Changes in Makefile.vmlinux_a

a48bd961fb203a7ce68f8110fc53a85f90e24b33 - kbuild: Remove unnecessary 'T' modifier in cmd_ar_builtin_fixup

Wed, 03 Jun 2026 03:41:50 +0200

kbuild: Remove unnecessary 'T' modifier in cmd_ar_builtin_fixupIn cmd_ar_builtin_fixup, the 'T' modifier was added to '$(AR) mPi' towork around a bug in llvm-ar that caused thin archives to be silentlyconverted to full archives [1]. Since commit 20c098928356 ("kbuild: Bumpminimum version of LLVM for building the kernel to 15.0.0"), allsupported versions of llvm-ar have this issue fixed, so the 'T' modifierand comment can be removed.Link: https://github.com/llvm/llvm-project/commit/d17c54d17de22d2961a04163f3dbc8e973de89b8 [1]Signed-off-by: Nathan Chancellor List of files: /linux/scripts/Makefile.vmlinux_a

9f2aee8f7d1842be08da860e45265d30dba0d1f7 - kbuild: distributed build support for Clang ThinLTO

Fri, 29 May 2026 20:53:46 +0200

kbuild: distributed build support for Clang ThinLTOAdd distributed ThinLTO build support for the Linux kernel.This new mode offers several advantages: (1) Increasedflexibility in handling user-specified build options.(2) Improved user-friendliness for developers. (3) Greaterconvenience for integrating with objtool and livepatch.Note that "distributed" in this context refers to a termthat differentiates in-process ThinLTO builds by invokingbackend compilation through the linker, not necessarilybuilding in distributed environments.Distributed ThinLTO is enabled via the`CONFIG_LTO_CLANG_THIN_DIST` Kconfig option. For example: > make LLVM=1 defconfig > scripts/config -e LTO_CLANG_THIN_DIST > make LLVM=1 oldconfig > make LLVM=1 vmlinux -j <..>The build flow proceeds in four stages: 1. Perform FE compilation, mirroring the in-process ThinLTO mode. 2. Thin-link the generated IR files and object files. 3. Find all IR files and perform BE compilation, using the flags stored in the .*.o.cmd files. 4. Link the BE results to generate the final vmlinux.o.NOTE: This patch currently implements the build for the main kernelimage (vmlinux) only. Kernel module support is planned for asubsequent patch.Tested on the following arch: x86, arm64, loongarch, andriscv.The earlier implementation details can be found here:https://discourse.llvm.org/t/rfc-distributed-thinlto-build-for-kernel/85934Signed-off-by: Rong Xu Co-developed-by: Masahiro Yamada Signed-off-by: Masahiro Yamada Tested-by: Piotr Gorski Tested-by: Nathan Chancellor Link: https://patch.msgid.link/20260529185347.2418373-4-xur@google.comSigned-off-by: Nathan Chancellor List of files: /linux/scripts/Makefile.vmlinux_a

9c72d26e9fe3be79dd1d8a2ba00a033503ffd27d - kbuild: move vmlinux.a build rule to scripts/Makefile.vmlinux_a

Fri, 29 May 2026 20:53:44 +0200

kbuild: move vmlinux.a build rule to scripts/Makefile.vmlinux_aMove the build rule for vmlinux.a to a separate file in preparationfor supporting distributed builds with Clang ThinLTO.Signed-off-by: Masahiro Yamada Tested-by: Rong Xu Tested-by: Piotr Gorski Tested-by: Nathan Chancellor Signed-off-by: Rong Xu Link: https://patch.msgid.link/20260529185347.2418373-2-xur@google.com[nathan: Squash in forward fix from Rong around '--thin' to $(AR) https://patch.msgid.link/20260529185347.2418373-3-xur@google.com]Signed-off-by: Nathan Chancellor List of files: /linux/scripts/Makefile.vmlinux_a