Files
Joe Lawrence 3e3c57a0ec objtool: Remove --no-unreachable for noinstr-only vmlinux.o runs
JIRA: https://issues.redhat.com/browse/RHEL-114921

commit 876a4bce3849b235d752d13ec3180e15a35e52de
Author: Josh Poimboeuf <jpoimboe@kernel.org>
Date:   Mon Mar 24 14:56:02 2025 -0700

    objtool: Remove --no-unreachable for noinstr-only vmlinux.o runs

    For (!X86_KERNEL_IBT && !LTO_CLANG && NOINSTR_VALIDATION), objtool runs
    on both translation units and vmlinux.o.  The vmlinux.o run only does
    noinstr/noret validation.  In that case --no-unreachable has no effect.
    Remove it.

    Note that for ((X86_KERNEL_IBT || LTO_CLANG) && KCOV), --no-unreachable
    still gets set in objtool-args-y by scripts/Makefile.lib.

    Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Link: https://lore.kernel.org/r/05414246a0124db2f21b0d071b652aa9043d039d.1742852847.git.jpoimboe@kernel.org

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
2025-11-04 20:01:19 -05:00

89 lines
2.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
PHONY := __default
__default: vmlinux.o
include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
# for objtool
include $(srctree)/scripts/Makefile.lib
# Generate a linker script to ensure correct ordering of initcalls for Clang LTO
# ---------------------------------------------------------------------------
quiet_cmd_gen_initcalls_lds = GEN $@
cmd_gen_initcalls_lds = \
$(PYTHON3) $(srctree)/scripts/jobserver-exec \
$(PERL) $(real-prereqs) > $@
.tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \
$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed,gen_initcalls_lds)
targets := .tmp_initcalls.lds
ifdef CONFIG_LTO_CLANG
initcalls-lds := .tmp_initcalls.lds
endif
# objtool for vmlinux.o
# ---------------------------------------------------------------------------
#
# For delay-objtool (IBT or LTO), objtool doesn't run on individual translation
# units. Instead it runs on vmlinux.o.
#
# For !delay-objtool + CONFIG_NOINSTR_VALIDATION, it runs on both translation
# units and vmlinux.o, with the latter only used for noinstr/unret validation.
objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION))
ifeq ($(delay-objtool),y)
vmlinux-objtool-args-y += $(objtool-args-y)
else
vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror
endif
vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr \
$(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret)
objtool-args = $(vmlinux-objtool-args-y) --link
# Link of vmlinux.o used for section mismatch analysis
# ---------------------------------------------------------------------------
quiet_cmd_ld_vmlinux.o = LD $@
cmd_ld_vmlinux.o = \
$(LD) ${KBUILD_LDFLAGS} -r -o $@ \
$(addprefix -T , $(initcalls-lds)) \
--whole-archive $(KBUILD_VMLINUX_OBJS) --no-whole-archive \
--start-group $(KBUILD_VMLINUX_LIBS) --end-group \
$(cmd_objtool)
define rule_ld_vmlinux.o
$(call cmd_and_savecmd,ld_vmlinux.o)
$(call cmd,gen_objtooldep)
endef
vmlinux.o: $(initcalls-lds) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS) FORCE
$(call if_changed_rule,ld_vmlinux.o)
targets += vmlinux.o
# Add FORCE to the prequisites 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)