Files
linux/scripts/Makefile.vmlinux
Nathan Chancellor 8e5e13c8df kbuild: Add '.rel.*' strip pattern for vmlinux
[ Upstream commit 8ec3af916f ]

Prior to binutils commit c12d9fa2afe ("Support objcopy
--remove-section=.relaFOO") [1] in 2.32, stripping relocation sections
required the trailing period (i.e., '.rel.*') to work properly.

After commit 3e86e4d74c ("kbuild: keep .modinfo section in
vmlinux.unstripped"), there is an error with binutils 2.31.1 or earlier
because these sections are not properly removed:

  s390-linux-objcopy: st6tO8Ev: symbol `.modinfo' required but not present
  s390-linux-objcopy:st6tO8Ev: no symbols

Add the old pattern to resolve this issue (along with a comment to allow
cleaning this when binutils 2.32 or newer is the minimum supported
version). While the aforementioned kbuild change exposes this, the
pattern was originally changed by commit 71d815bf5d ("kbuild: Strip
runtime const RELA sections correctly"), where it would still be
incorrect with binutils older than 2.32.

Fixes: 71d815bf5d ("kbuild: Strip runtime const RELA sections correctly")
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7 [1]
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYvVktRhFtZXdNgVOL8j+ArsJDpvMLgCitaQvQmCx=hwOQ@mail.gmail.com/
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Alexey Gladkov <legion@kernel.org>
Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20251008-kbuild-fix-modinfo-regressions-v1-2-9fc776c5887c@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19 16:37:15 +02:00

139 lines
4.3 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
PHONY := __default
__default: vmlinux
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
include $(srctree)/scripts/Makefile.lib
targets :=
%.o: %.c FORCE
$(call if_changed_rule,cc_o_c)
%.o: %.S FORCE
$(call if_changed_rule,as_o_S)
# 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 $(CONFIG_BUILTIN_DTB_ALL),copy,gen_dtbs_list))
targets += .builtin-dtbs-list
ifdef CONFIG_GENERIC_BUILTIN_DTB
targets += .builtin-dtbs.S .builtin-dtbs.o
vmlinux.unstripped: .builtin-dtbs.o
endif
# vmlinux.unstripped
# ---------------------------------------------------------------------------
ifdef CONFIG_MODULES
targets += .vmlinux.export.o
vmlinux.unstripped: .vmlinux.export.o
endif
ifdef CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX
vmlinux.unstripped: arch/$(SRCARCH)/tools/vmlinux.arch.o
arch/$(SRCARCH)/tools/vmlinux.arch.o: vmlinux.o FORCE
$(Q)$(MAKE) $(build)=arch/$(SRCARCH)/tools $@
endif
ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
# Final link of vmlinux with optional arch pass after final link
cmd_link_vmlinux = \
$< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
targets += vmlinux.unstripped
vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o $(KBUILD_LDS) FORCE
+$(call if_changed_dep,link_vmlinux)
ifdef CONFIG_DEBUG_INFO_BTF
vmlinux.unstripped: $(RESOLVE_BTFIDS)
endif
ifdef CONFIG_BUILDTIME_TABLE_SORT
vmlinux.unstripped: scripts/sorttable
endif
# vmlinux
# ---------------------------------------------------------------------------
remove-section-y := .modinfo
remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' '!.rel*.dyn'
# for compatibility with binutils < 2.32
# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7
remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel.*'
# To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy,
# it is necessary to remove the PT_LOAD flag from the segment.
quiet_cmd_strip_relocs = OBJCOPY $@
cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags %=noload,$(remove-section-y)) $< $@; \
$(OBJCOPY) $(addprefix --remove-section=,$(remove-section-y)) $@
targets += vmlinux
vmlinux: vmlinux.unstripped FORCE
$(call if_changed,strip_relocs)
# modules.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)
vmlinux.map: vmlinux.unstripped
@:
endif
# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
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)