fix: Add option to disable stacktrace feature (#3345)

Author: goatgoose

CMakeLists.txt

@@ -27,6 +27,8 @@ option(S2N_INTERN_LIBCRYPTO "This ensures that s2n-tls is compiled and deployed
 version of libcrypto by interning the code and hiding symbols. This also enables s2n-tls to be
 loaded in an application with an otherwise conflicting libcrypto version." OFF)
 option(S2N_LTO, "Enables link time optimizations when building s2n-tls." OFF)
+option(S2N_STACKTRACE "Enables stacktrace functionality in s2n-tls." ON)
+
 # Turn BUILD_TESTING=ON by default
 include(CTest)
 
@@ -434,8 +436,10 @@ if(ADX_SUPPORTED)
     message(STATUS "Support for ADX assembly instructions detected")
 endif()
 
-if(S2N_HAVE_EXECINFO)
-    target_compile_options(${PROJECT_NAME} PUBLIC -DS2N_HAVE_EXECINFO)
+if(S2N_HAVE_EXECINFO AND S2N_STACKTRACE)
+    target_compile_options(${PROJECT_NAME} PUBLIC -DS2N_STACKTRACE)
+else()
+    message(STATUS "Disabling stacktrace functionality")
 endif()
 
 if(S2N_CPUID_AVAILABLE)

error/s2n_errno.c

@@ -24,7 +24,7 @@
 #include "utils/s2n_map.h"
 #include "utils/s2n_safety.h"
 
-#if S2N_HAVE_EXECINFO
+#ifdef S2N_STACKTRACE
 #   include <execinfo.h>
 #endif
 
@@ -367,7 +367,7 @@ int s2n_stack_traces_enabled_set(bool newval)
     return S2N_SUCCESS;
 }
 
-#ifdef S2N_HAVE_EXECINFO
+#ifdef S2N_STACKTRACE
 
 #define MAX_BACKTRACE_DEPTH 20
 __thread struct s2n_stacktrace tl_stacktrace = {0};
@@ -418,7 +418,7 @@ int s2n_print_stacktrace(FILE *fptr)
     return S2N_SUCCESS;
 }
 
-#else /* !S2N_HAVE_EXECINFO */
+#else /* !S2N_STACKTRACE */
 int s2n_free_stacktrace(void)
 {
     S2N_ERROR(S2N_ERR_UNIMPLEMENTED);
@@ -443,4 +443,4 @@ int s2n_print_stacktrace(FILE *fptr)
 {
     S2N_ERROR(S2N_ERR_UNIMPLEMENTED);
 }
-#endif /* S2N_HAVE_EXECINFO */
+#endif /* S2N_STACKTRACE */

s2n.mk

@@ -186,7 +186,7 @@ try_compile = $(shell $(CC) $(CFLAGS) -c -o tmp.o $(1) > /dev/null 2>&1; echo $$
 # Determine if execinfo.h is available
 TRY_COMPILE_EXECINFO := $(call try_compile,$(S2N_ROOT)/tests/features/execinfo.c)
 ifeq ($(TRY_COMPILE_EXECINFO), 0)
-	DEFAULT_CFLAGS += -DS2N_HAVE_EXECINFO
+	DEFAULT_CFLAGS += -DS2N_STACKTRACE
 endif
 
 # Determine if cpuid.h is available

tests/unit/s2n_stacktrace_test.c

@@ -28,7 +28,7 @@ int main(int argc, char **argv)
 {
     BEGIN_TEST();
     EXPECT_SUCCESS(s2n_disable_tls13_in_test());
-#ifdef S2N_HAVE_EXECINFO
+#ifdef S2N_STACKTRACE
     EXPECT_SUCCESS(s2n_stack_traces_enabled_set(true));
     struct s2n_stacktrace trace;
     /* If nothing has errored yet, we have no stacktrace */