Hi Ard, On Wed, Jun 21, 2023 at 1:45 PM Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> wrote: > > Static linking is done at an object file (actually section) granularity, > meaning that if a function in an object has an undefined reference, the > link will fail, even though this function is not used in the resulting > ELF. > > To avoid such failures, allow the linker to garbage collect unused sections > (which actually are functions). > > Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> > --- > drivers/firmware/efi/libstub/Makefile | 1 + > drivers/firmware/efi/libstub/Makefile.zboot | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > index 3abb2b357482..6182366d00c0 100644 > --- a/drivers/firmware/efi/libstub/Makefile > +++ b/drivers/firmware/efi/libstub/Makefile > @@ -40,6 +40,7 @@ KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(cflags-y)) \ > -ffreestanding \ > -fno-stack-protector \ > $(call cc-option,-fno-addrsig) \ > + -ffunction-sections \ > -D__DISABLE_EXPORTS > > # > diff --git a/drivers/firmware/efi/libstub/Makefile.zboot b/drivers/firmware/efi/libstub/Makefile.zboot > index 89ef820f3b34..5bb52d262133 100644 > --- a/drivers/firmware/efi/libstub/Makefile.zboot > +++ b/drivers/firmware/efi/libstub/Makefile.zboot > @@ -51,7 +51,7 @@ $(obj)/zboot-header.o: $(srctree)/drivers/firmware/efi/libstub/zboot-header.S FO > > ZBOOT_DEPS := $(obj)/zboot-header.o $(objtree)/drivers/firmware/efi/libstub/lib.a > > -LDFLAGS_vmlinuz.efi.elf := -T $(srctree)/drivers/firmware/efi/libstub/zboot.lds > +LDFLAGS_vmlinuz.efi.elf := -T $(srctree)/drivers/firmware/efi/libstub/zboot.lds --gc-sections > $(obj)/vmlinuz.efi.elf: $(obj)/vmlinuz.o $(ZBOOT_DEPS) FORCE > $(call if_changed,ld) > > -- > 2.39.2 > Sorry to bother you, do you have any opinion about this patch? Does that make sense? If not, I should find another solution for my riscv KASLR series! Thanks, Alex
