[PATCH v2] kbuild: preprocess module linker script
Palmer Dabbelt
palmer at dabbelt.com
Wed Sep 9 14:27:06 AEST 2020
On Mon, 07 Sep 2020 21:27:08 PDT (-0700), masahiroy at kernel.org wrote:
> There was a request to preprocess the module linker script like we
> do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)
>
> The difference between vmlinux.lds and module.lds is that the latter
> is needed for external module builds, thus must be cleaned up by
> 'make mrproper' instead of 'make clean'. Also, it must be created
> by 'make modules_prepare'.
>
> You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
> 'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
> arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
> scripts/module.lds.S.
>
> scripts/module.lds is fine because 'make clean' keeps all the
> build artifacts under scripts/.
>
> You can add arch-specific sections in <asm/module.lds.h>.
for the arch/riscv stuff
Acked-by: Palmer Dabbelt <palmerdabbelt at google.com>
Thanks!
> Signed-off-by: Masahiro Yamada <masahiroy at kernel.org>
> Tested-by: Jessica Yu <jeyu at kernel.org>
> Acked-by: Will Deacon <will at kernel.org>
> ---
>
> Changes in v2:
> - Fix the race between the two targets 'scripts' and 'asm-generic'
>
> Makefile | 10 ++++++----
> arch/arm/Makefile | 4 ----
> .../{kernel/module.lds => include/asm/module.lds.h} | 2 ++
> arch/arm64/Makefile | 4 ----
> .../{kernel/module.lds => include/asm/module.lds.h} | 2 ++
> arch/ia64/Makefile | 1 -
> arch/ia64/{module.lds => include/asm/module.lds.h} | 0
> arch/m68k/Makefile | 1 -
> .../{kernel/module.lds => include/asm/module.lds.h} | 0
> arch/powerpc/Makefile | 1 -
> .../{kernel/module.lds => include/asm/module.lds.h} | 0
> arch/riscv/Makefile | 3 ---
> .../{kernel/module.lds => include/asm/module.lds.h} | 3 ++-
> arch/um/include/asm/Kbuild | 1 +
> include/asm-generic/Kbuild | 1 +
> include/asm-generic/module.lds.h | 10 ++++++++++
> scripts/.gitignore | 1 +
> scripts/Makefile | 3 +++
> scripts/Makefile.modfinal | 5 ++---
> scripts/{module-common.lds => module.lds.S} | 3 +++
> scripts/package/builddeb | 2 +-
> 21 files changed, 34 insertions(+), 23 deletions(-)
> rename arch/arm/{kernel/module.lds => include/asm/module.lds.h} (72%)
> rename arch/arm64/{kernel/module.lds => include/asm/module.lds.h} (76%)
> rename arch/ia64/{module.lds => include/asm/module.lds.h} (100%)
> rename arch/m68k/{kernel/module.lds => include/asm/module.lds.h} (100%)
> rename arch/powerpc/{kernel/module.lds => include/asm/module.lds.h} (100%)
> rename arch/riscv/{kernel/module.lds => include/asm/module.lds.h} (84%)
> create mode 100644 include/asm-generic/module.lds.h
> rename scripts/{module-common.lds => module.lds.S} (93%)
>
> diff --git a/Makefile b/Makefile
> index 37739ee53f27..97b1dae1783b 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -505,7 +505,6 @@ KBUILD_CFLAGS_KERNEL :=
> KBUILD_AFLAGS_MODULE := -DMODULE
> KBUILD_CFLAGS_MODULE := -DMODULE
> KBUILD_LDFLAGS_MODULE :=
> -export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
> KBUILD_LDFLAGS :=
> CLANG_FLAGS :=
>
> @@ -1395,7 +1394,7 @@ endif
> # using awk while concatenating to the final file.
>
> PHONY += modules
> -modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check
> +modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
> $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
>
> PHONY += modules_check
> @@ -1412,6 +1411,7 @@ targets += modules.order
> # Target to prepare building external modules
> PHONY += modules_prepare
> modules_prepare: prepare
> + $(Q)$(MAKE) $(build)=scripts scripts/module.lds
>
> # Target to install modules
> PHONY += modules_install
> @@ -1743,7 +1743,9 @@ help:
> @echo ' clean - remove generated files in module directory only'
> @echo ''
>
> -PHONY += prepare
> +# no-op for external module builds
> +PHONY += prepare modules_prepare
> +
> endif # KBUILD_EXTMOD
>
> # Single targets
> @@ -1776,7 +1778,7 @@ MODORDER := .modules.tmp
> endif
>
> PHONY += single_modpost
> -single_modpost: $(single-no-ko)
> +single_modpost: $(single-no-ko) modules_prepare
> $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
> $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
>
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 4e877354515f..a0cb15de9677 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -16,10 +16,6 @@ LDFLAGS_vmlinux += --be8
> KBUILD_LDFLAGS_MODULE += --be8
> endif
>
> -ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
> -KBUILD_LDS_MODULE += $(srctree)/arch/arm/kernel/module.lds
> -endif
> -
> GZFLAGS :=-9
> #KBUILD_CFLAGS +=-pipe
>
> diff --git a/arch/arm/kernel/module.lds b/arch/arm/include/asm/module.lds.h
> similarity index 72%
> rename from arch/arm/kernel/module.lds
> rename to arch/arm/include/asm/module.lds.h
> index 79cb6af565e5..0e7cb4e314b4 100644
> --- a/arch/arm/kernel/module.lds
> +++ b/arch/arm/include/asm/module.lds.h
> @@ -1,5 +1,7 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> +#ifdef CONFIG_ARM_MODULE_PLTS
> SECTIONS {
> .plt : { BYTE(0) }
> .init.plt : { BYTE(0) }
> }
> +#endif
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index b45f0124cc16..76667ad47980 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -115,10 +115,6 @@ endif
>
> CHECKFLAGS += -D__aarch64__
>
> -ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
> -KBUILD_LDS_MODULE += $(srctree)/arch/arm64/kernel/module.lds
> -endif
> -
> ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
> KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
> CC_FLAGS_FTRACE := -fpatchable-function-entry=2
> diff --git a/arch/arm64/kernel/module.lds b/arch/arm64/include/asm/module.lds.h
> similarity index 76%
> rename from arch/arm64/kernel/module.lds
> rename to arch/arm64/include/asm/module.lds.h
> index 22e36a21c113..691f15af788e 100644
> --- a/arch/arm64/kernel/module.lds
> +++ b/arch/arm64/include/asm/module.lds.h
> @@ -1,5 +1,7 @@
> +#ifdef CONFIG_ARM64_MODULE_PLTS
> SECTIONS {
> .plt (NOLOAD) : { BYTE(0) }
> .init.plt (NOLOAD) : { BYTE(0) }
> .text.ftrace_trampoline (NOLOAD) : { BYTE(0) }
> }
> +#endif
> diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
> index 2876a7df1b0a..703b1c4f6d12 100644
> --- a/arch/ia64/Makefile
> +++ b/arch/ia64/Makefile
> @@ -20,7 +20,6 @@ CHECKFLAGS += -D__ia64=1 -D__ia64__=1 -D_LP64 -D__LP64__
>
> OBJCOPYFLAGS := --strip-all
> LDFLAGS_vmlinux := -static
> -KBUILD_LDS_MODULE += $(srctree)/arch/ia64/module.lds
> KBUILD_AFLAGS_KERNEL := -mconstant-gp
> EXTRA :=
>
> diff --git a/arch/ia64/module.lds b/arch/ia64/include/asm/module.lds.h
> similarity index 100%
> rename from arch/ia64/module.lds
> rename to arch/ia64/include/asm/module.lds.h
> diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
> index 4438ffb4bbe1..ea14f2046fb4 100644
> --- a/arch/m68k/Makefile
> +++ b/arch/m68k/Makefile
> @@ -75,7 +75,6 @@ KBUILD_CPPFLAGS += -D__uClinux__
> endif
>
> KBUILD_LDFLAGS := -m m68kelf
> -KBUILD_LDS_MODULE += $(srctree)/arch/m68k/kernel/module.lds
>
> ifdef CONFIG_SUN3
> LDFLAGS_vmlinux = -N
> diff --git a/arch/m68k/kernel/module.lds b/arch/m68k/include/asm/module.lds.h
> similarity index 100%
> rename from arch/m68k/kernel/module.lds
> rename to arch/m68k/include/asm/module.lds.h
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 3e8da9cf2eb9..8935658fcd06 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -65,7 +65,6 @@ UTS_MACHINE := $(subst $(space),,$(machine-y))
> ifdef CONFIG_PPC32
> KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
> else
> -KBUILD_LDS_MODULE += $(srctree)/arch/powerpc/kernel/module.lds
> ifeq ($(call ld-ifversion, -ge, 225000000, y),y)
> # Have the linker provide sfpr if possible.
> # There is a corresponding test in arch/powerpc/lib/Makefile
> diff --git a/arch/powerpc/kernel/module.lds b/arch/powerpc/include/asm/module.lds.h
> similarity index 100%
> rename from arch/powerpc/kernel/module.lds
> rename to arch/powerpc/include/asm/module.lds.h
> diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
> index fb6e37db836d..8edaa8bd86d6 100644
> --- a/arch/riscv/Makefile
> +++ b/arch/riscv/Makefile
> @@ -53,9 +53,6 @@ endif
> ifeq ($(CONFIG_CMODEL_MEDANY),y)
> KBUILD_CFLAGS += -mcmodel=medany
> endif
> -ifeq ($(CONFIG_MODULE_SECTIONS),y)
> - KBUILD_LDS_MODULE += $(srctree)/arch/riscv/kernel/module.lds
> -endif
> ifeq ($(CONFIG_PERF_EVENTS),y)
> KBUILD_CFLAGS += -fno-omit-frame-pointer
> endif
> diff --git a/arch/riscv/kernel/module.lds b/arch/riscv/include/asm/module.lds.h
> similarity index 84%
> rename from arch/riscv/kernel/module.lds
> rename to arch/riscv/include/asm/module.lds.h
> index 295ecfb341a2..4254ff2ff049 100644
> --- a/arch/riscv/kernel/module.lds
> +++ b/arch/riscv/include/asm/module.lds.h
> @@ -1,8 +1,9 @@
> /* SPDX-License-Identifier: GPL-2.0 */
> /* Copyright (C) 2017 Andes Technology Corporation */
> -
> +#ifdef CONFIG_MODULE_SECTIONS
> SECTIONS {
> .plt (NOLOAD) : { BYTE(0) }
> .got (NOLOAD) : { BYTE(0) }
> .got.plt (NOLOAD) : { BYTE(0) }
> }
> +#endif
> diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
> index 8d435f8a6dec..1c63b260ecc4 100644
> --- a/arch/um/include/asm/Kbuild
> +++ b/arch/um/include/asm/Kbuild
> @@ -16,6 +16,7 @@ generic-y += kdebug.h
> generic-y += mcs_spinlock.h
> generic-y += mm-arch-hooks.h
> generic-y += mmiowb.h
> +generic-y += module.lds.h
> generic-y += param.h
> generic-y += pci.h
> generic-y += percpu.h
> diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
> index 74b0612601dd..7cd4e627e00e 100644
> --- a/include/asm-generic/Kbuild
> +++ b/include/asm-generic/Kbuild
> @@ -40,6 +40,7 @@ mandatory-y += mmiowb.h
> mandatory-y += mmu.h
> mandatory-y += mmu_context.h
> mandatory-y += module.h
> +mandatory-y += module.lds.h
> mandatory-y += msi.h
> mandatory-y += pci.h
> mandatory-y += percpu.h
> diff --git a/include/asm-generic/module.lds.h b/include/asm-generic/module.lds.h
> new file mode 100644
> index 000000000000..f210d5c1b78b
> --- /dev/null
> +++ b/include/asm-generic/module.lds.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ASM_GENERIC_MODULE_LDS_H
> +#define __ASM_GENERIC_MODULE_LDS_H
> +
> +/*
> + * <asm/module.lds.h> can specify arch-specific sections for linking modules.
> + * Empty for the asm-generic header.
> + */
> +
> +#endif /* __ASM_GENERIC_MODULE_LDS_H */
> diff --git a/scripts/.gitignore b/scripts/.gitignore
> index 0d1c8e217cd7..a6c11316c969 100644
> --- a/scripts/.gitignore
> +++ b/scripts/.gitignore
> @@ -8,3 +8,4 @@ asn1_compiler
> extract-cert
> sign-file
> insert-sys-cert
> +/module.lds
> diff --git a/scripts/Makefile b/scripts/Makefile
> index bc018e4b733e..b5418ec587fb 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -29,6 +29,9 @@ endif
> # The following programs are only built on demand
> hostprogs += unifdef
>
> +# The module linker script is preprocessed on demand
> +targets += module.lds
> +
> subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
> subdir-$(CONFIG_MODVERSIONS) += genksyms
> subdir-$(CONFIG_SECURITY_SELINUX) += selinux
> diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
> index 411c1e600e7d..ae01baf96f4e 100644
> --- a/scripts/Makefile.modfinal
> +++ b/scripts/Makefile.modfinal
> @@ -33,11 +33,10 @@ quiet_cmd_ld_ko_o = LD [M] $@
> cmd_ld_ko_o = \
> $(LD) -r $(KBUILD_LDFLAGS) \
> $(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE) \
> - $(addprefix -T , $(KBUILD_LDS_MODULE)) \
> - -o $@ $(filter %.o, $^); \
> + -T scripts/module.lds -o $@ $(filter %.o, $^); \
> $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
>
> -$(modules): %.ko: %.o %.mod.o $(KBUILD_LDS_MODULE) FORCE
> +$(modules): %.ko: %.o %.mod.o scripts/module.lds FORCE
> +$(call if_changed,ld_ko_o)
>
> targets += $(modules) $(modules:.ko=.mod.o)
> diff --git a/scripts/module-common.lds b/scripts/module.lds.S
> similarity index 93%
> rename from scripts/module-common.lds
> rename to scripts/module.lds.S
> index d61b9e8678e8..69b9b71a6a47 100644
> --- a/scripts/module-common.lds
> +++ b/scripts/module.lds.S
> @@ -24,3 +24,6 @@ SECTIONS {
>
> __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
> }
> +
> +/* bring in arch-specific sections */
> +#include <asm/module.lds.h>
> diff --git a/scripts/package/builddeb b/scripts/package/builddeb
> index 6df3c9f8b2da..44f212e37935 100755
> --- a/scripts/package/builddeb
> +++ b/scripts/package/builddeb
> @@ -55,7 +55,7 @@ deploy_kernel_headers () {
> cd $srctree
> find . arch/$SRCARCH -maxdepth 1 -name Makefile\*
> find include scripts -type f -o -type l
> - find arch/$SRCARCH -name module.lds -o -name Kbuild.platforms -o -name Platform
> + find arch/$SRCARCH -name Kbuild.platforms -o -name Platform
> find $(find arch/$SRCARCH -name include -o -name scripts -type d) -type f
> ) > debian/hdrsrcfiles
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