Update code related to OOM errors in sanitizer builds.

Remove outdated comment and enable OOM tests under sanitizers. Also, document
the fact that the newly introduced UncheckedMalloc()/UncheckedCalloc() don't
work as intended in sanitizer builds.

BUG=357732
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/217343002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260379 0039d316-1c4b-4281-b951-d872f2087c98

base/process/memory.h

@@ -67,6 +67,8 @@ BASE_EXPORT bool AdjustOOMScore(ProcessId process, int score);
 // This can be useful for huge and/or unpredictable size memory allocations.
 // Please only use this if you really handle the case when the allocation
 // fails. Doing otherwise would risk security.
+// These functions may still crash on OOM when running under memory tools,
+// specifically ASan and other sanitizers.
 // Return value tells whether the allocation succeeded. If it fails |result| is
 // set to NULL, otherwise it holds the memory address.
 BASE_EXPORT WARN_UNUSED_RESULT bool UncheckedMalloc(size_t size,

base/process/memory_linux.cc

@@ -199,8 +199,7 @@ bool AdjustOOMScore(ProcessId process, int score) {
 }
 
 bool UncheckedMalloc(size_t size, void** result) {
-#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
-    defined(THREAD_SANITIZER) || defined(LEAK_SANITIZER) || \
+#if defined(MEMORY_TOOL_REPLACES_ALLOCATOR) || \
     (!defined(LIBC_GLIBC) && !defined(USE_TCMALLOC))
   *result = malloc(size);
 #elif defined(LIBC_GLIBC) && !defined(USE_TCMALLOC)

base/process/memory_unittest.cc

@@ -152,13 +152,9 @@ TEST(ProcessMemoryTest, MacTerminateOnHeapCorruption) {
 // Android doesn't implement set_new_handler, so we can't use the
 // OutOfMemoryTest cases.
 // OpenBSD does not support these tests either.
-// AddressSanitizer and ThreadSanitizer define the malloc()/free()/etc.
-// functions so that they don't crash if the program is out of memory, so the
-// OOM tests aren't supposed to work.
 // TODO(vandebo) make this work on Windows too.
 #if !defined(OS_ANDROID) && !defined(OS_OPENBSD) && \
-    !defined(OS_WIN) && \
-    !defined(ADDRESS_SANITIZER) && !defined(THREAD_SANITIZER)
+    !defined(OS_WIN)
 
 #if defined(USE_TCMALLOC)
 extern "C" {
@@ -397,7 +393,9 @@ class OutOfMemoryHandledTest : public OutOfMemoryTest {
 
 // TODO(b.kelemen): make UncheckedMalloc and UncheckedCalloc work
 // on Windows as well.
-
+// UncheckedMalloc() and UncheckedCalloc() work as regular malloc()/calloc()
+// under sanitizer tools.
+#if !defined(MEMORY_TOOL_REPLACES_ALLOCATOR)
 TEST_F(OutOfMemoryHandledTest, UncheckedMalloc) {
   EXPECT_TRUE(base::UncheckedMalloc(kSafeMallocSize, &value_));
   EXPECT_TRUE(value_ != NULL);
@@ -426,6 +424,5 @@ TEST_F(OutOfMemoryHandledTest, UncheckedCalloc) {
   EXPECT_FALSE(base::UncheckedCalloc(1, test_size_, &value_));
   EXPECT_TRUE(value_ == NULL);
 }
-
-#endif  // !defined(OS_ANDROID) && !defined(OS_OPENBSD) &&
-        // !defined(OS_WIN) && !defined(ADDRESS_SANITIZER)
+#endif  // !defined(MEMORY_TOOL_REPLACES_ALLOCATOR)
+#endif  // !defined(OS_ANDROID) && !defined(OS_OPENBSD) && !defined(OS_WIN)