test/secmemtest.c: clarify limitations for huge secure memory arena test.

[openssl.git] / test / secmemtest.c

diff --git a/test/secmemtest.c b/test/secmemtest.c
index c92db50ace21050681b8fc469e73b5ff624fa8ce..cb7d1ec63de142b422ea89e1dd59491b0287bdc6 100644 (file)
--- a/test/secmemtest.c
+++ b/test/secmemtest.c
@@ -75,12 +75,36 @@ static int test_sec_mem(void)
     TEST_ptr_null(OPENSSL_secure_malloc((size_t)-1));
     TEST_true(CRYPTO_secure_malloc_done());
 
+    /*-
+     * There was also a possible infinite loop when the number of
+     * elements was 1<<31, as |int i| was set to that, which is a
+     * negative number. However, it requires minimum input values:
+     *
+     * CRYPTO_secure_malloc_init((size_t)1<<34, (size_t)1<<4);
+     *
+     * Which really only works on 64-bit systems, since it took 16 GB
+     * secure memory arena to trigger the problem. It naturally takes
+     * corresponding amount of available virtual and physical memory
+     * for test to be feasible/representative. Since we can't assume
+     * that every system is equipped with that much memory, the test
+     * remains disabled. If the reader of this comment really wants
+     * to make sure that infinite loop is fixed, they can enable the
+     * code below.
+     */
+# if 0
+    /*-
+     * On Linux and BSD this test has a chance to complete in minimal
+     * time and with minimum side effects, because mlock is likely to
+     * fail because of RLIMIT_MEMLOCK, which is customarily [much]
+     * smaller than 16GB. In other words Linux and BSD users can be
+     * limited by virtual space alone...
+     */
     if (sizeof(size_t) > 4) {
         TEST_info("Possible infinite loop: 1<<31 limit");
-        if (!TEST_true(CRYPTO_secure_malloc_init((size_t)1<<34, (size_t)1<<4) != 0))
-            goto end;
-        TEST_true(CRYPTO_secure_malloc_done());
+        if (TEST_true(CRYPTO_secure_malloc_init((size_t)1<<34, (size_t)1<<4) != 0))
+            TEST_true(CRYPTO_secure_malloc_done());
     }
+# endif
     
     /* this can complete - it was not really secure */
     testresult = 1;