kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
# SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
|
|
2022-09-28 15:39:41 +09:00
|
|
|
PHONY := __default
|
|
|
|
|
__default: vmlinux
|
|
|
|
|
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
include include/config/auto.conf
|
|
|
|
|
include $(srctree)/scripts/Kbuild.include
|
|
|
|
|
include $(srctree)/scripts/Makefile.lib
|
|
|
|
|
|
2022-09-28 15:39:41 +09:00
|
|
|
targets :=
|
|
|
|
|
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
ifdef CONFIG_ARCH_VMLINUX_NEEDS_RELOCS
|
|
|
|
|
vmlinux-final := vmlinux.unstripped
|
|
|
|
|
|
|
|
|
|
quiet_cmd_strip_relocs = RSTRIP $@
|
2025-04-08 09:28:51 +02:00
|
|
|
cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' --remove-section=!'.rel*.dyn' $< $@
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
|
|
|
|
|
vmlinux: $(vmlinux-final) FORCE
|
|
|
|
|
$(call if_changed,strip_relocs)
|
|
|
|
|
|
|
|
|
|
targets += vmlinux
|
|
|
|
|
else
|
|
|
|
|
vmlinux-final := vmlinux
|
|
|
|
|
endif
|
|
|
|
|
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
%.o: %.c FORCE
|
2024-11-14 08:45:22 +09:00
|
|
|
$(call if_changed_rule,cc_o_c)
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
|
2024-09-23 16:56:03 +09:00
|
|
|
%.o: %.S FORCE
|
2024-11-14 08:45:22 +09:00
|
|
|
$(call if_changed_rule,as_o_S)
|
2024-09-23 16:56:03 +09:00
|
|
|
|
|
|
|
|
# Built-in dtb
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
quiet_cmd_wrap_dtbs = WRAP $@
|
|
|
|
|
cmd_wrap_dtbs = { \
|
|
|
|
|
echo '\#include <asm-generic/vmlinux.lds.h>'; \
|
|
|
|
|
echo '.section .dtb.init.rodata,"a"'; \
|
|
|
|
|
while read dtb; do \
|
|
|
|
|
symbase=__dtb_$$(basename -s .dtb "$${dtb}" | tr - _); \
|
|
|
|
|
echo '.balign STRUCT_ALIGNMENT'; \
|
|
|
|
|
echo ".global $${symbase}_begin"; \
|
|
|
|
|
echo "$${symbase}_begin:"; \
|
|
|
|
|
echo '.incbin "'$$dtb'" '; \
|
|
|
|
|
echo ".global $${symbase}_end"; \
|
|
|
|
|
echo "$${symbase}_end:"; \
|
|
|
|
|
done < $<; \
|
|
|
|
|
} > $@
|
|
|
|
|
|
|
|
|
|
.builtin-dtbs.S: .builtin-dtbs-list FORCE
|
|
|
|
|
$(call if_changed,wrap_dtbs)
|
|
|
|
|
|
|
|
|
|
quiet_cmd_gen_dtbs_list = GEN $@
|
|
|
|
|
cmd_gen_dtbs_list = \
|
|
|
|
|
$(if $(CONFIG_BUILTIN_DTB_NAME), echo "arch/$(SRCARCH)/boot/dts/$(CONFIG_BUILTIN_DTB_NAME).dtb",:) > $@
|
|
|
|
|
|
|
|
|
|
.builtin-dtbs-list: arch/$(SRCARCH)/boot/dts/dtbs-list FORCE
|
|
|
|
|
$(call if_changed,$(if $(CONFIG_BUILTIN_DTB_ALL),copy,gen_dtbs_list))
|
|
|
|
|
|
|
|
|
|
targets += .builtin-dtbs-list
|
|
|
|
|
|
|
|
|
|
ifdef CONFIG_GENERIC_BUILTIN_DTB
|
|
|
|
|
targets += .builtin-dtbs.S .builtin-dtbs.o
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
$(vmlinux-final): .builtin-dtbs.o
|
2024-09-23 16:56:03 +09:00
|
|
|
endif
|
|
|
|
|
|
|
|
|
|
# vmlinux
|
|
|
|
|
# ---------------------------------------------------------------------------
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
|
2022-09-28 15:39:41 +09:00
|
|
|
ifdef CONFIG_MODULES
|
|
|
|
|
targets += .vmlinux.export.o
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
$(vmlinux-final): .vmlinux.export.o
|
2022-09-28 15:39:41 +09:00
|
|
|
endif
|
|
|
|
|
|
2024-10-30 12:38:44 +05:30
|
|
|
ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
$(vmlinux-final): arch/$(SRCARCH)/tools/vmlinux.arch.o
|
2024-10-30 12:38:44 +05:30
|
|
|
|
|
|
|
|
arch/$(SRCARCH)/tools/vmlinux.arch.o: vmlinux.o FORCE
|
|
|
|
|
$(Q)$(MAKE) $(build)=arch/$(SRCARCH)/tools $@
|
|
|
|
|
endif
|
|
|
|
|
|
2022-09-28 15:39:41 +09:00
|
|
|
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
|
|
|
|
|
|
|
|
|
|
# Final link of vmlinux with optional arch pass after final link
|
|
|
|
|
cmd_link_vmlinux = \
|
2025-03-11 12:06:18 +01:00
|
|
|
$< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \
|
2022-09-28 15:39:41 +09:00
|
|
|
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
|
|
|
|
|
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
targets += $(vmlinux-final)
|
|
|
|
|
$(vmlinux-final): scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
|
2022-09-28 15:39:41 +09:00
|
|
|
+$(call if_changed_dep,link_vmlinux)
|
2024-11-23 14:33:37 +01:00
|
|
|
ifdef CONFIG_DEBUG_INFO_BTF
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
$(vmlinux-final): $(RESOLVE_BTFIDS)
|
2024-11-23 14:33:37 +01:00
|
|
|
endif
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
|
2025-02-26 21:30:14 +08:00
|
|
|
ifdef CONFIG_BUILDTIME_TABLE_SORT
|
2025-05-11 12:55:19 +09:00
|
|
|
$(vmlinux-final): scripts/sorttable
|
2025-02-26 21:30:14 +08:00
|
|
|
endif
|
|
|
|
|
|
kbuild: generate offset range data for builtin modules
Create file module.builtin.ranges that can be used to find where
built-in modules are located by their addresses. This will be useful for
tracing tools to find what functions are for various built-in modules.
The offset range data for builtin modules is generated using:
- modules.builtin: associates object files with module names
- vmlinux.map: provides load order of sections and offset of first member
per section
- vmlinux.o.map: provides offset of object file content per section
- .*.cmd: build cmd file with KBUILD_MODFILE
The generated data will look like:
.text 00000000-00000000 = _text
.text 0000baf0-0000cb10 amd_uncore
.text 0009bd10-0009c8e0 iosf_mbi
...
.text 00b9f080-00ba011a intel_skl_int3472_discrete
.text 00ba0120-00ba03c0 intel_skl_int3472_discrete intel_skl_int3472_tps68470
.text 00ba03c0-00ba08d6 intel_skl_int3472_tps68470
...
.data 00000000-00000000 = _sdata
.data 0000f020-0000f680 amd_uncore
For each ELF section, it lists the offset of the first symbol. This can
be used to determine the base address of the section at runtime.
Next, it lists (in strict ascending order) offset ranges in that section
that cover the symbols of one or more builtin modules. Multiple ranges
can apply to a single module, and ranges can be shared between modules.
The CONFIG_BUILTIN_MODULE_RANGES option controls whether offset range data
is generated for kernel modules that are built into the kernel image.
How it works:
1. The modules.builtin file is parsed to obtain a list of built-in
module names and their associated object names (the .ko file that
the module would be in if it were a loadable module, hereafter
referred to as <kmodfile>). This object name can be used to
identify objects in the kernel compile because any C or assembler
code that ends up into a built-in module will have the option
-DKBUILD_MODFILE=<kmodfile> present in its build command, and those
can be found in the .<obj>.cmd file in the kernel build tree.
If an object is part of multiple modules, they will all be listed
in the KBUILD_MODFILE option argument.
This allows us to conclusively determine whether an object in the
kernel build belong to any modules, and which.
2. The vmlinux.map is parsed next to determine the base address of each
top level section so that all addresses into the section can be
turned into offsets. This makes it possible to handle sections
getting loaded at different addresses at system boot.
We also determine an 'anchor' symbol at the beginning of each
section to make it possible to calculate the true base address of
a section at runtime (i.e. symbol address - symbol offset).
We collect start addresses of sections that are included in the top
level section. This is used when vmlinux is linked using vmlinux.o,
because in that case, we need to look at the vmlinux.o linker map to
know what object a symbol is found in.
And finally, we process each symbol that is listed in vmlinux.map
(or vmlinux.o.map) based on the following structure:
vmlinux linked from vmlinux.a:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
vmlinux linked from vmlinux.o:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
vmlinux.o -- need to use vmlinux.o.map
<symbol> -- ignored
...
vmlinux.o.map:
<section>
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
3. As sections, objects, and symbols are processed, offset ranges are
constructed in a straight-forward way:
- If the symbol belongs to one or more built-in modules:
- If we were working on the same module(s), extend the range
to include this object
- If we were working on another module(s), close that range,
and start the new one
- If the symbol does not belong to any built-in modules:
- If we were working on a module(s) range, close that range
Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Sam James <sam@gentoo.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-06 10:45:03 -04:00
|
|
|
# module.builtin.ranges
|
|
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
ifdef CONFIG_BUILTIN_MODULE_RANGES
|
|
|
|
|
__default: modules.builtin.ranges
|
|
|
|
|
|
|
|
|
|
quiet_cmd_modules_builtin_ranges = GEN $@
|
|
|
|
|
cmd_modules_builtin_ranges = gawk -f $(real-prereqs) > $@
|
|
|
|
|
|
|
|
|
|
targets += modules.builtin.ranges
|
|
|
|
|
modules.builtin.ranges: $(srctree)/scripts/generate_builtin_ranges.awk \
|
|
|
|
|
modules.builtin vmlinux.map vmlinux.o.map FORCE
|
|
|
|
|
$(call if_changed,modules_builtin_ranges)
|
|
|
|
|
|
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 <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-11 12:06:20 +01:00
|
|
|
vmlinux.map: $(vmlinux-final)
|
kbuild: generate offset range data for builtin modules
Create file module.builtin.ranges that can be used to find where
built-in modules are located by their addresses. This will be useful for
tracing tools to find what functions are for various built-in modules.
The offset range data for builtin modules is generated using:
- modules.builtin: associates object files with module names
- vmlinux.map: provides load order of sections and offset of first member
per section
- vmlinux.o.map: provides offset of object file content per section
- .*.cmd: build cmd file with KBUILD_MODFILE
The generated data will look like:
.text 00000000-00000000 = _text
.text 0000baf0-0000cb10 amd_uncore
.text 0009bd10-0009c8e0 iosf_mbi
...
.text 00b9f080-00ba011a intel_skl_int3472_discrete
.text 00ba0120-00ba03c0 intel_skl_int3472_discrete intel_skl_int3472_tps68470
.text 00ba03c0-00ba08d6 intel_skl_int3472_tps68470
...
.data 00000000-00000000 = _sdata
.data 0000f020-0000f680 amd_uncore
For each ELF section, it lists the offset of the first symbol. This can
be used to determine the base address of the section at runtime.
Next, it lists (in strict ascending order) offset ranges in that section
that cover the symbols of one or more builtin modules. Multiple ranges
can apply to a single module, and ranges can be shared between modules.
The CONFIG_BUILTIN_MODULE_RANGES option controls whether offset range data
is generated for kernel modules that are built into the kernel image.
How it works:
1. The modules.builtin file is parsed to obtain a list of built-in
module names and their associated object names (the .ko file that
the module would be in if it were a loadable module, hereafter
referred to as <kmodfile>). This object name can be used to
identify objects in the kernel compile because any C or assembler
code that ends up into a built-in module will have the option
-DKBUILD_MODFILE=<kmodfile> present in its build command, and those
can be found in the .<obj>.cmd file in the kernel build tree.
If an object is part of multiple modules, they will all be listed
in the KBUILD_MODFILE option argument.
This allows us to conclusively determine whether an object in the
kernel build belong to any modules, and which.
2. The vmlinux.map is parsed next to determine the base address of each
top level section so that all addresses into the section can be
turned into offsets. This makes it possible to handle sections
getting loaded at different addresses at system boot.
We also determine an 'anchor' symbol at the beginning of each
section to make it possible to calculate the true base address of
a section at runtime (i.e. symbol address - symbol offset).
We collect start addresses of sections that are included in the top
level section. This is used when vmlinux is linked using vmlinux.o,
because in that case, we need to look at the vmlinux.o linker map to
know what object a symbol is found in.
And finally, we process each symbol that is listed in vmlinux.map
(or vmlinux.o.map) based on the following structure:
vmlinux linked from vmlinux.a:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
vmlinux linked from vmlinux.o:
vmlinux.map:
<top level section>
<included section> -- might be same as top level section)
vmlinux.o -- need to use vmlinux.o.map
<symbol> -- ignored
...
vmlinux.o.map:
<section>
<object> -- built-in association known
<symbol> -- belongs to module(s) object belongs to
...
3. As sections, objects, and symbols are processed, offset ranges are
constructed in a straight-forward way:
- If the symbol belongs to one or more built-in modules:
- If we were working on the same module(s), extend the range
to include this object
- If we were working on another module(s), close that range,
and start the new one
- If the symbol does not belong to any built-in modules:
- If we were working on a module(s) range, close that range
Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Sam James <sam@gentoo.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-09-06 10:45:03 -04:00
|
|
|
@:
|
|
|
|
|
|
|
|
|
|
endif
|
|
|
|
|
|
2024-08-18 16:07:11 +09:00
|
|
|
# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
|
kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.
Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.
It is time to get rid of this complexity.
Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.
Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.
Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.
No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.
Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-13 20:39:22 +09:00
|
|
|
# ---------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
|
PHONY += FORCE
|
|
|
|
|
FORCE:
|
|
|
|
|
|
|
|
|
|
# Read all saved command lines and dependencies for the $(targets) we
|
|
|
|
|
# may be building above, using $(if_changed{,_dep}). As an
|
|
|
|
|
# optimization, we don't need to read them if the target does not
|
|
|
|
|
# exist, we will rebuild anyway in that case.
|
|
|
|
|
|
|
|
|
|
existing-targets := $(wildcard $(sort $(targets)))
|
|
|
|
|
|
|
|
|
|
-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
|
|
|
|
|
|
|
|
|
|
.PHONY: $(PHONY)
|