MDEV-17702 fix unaligned access UB in sint4korr() and similar functions

Disable (hopefully temprorary) this check. Also add tests for some serialized
functions.

CMakeLists.txt

@@ -217,7 +217,7 @@ IF (WITH_UBSAN)
   IF(SECURITY_HARDENED)
     MESSAGE(FATAL_ERROR "WITH_UBSAN and SECURITY_HARDENED are mutually exclusive")
   ENDIF()
-  MY_CHECK_AND_SET_COMPILER_FLAG("-fsanitize=undefined" DEBUG RELWITHDEBINFO)
+  MY_CHECK_AND_SET_COMPILER_FLAG("-fsanitize=undefined -fno-sanitize=alignment" DEBUG RELWITHDEBINFO)
 ENDIF()
 
 

unittest/mysys/CMakeLists.txt

@@ -14,7 +14,7 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 
 MY_ADD_TESTS(bitmap base64 my_atomic my_rdtsc lf my_malloc my_getopt dynstring
-             aes
+             aes byte_order
              LINK_LIBRARIES mysys)
 MY_ADD_TESTS(my_vsnprintf LINK_LIBRARIES strings mysys)
 

unittest/mysys/byte_order-t.c

+/* Copyright (c) 2019, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+/**
+  @file
+
+  Unit tests for serialization and deserialization functions
+*/
+
+#include "tap.h"
+
+#include "my_byteorder.h"
+#include "myisampack.h"
+#include "m_string.h"
+
+void test_byte_order()
+{
+  MY_ALIGNED(CPU_LEVEL1_DCACHE_LINESIZE)
+  uchar buf[CPU_LEVEL1_DCACHE_LINESIZE * 2];
+
+  uchar *aligned= buf;
+  uchar *not_aligned= buf + CPU_LEVEL1_DCACHE_LINESIZE - 1;
+
+#define TEST(STORE_NAME, LOAD_NAME, TYPE, VALUE, BYTES)                        \
+  {                                                                            \
+    TYPE value= VALUE;                                                         \
+    uchar bytes[]= BYTES;                                                      \
+    STORE_NAME(aligned, value);                                                \
+    ok(!memcmp(aligned, bytes, sizeof(bytes)), "aligned\t\t" #STORE_NAME);     \
+    ok(LOAD_NAME(aligned) == value, "aligned\t\t" #LOAD_NAME);                 \
+    STORE_NAME(not_aligned, value);                                            \
+    ok(!memcmp(not_aligned, bytes, sizeof(bytes)),                             \
+       "not aligned\t" #STORE_NAME);                                           \
+    ok(LOAD_NAME(not_aligned) == value, "not aligned\t" #LOAD_NAME);           \
+  }
+
+#define ARRAY_2(A, B) {A, B}
+#define ARRAY_3(A, B, C) {A, B, C}
+#define ARRAY_4(A, B, C, D) {A, B, C, D}
+#define ARRAY_5(A, B, C, D, E) {A, B, C, D, E}
+#define ARRAY_6(A, B, C, D, E, F) {A, B, C, D, E, F}
+#define ARRAY_7(A, B, C, D, E, F, G) {A, B, C, D, E, F, G}
+#define ARRAY_8(A, B, C, D, E, F, G, H) {A, B, C, D, E, F, G, H}
+
+  TEST(int2store, sint2korr, int16, 0x0201, ARRAY_2(1, 2));
+  TEST(int3store, sint3korr, int32, 0xffffffff, ARRAY_3(0xff, 0xff, 0xff));
+  TEST(int3store, sint3korr, int32, 0x030201, ARRAY_3(1, 2, 3));
+  TEST(int4store, sint4korr, int32, 0xffffffff,
+       ARRAY_4(0xff, 0xff, 0xff, 0xff));
+  TEST(int4store, sint4korr, int32, 0x04030201, ARRAY_4(1, 2, 3, 4));
+  TEST(int8store, sint8korr, longlong, 0x0807060504030201,
+       ARRAY_8(1, 2, 3, 4, 5, 6, 7, 8));
+  TEST(int8store, sint8korr, longlong, 0xffffffffffffffff,
+       ARRAY_8(0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff));
+
+  TEST(int2store, uint2korr, uint16, 0x0201, ARRAY_2(1, 2));
+  TEST(int3store, uint3korr, uint32, 0x030201, ARRAY_3(1, 2, 3));
+  TEST(int4store, uint4korr, uint32, 0x04030201, ARRAY_4(1, 2, 3, 4));
+  TEST(int5store, uint5korr, ulonglong, 0x0504030201, ARRAY_5(1, 2, 3, 4, 5));
+  TEST(int6store, uint6korr, ulonglong, 0x060504030201,
+       ARRAY_6(1, 2, 3, 4, 5, 6));
+  TEST(int8store, uint8korr, ulonglong, 0x0807060504030201,
+       ARRAY_8(1, 2, 3, 4, 5, 6, 7, 8));
+
+  TEST(mi_int5store, mi_uint5korr, ulonglong, 0x0504030201,
+       ARRAY_5(5, 4, 3, 2, 1));
+  TEST(mi_int6store, mi_uint6korr, ulonglong, 0x060504030201,
+       ARRAY_6(6, 5, 4, 3, 2, 1));
+  TEST(mi_int7store, mi_uint7korr, ulonglong, 0x07060504030201,
+       ARRAY_7(7, 6, 5, 4, 3, 2, 1));
+  TEST(mi_int8store, mi_uint8korr, ulonglong, 0x0807060504030201,
+       ARRAY_8(8, 7, 6, 5, 4, 3, 2, 1));
+
+#undef ARRAY_8
+#undef ARRAY_7
+#undef ARRAY_6
+#undef ARRAY_5
+#undef ARRAY_4
+#undef ARRAY_3
+#undef ARRAY_2
+
+#undef TEST
+}
+
+int main(int argc, char **argv)
+{
+  plan(68);
+  test_byte_order();
+  return exit_status();
+}