ b/scripts/Makefile.lib
@@ -0,0 +1,515 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Finds the multi-part object the current object will be linked into.
+# If the object belongs to two or more multi-part objects, list them all.
+modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
+		$(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
+
+__modname = $(or $(modname-multi),$(basetarget))
+
+modname = $(subst $(space),:,$(__modname))
+modfile = $(addprefix $(obj)/,$(__modname))
+
+# target with $(obj)/ and its suffix stripped
+target-stem = $(basename $(patsubst $(obj)/%,%,$@))
+
+# These flags are needed for modversions and compiling, so we define them here
+# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
+# end up in (or would, if it gets compiled in)
+name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
+name-fix = $(call stringify,$(call name-fix-token,$1))
+basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
+modname_flags  = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
+		 -D__KBUILD_MODNAME=$(call name-fix-token,$(modname))
+modfile_flags  = -DKBUILD_MODFILE=$(call stringify,$(modfile))
+
+_c_flags       = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
+                     $(filter-out $(ccflags-remove-y), \
+                         $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
+                     $(CFLAGS_$(target-stem).o))
+_rust_flags    = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
+                     $(filter-out $(rustflags-remove-y), \
+                         $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
+                     $(RUSTFLAGS_$(target-stem).o))
+_a_flags       = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
+                     $(filter-out $(asflags-remove-y), \
+                         $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
+                     $(AFLAGS_$(target-stem).o))
+_cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
+
+#
+# Enable gcov profiling flags for a file, directory or for all files depending
+# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
+# (in this order)
+#
+ifeq ($(CONFIG_GCOV_KERNEL),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(if $(is-kernel-object),$(CONFIG_GCOV_PROFILE_ALL))), \
+		$(CFLAGS_GCOV))
+endif
+
+#
+# Enable address sanitizer flags for kernel except some files or directories
+# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
+#
+ifeq ($(CONFIG_KASAN),y)
+ifneq ($(CONFIG_KASAN_HW_TAGS),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
+		$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
+_rust_flags += $(if $(patsubst n%,, \
+		$(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
+		$(RUSTFLAGS_KASAN))
+endif
+endif
+
+ifeq ($(CONFIG_KMSAN),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)$(is-kernel-object)), \
+		$(CFLAGS_KMSAN))
+_c_flags += $(if $(patsubst n%,, \
+		$(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)$(is-kernel-object)), \
+		, -mllvm -msan-disable-checks=1)
+endif
+
+ifeq ($(CONFIG_UBSAN),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(is-kernel-object)), \
+		$(CFLAGS_UBSAN))
+_c_flags += $(if $(patsubst n%,, \
+		$(UBSAN_INTEGER_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_INTEGER_WRAP)$(UBSAN_SANITIZE)$(is-kernel-object)), \
+		$(CFLAGS_UBSAN_INTEGER_WRAP))
+endif
+
+ifeq ($(CONFIG_KCOV),y)
+_c_flags += $(if $(patsubst n%,, \
+	$(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \
+	$(CFLAGS_KCOV))
+_rust_flags += $(if $(patsubst n%,, \
+	$(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \
+	$(RUSTFLAGS_KCOV))
+endif
+
+#
+# Enable KCSAN flags except some files or directories we don't want to check
+# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
+#
+ifeq ($(CONFIG_KCSAN),y)
+_c_flags += $(if $(patsubst n%,, \
+	$(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)$(is-kernel-object)), \
+	$(CFLAGS_KCSAN))
+# Some uninstrumented files provide implied barriers required to avoid false
+# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
+_c_flags += $(if $(patsubst n%,, \
+	$(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
+	-D__KCSAN_INSTRUMENT_BARRIERS__)
+endif
+
+#
+# Enable context analysis flags only where explicitly opted in.
+# (depends on variables CONTEXT_ANALYSIS_obj.o, CONTEXT_ANALYSIS)
+#
+ifeq ($(CONFIG_WARN_CONTEXT_ANALYSIS),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(CONTEXT_ANALYSIS_$(target-stem).o)$(CONTEXT_ANALYSIS)$(if $(is-kernel-object),$(CONFIG_WARN_CONTEXT_ANALYSIS_ALL))), \
+		$(CFLAGS_CONTEXT_ANALYSIS))
+endif
+
+#
+# Enable AutoFDO build flags except some files or directories we don't want to
+# enable (depends on variables AUTOFDO_PROFILE_obj.o and AUTOFDO_PROFILE).
+#
+ifeq ($(CONFIG_AUTOFDO_CLANG),y)
+_c_flags += $(if $(patsubst n%,, \
+	$(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(is-kernel-object)), \
+	$(CFLAGS_AUTOFDO_CLANG))
+_rust_flags += $(if $(patsubst n%,, \
+	$(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(is-kernel-object)), \
+	$(RUSTFLAGS_AUTOFDO_CLANG))
+endif
+
+#
+# Enable Propeller build flags except some files or directories we don't want to
+# enable (depends on variables AUTOFDO_PROPELLER_obj.o and PROPELLER_PROFILE).
+#
+ifdef CONFIG_PROPELLER_CLANG
+_c_flags += $(if $(patsubst n%,, \
+	$(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(PROPELLER_PROFILE))$(is-kernel-object), \
+	$(CFLAGS_PROPELLER_CLANG))
+endif
+
+# $(src) for including checkin headers from generated source files
+# $(obj) for including generated headers from checkin source files
+ifdef building_out_of_srctree
+_c_flags   += $(addprefix -I, $(src) $(obj))
+_a_flags   += $(addprefix -I, $(src) $(obj))
+_cpp_flags += $(addprefix -I, $(src) $(obj))
+endif
+
+# If $(is-kernel-object) is 'y', this object will be linked to vmlinux or modules
+is-kernel-object = $(or $(part-of-builtin),$(part-of-module))
+
+part-of-builtin = $(if $(filter $(basename $@).o, $(real-obj-y) $(lib-y)),y)
+part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
+quiet_modtag = $(if $(part-of-module),[M],   )
+
+modkern_cflags =                                          \
+	$(if $(part-of-module),                           \
+		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
+		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
+
+modkern_rustflags =                                              \
+	$(if $(part-of-module),                                   \
+		$(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
+		$(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
+
+modkern_aflags = $(if $(part-of-module),				\
+			$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE),	\
+			$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags))
+
+c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
+		 -include $(srctree)/include/linux/compiler_types.h       \
+		 $(_c_flags) $(modkern_cflags)                           \
+		 $(basename_flags) $(modname_flags)
+
+rust_flags     = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
+
+a_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
+		 $(_a_flags) $(modkern_aflags) $(modname_flags)
+
+cpp_flags      = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
+		 $(_cpp_flags)
+
+ld_flags       = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
+
+ifdef CONFIG_OBJTOOL
+
+objtool := $(objtree)/tools/objtool/objtool
+
+objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK)		+= --hacks=jump_label
+objtool-args-$(CONFIG_HAVE_NOINSTR_HACK)		+= --hacks=noinstr
+objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING)	+= --hacks=skylake
+objtool-args-$(CONFIG_X86_KERNEL_IBT)			+= --ibt
+objtool-args-$(CONFIG_CALL_PADDING)			+= --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
+ifdef CONFIG_CALL_PADDING
+objtool-args-$(CONFIG_CFI)				+= --cfi
+objtool-args-$(CONFIG_FINEIBT)				+= --fineibt
+endif
+objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL)	+= --mcount
+ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
+objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT)		+= --mnop
+endif
+objtool-args-$(CONFIG_UNWINDER_ORC)			+= --orc
+objtool-args-$(CONFIG_MITIGATION_RETPOLINE)		+= --retpoline
+objtool-args-$(CONFIG_MITIGATION_RETHUNK)		+= --rethunk
+objtool-args-$(CONFIG_MITIGATION_SLS)			+= --sls
+objtool-args-$(CONFIG_STACK_VALIDATION)			+= --stackval
+objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE)		+= --static-call
+objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION)		+= --uaccess
+objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV))	+= --no-unreachable
+objtool-args-$(CONFIG_OBJTOOL_WERROR)			+= --werror
+
+objtool-args = $(objtool-args-y)					\
+	$(if $(delay-objtool), --link)					\
+	$(if $(part-of-module), --module)
+
+delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT),$(CONFIG_KLP_BUILD))
+
+cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
+cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
+
+objtool-enabled := y
+
+endif # CONFIG_OBJTOOL
+
+# Useful for describing the dependency of composite objects
+# Usage:
+#   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
+define multi_depend
+$(foreach m, $1, \
+	$(eval $m: \
+	$(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
+endef
+
+# Remove ".." and "." from a path, without using "realpath"
+# Usage:
+#   $(call normalize_path,path/to/../file)
+define normalize_path
+$(strip $(eval elements :=) \
+$(foreach elem,$(subst /, ,$1), \
+	$(if $(filter-out .,$(elem)), \
+	     $(if $(filter ..,$(elem)), \
+		  $(eval elements := $(wordlist 2,$(words $(elements)),x $(elements))), \
+		  $(eval elements := $(elements) $(elem))))) \
+$(subst $(space),/,$(elements)))
+endef
+
+# Build commands
+# ===========================================================================
+# These are shared by some Makefile.* files.
+
+ifdef CONFIG_LTO_CLANG
+# Run $(LD) here to convert LLVM IR to ELF in the following cases:
+#  - when this object needs objtool processing, as objtool cannot process LLVM IR
+#  - when this is a single-object module, as modpost cannot process LLVM IR
+cmd_ld_single = $(if $(objtool-enabled)$(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
+endif
+
+ifdef CONFIG_LTO_CLANG_THIN_DIST
+# Save the _c_flags, sliently.
+quiet_cmd_save_c_flags =
+      saved_c_flags = $(_c_flags) $(modkern_cflags)
+      cmd_save_c_flags = printf '\n%s\n' 'saved_c_flags_$@ := $(call escsq,$(saved_c_flags))' >> $(dot-target).cmd
+endif
+
+quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
+      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
+		$(cmd_ld_single) \
+		$(cmd_objtool)
+
+define rule_cc_o_c
+	$(call cmd_and_fixdep,cc_o_c)
+	$(call cmd,save_c_flags)
+	$(call cmd,checksrc)
+	$(call cmd,checkdoc)
+	$(call cmd,gen_objtooldep)
+	$(call cmd,gen_symversions_c)
+	$(call cmd,record_mcount)
+	$(call cmd,warn_shared_object)
+endef
+
+quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
+      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
+
+define rule_as_o_S
+	$(call cmd_and_fixdep,as_o_S)
+	$(call cmd,gen_objtooldep)
+	$(call cmd,gen_symversions_S)
+	$(call cmd,warn_shared_object)
+endef
+
+# Copy a file
+# ===========================================================================
+# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
+# the copy would be read-only as well, leading to an error when executing the
+# rule next time. Use 'cat' instead in order to generate a writable file.
+quiet_cmd_copy = COPY    $@
+      cmd_copy = cat $< > $@
+
+$(obj)/%: $(src)/%_shipped
+	$(call cmd,copy)
+
+# Touch a file
+# ===========================================================================
+quiet_cmd_touch = TOUCH   $(call normalize_path,$@)
+      cmd_touch = touch $@
+
+# Commands useful for building a boot image
+# ===========================================================================
+#
+#	Use as following:
+#
+#	target: source(s) FORCE
+#		$(if_changed,ld/objcopy/gzip)
+#
+#	and add target to 'targets' so that we know we have to
+#	read in the saved command line
+
+# Linking
+# ---------------------------------------------------------------------------
+
+quiet_cmd_ld = LD      $@
+      cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
+
+# Archive
+# ---------------------------------------------------------------------------
+
+quiet_cmd_ar = AR      $@
+      cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
+
+# Objcopy
+# ---------------------------------------------------------------------------
+
+quiet_cmd_objcopy = OBJCOPY $@
+cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
+
+# Gzip
+# ---------------------------------------------------------------------------
+
+quiet_cmd_gzip = GZIP    $@
+      cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
+
+# Bzip2
+# ---------------------------------------------------------------------------
+
+# Bzip2 and LZMA do not include size in file... so we have to fake that;
+# append the size as a 32-bit littleendian number as gzip does.
+size_append = printf $(shell						\
+dec_size=0;								\
+for F in $(real-prereqs); do					\
+	fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);	\
+	dec_size=$$(expr $$dec_size + $$fsize);				\
+done;									\
+printf "%08x\n" $$dec_size |						\
+	sed 's/\(..\)/\1 /g' | {					\
+		read ch0 ch1 ch2 ch3;					\
+		for ch in $$ch3 $$ch2 $$ch1 $$ch0; do			\
+			printf '%s%03o' '\\' $$((0x$$ch)); 		\
+		done;							\
+	}								\
+)
+
+quiet_cmd_file_size = GEN     $@
+      cmd_file_size = $(size_append) > $@
+
+quiet_cmd_bzip2 = BZIP2   $@
+      cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
+
+quiet_cmd_bzip2_with_size = BZIP2   $@
+      cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
+
+# Lzma
+# ---------------------------------------------------------------------------
+
+quiet_cmd_lzma = LZMA    $@
+      cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
+
+quiet_cmd_lzma_with_size = LZMA    $@
+      cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
+
+quiet_cmd_lzo = LZO     $@
+      cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
+
+quiet_cmd_lzo_with_size = LZO     $@
+      cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
+
+quiet_cmd_lz4 = LZ4     $@
+      cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -9 - - > $@
+
+quiet_cmd_lz4_with_size = LZ4     $@
+      cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -9 - -; \
+                  $(size_append); } > $@
+
+# U-Boot mkimage
+# ---------------------------------------------------------------------------
+
+MKIMAGE := $(srctree)/scripts/mkuboot.sh
+
+# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
+# the number of overrides in arch makefiles
+UIMAGE_ARCH ?= $(SRCARCH)
+UIMAGE_COMPRESSION ?= $(or $(2),none)
+UIMAGE_OPTS-y ?=
+UIMAGE_TYPE ?= kernel
+UIMAGE_LOADADDR ?= arch_must_set_this
+UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
+UIMAGE_NAME ?= Linux-$(KERNELRELEASE)
+
+quiet_cmd_uimage = UIMAGE  $@
+      cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
+			-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
+			-T $(UIMAGE_TYPE) \
+			-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
+			-n '$(UIMAGE_NAME)' -d $< $@
+
+# Flat Image Tree (FIT)
+# This allows for packaging of a kernel and all devicetrees files, using
+# compression.
+# ---------------------------------------------------------------------------
+
+MAKE_FIT := $(srctree)/scripts/make_fit.py
+
+# Use this to override the compression algorithm
+FIT_COMPRESSION ?= gzip
+
+quiet_cmd_fit = FIT     $@
+      cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \
+		--name '$(UIMAGE_NAME)' $(FIT_EXTRA_ARGS) \
+		$(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \
+		$(if $(FIT_DECOMPOSE_DTBS),--decompose-dtbs) \
+		--compress $(FIT_COMPRESSION) -k $< @$(word 2,$^)
+
+# XZ
+# ---------------------------------------------------------------------------
+# Use xzkern or xzkern_with_size to compress the kernel image and xzmisc to
+# compress other things.
+#
+# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
+# of the kernel decompressor. A BCJ filter is used if it is available for
+# the target architecture.
+#
+# xzkern_with_size also appends uncompressed size of the data using
+# size_append. The .xz format has the size information available at the end
+# of the file too, but it's in more complex format and it's good to avoid
+# changing the part of the boot code that reads the uncompressed size.
+# Note that the bytes added by size_append will make the xz tool think that
+# the file is corrupt. This is expected.
+#
+# xzmisc doesn't use size_append, so it can be used to create normal .xz
+# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
+# big dictionary would increase the memory usage too much in the multi-call
+# decompression mode. A BCJ filter isn't used either.
+quiet_cmd_xzkern = XZKERN  $@
+      cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
+
+quiet_cmd_xzkern_with_size = XZKERN  $@
+      cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
+                     $(size_append); } > $@
+
+quiet_cmd_xzmisc = XZMISC  $@
+      cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
+
+# ZSTD
+# ---------------------------------------------------------------------------
+# Appends the uncompressed size of the data using size_append. The .zst
+# format has the size information available at the beginning of the file too,
+# but it's in a more complex format and it's good to avoid changing the part
+# of the boot code that reads the uncompressed size.
+#
+# Note that the bytes added by size_append will make the zstd tool think that
+# the file is corrupt. This is expected.
+#
+# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
+# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
+# single pass, so zstd doesn't need to allocate a window buffer. When streaming
+# decompression is used, like initramfs decompression, zstd22 should likely not
+# be used because it would require zstd to allocate a 128 MB buffer.
+
+quiet_cmd_zstd = ZSTD    $@
+      cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
+
+quiet_cmd_zstd22 = ZSTD22  $@
+      cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
+
+quiet_cmd_zstd22_with_size = ZSTD22  $@
+      cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
+
+# ASM offsets
+# ---------------------------------------------------------------------------
+
+# Default sed regexp - multiline due to syntax constraints
+#
+# Use [:space:] because LLVM's integrated assembler inserts <tab> around
+# the .ascii directive whereas GCC keeps the <space> as-is.
+define sed-offsets
+	's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
+	/^->/{s:->#\(.*\):/* \1 */:; \
+	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
+	s:->::; p;}'
+endef
+
+# Use filechk to avoid rebuilds when a header changes, but the resulting file
+# does not
+define filechk_offsets
+	 echo "#ifndef $2"; \
+	 echo "#define $2"; \
+	 echo "/*"; \
+	 echo " * DO NOT MODIFY."; \
+	 echo " *"; \
+	 echo " * This file was generated by Kbuild"; \
+	 echo " */"; \
+	 echo ""; \
+	 sed -ne $(sed-offsets) < $<; \
+	 echo ""; \
+	 echo "#endif"
+endef