The external tests manipulating page permissions expect encl_buffer to be
placed at the start of the test enclave's .data section. As this is not
guaranteed per the C standard, explicitly place encl_buffer in a separate
section that is explicitly placed at the start of the .data segment in the
linker script to avoid the compiler placing it somewhere else in .data.
Signed-off-by: Jo Van Bulck <jo.vanbulck@xxxxxxxxxxxxxx>
---
tools/testing/selftests/sgx/defines.h | 1 +
tools/testing/selftests/sgx/test_encl.c | 8 ++++----
tools/testing/selftests/sgx/test_encl.lds | 1 +
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index b8f482667..402f8787a 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -14,6 +14,7 @@
#define __aligned(x) __attribute__((__aligned__(x)))
#define __packed __attribute__((packed))
#define __used __attribute__((used))
+#define __section(x)__attribute__((__section__(x)))
#include "../../../../arch/x86/include/asm/sgx.h"
#include "../../../../arch/x86/include/asm/enclu.h"
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index c7bcbc85b..151600353 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -6,11 +6,11 @@
/*
* Data buffer spanning two pages that will be placed first in the .data
- * segment. Even if not used internally the second page is needed by external
- * test manipulating page permissions, so mark encl_buffer as "used" to make
- * sure it is entirely preserved by the compiler.
+ * segment via the linker script. Even if not used internally the second page
+ * is needed by external test manipulating page permissions, so mark
+ * encl_buffer as "used" to make sure it is entirely preserved by the compiler.
*/
-static uint8_t __used encl_buffer[8192] = { 1 };
+static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 };
enum sgx_enclu_function {
EACCEPT = 0x5,
diff --git a/tools/testing/selftests/sgx/test_encl.lds b/tools/testing/selftests/sgx/test_encl.lds
index 13144b045..ffe851a1c 100644
--- a/tools/testing/selftests/sgx/test_encl.lds
+++ b/tools/testing/selftests/sgx/test_encl.lds
@@ -24,6 +24,7 @@ SECTIONS
} : text
.data : {
+ *(.data.encl_buffer)
*(.data*)
} : data
--
2.25.1
