linux-dev/arch/x86/boot/Makefile, branch master

x86: kmsan: disable instrumentation of unsupported code

2022-10-03T21:03:24Z

Instrumenting some files with KMSAN will result in kernel being unable to link, boot or crashing at runtime for various reasons (e.g. infinite recursion caused by instrumentation hooks calling instrumented code again). 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.com Signed-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

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

2022-08-11T01:30:09Z

Users of GNU ld (BFD) from binutils 2.39+ will observe multiple instances 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 permissions Generally, we would like to avoid the stack being executable. Because there could be a need for the stack to be executable, assembler sources have to opt-in to this security feature via explicit creation of the .note.GNU-stack feature (which compilers create by default) or command line flag --noexecstack. Or we can simply tell the linker the production of such sections is irrelevant and to link the stack as --noexecstack. LLVM's LLD linker defaults to -z noexecstack, so this flag isn't strictly necessary when linking with LLD, only BFD, but it doesn't hurt to be explicit here for all linkers IMO. --no-warn-rwx-segments is currently 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 use permissions 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=ba951afb99912da01a6e8434126b8fac7aa75107 Link: https://github.com/llvm/llvm-project/issues/57009 Reported-and-tested-by: Jens Axboe Suggested-by: Fangrui Song Signed-off-by: Nick Desaulniers Signed-off-by: Linus Torvalds

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

2021-08-25T09:57:38Z

Currently, the install target in arch/x86/Makefile descends into arch/x86/boot/Makefile to invoke the shell script, but there is no good 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

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

2021-05-10T10:27:50Z

The image generation scripts in arch/x86/boot are pretty out of date, except for the isoimage target. Update and clean up the genimage.sh script, and make it support an arbitrary number of initramfs files in the image. Add a "hdimage" target, which can be booted by either BIOS or EFI (if the kernel is compiled with the EFI stub.) For EFI to be able to pass the command line to the kernel, we need the EFI shell, but the firmware builtin EFI shell, if it even exists, is pretty much always the last resort boot option, so search for OVMF or EDK2 and explicitly include 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 of mtools, but given all the other dependencies on this script this doesn'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

Rebase locking/kcsan to locking/urgent

2020-06-11T18:02:46Z

Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner

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

2020-04-21T16:30:58Z

These targets are correctly added to PHONY in arch/x86/Makefile, but not in arch/x86/boot/Makefile. Thus, with a file 'install' in the top directory, '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

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

2020-04-21T16:10:28Z

bzlilo is an installation target because it copies files to $(INSTALL_PATH)/, then runs 'lilo'. However, arch/x86/Makefile and arch/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

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

2020-04-21T08:17:29Z

Files in $(targets) are always cleaned up. Move the 'targets' assignment out 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

Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refresh

2020-04-13T07:44:39Z

Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar

Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-03-31T17:28:35Z

Pull x86 boot updates from Ingo Molnar: "Misc cleanups and small enhancements all around the map" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/compressed: Fix debug_puthex() parameter type x86/setup: Fix static memory detection x86/vmlinux: Drop unneeded linker script discard of .eh_frame x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections x86/boot/compressed: Remove .eh_frame section from bzImage x86/boot/compressed/64: Remove .bss/.pgtable from bzImage x86/boot/compressed/64: Use 32-bit (zero-extended) MOV for z_output_len x86/boot/compressed/64: Use LEA to initialize boot stack pointer