When building the x86 EFI stub with Clang, the libstub Makefile rules
that manipulate the ELF object files may throw an error like:
STUBCPY drivers/firmware/efi/libstub/efi-stub-helper.stub.o
strip: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10
objcopy: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10
This is the result of a LLVM 'feature' [0] where symbol references are
stored in a LLVM specific .llvm_addrsig section in a non-transparent way,
causing generic ELF tools such as strip or objcopy to choke on them.
So drop the .llvm_addrsig section explicitly as well, to work around
this behavior.
[0] https://sourceware.org/bugzilla/show_bug.cgi?id=23817
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/Makefile | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 8d246b51bd49..4d137615a666 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -66,7 +66,8 @@ CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
# .data section of the compressed kernel to ensure initialization. Rename the
# .bss section here so it's easy to pick out in the linker script.
#
-STUBCOPY_FLAGS-$(CONFIG_X86) += --rename-section .bss=.bss.efistub,load,alloc
+STUBCOPY_FLAGS-$(CONFIG_X86) += -R .llvm_addrsig \
+ --rename-section .bss=.bss.efistub,load,alloc
STUBCOPY_RELOC-$(CONFIG_X86_32) := R_386_32
STUBCOPY_RELOC-$(CONFIG_X86_64) := R_X86_64_64
@@ -111,7 +112,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE
#
quiet_cmd_stubcopy = STUBCPY $@
cmd_stubcopy = \
- $(STRIP) --strip-debug -o $@ $<; \
+ $(STRIP) --strip-debug -R .llvm_addrsig -o $@ $<; \
if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); then \
echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \
/bin/false; \
--
2.17.1
