Improve explanations of what bad thing a metatest does
Especially clarify the situation with respect to mutex usage.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/test/metatest.c b/programs/test/metatest.c
index 68e8da6..2973cce 100644
--- a/programs/test/metatest.c
+++ b/programs/test/metatest.c
@@ -74,6 +74,7 @@
(void) name;
volatile char *volatile p;
set_to_zero_but_the_compiler_does_not_know(&p, sizeof(p));
+ /* Undefined behavior (read from null data pointer) */
mbedtls_printf("%p -> %u\n", p, (unsigned) *p);
}
@@ -82,6 +83,7 @@
(void) name;
unsigned(*volatile p)(void);
set_to_zero_but_the_compiler_does_not_know(&p, sizeof(p));
+ /* Undefined behavior (execute null function pointer) */
/* The pointer representation may be truncated, but we don't care:
* the only point of printing it is to have some use of the pointer
* to dissuade the compiler from optimizing it away. */
@@ -99,6 +101,7 @@
volatile char *p = mbedtls_calloc(1, 1);
*p = 'a';
mbedtls_free((void *) p);
+ /* Undefined behavior (read after free) */
mbedtls_printf("%u\n", (unsigned) *p);
}
@@ -108,6 +111,7 @@
volatile char *p = mbedtls_calloc(1, 1);
*p = 'a';
mbedtls_free((void *) p);
+ /* Undefined behavior (double free) */
mbedtls_free((void *) p);
}
@@ -120,6 +124,7 @@
}
char *volatile p = buf;
if (*p != 0) {
+ /* Unspecified result (read from uninitialized memory) */
mbedtls_printf("%u\n", (unsigned) *p);
}
}
@@ -129,6 +134,7 @@
(void) name;
volatile char *p = mbedtls_calloc(1, 1);
mbedtls_printf("%u\n", (unsigned) *p);
+ /* Leak of a heap object */
}
@@ -139,11 +145,13 @@
void mutex_lock_not_initialized(const char *name)
{
(void) name;
- /* Mutex usage verification is only done with pthread, not with other
- * threading implementations. See tests/src/threading_helpers.c. */
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
memset(&mutex, 0, sizeof(mutex));
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
TEST_ASSERT(mbedtls_mutex_lock(&mutex) == 0);
exit:
;
@@ -153,11 +161,13 @@
void mutex_unlock_not_initialized(const char *name)
{
(void) name;
- /* Mutex usage verification is only done with pthread, not with other
- * threading implementations. See tests/src/threading_helpers.c. */
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
memset(&mutex, 0, sizeof(mutex));
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
TEST_ASSERT(mbedtls_mutex_unlock(&mutex) == 0);
exit:
;
@@ -167,11 +177,13 @@
void mutex_free_not_initialized(const char *name)
{
(void) name;
- /* Mutex usage verification is only done with pthread, not with other
- * threading implementations. See tests/src/threading_helpers.c. */
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
memset(&mutex, 0, sizeof(mutex));
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
mbedtls_mutex_free(&mutex);
#endif
}
@@ -182,6 +194,10 @@
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
mbedtls_mutex_init(&mutex);
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
mbedtls_mutex_init(&mutex);
mbedtls_mutex_free(&mutex);
#endif
@@ -194,6 +210,10 @@
mbedtls_threading_mutex_t mutex;
mbedtls_mutex_init(&mutex);
mbedtls_mutex_free(&mutex);
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
mbedtls_mutex_free(&mutex);
#endif
}
@@ -201,12 +221,14 @@
void mutex_leak(const char *name)
{
(void) name;
- /* Mutex usage verification is only done with pthread, not with other
- * threading implementations. See tests/src/threading_helpers.c. */
#if defined(MBEDTLS_THREADING_C)
mbedtls_threading_mutex_t mutex;
mbedtls_mutex_init(&mutex);
#endif
+ /* This mutex usage error is detected by our test framework's mutex usage
+ * verification framework. See tests/src/threading_helpers.c. Other
+ * threading implementations (e.g. pthread without our instrumentation)
+ * might consider this normal usage. */
}
@@ -225,7 +247,9 @@
* - "any": should work anywhere.
* - "asan": triggers ASan (Address Sanitizer).
* - "msan": triggers MSan (Memory Sanitizer).
- * - "pthread": requires MBEDTLS_THREADING_PTHREAD and MBEDTLS_TEST_HOOKS.
+ * - "pthread": requires MBEDTLS_THREADING_PTHREAD and MBEDTLS_TEST_HOOKS,
+ * which enables MBEDTLS_TEST_MUTEX_USAGE internally in the test
+ * framework (see tests/src/threading_helpers.c).
*/
const char *platform;
@@ -249,6 +273,9 @@
*
* Note that we always compile all the functions, so that `metatest --list`
* will always list all the available meta-tests.
+ *
+ * See the documentation of metatest_t::platform for the meaning of
+ * platform values.
*/
metatest_t metatests[] = {
{ "test_fail", "any", meta_test_fail },
@@ -258,8 +285,6 @@
{ "double_free", "asan", double_free },
{ "read_uninitialized_stack", "msan", read_uninitialized_stack },
{ "memory_leak", "asan", memory_leak },
- /* Mutex usage verification is only done with pthread, not with other
- * threading implementations. See tests/src/threading_helpers.c. */
{ "mutex_lock_not_initialized", "pthread", mutex_lock_not_initialized },
{ "mutex_unlock_not_initialized", "pthread", mutex_unlock_not_initialized },
{ "mutex_free_not_initialized", "pthread", mutex_free_not_initialized },