Nathan Chancellor <natechancellor@xxxxxxxxx> writes: > Currently, '--orphan-handling=warn' is spread out across four different > architectures in their respective Makefiles, which makes it a little > unruly to deal with in case it needs to be disabled for a specific > linker version (in this case, ld.lld 10.0.1). > > To make it easier to control this, hoist this warning into Kconfig and > the main Makefile so that disabling it is simpler, as the warning will > only be enabled in a couple places (main Makefile and a couple of > compressed boot folders that blow away LDFLAGS_vmlinx) and making it > conditional is easier due to Kconfig syntax. One small additional > benefit of this is saving a call to ld-option on incremental builds > because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. > > To keep the list of supported architectures the same, introduce > CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to > gain this automatically after all of the sections are specified and size > asserted. A special thanks to Kees Cook for the help text on this > config. > > Link: https://github.com/ClangBuiltLinux/linux/issues/1187 > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > Makefile | 6 ++++++ > arch/Kconfig | 9 +++++++++ > arch/arm/Kconfig | 1 + > arch/arm/Makefile | 4 ---- > arch/arm/boot/compressed/Makefile | 4 +++- > arch/arm64/Kconfig | 1 + > arch/arm64/Makefile | 4 ---- > arch/powerpc/Kconfig | 1 + > arch/powerpc/Makefile | 1 - Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc) > arch/x86/Kconfig | 1 + > arch/x86/Makefile | 3 --- > arch/x86/boot/compressed/Makefile | 4 +++- > init/Kconfig | 3 +++ > 13 files changed, 28 insertions(+), 14 deletions(-) > > diff --git a/Makefile b/Makefile > index 008aba5f1a20..c443afd61886 100644 > --- a/Makefile > +++ b/Makefile > @@ -984,6 +984,12 @@ ifeq ($(CONFIG_RELR),y) > LDFLAGS_vmlinux += --pack-dyn-relocs=relr > endif > > +# We never want expected sections to be placed heuristically by the > +# linker. All sections should be explicitly named in the linker script. > +ifeq ($(CONFIG_LD_ORPHAN_WARN),y) > +LDFLAGS_vmlinux += --orphan-handling=warn > +endif This is a nit, but you can use ifdef with bool CONFIG symbols in Makefiles, which reads a bit nicer, eg: ifdef CONFIG_LD_ORPHAN_WARN LDFLAGS_vmlinux += --orphan-handling=warn endif cheers
