Changes in Makefile

032ce1ea - x86/boot: Work around broken busybox 'truncate' tool

Thu, 24 Apr 2025 10:19:18 +0000

x86/boot: Work around broken busybox 'truncate' toolThe GNU coreutils version of truncate, which is the original, accepts a% prefix for the -s size argument which means the file in questionshould be padded to a multiple of the given size. This is currently usedto pad the setup block of bzImage to a multiple of 4k before appendingthe decompressor.busybox reimplements truncate but does not support this idiom, andtherefore fails the build since commit 9c54baab4401 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")Since very little build code within the kernel depends on the 'truncate'utility, work around this incompatibility by avoiding truncate altogether,and relying on dd to perform the padding.Fixes: 9c54baab4401 ("x86/boot: Drop CRC-32 checksum and the build tool that generates it")Reported-by: Tested-by: Philipp Stanner Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250424101917.1552527-2-ardb+git@google.com List of files: /linux-6.15/arch/x86/boot/Makefile

97282e6d - x86: drop unnecessary prefix map configuration

Sat, 22 Mar 2025 09:03:16 +0000

x86: drop unnecessary prefix map configurationThe toplevel Makefile already provides -fmacro-prefix-map as part ofKBUILD_CPPFLAGS. In contrast to the KBUILD_CFLAGS and KBUILD_AFLAGSvariables, KBUILD_CPPFLAGS is not redefined in the architecture specificMakefiles. Therefore the toplevel KBUILD_CPPFLAGS do apply just fine, toboth C and ASM sources.The custom configuration was necessary when it was added incommit 9e2276fa6eb3 ("arch/x86/boot: Use prefix map to avoid embeddedpaths") but has since become unnecessary in commit a716bd743210("kbuild: use -fmacro-prefix-map for .S sources").Drop the now unnecessary custom prefix map configuration.Signed-off-by: Thomas Weißschuh Signed-off-by: Masahiro Yamada List of files: /linux-6.15/arch/x86/boot/Makefile

9c54baab - x86/boot: Drop CRC-32 checksum and the build tool that generates it

Fri, 07 Mar 2025 16:48:02 +0000

x86/boot: Drop CRC-32 checksum and the build tool that generates itApart from some sanity checks on the size of setup.bin, the onlyremaining task carried out by the arch/x86/boot/tools/build.c build toolis generating the CRC-32 checksum of the bzImage. This feature was addedin commit 7d6e737c8d2698b6 ("x86: add a crc32 checksum to the kernel image.")without any motivation (or any commit log text, for that matter). Thischecksum is not verified by any known bootloader, and given that a) the checksum of the entire bzImage is reported by most tools (zlib, rhash) as 0xffffffff and not 0x0 as documented, b) the checksum is corrupted when the image is signed for secure boot, which means that no distro ships x86 images with valid CRCs,it seems quite unlikely that this checksum is being used, so let's justdrop it, along with the tool that generates it.Instead, use simple file concatenation and truncation to combine the twopieces into bzImage, and replace the checks on the size of the setupblock with a couple of ASSERT()s in the linker script.Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: "H. Peter Anvin" Cc: Ian Campbell Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250307164801.885261-2-ardb+git@google.com List of files: /linux-6.15/arch/x86/boot/Makefile

dd0716c2 - x86/boot: Add a fallthrough annotation

Thu, 16 May 2024 10:22:40 +0000

x86/boot: Add a fallthrough annotationAdd implicit fallthrough checking to the decompressor code and fix thiswarning: arch/x86/boot/printf.c: In function ‘vsprintf’: arch/x86/boot/printf.c:248:10: warning: this statement may fall through [-Wimplicit-fallthrough=] 248 | flags |= SMALL; | ^ arch/x86/boot/printf.c:249:3: note: here 249 | case 'X': | ^~~~This is a patch from three years ago which I found in my trees, thus theSUSE authorship still.Signed-off-by: Borislav Petkov Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240516102240.16270-1-bp@kernel.org List of files: /linux-6.15/arch/x86/boot/Makefile

7f7f6f7a - Makefile: remove redundant tool coverage variables

Mon, 06 May 2024 13:35:43 +0000

Makefile: remove redundant tool coverage variablesNow Kbuild provides reasonable defaults for objtool, sanitizers, andprofilers.Remove redundant variables.Note:This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOVI believe these are positive effects because all of them are kernelspace objects.Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu List of files: /linux-6.15/arch/x86/boot/Makefile

b1992c37 - kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Sat, 27 Apr 2024 14:55:02 +0000

kbuild: use $(src) instead of $(srctree)/$(src) for source directoryKbuild conventionally uses $(obj)/ for generated files, and $(src)/ forchecked-in source files. It is merely a convention without any functionaldifference. In fact, $(obj) and $(src) are exactly the same, as definedin scripts/Makefile.build: src := $(obj)When the kernel is built in a separate output directory, $(src) doesnot accurately reflect the source directory location. While Kbuildresolves this discrepancy by specifying VPATH=$(srctree) to search forsource files, it does not cover all cases. For example, when adding aheader search path for local headers, -I$(srctree)/$(src) is typicallypassed to the compiler.This introduces inconsistency between upstream and downstream Makefilesbecause $(src) is used instead of $(srctree)/$(src) for the latter.To address this inconsistency, this commit changes the semantics of$(src) so that it always points to the directory in the source tree.Going forward, the variables used in Makefiles will have the followingmeanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source treeConsequently, $(srctree)/$(src) in upstream Makefiles need to be replacedwith $(src).Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier List of files: /linux-6.15/arch/x86/boot/Makefile

34951f3c - x86/boot: Split off PE/COFF .data section

Fri, 15 Sep 2023 17:16:31 +0000

x86/boot: Split off PE/COFF .data sectionDescribe the code and data of the decompressor binary using separate.text and .data PE/COFF sections, so that we will be able to map themusing restricted permissions once we increase the section and filealignment sufficiently. This avoids the need for memory mappings thatare writable and executable at the same time, which is something thatis best avoided for security reasons.Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230915171623.655440-17-ardb@google.com List of files: /linux-6.15/arch/x86/boot/Makefile

aeb92067 - x86/boot: Derive file size from _edata symbol

Fri, 15 Sep 2023 17:16:28 +0000

x86/boot: Derive file size from _edata symbolTweak the linker script so that the value of _edata represents thedecompressor binary's file size rounded up to the appropriate alignment.This removes the need to calculate it in the build tool, and will makeit easier to refer to the file size from the header directly insubsequent changes to the PE header layout.While adding _edata to the sed regex that parses the compressedvmlinux's symbol list, tweak the regex a bit for conciseness.This change has no impact on the resulting bzImage binary whenconfigured with CONFIG_EFI_STUB=y.Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230915171623.655440-14-ardb@google.com List of files: /linux-6.15/arch/x86/boot/Makefile

b618d31f - x86/boot: Drop references to startup_64

Tue, 12 Sep 2023 09:00:59 +0000

x86/boot: Drop references to startup_64The x86 boot image generation tool assign a default value to startup_64and subsequently parses the actual value from zoffset.h but it neveractually uses the value anywhere. So remove this code.This change has no impact on the resulting bzImage binary.Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230912090051.4014114-25-ardb@google.com List of files: /linux-6.15/arch/x86/boot/Makefile

7583e8fb - x86/cpu: Remove X86_FEATURE_NAMES

Wed, 10 May 2023 06:57:13 +0000

x86/cpu: Remove X86_FEATURE_NAMESWhile discussing to change the visibility of X86_FEATURE_NAMES (see Link)in order to remove CONFIG_EMBEDDED, Boris suggested to simply make theX86_FEATURE_NAMES functionality unconditional.As the need for really tiny kernel images has gone away and kernel imageswith !X86_FEATURE_NAMES are hardly tested, remove this config and the wholeifdeffery in the source code.Suggested-by: Borislav Petkov Signed-off-by: Lukas Bulwahn Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/all/20230509084007.24373-1-lukas.bulwahn@gmail.com/Link: https://lore.kernel.org/r/20230510065713.10996-3-lukas.bulwahn@gmail.com List of files: /linux-6.15/arch/x86/boot/Makefile

083cad78 - kbuild: fix "cat: .version: No such file or directory"

Tue, 22 Nov 2022 14:39:02 +0000

kbuild: fix "cat: .version: No such file or directory"Since commit 2df8220cc511 ("kbuild: build init/built-in.a just once"),the .version file is not touched at all when KBUILD_BUILD_VERSION isgiven.If KBUILD_BUILD_VERSION is specified and the .version file is missing(for example right after 'make mrproper'), "No such file or director"is shown. Even if the .version exists, it is irrelevant to the versionof the current build. $ make -j$(nproc) KBUILD_BUILD_VERSION=100 mrproper defconfig all [ snip ] BUILD arch/x86/boot/bzImage cat: .version: No such file or directory Kernel: arch/x86/boot/bzImage is ready (#)Show KBUILD_BUILD_VERSION if it is given.Fixes: 2df8220cc511 ("kbuild: build init/built-in.a just once")Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier List of files: /linux-6.15/arch/x86/boot/Makefile

93324e68 - x86: kmsan: disable instrumentation of unsupported code

Thu, 15 Sep 2022 15:04:06 +0000

x86: kmsan: disable instrumentation of unsupported codeInstrumenting some files with KMSAN will result in kernel being unable tolink, boot or crashing at runtime for various reasons (e.g. infiniterecursion caused by instrumentation hooks calling instrumented codeagain).Completely omit KMSAN instrumentation in the following places: - arch/x86/boot and arch/x86/realmode/rm, as KMSAN doesn't work for i386; - arch/x86/entry/vdso, which isn't linked with KMSAN runtime; - three files in arch/x86/kernel - boot problems; - arch/x86/mm/cpu_entry_area.c - recursion.Link: https://lkml.kernel.org/r/20220915150417.722975-33-glider@google.comSigned-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton List of files: /linux-6.15/arch/x86/boot/Makefile

ffcf9c57 - x86: link vdso and boot with -z noexecstack --no-warn-rwx-segments

Wed, 10 Aug 2022 22:24:41 +0000

x86: link vdso and boot with -z noexecstack --no-warn-rwx-segmentsUsers of GNU ld (BFD) from binutils 2.39+ will observe multipleinstances of a new warning when linking kernels in the form: ld: warning: arch/x86/boot/pmjump.o: missing .note.GNU-stack section implies executable stack ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker ld: warning: arch/x86/boot/compressed/vmlinux has a LOAD segment with RWX permissionsGenerally, we would like to avoid the stack being executable. Becausethere could be a need for the stack to be executable, assembler sourceshave to opt-in to this security feature via explicit creation of the.note.GNU-stack feature (which compilers create by default) or commandline flag --noexecstack. Or we can simply tell the linker theproduction of such sections is irrelevant and to link the stack as--noexecstack.LLVM's LLD linker defaults to -z noexecstack, so this flag isn'tstrictly necessary when linking with LLD, only BFD, but it doesn't hurtto be explicit here for all linkers IMO. --no-warn-rwx-segments iscurrently BFD specific and only available in the current latest release,so it's wrapped in an ld-option check.While the kernel makes extensive usage of ELF sections, it doesn't usepermissions from ELF segments.Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107Link: https://github.com/llvm/llvm-project/issues/57009Reported-and-tested-by: Jens Axboe Suggested-by: Fangrui Song Signed-off-by: Nick Desaulniers Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/x86/boot/Makefile

08155126 - x86/build: Move the install rule to arch/x86/Makefile

Thu, 29 Jul 2021 14:00:23 +0000

x86/build: Move the install rule to arch/x86/MakefileCurrently, the install target in arch/x86/Makefile descends intoarch/x86/boot/Makefile to invoke the shell script, but there is nogood reason to do so.arch/x86/Makefile can run the shell script directly.Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210729140023.442101-2-masahiroy@kernel.org List of files: /linux-6.15/arch/x86/boot/Makefile

f279b49f - x86/boot: Modernize genimage script; hdimage+EFI support

Mon, 10 May 2021 08:28:40 +0000

x86/boot: Modernize genimage script; hdimage+EFI supportThe image generation scripts in arch/x86/boot are pretty out of date,except for the isoimage target. Update and clean up thegenimage.sh script, and make it support an arbitrary number ofinitramfs files in the image.Add a "hdimage" target, which can be booted by either BIOS orEFI (if the kernel is compiled with the EFI stub.) For EFI to be ableto pass the command line to the kernel, we need the EFI shell, but thefirmware builtin EFI shell, if it even exists, is pretty much alwaysthe last resort boot option, so search for OVMF or EDK2 and explicitlyinclude a copy of the EFI shell.To make this all work, use bash features in the script. Furthermore,this version of the script makes use of some mtools features,especially mpartition, that might not exist in very old version ofmtools, but given all the other dependencies on this script thisdoesn't seem such a big deal.Finally, put a volume label ("LINUX_BOOT") on all generated images.Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210510082840.628372-1-hpa@zytor.com List of files: /linux-6.15/arch/x86/boot/Makefile

675a59b7 - x86/boot/build: Add phony targets in arch/x86/boot/Makefile to PHONY

Sat, 15 Feb 2020 06:38:52 +0000

x86/boot/build: Add phony targets in arch/x86/boot/Makefile to PHONYThese targets are correctly added to PHONY in arch/x86/Makefile, butnot in arch/x86/boot/Makefile. Thus, with a file 'install' in the topdirectory, 'make install' does nothing: $ touch install $ make install make[1]: 'install' is up to date.Add them to the PHONY targets in the boot Makefile too. [ bp: Massage. ]Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200215063852.8298-2-masahiroy@kernel.org List of files: /linux-6.15/arch/x86/boot/Makefile

30ce434e - x86/boot/build: Make 'make bzlilo' not depend on vmlinux or $(obj)/bzImage

Sat, 15 Feb 2020 06:38:51 +0000

x86/boot/build: Make 'make bzlilo' not depend on vmlinux or $(obj)/bzImagebzlilo is an installation target because it copies files to$(INSTALL_PATH)/, then runs 'lilo'. However, arch/x86/Makefile andarch/x86/boot/Makefile have it depend on vmlinux and $(obj)/bzImage,respectively.'make bzlilo' may update some build artifacts in the source tree.As commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux")explained, this should not happen.Make 'bzlilo' not depend on any build artifact.Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200215063852.8298-1-masahiroy@kernel.org List of files: /linux-6.15/arch/x86/boot/Makefile

e3c7c105 - x86/boot/build: Add cpustr.h to targets and remove clean-files

Sat, 15 Feb 2020 06:32:41 +0000

x86/boot/build: Add cpustr.h to targets and remove clean-filesFiles in $(targets) are always cleaned up. Move the 'targets' assignmentout of the ifdef and remove 'clean-files'.Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200215063241.7437-1-masahiroy@kernel.org List of files: /linux-6.15/arch/x86/boot/Makefile

003602ad - x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections

Mon, 24 Feb 2020 23:21:28 +0000

x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sectionsWhile discussing a patch to discard .eh_frame from the compressedvmlinux using the linker script, Fangrui Song pointed out [1] that thesesections shouldn't exist in the first place because arch/x86/Makefileuses -fno-asynchronous-unwind-tables.It turns out this is because the Makefiles used to build the compressedkernel redefine KBUILD_CFLAGS, dropping this flag.Add the flag to the Makefile for the compressed kernel, as well as theEFI stub Makefile to fix this.Also add the flag to boot/Makefile and realmode/rm/Makefile so that thekernel's boot code (boot/setup.elf) and realmode trampoline(realmode/rm/realmode.elf) won't be compiled with .eh_frame sections,since their linker scripts also just discard them. [1] https://lore.kernel.org/lkml/20200222185806.ywnqhfqmy67akfsa@google.com/Suggested-by: Fangrui Song Signed-off-by: Arvind Sankar Signed-off-by: Borislav Petkov Reviewed-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Reviewed-by: Kees Cook Tested-by: Nathan Chancellor Link: https://lkml.kernel.org/r/20200224232129.597160-2-nivedita@alum.mit.edu List of files: /linux-6.15/arch/x86/boot/Makefile

97aa2765 - efi/x86: Add true mixed mode entry point into .compat section

Wed, 12 Feb 2020 11:18:17 +0000

efi/x86: Add true mixed mode entry point into .compat sectionCurrently, mixed mode is closely tied to the EFI handover protocoland relies on intimate knowledge of the bootparams structure, setupheader etc, all of which are rather byzantine and entirely specificto x86.Even though no other EFI supported architectures are currently knownthat could support something like mixed mode, it still makes sense toabstract a bit from this, and make it part of a generic Linux on EFIboot protocol.To that end, add a .compat section to the mixed mode binary, and populateit with the PE machine type and entry point address, allowing firmwareimplementations to match it to their native machine type, and invokenon-native binaries using a secondary entry point.Signed-off-by: Ard Biesheuvel List of files: /linux-6.15/arch/x86/boot/Makefile