Add support for UBsan builds to RocksDB

Summary:
Undefined Behavior Sanitizer (ubsan) is //a good thing// which will help us to find sneaky bugs with low cost. Please see http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ for more details and official GCC documentation for more context: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html.

Changes itself are quite simple and pretty much imitating whatever is implemented for ASan.

Hooking the UBsan validation build to Sandcastle is a separate step and will be dealt as separate diff because code is in internal repository.

Test Plan: Make sure that that there no regressions when it comes to builds and test pass rate.

Reviewers: leveldb, sdong, IslamAbdelRahman, yhchiang

Reviewed By: yhchiang

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56049

Makefile

@@ -174,6 +174,15 @@ else
 	pg = -pg
 endif
 
+# USAN doesn't work well with jemalloc. If we're compiling with USAN, we should use regular malloc.
+ifdef COMPILE_WITH_UBSAN
+	DISABLE_JEMALLOC=1
+	EXEC_LDFLAGS += -fsanitize=undefined
+	PLATFORM_CCFLAGS += -fsanitize=undefined
+	PLATFORM_CXXFLAGS += -fsanitize=undefined
+endif
+
+
 ifndef DISABLE_JEMALLOC
 	EXEC_LDFLAGS := $(JEMALLOC_LIB) $(EXEC_LDFLAGS)
 	PLATFORM_CXXFLAGS += $(JEMALLOC_INCLUDE)
@@ -617,6 +626,16 @@ asan_crash_test:
 	COMPILE_WITH_ASAN=1 $(MAKE) crash_test
 	$(MAKE) clean
 
+ubsan_check:
+	$(MAKE) clean
+	COMPILE_WITH_UBSAN=1 $(MAKE) check -j32
+	$(MAKE) clean
+
+ubsan_crash_test:
+	$(MAKE) clean
+	COMPILE_WITH_UBSAN=1 $(MAKE) crash_test
+	$(MAKE) clean
+
 valgrind_check: $(TESTS)
 	for t in $(filter-out %skiplist_test,$(TESTS)); do \
 		$(VALGRIND_VER) $(VALGRIND_OPTS) ./$$t; \
@@ -1221,7 +1240,7 @@ jdb_bench:
 
 commit_prereq: build_tools/rocksdb-lego-determinator \
                build_tools/precommit_checker.py
-	J=$(J) build_tools/precommit_checker.py unit unit_481 clang_unit tsan asan lite
+	J=$(J) build_tools/precommit_checker.py unit unit_481 clang_unit tsan asan ubsan lite
 	$(MAKE) clean && $(MAKE) jclean && $(MAKE) rocksdbjava;
 
 xfunc:

build_tools/precommit_checker.py

@@ -184,7 +184,7 @@ parser = argparse.ArgumentParser(description='RocksDB pre-commit checker.')
 
 # <test ....>
 parser.add_argument('test', nargs='+',
-                    help='CI test(s) to run. e.g: unit punit asan tsan')
+                    help='CI test(s) to run. e.g: unit punit asan tsan ubsan')
 
 print("Please follow log %s" % Log.LOG_FILE)
 

build_tools/rocksdb-lego-determinator

@@ -67,6 +67,7 @@ ASAN="COMPILE_WITH_ASAN=1"
 CLANG="USE_CLANG=1"
 LITE="OPT=-DROCKSDB_LITE"
 TSAN="COMPILE_WITH_TSAN=1"
+UBSAN="COMPILE_WITH_UBSAN=1"
 DISABLE_JEMALLOC="DISABLE_JEMALLOC=1"
 PARSER="'parser':'egrep \'Failure|^#|Abort|Expected|Actual|GoogleTestFailure|^==\''"
 
@@ -376,6 +377,48 @@ ASAN_CRASH_TEST_COMMANDS="[
     }
 ]"
 
+#
+# RocksDB test under undefined behavior sanitizer
+#
+UBSAN_TEST_COMMANDS="[
+    {
+        'name':'Rocksdb Unit Test under UBSAN',
+        'oncall':'$ONCALL',
+        'steps': [
+            $CLEANUP_ENV,
+            {
+                'name':'Test RocksDB debug under UBSAN',
+                'shell':'set -o pipefail && $SHM $UBSAN $DEBUG make J=1 ubsan_check',
+                'user':'root',
+                $PARSER
+            }
+        ],
+        $REPORT
+    }
+]"
+
+#
+# RocksDB crash testing under udnefined behavior sanitizer
+#
+UBSAN_CRASH_TEST_COMMANDS="[
+    {
+        'name':'Rocksdb crash test under UBSAN',
+        'oncall':'$ONCALL',
+        'timeout': 86400,
+        'steps': [
+            $CLEANUP_ENV,
+            {
+                'name':'Build and run RocksDB debug ubsan_crash_test',
+                'timeout': 86400,
+                'shell':'$SHM $DEBUG make J=1 ubsan_crash_test',
+                'user':'root',
+                $PARSER
+            },
+        ],
+        $REPORT
+    }
+]"
+
 #
 # RocksDB unit test under valgrind
 #
@@ -632,6 +675,12 @@ case $1 in
   asan_crash)
     echo $ASAN_CRASH_TEST_COMMANDS
     ;;
+  ubsan)
+    echo $UBSAN_TEST_COMMANDS
+    ;;
+  ubsan_crash)
+    echo $UBSAN_CRASH_TEST_COMMANDS
+    ;;
   valgrind)
     echo $VALGRIND_TEST_COMMANDS
     ;;

tools/sst_dump_tool.cc

@@ -59,7 +59,10 @@ extern const uint64_t kLegacyPlainTableMagicNumber;
 const char* testFileName = "test_file_name";
 
 Status SstFileReader::GetTableReader(const std::string& file_path) {
-  uint64_t magic_number;
+  // Warning about 'magic_number' being uninitialized shows up only in UBsan
+  // builds. Though access is guarded by 's.ok()' checks, fix the issue to
+  // avoid any warnings.
+  uint64_t magic_number = Footer::kInvalidTableMagicNumber;
 
   // read table magic number
   Footer footer;