kernel/linux.git/arch/x86/Makefile, branch v6.6.141

x86/boot: Compile boot code with -std=gnu11 too

2025-06-04T12:42:21+00:00

commit b3bee1e7c3f2b1b77182302c7b2131c804175870 upstream. Use -std=gnu11 for consistency with main kernel code. It doesn't seem to change anything in vmlinux. Signed-off-by: Alexey Dobriyan Signed-off-by: Ingo Molnar Acked-by: H. Peter Anvin (Intel) Link: https://lore.kernel.org/r/2058761e-12a4-4b2f-9690-3c3c1c9902a5@p183 Cc: Hendrik Donner Signed-off-by: Greg Kroah-Hartman

x86/stackprotector: Work around strict Clang TLS symbol requirements

2024-12-09T09:31:41+00:00

[ Upstream commit 577c134d311b9b94598d7a0c86be1f431f823003 ] GCC and Clang both implement stack protector support based on Thread Local Storage (TLS) variables, and this is used in the kernel to implement per-task stack cookies, by copying a task's stack cookie into a per-CPU variable every time it is scheduled in. Both now also implement -mstack-protector-guard-symbol=, which permits the TLS variable to be specified directly. This is useful because it will allow to move away from using a fixed offset of 40 bytes into the per-CPU area on x86_64, which requires a lot of special handling in the per-CPU code and the runtime relocation code. However, while GCC is rather lax in its implementation of this command line option, Clang actually requires that the provided symbol name refers to a TLS variable (i.e., one declared with __thread), although it also permits the variable to be undeclared entirely, in which case it will use an implicit declaration of the right type. The upshot of this is that Clang will emit the correct references to the stack cookie variable in most cases, e.g., 10d: 64 a1 00 00 00 00 mov %fs:0x0,%eax 10f: R_386_32 __stack_chk_guard However, if a non-TLS definition of the symbol in question is visible in the same compilation unit (which amounts to the whole of vmlinux if LTO is enabled), it will drop the per-CPU prefix and emit a load from a bogus address. Work around this by using a symbol name that never occurs in C code, and emit it as an alias in the linker script. Fixes: 3fb0fdb3bbe7 ("x86/stackprotector/32: Make the canary into a regular percpu variable") Signed-off-by: Ard Biesheuvel Signed-off-by: Brian Gerst Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1854 Link: https://lore.kernel.org/r/20241105155801.1779119-2-brgerst@gmail.com Signed-off-by: Sasha Levin

kbuild: unify vdso_install rules

2024-06-12T09:12:32+00:00

[ Upstream commit 56769ba4b297a629148eb24d554aef72d1ddfd9e ] Currently, there is no standard implementation for vdso_install, leading to various issues: 1. Code duplication Many architectures duplicate similar code just for copying files to the install destination. Some architectures (arm, sparc, x86) create build-id symlinks, introducing more code duplication. 2. Unintended updates of in-tree build artifacts The vdso_install rule depends on the vdso files to install. It may update in-tree build artifacts. This can be problematic, as explained in commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"). 3. Broken code in some architectures Makefile code is often copied from one architecture to another without proper adaptation. 'make vdso_install' for parisc does not work. 'make vdso_install' for s390 installs vdso64, but not vdso32. To address these problems, this commit introduces a generic vdso_install rule. Architectures that support vdso_install need to define vdso-install-y in arch/*/Makefile. vdso-install-y lists the files to install. For example, arch/x86/Makefile looks like this: vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix, if exists, stripped away. vdso-install-y can optionally take the second field after the colon separator. This is needed because some architectures install a vdso file as a different base name. The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so This will rename vdso.so.dbg to vdso32.so during installation. If such architectures change their implementation so that the base names match, this workaround will go away. Signed-off-by: Masahiro Yamada Acked-by: Sven Schnelle # s390 Reviewed-by: Nicolas Schier Reviewed-by: Guo Ren Acked-by: Helge Deller # parisc Acked-by: Catalin Marinas Acked-by: Russell King (Oracle) Stable-dep-of: fc2f5f10f9bc ("s390/vdso: Create .build-id links for unstripped vdso files") Signed-off-by: Sasha Levin

Merge tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2023-09-05T18:01:47+00:00

Pull Kbuild updates from Masahiro Yamada: - Enable -Wenum-conversion warning option - Refactor the rpm-pkg target - Fix scripts/setlocalversion to consider annotated tags for rt-kernel - Add a jump key feature for the search menu of 'make nconfig' - Support Qt6 for 'make xconfig' - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow, and -Wrestrict warnings for W=1 builds - Replace with for alpha, ia64, and sparc - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package - Refactor scripts/Makefile.modinst and fix some modules_sign issues - Add a new Kconfig env variable to warn symbols that are not defined anywhere - Show help messages of config fragments in 'make help' * tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (62 commits) kconfig: fix possible buffer overflow kbuild: Show marked Kconfig fragments in "help" kconfig: add warn-unknown-symbols sanity check kbuild: dummy-tools: make MPROFILE_KERNEL checks work on BE Documentation/llvm: refresh docs modpost: Skip .llvm.call-graph-profile section check kbuild: support modules_sign for external modules as well kbuild: support 'make modules_sign' with CONFIG_MODULE_SIG_ALL=n kbuild: move more module installation code to scripts/Makefile.modinst kbuild: reduce the number of mkdir calls during modules_install kbuild: remove $(MODLIB)/source symlink kbuild: move depmod rule to scripts/Makefile.modinst kbuild: add modules_sign to no-{compiler,sync-config}-targets kbuild: do not run depmod for 'make modules_sign' kbuild: deb-pkg: support DEB_BUILD_OPTIONS=parallel=N in debian/rules alpha: remove alpha: replace #include with #include ia64: remove ia64: replace #include with #include sparc: remove ...

kbuild: Show marked Kconfig fragments in "help"

2023-09-03T17:04:20+00:00

Currently the Kconfig fragments in kernel/configs and arch/*/configs that aren't used internally aren't discoverable through "make help", which consists of hard-coded lists of config fragments. Instead, list all the fragment targets that have a "# Help: " comment prefix so the targets can be generated dynamically. Add logic to the Makefile to search for and display the fragment and comment. Add comments to fragments that are intended to be direct targets. Signed-off-by: Kees Cook Co-developed-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Reviewed-by: Nicolas Schier Signed-off-by: Masahiro Yamada

Merge drm/drm-next into drm-misc-next

2023-07-24T13:44:47+00:00

Backmerging to get v6.5-rc2. Signed-off-by: Thomas Zimmermann

fbdev: Split frame buffer support in FB and FB_CORE symbols

2023-07-22T10:25:04+00:00

Currently the CONFIG_FB option has to be enabled even if no legacy fbdev drivers are needed (e.g: only to have support for framebuffer consoles). The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB and so it can only be enabled if that dependency is enabled as well. That means fbdev drivers have to be explicitly disabled if users want to enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer. This patch introduces a non-visible CONFIG_FB_CORE symbol that could be enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION, allowing CONFIG_FB to be disabled (and automatically disabling all the fbdev drivers). Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulation layer so these two objects can be compiled out when CONFIG_FB is disabled. Signed-off-by: Javier Martinez Canillas Reviewed-by: Arnd Bergmann Tested-by: Arnd Bergmann Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com

x86/unwind/orc: Add ELF section with ORC version identifier

2023-06-16T15:17:42+00:00

Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") changed the ORC format. Although ORC is internal to the kernel, it's the only way for external tools to get reliable kernel stack traces on x86-64. In particular, the drgn debugger [1] uses ORC for stack unwinding, and these format changes broke it [2]. As the drgn maintainer, I don't care how often or how much the kernel changes the ORC format as long as I have a way to detect the change. It suffices to store a version identifier in the vmlinux and kernel module ELF files (to use when parsing ORC sections from ELF), and in kernel memory (to use when parsing ORC from a core dump+symbol table). Rather than hard-coding a version number that needs to be manually bumped, Peterz suggested hashing the definitions from orc_types.h. If there is a format change that isn't caught by this, the hashing script can be updated. This patch adds an .orc_header allocated ELF section containing the 20-byte hash to vmlinux and kernel modules, along with the corresponding __start_orc_header and __stop_orc_header symbols in vmlinux. 1: https://github.com/osandov/drgn 2: https://github.com/osandov/drgn/issues/303 Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") Signed-off-by: Omar Sandoval Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com

x86/build: Make 64-bit defconfig the default

2023-02-15T13:20:17+00:00

Running 'make ARCH=x86 defconfig' on anything other than an x86_64 machine currently results in a 32-bit build, which is rarely what anyone wants these days. Change the default so that the 64-bit config gets used unless the user asks for i386_defconfig, uses ARCH=i386 or runs on a system that "uname -m" identifies as i386/i486/i586/i686. Signed-off-by: Arnd Bergmann Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230215091706.1623070-1-arnd@kernel.org

x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block

2023-01-22T10:36:45+00:00

LLVM 16 will have support for this flag so move it out of the GCC-only block to allow LLVM builds to take advantage of it. Signed-off-by: Nathan Chancellor Signed-off-by: Ingo Molnar Tested-by: Nick Desaulniers Reviewed-by: Nick Desaulniers Acked-by: Peter Zijlstra (Intel) Link: https://github.com/ClangBuiltLinux/linux/issues/1665 Link: https://github.com/llvm/llvm-project/commit/6f867f9102838ebe314c1f3661fdf95700386e5a Link: https://lore.kernel.org/r/20230120165826.2469302-1-nathan@kernel.org