1 files changed, 420 insertions, 0 deletions
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
new file mode 100644
index 000000000..1c3f53fd6
--- /dev/null
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -0,0 +1,420 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_STATIC)
+#error This file should not be compiled for static targets.
+#endif
+
+// Contains a thin layer that calls whatever real native allocator
+// has been defined. For the libc shared library, this allows the
+// implementation of a debug malloc that can intercept all of the allocation
+// calls and add special debugging code to attempt to catch allocation
+// errors. All of the debugging code is implemented in a separate shared
+// library that is only loaded when the property "libc.debug.malloc.options"
+// is set to a non-zero value. There are three functions exported to
+// allow ddms, or other external users to get information from the debug
+// allocation.
+//   get_malloc_leak_info: Returns information about all of the known native
+//                         allocations that are currently in use.
+//   free_malloc_leak_info: Frees the data allocated by the call to
+//                          get_malloc_leak_info.
+//   write_malloc_leak_info: Writes the leak info data to a file.
+
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <private/bionic_config.h>
+#include <private/bionic_defs.h>
+#include <private/bionic_malloc_dispatch.h>
+
+#include <sys/system_properties.h>
+
+#include "malloc_common.h"
+#include "malloc_common_dynamic.h"
+#include "malloc_heapprofd.h"
+
+static constexpr MallocDispatch __libc_malloc_default_dispatch
+  __attribute__((unused)) = {
+    Malloc(calloc),
+    Malloc(free),
+    Malloc(mallinfo),
+    Malloc(malloc),
+    Malloc(malloc_usable_size),
+    Malloc(memalign),
+    Malloc(posix_memalign),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+    Malloc(pvalloc),
+#endif
+    Malloc(realloc),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+    Malloc(valloc),
+#endif
+    Malloc(iterate),
+    Malloc(malloc_disable),
+    Malloc(malloc_enable),
+    Malloc(mallopt),
+    Malloc(aligned_alloc),
+  };
+
+static constexpr char kHooksSharedLib[] = "libc_malloc_hooks.so";
+static constexpr char kHooksPrefix[] = "hooks";
+static constexpr char kHooksPropertyEnable[] = "libc.debug.hooks.enable";
+static constexpr char kHooksEnvEnable[] = "LIBC_HOOKS_ENABLE";
+
+static constexpr char kDebugSharedLib[] = "libc_malloc_debug.so";
+static constexpr char kDebugPrefix[] = "debug";
+static constexpr char kDebugPropertyOptions[] = "libc.debug.malloc.options";
+static constexpr char kDebugPropertyProgram[] = "libc.debug.malloc.program";
+static constexpr char kDebugEnvOptions[] = "LIBC_DEBUG_MALLOC_OPTIONS";
+
+typedef void (*finalize_func_t)();
+typedef bool (*init_func_t)(const MallocDispatch*, int*, const char*);
+typedef void (*get_malloc_leak_info_func_t)(uint8_t**, size_t*, size_t*, size_t*, size_t*);
+typedef void (*free_malloc_leak_info_func_t)(uint8_t*);
+typedef bool (*write_malloc_leak_info_func_t)(FILE*);
+typedef ssize_t (*malloc_backtrace_func_t)(void*, uintptr_t*, size_t);
+
+enum FunctionEnum : uint8_t {
+  FUNC_INITIALIZE,
+  FUNC_FINALIZE,
+  FUNC_GET_MALLOC_LEAK_INFO,
+  FUNC_FREE_MALLOC_LEAK_INFO,
+  FUNC_MALLOC_BACKTRACE,
+  FUNC_WRITE_LEAK_INFO,
+  FUNC_LAST,
+};
+static void* gFunctions[FUNC_LAST];
+
+extern "C" int __cxa_atexit(void (*func)(void *), void *arg, void *dso);
+
+template<typename FunctionType>
+static bool InitMallocFunction(void* malloc_impl_handler, FunctionType* func, const char* prefix, const char* suffix) {
+  char symbol[128];
+  snprintf(symbol, sizeof(symbol), "%s_%s", prefix, suffix);
+  *func = reinterpret_cast<FunctionType>(dlsym(malloc_impl_handler, symbol));
+  if (*func == nullptr) {
+    error_log("%s: dlsym(\"%s\") failed", getprogname(), symbol);
+    return false;
+  }
+  return true;
+}
+
+static bool InitMallocFunctions(void* impl_handler, MallocDispatch* table, const char* prefix) {
+  if (!InitMallocFunction<MallocFree>(impl_handler, &table->free, prefix, "free")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocCalloc>(impl_handler, &table->calloc, prefix, "calloc")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMallinfo>(impl_handler, &table->mallinfo, prefix, "mallinfo")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMallopt>(impl_handler, &table->mallopt, prefix, "mallopt")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMalloc>(impl_handler, &table->malloc, prefix, "malloc")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMallocUsableSize>(impl_handler, &table->malloc_usable_size, prefix,
+                                                  "malloc_usable_size")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMemalign>(impl_handler, &table->memalign, prefix, "memalign")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocPosixMemalign>(impl_handler, &table->posix_memalign, prefix,
+                                               "posix_memalign")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocAlignedAlloc>(impl_handler, &table->aligned_alloc,
+                                              prefix, "aligned_alloc")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocRealloc>(impl_handler, &table->realloc, prefix, "realloc")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocIterate>(impl_handler, &table->iterate, prefix, "iterate")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMallocDisable>(impl_handler, &table->malloc_disable, prefix,
+                                               "malloc_disable")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocMallocEnable>(impl_handler, &table->malloc_enable, prefix,
+                                              "malloc_enable")) {
+    return false;
+  }
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  if (!InitMallocFunction<MallocPvalloc>(impl_handler, &table->pvalloc, prefix, "pvalloc")) {
+    return false;
+  }
+  if (!InitMallocFunction<MallocValloc>(impl_handler, &table->valloc, prefix, "valloc")) {
+    return false;
+  }
+#endif
+
+  return true;
+}
+
+static void MallocFiniImpl(void*) {
+  // Our BSD stdio implementation doesn't close the standard streams,
+  // it only flushes them. Other unclosed FILE*s will show up as
+  // malloc leaks, but to avoid the standard streams showing up in
+  // leak reports, close them here.
+  fclose(stdin);
+  fclose(stdout);
+  fclose(stderr);
+
+  reinterpret_cast<finalize_func_t>(gFunctions[FUNC_FINALIZE])();
+}
+
+static bool CheckLoadMallocHooks(char** options) {
+  char* env = getenv(kHooksEnvEnable);
+  if ((env == nullptr || env[0] == '\0' || env[0] == '0') &&
+    (__system_property_get(kHooksPropertyEnable, *options) == 0 || *options[0] == '\0' || *options[0] == '0')) {
+    return false;
+  }
+  *options = nullptr;
+  return true;
+}
+
+static bool CheckLoadMallocDebug(char** options) {
+  // If kDebugMallocEnvOptions is set then it overrides the system properties.
+  char* env = getenv(kDebugEnvOptions);
+  if (env == nullptr || env[0] == '\0') {
+    if (__system_property_get(kDebugPropertyOptions, *options) == 0 || *options[0] == '\0') {
+      return false;
+    }
+
+    // Check to see if only a specific program should have debug malloc enabled.
+    char program[PROP_VALUE_MAX];
+    if (__system_property_get(kDebugPropertyProgram, program) != 0 &&
+        strstr(getprogname(), program) == nullptr) {
+      return false;
+    }
+  } else {
+    *options = env;
+  }
+  return true;
+}
+
+static void ClearGlobalFunctions() {
+  for (size_t i = 0; i < FUNC_LAST; i++) {
+    gFunctions[i] = nullptr;
+  }
+}
+
+bool InitSharedLibrary(void* impl_handle, const char* shared_lib, const char* prefix, MallocDispatch* dispatch_table) {
+  static constexpr const char* names[] = {
+    "initialize",
+    "finalize",
+    "get_malloc_leak_info",
+    "free_malloc_leak_info",
+    "malloc_backtrace",
+    "write_malloc_leak_info",
+  };
+  for (size_t i = 0; i < FUNC_LAST; i++) {
+    char symbol[128];
+    snprintf(symbol, sizeof(symbol), "%s_%s", prefix, names[i]);
+    gFunctions[i] = dlsym(impl_handle, symbol);
+    if (gFunctions[i] == nullptr) {
+      error_log("%s: %s routine not found in %s", getprogname(), symbol, shared_lib);
+      ClearGlobalFunctions();
+      return false;
+    }
+  }
+
+  if (!InitMallocFunctions(impl_handle, dispatch_table, prefix)) {
+    ClearGlobalFunctions();
+    return false;
+  }
+  return true;
+}
+
+void* LoadSharedLibrary(const char* shared_lib, const char* prefix, MallocDispatch* dispatch_table) {
+  void* impl_handle = dlopen(shared_lib, RTLD_NOW | RTLD_LOCAL);
+  if (impl_handle == nullptr) {
+    error_log("%s: Unable to open shared library %s: %s", getprogname(), shared_lib, dlerror());
+    return nullptr;
+  }
+
+  if (!InitSharedLibrary(impl_handle, shared_lib, prefix, dispatch_table)) {
+    dlclose(impl_handle);
+    impl_handle = nullptr;
+  }
+
+  return impl_handle;
+}
+
+bool FinishInstallHooks(libc_globals* globals, const char* options, const char* prefix) {
+  init_func_t init_func = reinterpret_cast<init_func_t>(gFunctions[FUNC_INITIALIZE]);
+  if (!init_func(&__libc_malloc_default_dispatch, &gMallocLeakZygoteChild, options)) {
+    error_log("%s: failed to enable malloc %s", getprogname(), prefix);
+    ClearGlobalFunctions();
+    return false;
+  }
+
+  // Do a pointer swap so that all of the functions become valid at once to
+  // avoid any initialization order problems.
+  atomic_store(&globals->current_dispatch_table, &globals->malloc_dispatch_table);
+
+  info_log("%s: malloc %s enabled", getprogname(), prefix);
+
+  // Use atexit to trigger the cleanup function. This avoids a problem
+  // where another atexit function is used to cleanup allocated memory,
+  // but the finalize function was already called. This particular error
+  // seems to be triggered by a zygote spawned process calling exit.
+  int ret_value = __cxa_atexit(MallocFiniImpl, nullptr, nullptr);
+  if (ret_value != 0) {
+    // We don't consider this a fatal error.
+    info_log("failed to set atexit cleanup function: %d", ret_value);
+  }
+  return true;
+}
+
+static void InstallHooks(libc_globals* globals, const char* options, const char* prefix,
+                         const char* shared_lib) {
+  void* impl_handle = LoadSharedLibrary(shared_lib, prefix, &globals->malloc_dispatch_table);
+  if (impl_handle == nullptr) {
+    return;
+  }
+
+  init_func_t init_func = reinterpret_cast<init_func_t>(gFunctions[FUNC_INITIALIZE]);
+  if (!init_func(&__libc_malloc_default_dispatch, &gMallocLeakZygoteChild, options)) {
+    error_log("%s: failed to enable malloc %s", getprogname(), prefix);
+    ClearGlobalFunctions();
+    return;
+  }
+
+  if (!FinishInstallHooks(globals, options, prefix)) {
+    dlclose(impl_handle);
+  }
+}
+
+// Initializes memory allocation framework once per process.
+static void MallocInitImpl(libc_globals* globals) {
+  char prop[PROP_VALUE_MAX];
+  char* options = prop;
+
+  // Prefer malloc debug since it existed first and is a more complete
+  // malloc interceptor than the hooks.
+  if (CheckLoadMallocDebug(&options)) {
+    InstallHooks(globals, options, kDebugPrefix, kDebugSharedLib);
+  } else if (CheckLoadMallocHooks(&options)) {
+    InstallHooks(globals, options, kHooksPrefix, kHooksSharedLib);
+  } else if (HeapprofdShouldLoad()) {
+    HeapprofdInstallHooksAtInit(globals);
+  }
+
+  // Install this last to avoid as many race conditions as possible.
+  HeapprofdInstallSignalHandler();
+}
+
+// Initializes memory allocation framework.
+// This routine is called from __libc_init routines in libc_init_dynamic.cpp.
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
+__LIBC_HIDDEN__ void __libc_init_malloc(libc_globals* globals) {
+  MallocInitImpl(globals);
+}
+
+// =============================================================================
+// Functions to support dumping of native heap allocations using malloc debug.
+// =============================================================================
+
+// Retrieve native heap information.
+//
+// "*info" is set to a buffer we allocate
+// "*overall_size" is set to the size of the "info" buffer
+// "*info_size" is set to the size of a single entry
+// "*total_memory" is set to the sum of all allocations we're tracking; does
+//   not include heap overhead
+// "*backtrace_size" is set to the maximum number of entries in the back trace
+extern "C" void get_malloc_leak_info(uint8_t** info, size_t* overall_size,
+    size_t* info_size, size_t* total_memory, size_t* backtrace_size) {
+  void* func = gFunctions[FUNC_GET_MALLOC_LEAK_INFO];
+  if (func == nullptr) {
+    return;
+  }
+  reinterpret_cast<get_malloc_leak_info_func_t>(func)(info, overall_size, info_size, total_memory,
+                                                      backtrace_size);
+}
+
+extern "C" void free_malloc_leak_info(uint8_t* info) {
+  void* func = gFunctions[FUNC_FREE_MALLOC_LEAK_INFO];
+  if (func == nullptr) {
+    return;
+  }
+  reinterpret_cast<free_malloc_leak_info_func_t>(func)(info);
+}
+
+extern "C" void write_malloc_leak_info(FILE* fp) {
+  if (fp == nullptr) {
+    error_log("write_malloc_leak_info called with a nullptr");
+    return;
+  }
+
+  void* func = gFunctions[FUNC_WRITE_LEAK_INFO];
+  bool written = false;
+  if (func != nullptr) {
+    written = reinterpret_cast<write_malloc_leak_info_func_t>(func)(fp);
+  }
+
+  if (!written) {
+    fprintf(fp, "Native heap dump not available. To enable, run these commands (requires root):\n");
+    fprintf(fp, "# adb shell stop\n");
+    fprintf(fp, "# adb shell setprop libc.debug.malloc.options backtrace\n");
+    fprintf(fp, "# adb shell start\n");
+  }
+}
+// =============================================================================
+
+// =============================================================================
+// Exported for use by libmemunreachable.
+// =============================================================================
+extern "C" ssize_t malloc_backtrace(void* pointer, uintptr_t* frames, size_t frame_count) {
+  void* func = gFunctions[FUNC_MALLOC_BACKTRACE];
+  if (func == nullptr) {
+    return 0;
+  }
+  return reinterpret_cast<malloc_backtrace_func_t>(func)(pointer, frames, frame_count);
+}
+// =============================================================================
+
+// =============================================================================
+// Platform-internal mallopt variant.
+// =============================================================================
+extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size) {
+  return HeapprofdMallopt(opcode, arg, arg_size);
+}
+// =============================================================================