From 6717e8f91db71641cb52855ed14c7900972ed0bc Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:03:16 -0700 Subject: kbuild: Remove 'kmod_' prefix from __KBUILD_MODNAME In preparation for the objtool klp diff subcommand, remove the arbitrary 'kmod_' prefix from __KBUILD_MODNAME and instead add it explicitly in the __initcall_id() macro. This change supports the standardization of "unique" symbol naming by ensuring the non-unique portion of the name comes before the unique part. That will enable objtool to properly correlate symbols across builds. Cc: Masahiro Yamada Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- scripts/Makefile.lib | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 1d581ba5df66..b95560266124 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -20,7 +20,7 @@ name-fix-token = $(subst $(comma),_,$(subst -,_,$1)) name-fix = $(call stringify,$(call name-fix-token,$1)) basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \ - -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname)) + -D__KBUILD_MODNAME=$(call name-fix-token,$(modname)) modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ -- cgit v1.2.3 From 56754f0f46f6a36ba66e8c1b2878f7a4f1edfe3b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:03:42 -0700 Subject: objtool: Rename --Werror to --werror The objtool --Werror option name is stylistically inconsistent: halfway between GCC's single-dash capitalized -Werror and objtool's double-dash --lowercase convention, making it unnecessarily hard to remember. Make the 'W' lower case (--werror) for consistency with objtool's other options. Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- scripts/Makefile.lib | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index b95560266124..15fee73e9289 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -191,7 +191,7 @@ objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV)) += --no-unreachable objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES) -objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror +objtool-args-$(CONFIG_OBJTOOL_WERROR) += --werror objtool-args = $(objtool-args-y) \ $(if $(delay-objtool), --link) \ -- cgit v1.2.3 From f2c356d1d0f048e88c281a4178c8b2db138d3ac1 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:04:05 -0700 Subject: kbuild,objtool: Defer objtool validation step for CONFIG_KLP_BUILD In preparation for klp-build, defer objtool validation for CONFIG_KLP_BUILD kernels until the final pre-link archive (e.g., vmlinux.o, module-foo.o) is built. This will simplify the process of generating livepatch modules. Delayed objtool is generally preferred anyway, and is already standard for IBT and LTO. Eventually the per-translation-unit mode will be phased out. Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- scripts/Makefile.lib | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 15fee73e9289..28a1c08e3b22 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -197,7 +197,7 @@ objtool-args = $(objtool-args-y) \ $(if $(delay-objtool), --link) \ $(if $(part-of-module), --module) -delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) +delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT),$(CONFIG_KLP_BUILD)) cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@) cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) -- cgit v1.2.3 From 24ebfcd65a871df4555b98c49c9ed9a92f146113 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 17 Sep 2025 09:04:08 -0700 Subject: livepatch/klp-build: Introduce klp-build script for generating livepatch modules Add a klp-build script which automates the generation of a livepatch module from a source .patch file by performing the following steps: - Builds an original kernel with -function-sections and -fdata-sections, plus objtool function checksumming. - Applies the .patch file and rebuilds the kernel using the same options. - Runs 'objtool klp diff' to detect changed functions and generate intermediate binary diff objects. - Builds a kernel module which links the diff objects with some livepatch module init code (scripts/livepatch/init.c). - Finalizes the livepatch module (aka work around linker wreckage) using 'objtool klp post-link'. Acked-by: Petr Mladek Tested-by: Joe Lawrence Signed-off-by: Josh Poimboeuf --- scripts/Makefile.lib | 1 + 1 file changed, 1 insertion(+) (limited to 'scripts/Makefile.lib') diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 28a1c08e3b22..f4b33919ec37 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -173,6 +173,7 @@ ifdef CONFIG_OBJTOOL objtool := $(objtree)/tools/objtool/objtool +objtool-args-$(CONFIG_KLP_BUILD) += --checksum objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake -- cgit v1.2.3