Add support for new scudo mallopt options.

Bug: 162092537

Test: Ran new unit tests.
Change-Id: I4b7d17a9e98166c03cd153eb9e9d847693914ea3
Merged-In: I4b7d17a9e98166c03cd153eb9e9d847693914ea3
(cherry picked from commit 8844879212852a70918df1c9ebcac4d574f1fcd9)

2 files changed, 62 insertions, 0 deletions

diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index ba0af3ca3..833fa59b5 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -170,6 +170,28 @@ int malloc_info(int __must_be_zero, FILE* __fp) __INTRODUCED_IN(23);
  * Available since API level 28.
  */
 #define M_PURGE (-101)
+/**
+ * mallopt() option to set the maximum number of items in the secondary
+ * cache of the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_CACHE_COUNT_MAX (-200)
+/**
+ * mallopt() option to set the maximum size in bytes of a cacheable item in
+ * the secondary cache of the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_CACHE_SIZE_MAX (-201)
+/**
+ * mallopt() option to increase the maximum number of shared thread-specific
+ * data structures that can be created. This number cannot be decreased,
+ * only increased and only applies to the scudo allocator.
+ *
+ * Available since API level 31.
+ */
+#define M_TSDS_COUNT_MAX (-202)
 
 /**
  * [mallopt(3)](http://man7.org/linux/man-pages/man3/mallopt.3.html) modifies
diff --git a/tests/malloc_test.cpp b/tests/malloc_test.cpp
index 594441487..bd0daddbd 100644
--- a/tests/malloc_test.cpp
+++ b/tests/malloc_test.cpp
@@ -662,6 +662,46 @@ TEST(malloc, mallopt_purge) {
 #endif
 }
 
+#if defined(__BIONIC__)
+static void GetAllocatorVersion(bool* allocator_scudo) {
+  TemporaryFile tf;
+  ASSERT_TRUE(tf.fd != -1);
+  FILE* fp = fdopen(tf.fd, "w+");
+  tf.release();
+  ASSERT_TRUE(fp != nullptr);
+  ASSERT_EQ(0, malloc_info(0, fp));
+  ASSERT_EQ(0, fclose(fp));
+
+  std::string contents;
+  ASSERT_TRUE(android::base::ReadFileToString(tf.path, &contents));
+
+  tinyxml2::XMLDocument doc;
+  ASSERT_EQ(tinyxml2::XML_SUCCESS, doc.Parse(contents.c_str()));
+
+  auto root = doc.FirstChildElement();
+  ASSERT_NE(nullptr, root);
+  ASSERT_STREQ("malloc", root->Name());
+  std::string version(root->Attribute("version"));
+  *allocator_scudo = (version == "scudo-1");
+}
+#endif
+
+TEST(malloc, mallopt_scudo_only_options) {
+#if defined(__BIONIC__)
+  SKIP_WITH_HWASAN << "hwasan does not implement mallopt";
+  bool allocator_scudo;
+  GetAllocatorVersion(&allocator_scudo);
+  if (!allocator_scudo) {
+    GTEST_SKIP() << "scudo allocator only test";
+  }
+  ASSERT_EQ(1, mallopt(M_CACHE_COUNT_MAX, 100));
+  ASSERT_EQ(1, mallopt(M_CACHE_SIZE_MAX, 1024 * 1024 * 2));
+  ASSERT_EQ(1, mallopt(M_TSDS_COUNT_MAX, 8));
+#else
+  GTEST_SKIP() << "bionic-only test";
+#endif
+}
+
 TEST(malloc, reallocarray_overflow) {
 #if HAVE_REALLOCARRAY
   // Values that cause overflow to a result small enough (8 on LP64) that malloc would "succeed".