[PATCH v7 05/13] selftests/sgx: Specify freestanding environment for enclave compilation

From: Jo Van Bulck
Date: Thu Oct 05 2023 - 12:18:01 EST


Use -ffreestanding to assert the enclave compilation targets a
freestanding environment (i.e., without "main" or standard libraries).
This fixes clang reporting "undefined reference to `memset'" after
erroneously optimizing away the provided memset/memcpy implementations.

Still need to instruct the linker from using standard system startup
functions, but drop -nostartfiles as it is implied by -nostdlib.

Signed-off-by: Jo Van Bulck <jo.vanbulck@xxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Acked-by: Kai Huang <kai.huang@xxxxxxxxx>
---
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 dcdd04b322f8..7eb890bdd3f0 100644
--- a/tools/testing/selftests/sgx/Makefile
+++ b/tools/testing/selftests/sgx/Makefile
@@ -14,7 +14,7 @@ endif
INCLUDES := -I$(top_srcdir)/tools/include
HOST_CFLAGS := -Wall -Werror -g $(INCLUDES) -fPIC
HOST_LDFLAGS := -z noexecstack -lcrypto
-ENCL_CFLAGS += -Wall -Werror -static -nostdlib -nostartfiles -fPIC \
+ENCL_CFLAGS += -Wall -Werror -static -nostdlib -ffreestanding -fPIC \
-fno-stack-protector -mrdrnd $(INCLUDES)
ENCL_LDFLAGS := -Wl,-T,test_encl.lds,--build-id=none

--
2.25.1