Re: [PATCH 10/12] efi/libstub: Remove obsolete .note.gnu.property workaround
Nick Desaulniers <[email protected]>
| Newsgroups | org.kernel.vger.live-patching,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-toolchains |
|---|---|
| Message-ID | <CAKwvOd=Vn4L1sJ=8zVk9qcDLtaDYxfxn+0aG4tMrbETsqY5_PQ@mail.gmail.com> |
On Fri, Aug 14, 2026 at 9:45 PM Josh Poimboeuf <[email protected]> wrote: > > Commit e2179a09ab08 ("efi/libstub: Disable -mbranch-protection") added > --remove-section=.note.gnu.property to the stub objcopy invocation to > work around a Clang bug where the note was emitted for code-less object > files even with -mbranch-protection=none. > > That was fixed by LLVM commit a48f6079f288 ("[AArch64] Generate > .note.gnu.property based on module flags") which was released with > Clang 12. The minimum Clang version is now Clang 17, so this workaround > is no longer needed. > > On arm64, the stub also no longer builds with -mbranch-protection=none, > as it has inherited the kernel's flags since commit 8358098b9787 > ("arm64: efi: Enable BTI codegen and add PE/COFF annotation"). I verified the above all looks correct. Thanks for the cleanup. Reviewed-by: Nick Desaulniers <[email protected]> > > Remove the workaround. This fixes BTI on arm64, and is a no-op on > RISC-V and LoongArch where the vmlinux generic NOTES macro discards it, > and the x86 and ARM decompressors discard .note.* explicitly. > > Signed-off-by: Josh Poimboeuf <[email protected]> > --- > drivers/firmware/efi/libstub/Makefile | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > index b1c95f69e807d..e18e124a89acf 100644 > --- a/drivers/firmware/efi/libstub/Makefile > +++ b/drivers/firmware/efi/libstub/Makefile > @@ -106,12 +106,6 @@ lib-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o bitmap.o find.o > targets := $(lib-y) > lib-y := $(patsubst %.o,%.stub.o,$(lib-y)) > > -# Even when -mbranch-protection=none is set, Clang will generate a > -# .note.gnu.property for code-less object files (like lib/ctype.c), > -# so work around this by explicitly removing the unwanted section. > -# https://llvm.org/pr46480 > -STUBCOPY_FLAGS-y += --remove-section=.note.gnu.property > - > STUBCOPY_RELOC-$(CONFIG_X86_32) := R_386_32 > STUBCOPY_RELOC-$(CONFIG_X86_64) := R_X86_64_64 > > -- > 2.55.0 > -- Thanks, ~Nick Desaulniers