From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dmitry Muhomor <muhomor.dmitry@gmail.com>
Date: Sun, 14 Aug 2022 15:13:01 +0300
Subject: [PATCH] add a runtime option to disable hardened_malloc

---
 libc/bionic/malloc_common.cpp         | 50 +++++++++++++++++++++++++++
 libc/bionic/malloc_common.h           |  1 +
 libc/bionic/malloc_common_dynamic.cpp |  4 +++
 3 files changed, 55 insertions(+)

diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 3c4884b2c..86e6fdcf9 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -393,6 +393,56 @@ static constexpr MallocDispatch __libc_malloc_default_dispatch __attribute__((un
   Malloc(malloc_info),
 };
 
+#if defined(BOTH_H_MALLOC_AND_SCUDO)
+
+#define ScudoMalloc(function)  scudo_ ## function
+
+static constexpr MallocDispatch __scudo_malloc_dispatch __attribute__((unused)) = {
+  ScudoMalloc(calloc),
+  ScudoMalloc(free),
+  ScudoMalloc(mallinfo),
+  ScudoMalloc(malloc),
+  ScudoMalloc(malloc_usable_size),
+  ScudoMalloc(memalign),
+  ScudoMalloc(posix_memalign),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  ScudoMalloc(pvalloc),
+#endif
+  ScudoMalloc(realloc),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  ScudoMalloc(valloc),
+#endif
+  ScudoMalloc(malloc_iterate),
+  ScudoMalloc(malloc_disable),
+  ScudoMalloc(malloc_enable),
+  ScudoMalloc(mallopt),
+  ScudoMalloc(aligned_alloc),
+  ScudoMalloc(malloc_info),
+};
+
+static const MallocDispatch* native_allocator_dispatch;
+
+void InitNativeAllocatorDispatch(libc_globals* globals) {
+  const bool hardened_impl = getenv("DISABLE_HARDENED_MALLOC") == nullptr;
+
+  const MallocDispatch* table = hardened_impl ?
+    &__libc_malloc_default_dispatch :
+    &__scudo_malloc_dispatch;
+
+  if (!hardened_impl) {
+    globals->malloc_dispatch_table = __scudo_malloc_dispatch;
+    globals->current_dispatch_table = &globals->malloc_dispatch_table;
+    globals->default_dispatch_table = &globals->malloc_dispatch_table;
+  }
+
+  native_allocator_dispatch = table;
+}
+
+const MallocDispatch* NativeAllocatorDispatch() {
+  return native_allocator_dispatch;
+}
+#else
 const MallocDispatch* NativeAllocatorDispatch() {
   return &__libc_malloc_default_dispatch;
 }
+#endif
diff --git a/libc/bionic/malloc_common.h b/libc/bionic/malloc_common.h
index 8852c85a2..ef4b1a4be 100644
--- a/libc/bionic/malloc_common.h
+++ b/libc/bionic/malloc_common.h
@@ -68,6 +68,7 @@ __END_DECLS
 
 #if defined(USE_SCUDO)
 #include "scudo.h"
+void InitNativeAllocatorDispatch(libc_globals* globals);
 #endif
 
 #define BOTH_H_MALLOC_AND_SCUDO
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index a6bf7a7bb..2cafe9249 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -376,6 +376,10 @@ extern "C" size_t __scudo_get_stack_depot_size();
 
 // Initializes memory allocation framework once per process.
 static void MallocInitImpl(libc_globals* globals) {
+#if defined(BOTH_H_MALLOC_AND_SCUDO)
+  InitNativeAllocatorDispatch(globals);
+#endif
+
   char prop[PROP_VALUE_MAX];
   char* options = prop;