strncpy: implement _FORTIFY_SOURCE=2

Add support for fortify source level 2 to strncpy.
This will enable detection of more areas where strncpy
is used inappropriately. For example, this would have detected
bug 8727221.

Move the fortify_source tests out of string_test.cpp, and
put it into fortify1_test.cpp.

Create a new fortify2_test.cpp file, which copies all
the tests in fortify1_test.cpp, and adds fortify_source level
2 specific tests.

Change-Id: Ica0fba531cc7d0609e4f23b8176739b13f7f7a83

tests/fortify2_test.cpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef _FORTIFY_SOURCE
+#define _FORTIFY_SOURCE 2
+
+#include <gtest/gtest.h>
+#include <string.h>
+
+struct foo {
+  char a[10];
+  char b[10];
+};
+
+// We have to say "DeathTest" here so gtest knows to run this test (which exits)
+// in its own process.
+TEST(Fortify2_DeathTest, strncpy_fortified) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  foo myfoo;
+  int copy_amt = atoi("11");
+  ASSERT_EXIT(strncpy(myfoo.a, "01234567890", copy_amt),
+              testing::KilledBySignal(SIGSEGV), "");
+}
+
+#if __BIONIC__
+TEST(Fortify2_DeathTest, strcpy_fortified) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  char buf[10];
+  char *orig = strdup("0123456789");
+  ASSERT_EXIT(strcpy(buf, orig), testing::KilledBySignal(SIGSEGV), "");
+  free(orig);
+}
+
+TEST(Fortify2_DeathTest, strlen_fortified) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  char buf[10];
+  memcpy(buf, "0123456789", sizeof(buf));
+  ASSERT_EXIT(printf("%d", strlen(buf)), testing::KilledBySignal(SIGSEGV), "");
+}
+
+TEST(Fortify2_DeathTest, strchr_fortified) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  char buf[10];
+  memcpy(buf, "0123456789", sizeof(buf));
+  ASSERT_EXIT(printf("%s", strchr(buf, 'a')), testing::KilledBySignal(SIGSEGV), "");
+}
+
+TEST(Fortify2_DeathTest, strrchr_fortified) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  char buf[10];
+  memcpy(buf, "0123456789", sizeof(buf));
+  ASSERT_EXIT(printf("%s", strrchr(buf, 'a')), testing::KilledBySignal(SIGSEGV), "");
+}
+#endif