Backport of: 0d362be5b142 ("Makefile: link with -z noexecstack --no-warn-rwx-segments") breaks arm64 Build ID when CONFIG_MODVERSIONS=y.
CONFIG_MODVERSIONS adds extra tooling to calculate symbol versions. This kernel's KBUILD tooling uses both relocatable (-r) and (-z noexecstack) to link head.o which results in ld adding a .note.GNU-stack section. Final linking of vmlinux should add a .NOTES segment containing the Build ID, but does NOT if head.o has a .note.GNU-stack section.
Selectively remove -z noexecstack from head.o's KBUILD_LDFLAGS to prevent .note.GNU-stack from being added to head.o. Final link of vmlinux then properly adds .NOTES segment containing Build ID that can be read using tools like 'readelf -n'.
Cc: stable@vger.kernel.org # 5.15, 5.10, 5.4 Signed-off-by: Tom Saeger tom.saeger@oracle.com --- arch/arm64/kernel/Makefile | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 749e31475e41..8bdee0f655e2 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -85,3 +85,8 @@ extra-y += $(head-y) vmlinux.lds ifeq ($(CONFIG_DEBUG_EFI),y) AFLAGS_head.o += -DVMLINUX_PATH=""$(realpath $(objtree)/vmlinux)"" endif + +ifeq ($(CONFIG_MODVERSIONS),y) +# filter-out -z noexecstack for head.S +$(obj)/head.o: KBUILD_LDFLAGS := $(shell echo "$(KBUILD_LDFLAGS)" | sed -e 's/-z\s+noexecstack//') +endif