From: Sean Christopherson sean.j.christopherson@intel.com
The enclave binary (test_encl.elf) is built with only three sections (tcs, text, and data) as controlled by its custom linker script.
If gcc is built with "--enable-linker-build-id" (this appears to be a common configuration even if it is by default off) then gcc will pass "--build-id" to the linker that will prompt it (the linker) to write unique bits identifying the linked file to a ".note.gnu.build-id" section.
The section ".note.gnu.build-id" does not exist in the test enclave resulting in the following warning emitted by the linker:
/usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id ignored
The test enclave does not use the build id within the binary so fix the warning by passing a build id of "none" to the linker that will disable the setting from any earlier "--build-id" options and thus disable the attempt to write the build id to a ".note.gnu.build-id" section that does not exist.
Link: https://lore.kernel.org/linux-sgx/20191017030340.18301-2-sean.j.christophers... Suggested-by: Cedric Xing cedric.xing@intel.com Signed-off-by: Sean Christopherson sean.j.christopherson@intel.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Acked-by: Dave Hansen dave.hansen@linux.intel.com Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- Changes since V2: - Rewrite commit message (Dave).
Changes since V1: - Change Cedric's signature to a "Suggested-by" (Jarkko and Cedric). - Add signatures from Jarkko and Dave.
tools/testing/selftests/sgx/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile index 7f12d55b97f8..2956584e1e37 100644 --- a/tools/testing/selftests/sgx/Makefile +++ b/tools/testing/selftests/sgx/Makefile @@ -45,7 +45,7 @@ $(OUTPUT)/sign_key.o: sign_key.S $(CC) $(HOST_CFLAGS) -c $< -o $@
$(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S - $(CC) $(ENCL_CFLAGS) -T $^ -o $@ + $(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none
EXTRA_CLEAN := \ $(OUTPUT)/test_encl.elf \