From c15253494fd98cd76250c9faaebbc8b45f7d0072 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 16 Feb 2025 01:15:52 +0900 Subject: kbuild: move -fzero-init-padding-bits=all to the top-level Makefile The -fzero-init-padding-bits=all option is not a warning flag, so defining it in scripts/Makefile.extrawarn is inconsistent. Move it to the top-level Makefile for consistency. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor Reviewed-by: Kees Cook --- Makefile | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 1d6a9ec8a2ac..7cd80ff2d69b 100644 --- a/Makefile +++ b/Makefile @@ -928,6 +928,9 @@ KBUILD_CFLAGS += $(CC_AUTO_VAR_INIT_ZERO_ENABLER) endif endif +# Explicitly clear padding bits during variable initialization +KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all) + # While VLAs have been removed, GCC produces unreachable stack probes # for the randomize_kstack_offset feature. Disable it for all compilers. KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection) -- cgit v1.2.3 From d0beb73d1d8a89c6c6830d8d873ac9d3163132dc Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 17 Feb 2025 20:36:48 +0900 Subject: kbuild: remove KBUILD_ENABLE_EXTRA_GCC_CHECKS support Commit e27128db6283 ("kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN") renamed KBUILD_ENABLE_EXTRA_GCC_CHECKS in 2019. The migration in downstream code should be complete. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor --- Makefile | 3 --- 1 file changed, 3 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 7cd80ff2d69b..3428e4630069 100644 --- a/Makefile +++ b/Makefile @@ -151,9 +151,6 @@ endif export KBUILD_EXTMOD -# backward compatibility -KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS) - ifeq ("$(origin W)", "command line") KBUILD_EXTRA_WARN := $(W) endif -- cgit v1.2.3 From 268d191abc57a89f4ed92efcb276aae54f86c88c Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Mon, 17 Feb 2025 11:59:21 +0100 Subject: kbuild: implement CONFIG_HEADERS_INSTALL for Usermode Linux MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit userprogs sometimes need access to UAPI headers. This is currently not possible for Usermode Linux, as UM is only a pseudo architecture built on top of a regular architecture and does not have its own UAPI. Instead use the UAPI headers from the underlying regular architecture. Signed-off-by: Thomas Weißschuh Signed-off-by: Masahiro Yamada --- Makefile | 5 ++++- lib/Kconfig.debug | 1 - 2 files changed, 4 insertions(+), 2 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 3428e4630069..f2ec8d05c0f5 100644 --- a/Makefile +++ b/Makefile @@ -1361,9 +1361,12 @@ hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj PHONY += headers headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts - $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML)) +ifdef HEADER_ARCH + $(Q)$(MAKE) -f $(srctree)/Makefile HEADER_ARCH= SRCARCH=$(HEADER_ARCH) headers +else $(Q)$(MAKE) $(hdr-inst)=include/uapi $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi +endif ifdef CONFIG_HEADERS_INSTALL prepare: headers diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 35796c290ca3..17ccd913975d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -473,7 +473,6 @@ config READABLE_ASM config HEADERS_INSTALL bool "Install uapi headers to usr/include" - depends on !UML help This option will install uapi headers (headers exported to user-space) into the usr/include directory for use during the kernel build. -- cgit v1.2.3 From dbdffaf50ff9cee3259a7cef8a7bd9e0f0ba9f13 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Wed, 19 Feb 2025 22:22:13 +0100 Subject: kbuild, rust: use -fremap-path-prefix to make paths relative MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remap source path prefixes in all output, including compiler diagnostics, debug information, macro expansions, etc. This removes a few absolute paths from the binary and also makes it possible to use core::panic::Location properly. Equivalent to the same configuration done for C sources in commit 1d3730f0012f ("kbuild: support -fmacro-prefix-map for external modules") and commit a73619a845d5 ("kbuild: use -fmacro-prefix-map to make __FILE__ a relative path"). Link: https://doc.rust-lang.org/rustc/command-line-arguments.html#--remap-path-prefix-remap-source-names-in-output Acked-by: Miguel Ojeda Signed-off-by: Thomas Weißschuh Tested-by: Gary Guo Signed-off-by: Masahiro Yamada --- Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index f2ec8d05c0f5..30242e731a0d 100644 --- a/Makefile +++ b/Makefile @@ -1068,6 +1068,7 @@ endif # change __FILE__ to the relative path to the source directory ifdef building_out_of_srctree KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=) +KBUILD_RUSTFLAGS += --remap-path-prefix=$(srcroot)/= endif # include additional Makefiles when needed -- cgit v1.2.3 From 9b400d17259b70d1d68585028e96b30152d0796a Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 11 Mar 2025 12:06:19 +0100 Subject: kbuild: Introduce Kconfig symbol for linking vmlinux with relocations Some architectures build vmlinux with static relocations preserved, but strip them again from the final vmlinux image. Arch specific tools consume these static relocations in order to construct relocation tables for KASLR. The fact that vmlinux is created, consumed and subsequently updated goes against the typical, declarative paradigm used by Make, which is based on rules and dependencies. So as a first step towards cleaning this up, introduce a Kconfig symbol to declare that the arch wants to consume the static relocations emitted into vmlinux. This will be wired up further in subsequent patches. Signed-off-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada --- Makefile | 4 ++++ arch/Kconfig | 7 +++++++ arch/mips/Kconfig | 1 + arch/mips/Makefile | 4 ---- arch/riscv/Kconfig | 1 + arch/riscv/Makefile | 2 +- arch/s390/Kconfig | 1 + arch/s390/Makefile | 2 +- arch/x86/Kconfig | 1 + arch/x86/Makefile | 6 ------ 10 files changed, 17 insertions(+), 12 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 30242e731a0d..0904b73872cb 100644 --- a/Makefile +++ b/Makefile @@ -1120,6 +1120,10 @@ ifdef CONFIG_LD_ORPHAN_WARN LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) endif +ifneq ($(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS),) +LDFLAGS_vmlinux += --emit-relocs --discard-none +endif + # Align the bit size of userspace programs with the kernel KBUILD_USERCFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) diff --git a/arch/Kconfig b/arch/Kconfig index b8a4ff365582..101a13fcde8e 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1695,6 +1695,13 @@ config ARCH_HAS_KERNEL_FPU_SUPPORT Architectures that select this option can run floating-point code in the kernel, as described in Documentation/core-api/floating-point.rst. +config ARCH_VMLINUX_NEEDS_RELOCS + bool + help + Whether the architecture needs vmlinux to be built with static + relocations preserved. This is used by some architectures to + construct bespoke relocation tables for KASLR. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 1924f2d83932..5aedbd7afadb 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2617,6 +2617,7 @@ config RELOCATABLE CPU_MIPS32_R6 || CPU_MIPS64_R6 || \ CPU_P5600 || CAVIUM_OCTEON_SOC || \ CPU_LOONGSON64 + select ARCH_VMLINUX_NEEDS_RELOCS help This builds a kernel image that retains relocation information so it can be loaded someplace besides the default 1MB. diff --git a/arch/mips/Makefile b/arch/mips/Makefile index be8cb44a89fd..d9057e29bc62 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -100,10 +100,6 @@ LDFLAGS_vmlinux += -G 0 -static -n -nostdlib KBUILD_AFLAGS_MODULE += -mlong-calls KBUILD_CFLAGS_MODULE += -mlong-calls -ifeq ($(CONFIG_RELOCATABLE),y) -LDFLAGS_vmlinux += --emit-relocs -endif - cflags-y += -ffreestanding cflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 7612c52e9b1e..6f5800114416 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -1077,6 +1077,7 @@ config RELOCATABLE bool "Build a relocatable kernel" depends on MMU && 64BIT && !XIP_KERNEL select MODULE_SECTIONS if MODULES + select ARCH_VMLINUX_NEEDS_RELOCS help This builds a kernel as a Position Independent Executable (PIE), which retains all relocation metadata required to relocate the diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 13fbc0f94238..6ef0d10e0c50 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -8,7 +8,7 @@ LDFLAGS_vmlinux := -z norelro ifeq ($(CONFIG_RELOCATABLE),y) - LDFLAGS_vmlinux += -shared -Bsymbolic -z notext --emit-relocs + LDFLAGS_vmlinux += -shared -Bsymbolic -z notext KBUILD_CFLAGS += -fPIE endif ifeq ($(CONFIG_DYNAMIC_FTRACE),y) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 9c9ec08d78c7..ea67b7317138 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -630,6 +630,7 @@ endchoice config RELOCATABLE def_bool y + select ARCH_VMLINUX_NEEDS_RELOCS help This builds a kernel image that retains relocation information so it can be loaded at an arbitrary address. diff --git a/arch/s390/Makefile b/arch/s390/Makefile index 5fae311203c2..d5f4be440879 100644 --- a/arch/s390/Makefile +++ b/arch/s390/Makefile @@ -15,7 +15,7 @@ KBUILD_CFLAGS_MODULE += -fPIC KBUILD_AFLAGS += -m64 KBUILD_CFLAGS += -m64 KBUILD_CFLAGS += -fPIC -LDFLAGS_vmlinux := -no-pie --emit-relocs --discard-none +LDFLAGS_vmlinux := -no-pie extra_tools := relocs aflags_dwarf := -Wa,-gdwarf-2 KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0e27ebd7e36a..57fc0e7635c9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2200,6 +2200,7 @@ config RANDOMIZE_BASE config X86_NEED_RELOCS def_bool y depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) + select ARCH_VMLINUX_NEEDS_RELOCS config PHYSICAL_ALIGN hex "Alignment value to which kernel should be aligned" diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 5b773b34768d..f65ed6dcd6fb 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -251,12 +251,6 @@ endif KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE) -ifdef CONFIG_X86_NEED_RELOCS -LDFLAGS_vmlinux := --emit-relocs --discard-none -else -LDFLAGS_vmlinux := -endif - # # The 64-bit kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to # the linker to force 2MB page size regardless of the default page size used -- cgit v1.2.3 From ac4f06789b4f9c17357e81e918879c6e2ffdd075 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 11 Mar 2025 12:06:20 +0100 Subject: kbuild: Create intermediate vmlinux build with relocations preserved The imperative paradigm used to build vmlinux, extract some info from it or perform some checks on it, and subsequently modify it again goes against the declarative paradigm that is usually employed for defining make rules. In particular, the Makefile.postlink files that consume their input via an output rule result in some dodgy logic in the decompressor makefiles for RISC-V and x86, given that the vmlinux.relocs input file needed to generate the arch-specific relocation tables may not exist or be out of date, but cannot be constructed using the ordinary Make dependency based rules, because the info needs to be extracted while vmlinux is in its ephemeral, non-stripped form. So instead, for architectures that require the static relocations that are emitted into vmlinux when passing --emit-relocs to the linker, and are subsequently stripped out again, introduce an intermediate vmlinux target called vmlinux.unstripped, and organize the reset of the build logic accordingly: - vmlinux.unstripped is created only once, and not updated again - build rules under arch/*/boot can depend on vmlinux.unstripped without running the risk of the data disappearing or being out of date - the final vmlinux generated by the build is not bloated with static relocations that are never needed again after the build completes. Signed-off-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada --- .gitignore | 1 + Makefile | 2 +- arch/mips/Makefile.postlink | 2 +- arch/riscv/Makefile.postlink | 11 +---------- arch/riscv/boot/Makefile | 5 +---- arch/s390/Makefile.postlink | 4 +--- arch/x86/Makefile.postlink | 8 +++----- scripts/Makefile.lib | 3 --- scripts/Makefile.vmlinux | 28 +++++++++++++++++++++------- 9 files changed, 30 insertions(+), 34 deletions(-) (limited to 'Makefile') diff --git a/.gitignore b/.gitignore index 5937c74d3dc1..f2f63e47fb88 100644 --- a/.gitignore +++ b/.gitignore @@ -65,6 +65,7 @@ modules.order /vmlinux.32 /vmlinux.map /vmlinux.symvers +/vmlinux.unstripped /vmlinux-gdb.py /vmlinuz /System.map diff --git a/Makefile b/Makefile index 0904b73872cb..22593a774cf6 100644 --- a/Makefile +++ b/Makefile @@ -1569,7 +1569,7 @@ endif # CONFIG_MODULES # Directories & files removed with 'make clean' CLEAN_FILES += vmlinux.symvers modules-only.symvers \ modules.builtin modules.builtin.modinfo modules.nsdeps \ - modules.builtin.ranges vmlinux.o.map \ + modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \ compile_commands.json rust/test \ rust-project.json .vmlinux.objs .vmlinux.export.c \ .builtin-dtbs-list .builtin-dtb.S diff --git a/arch/mips/Makefile.postlink b/arch/mips/Makefile.postlink index 6cfdc149d3bc..ea0add7d56b2 100644 --- a/arch/mips/Makefile.postlink +++ b/arch/mips/Makefile.postlink @@ -22,7 +22,7 @@ quiet_cmd_relocs = RELOCS $@ # `@true` prevents complaint when there is nothing to be done -vmlinux: FORCE +vmlinux vmlinux.unstripped: FORCE @true ifeq ($(CONFIG_CPU_LOONGSON3_WORKAROUNDS),y) $(call if_changed,ls3_llsc) diff --git a/arch/riscv/Makefile.postlink b/arch/riscv/Makefile.postlink index 6b0580949b6a..0e4cf8ad2f14 100644 --- a/arch/riscv/Makefile.postlink +++ b/arch/riscv/Makefile.postlink @@ -10,26 +10,17 @@ __archpost: -include include/config/auto.conf include $(srctree)/scripts/Kbuild.include -include $(srctree)/scripts/Makefile.lib quiet_cmd_relocs_check = CHKREL $@ cmd_relocs_check = \ $(CONFIG_SHELL) $(srctree)/arch/riscv/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@" -ifdef CONFIG_RELOCATABLE -quiet_cmd_cp_vmlinux_relocs = CPREL vmlinux.relocs -cmd_cp_vmlinux_relocs = cp vmlinux vmlinux.relocs - -endif - # `@true` prevents complaint when there is nothing to be done -vmlinux: FORCE +vmlinux vmlinux.unstripped: FORCE @true ifdef CONFIG_RELOCATABLE $(call if_changed,relocs_check) - $(call if_changed,cp_vmlinux_relocs) - $(call if_changed,strip_relocs) endif clean: diff --git a/arch/riscv/boot/Makefile b/arch/riscv/boot/Makefile index b25d524ce5eb..bfc3d0b75b9b 100644 --- a/arch/riscv/boot/Makefile +++ b/arch/riscv/boot/Makefile @@ -32,10 +32,7 @@ $(obj)/xipImage: vmlinux FORCE endif ifdef CONFIG_RELOCATABLE -vmlinux.relocs: vmlinux - @ (! [ -f vmlinux.relocs ] && echo "vmlinux.relocs can't be found, please remove vmlinux and try again") || true - -$(obj)/Image: vmlinux.relocs FORCE +$(obj)/Image: vmlinux.unstripped FORCE else $(obj)/Image: vmlinux FORCE endif diff --git a/arch/s390/Makefile.postlink b/arch/s390/Makefile.postlink index 1ae5478cd6ac..c2b737500a91 100644 --- a/arch/s390/Makefile.postlink +++ b/arch/s390/Makefile.postlink @@ -11,7 +11,6 @@ __archpost: -include include/config/auto.conf include $(srctree)/scripts/Kbuild.include -include $(srctree)/scripts/Makefile.lib CMD_RELOCS=arch/s390/tools/relocs OUT_RELOCS = arch/s390/boot @@ -20,9 +19,8 @@ quiet_cmd_relocs = RELOCS $(OUT_RELOCS)/relocs.S mkdir -p $(OUT_RELOCS); \ $(CMD_RELOCS) $@ > $(OUT_RELOCS)/relocs.S -vmlinux: FORCE +vmlinux.unstripped: FORCE $(call cmd,relocs) - $(call cmd,strip_relocs) clean: @rm -f $(OUT_RELOCS)/relocs.S diff --git a/arch/x86/Makefile.postlink b/arch/x86/Makefile.postlink index 8b8a68162c94..445fce66630f 100644 --- a/arch/x86/Makefile.postlink +++ b/arch/x86/Makefile.postlink @@ -11,23 +11,21 @@ __archpost: -include include/config/auto.conf include $(srctree)/scripts/Kbuild.include -include $(srctree)/scripts/Makefile.lib CMD_RELOCS = arch/x86/tools/relocs OUT_RELOCS = arch/x86/boot/compressed -quiet_cmd_relocs = RELOCS $(OUT_RELOCS)/$@.relocs +quiet_cmd_relocs = RELOCS $(OUT_RELOCS)/vmlinux.relocs cmd_relocs = \ mkdir -p $(OUT_RELOCS); \ - $(CMD_RELOCS) $@ > $(OUT_RELOCS)/$@.relocs; \ + $(CMD_RELOCS) $@ > $(OUT_RELOCS)/vmlinux.relocs; \ $(CMD_RELOCS) --abs-relocs $@ # `@true` prevents complaint when there is nothing to be done -vmlinux: FORCE +vmlinux vmlinux.unstripped: FORCE @true ifeq ($(CONFIG_X86_NEED_RELOCS),y) $(call cmd,relocs) - $(call cmd,strip_relocs) endif clean: diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 47f56ef71937..d1856a70c919 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -371,9 +371,6 @@ quiet_cmd_ar = AR $@ quiet_cmd_objcopy = OBJCOPY $@ cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ -quiet_cmd_strip_relocs = RSTRIP $@ -cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' $@ - # Gzip # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 487f0bf716ad..b0a6cd5b818c 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -9,6 +9,20 @@ include $(srctree)/scripts/Makefile.lib targets := +ifdef CONFIG_ARCH_VMLINUX_NEEDS_RELOCS +vmlinux-final := vmlinux.unstripped + +quiet_cmd_strip_relocs = RSTRIP $@ + cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' $< $@ + +vmlinux: $(vmlinux-final) FORCE + $(call if_changed,strip_relocs) + +targets += vmlinux +else +vmlinux-final := vmlinux +endif + %.o: %.c FORCE $(call if_changed_rule,cc_o_c) @@ -47,7 +61,7 @@ targets += .builtin-dtbs-list ifdef CONFIG_GENERIC_BUILTIN_DTB targets += .builtin-dtbs.S .builtin-dtbs.o -vmlinux: .builtin-dtbs.o +$(vmlinux-final): .builtin-dtbs.o endif # vmlinux @@ -55,11 +69,11 @@ endif ifdef CONFIG_MODULES targets += .vmlinux.export.o -vmlinux: .vmlinux.export.o +$(vmlinux-final): .vmlinux.export.o endif ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX -vmlinux: arch/$(SRCARCH)/tools/vmlinux.arch.o +$(vmlinux-final): arch/$(SRCARCH)/tools/vmlinux.arch.o arch/$(SRCARCH)/tools/vmlinux.arch.o: vmlinux.o FORCE $(Q)$(MAKE) $(build)=arch/$(SRCARCH)/tools $@ @@ -72,11 +86,11 @@ cmd_link_vmlinux = \ $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true) -targets += vmlinux -vmlinux: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +targets += $(vmlinux-final) +$(vmlinux-final): scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE +$(call if_changed_dep,link_vmlinux) ifdef CONFIG_DEBUG_INFO_BTF -vmlinux: $(RESOLVE_BTFIDS) +$(vmlinux-final): $(RESOLVE_BTFIDS) endif ifdef CONFIG_BUILDTIME_TABLE_SORT @@ -96,7 +110,7 @@ modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \ modules.builtin vmlinux.map vmlinux.o.map FORCE $(call if_changed,modules_builtin_ranges) -vmlinux.map: vmlinux +vmlinux.map: $(vmlinux-final) @: endif -- cgit v1.2.3 From 00e81f4fc15aff8efef529ce9a4dc020686ab854 Mon Sep 17 00:00:00 2001 From: "Xin Li (Intel)" Date: Tue, 11 Mar 2025 20:34:21 -0700 Subject: kbuild: Add a help message for "headers" Meanwhile explicitly state that the headers are uapi headers. Suggested-by: Borislav Petkov Signed-off-by: Xin Li (Intel) Signed-off-by: Masahiro Yamada --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 22593a774cf6..5c333682dc91 100644 --- a/Makefile +++ b/Makefile @@ -1672,7 +1672,8 @@ help: @echo ' kernelrelease - Output the release version string (use with make -s)' @echo ' kernelversion - Output the version stored in Makefile (use with make -s)' @echo ' image_name - Output the image name (use with make -s)' - @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \ + @echo ' headers - Build ready-to-install UAPI headers in usr/include' + @echo ' headers_install - Install sanitised kernel UAPI headers to INSTALL_HDR_PATH'; \ echo ' (default: $(INSTALL_HDR_PATH))'; \ echo '' @echo 'Static analysers:' -- cgit v1.2.3 From cacd22ce69585a91c386243cd662ada962431e63 Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Sat, 15 Mar 2025 14:20:14 +0100 Subject: kbuild: make all file references relative to source root MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit -fmacro-prefix-map only affects __FILE__ and __BASE_FILE__. Other references, for example in debug information, are not affected. This makes handling of file references in the compiler outputs harder to use and creates problems for reproducible builds. Switch to -ffile-prefix map which affects all references. Also drop the documentation section advising manual specification of -fdebug-prefix-map for reproducible builds, as it is not necessary anymore. Suggested-by: Ben Hutchings Link: https://lore.kernel.org/lkml/c49cc967294f9a3a4a34f69b6a8727a6d3959ed8.camel@decadent.org.uk/ Signed-off-by: Thomas Weißschuh Signed-off-by: Masahiro Yamada --- Documentation/kbuild/reproducible-builds.rst | 17 ----------------- Makefile | 2 +- 2 files changed, 1 insertion(+), 18 deletions(-) (limited to 'Makefile') diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst index f2dcc39044e6..a7762486c93f 100644 --- a/Documentation/kbuild/reproducible-builds.rst +++ b/Documentation/kbuild/reproducible-builds.rst @@ -46,21 +46,6 @@ The kernel embeds the building user and host names in `KBUILD_BUILD_USER and KBUILD_BUILD_HOST`_ variables. If you are building from a git commit, you could use its committer address. -Absolute filenames ------------------- - -When the kernel is built out-of-tree, debug information may include -absolute filenames for the source files. This must be overridden by -including the ``-fdebug-prefix-map`` option in the `KCFLAGS`_ variable. - -Depending on the compiler used, the ``__FILE__`` macro may also expand -to an absolute filename in an out-of-tree build. Kbuild automatically -uses the ``-fmacro-prefix-map`` option to prevent this, if it is -supported. - -The Reproducible Builds web site has more information about these -`prefix-map options`_. - Generated files in source packages ---------------------------------- @@ -131,7 +116,5 @@ See ``scripts/setlocalversion`` for details. .. _KBUILD_BUILD_TIMESTAMP: kbuild.html#kbuild-build-timestamp .. _KBUILD_BUILD_USER and KBUILD_BUILD_HOST: kbuild.html#kbuild-build-user-kbuild-build-host -.. _KCFLAGS: kbuild.html#kcflags -.. _prefix-map options: https://reproducible-builds.org/docs/build-path/ .. _Reproducible Builds project: https://reproducible-builds.org/ .. _SOURCE_DATE_EPOCH: https://reproducible-builds.org/docs/source-date-epoch/ diff --git a/Makefile b/Makefile index 5c333682dc91..4f920187cee6 100644 --- a/Makefile +++ b/Makefile @@ -1067,7 +1067,7 @@ endif # change __FILE__ to the relative path to the source directory ifdef building_out_of_srctree -KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=) +KBUILD_CPPFLAGS += $(call cc-option,-ffile-prefix-map=$(srcroot)/=) KBUILD_RUSTFLAGS += --remap-path-prefix=$(srcroot)/= endif -- cgit v1.2.3