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Masahiro Yamada 7ce7e984ab kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}

GZIP-compressed files end with 4 byte data that represents the size
of the original input. The decompressors (the self-extracting kernel)
exploit it to know the vmlinux size beforehand. To mimic the GZIP's
trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}.
Unfortunately these macros are used everywhere despite the appended
size data is only useful for the decompressors.

There is no guarantee that such hand-crafted trailers are safely ignored.
In fact, the kernel refuses compressed initramdfs with the garbage data.
That is why usr/Makefile overrides size_append to make it no-op.

To limit the use of such broken compressed files, this commit renames
the existing macros as follows:

  cmd_bzip2   --> cmd_bzip2_with_size
  cmd_lzma    --> cmd_lzma_with_size
  cmd_lzo     --> cmd_lzo_with_size
  cmd_lz4     --> cmd_lz4_with_size
  cmd_xzkern  --> cmd_xzkern_with_size
  cmd_zstd22  --> cmd_zstd22_with_size

To keep the decompressors working, I updated the following Makefiles
accordingly:

  arch/arm/boot/compressed/Makefile
  arch/h8300/boot/compressed/Makefile
  arch/mips/boot/compressed/Makefile
  arch/parisc/boot/compressed/Makefile
  arch/s390/boot/compressed/Makefile
  arch/sh/boot/compressed/Makefile
  arch/x86/boot/compressed/Makefile

I reused the current macro names for the normal usecases; they produce
the compressed data in the proper format.

I did not touch the following:

  arch/arc/boot/Makefile
  arch/arm64/boot/Makefile
  arch/csky/boot/Makefile
  arch/mips/boot/Makefile
  arch/riscv/boot/Makefile
  arch/sh/boot/Makefile
  kernel/Makefile

This means those Makefiles will stop appending the size data.

I dropped the 'override size_append' hack from usr/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

2022-01-14 02:54:05 +09:00

2.1 KiB

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SPDX-License-Identifier: GPL-2.0

linux/arch/sh/boot/compressed/Makefile

create a compressed vmlinux image from the original vmlinux

OBJECTS := head_32.o misc.o cache.o piggy.o
ashiftrt.o ashldi3.o ashrsi3.o ashlsi3.o lshrsi3.o

These were previously generated files. When you are building the kernel

with O=, make sure to remove the stale files in the output tree. Otherwise,

the build system wrongly compiles the stale ones.

ifdef building_out_of_srctree $(shell rm -f $(addprefix $(obj)/, ashiftrt.S ashldi3.c ashrsi3.S ashlsi3.S lshrsi3.S)) endif

targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2
vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo $(OBJECTS)

GCOV_PROFILE := n

IMAGE_OFFSET is the load offset of the compression loader

ifeq ($(CONFIG_32BIT),y) IMAGE_OFFSET := $(shell /bin/bash -c 'printf "0x%08x"
$$[$(CONFIG_MEMORY_START) +
$(CONFIG_BOOT_LINK_OFFSET)]') else IMAGE_OFFSET := $(shell /bin/bash -c 'printf "0x%08x"
$$[$(CONFIG_PAGE_OFFSET) +
$(KERNEL_MEMORY) +
$(CONFIG_BOOT_LINK_OFFSET)]') endif

ccflags-remove-$(CONFIG_MCOUNT) += -pg

LDFLAGS_vmlinux := --oformat $(ld-bfd) -Ttext $(IMAGE_OFFSET) -e startup
-T $(obj)/../../kernel/vmlinux.lds

KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING

$(obj)/vmlinux: $(addprefix $(obj)/, $(OBJECTS)) FORCE $(call if_changed,ld)

$(obj)/vmlinux.bin: vmlinux FORCE $(call if_changed,objcopy)

vmlinux.bin.all-y := $(obj)/vmlinux.bin

$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE $(call if_changed,gzip) $(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE $(call if_changed,bzip2_with_size) $(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE $(call if_changed,lzma_with_size) $(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE $(call if_changed,xzkern_with_size) $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE $(call if_changed,lzo_with_size)

OBJCOPYFLAGS += -R .empty_zero_page

LDFLAGS_piggy.o := -r --format binary --oformat $(ld-bfd) -T

$(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.$(suffix_y) FORCE $(call if_changed,ld)

2.1 KiB Raw Blame History