Implement malloc hooks.
Use the malloc debug framework to implement the malloc debug hooks
since it can introduce a performance issue.
Also, modify the bionic/tests/utils.h slightly to dump an error message
when the exe failed.
Bug: 30561479
Test: Ran malloc hook unit tests.
Test: Ran malloc debug unit tests.
Test: Enabled malloc hooks and ran bionic unit tests and verified no
Test: unexpected failures.
Test: Enabled malloc debug and malloc hooks and verified malloc debug wins.
Test: Enabled malloc debug using env, property, and property with name
Test: still works.
Change-Id: Ib50046a0493c5c2050cf831befb812310bdcc249
(cherry picked from commit d6a1dc23796696f73f483943534d4c5c4b312d39)
diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 940c418..1ea4ac1 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -72,6 +72,12 @@
Malloc(aligned_alloc),
};
+// Malloc hooks.
+void* (*volatile __malloc_hook)(size_t, const void*);
+void* (*volatile __realloc_hook)(void*, size_t, const void*);
+void (*volatile __free_hook)(void*, const void*);
+void* (*volatile __memalign_hook)(size_t, size_t, const void*);
+
// In a VM process, this is set to 1 after fork()ing out of zygote.
int gMallocLeakZygoteChild = 0;
@@ -190,17 +196,30 @@
extern "C" int __cxa_atexit(void (*func)(void *), void *arg, void *dso);
+static const char* HOOKS_SHARED_LIB = "libc_malloc_hooks.so";
+static const char* HOOKS_PROPERTY_ENABLE = "libc.debug.hooks.enable";
+static const char* HOOKS_ENV_ENABLE = "LIBC_HOOKS_ENABLE";
+
static const char* DEBUG_SHARED_LIB = "libc_malloc_debug.so";
-static const char* DEBUG_MALLOC_PROPERTY_OPTIONS = "libc.debug.malloc.options";
-static const char* DEBUG_MALLOC_PROPERTY_PROGRAM = "libc.debug.malloc.program";
-static const char* DEBUG_MALLOC_ENV_OPTIONS = "LIBC_DEBUG_MALLOC_OPTIONS";
+static const char* DEBUG_PROPERTY_OPTIONS = "libc.debug.malloc.options";
+static const char* DEBUG_PROPERTY_PROGRAM = "libc.debug.malloc.program";
+static const char* DEBUG_ENV_OPTIONS = "LIBC_DEBUG_MALLOC_OPTIONS";
-static void* libc_malloc_impl_handle = nullptr;
+enum FunctionEnum : uint8_t {
+ FUNC_INITIALIZE,
+ FUNC_FINALIZE,
+ FUNC_GET_MALLOC_LEAK_INFO,
+ FUNC_FREE_MALLOC_LEAK_INFO,
+ FUNC_MALLOC_BACKTRACE,
+ FUNC_LAST,
+};
+static void* g_functions[FUNC_LAST];
-static void (*g_debug_finalize_func)();
-static void (*g_debug_get_malloc_leak_info_func)(uint8_t**, size_t*, size_t*, size_t*, size_t*);
-static void (*g_debug_free_malloc_leak_info_func)(uint8_t*);
-static ssize_t (*g_debug_malloc_backtrace_func)(void*, uintptr_t*, size_t);
+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 ssize_t (*malloc_backtrace_func_t)(void*, uintptr_t*, size_t);
// =============================================================================
// Log functions
@@ -225,17 +244,20 @@
// "*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) {
- if (g_debug_get_malloc_leak_info_func == nullptr) {
+ void* func = g_functions[FUNC_GET_MALLOC_LEAK_INFO];
+ if (func == nullptr) {
return;
}
- g_debug_get_malloc_leak_info_func(info, overall_size, info_size, total_memory, backtrace_size);
+ 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) {
- if (g_debug_free_malloc_leak_info_func == nullptr) {
+ void* func = g_functions[FUNC_FREE_MALLOC_LEAK_INFO];
+ if (func == nullptr) {
return;
}
- g_debug_free_malloc_leak_info_func(info);
+ reinterpret_cast<free_malloc_leak_info_func_t>(func)(info);
}
// =============================================================================
@@ -252,66 +274,56 @@
return true;
}
-static bool InitMalloc(void* malloc_impl_handler, MallocDispatch* table, const char* prefix) {
- if (!InitMallocFunction<MallocCalloc>(malloc_impl_handler, &table->calloc,
- prefix, "calloc")) {
+static bool InitMallocFunctions(void* impl_handler, MallocDispatch* table, const char* prefix) {
+ if (!InitMallocFunction<MallocCalloc>(impl_handler, &table->calloc, prefix, "calloc")) {
return false;
}
- if (!InitMallocFunction<MallocFree>(malloc_impl_handler, &table->free,
- prefix, "free")) {
+ if (!InitMallocFunction<MallocFree>(impl_handler, &table->free, prefix, "free")) {
return false;
}
- if (!InitMallocFunction<MallocMallinfo>(malloc_impl_handler, &table->mallinfo,
- prefix, "mallinfo")) {
+ if (!InitMallocFunction<MallocMallinfo>(impl_handler, &table->mallinfo, prefix, "mallinfo")) {
return false;
}
- if (!InitMallocFunction<MallocMallopt>(malloc_impl_handler, &table->mallopt,
- prefix, "mallopt")) {
+ if (!InitMallocFunction<MallocMallopt>(impl_handler, &table->mallopt, prefix, "mallopt")) {
return false;
}
- if (!InitMallocFunction<MallocMalloc>(malloc_impl_handler, &table->malloc,
- prefix, "malloc")) {
+ if (!InitMallocFunction<MallocMalloc>(impl_handler, &table->malloc, prefix, "malloc")) {
return false;
}
- if (!InitMallocFunction<MallocMallocUsableSize>(
- malloc_impl_handler, &table->malloc_usable_size, prefix, "malloc_usable_size")) {
+ if (!InitMallocFunction<MallocMallocUsableSize>(impl_handler, &table->malloc_usable_size, prefix,
+ "malloc_usable_size")) {
return false;
}
- if (!InitMallocFunction<MallocMemalign>(malloc_impl_handler, &table->memalign,
- prefix, "memalign")) {
+ if (!InitMallocFunction<MallocMemalign>(impl_handler, &table->memalign, prefix, "memalign")) {
return false;
}
- if (!InitMallocFunction<MallocPosixMemalign>(malloc_impl_handler, &table->posix_memalign,
- prefix, "posix_memalign")) {
+ if (!InitMallocFunction<MallocPosixMemalign>(impl_handler, &table->posix_memalign, prefix,
+ "posix_memalign")) {
return false;
}
- if (!InitMallocFunction<MallocAlignedAlloc>(malloc_impl_handler, &table->aligned_alloc,
+ if (!InitMallocFunction<MallocAlignedAlloc>(impl_handler, &table->aligned_alloc,
prefix, "aligned_alloc")) {
return false;
}
- if (!InitMallocFunction<MallocRealloc>(malloc_impl_handler, &table->realloc,
- prefix, "realloc")) {
+ if (!InitMallocFunction<MallocRealloc>(impl_handler, &table->realloc, prefix, "realloc")) {
return false;
}
- if (!InitMallocFunction<MallocIterate>(malloc_impl_handler, &table->iterate,
- prefix, "iterate")) {
+ if (!InitMallocFunction<MallocIterate>(impl_handler, &table->iterate, prefix, "iterate")) {
return false;
}
- if (!InitMallocFunction<MallocMallocDisable>(malloc_impl_handler, &table->malloc_disable,
- prefix, "malloc_disable")) {
+ if (!InitMallocFunction<MallocMallocDisable>(impl_handler, &table->malloc_disable, prefix,
+ "malloc_disable")) {
return false;
}
- if (!InitMallocFunction<MallocMallocEnable>(malloc_impl_handler, &table->malloc_enable,
- prefix, "malloc_enable")) {
+ if (!InitMallocFunction<MallocMallocEnable>(impl_handler, &table->malloc_enable, prefix,
+ "malloc_enable")) {
return false;
}
#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
- if (!InitMallocFunction<MallocPvalloc>(malloc_impl_handler, &table->pvalloc,
- prefix, "pvalloc")) {
+ if (!InitMallocFunction<MallocPvalloc>(impl_handler, &table->pvalloc, prefix, "pvalloc")) {
return false;
}
- if (!InitMallocFunction<MallocValloc>(malloc_impl_handler, &table->valloc,
- prefix, "valloc")) {
+ if (!InitMallocFunction<MallocValloc>(impl_handler, &table->valloc, prefix, "valloc")) {
return false;
}
#endif
@@ -328,102 +340,114 @@
fclose(stdout);
fclose(stderr);
- g_debug_finalize_func();
+ reinterpret_cast<finalize_func_t>(g_functions[FUNC_FINALIZE])();
+}
+
+static bool CheckLoadMallocHooks(char** options) {
+ char* env = getenv(HOOKS_ENV_ENABLE);
+ if ((env == nullptr || env[0] == '\0' || env[0] == '0') &&
+ (__system_property_get(HOOKS_PROPERTY_ENABLE, *options) == 0 || *options[0] == '\0' || *options[0] == '0')) {
+ return false;
+ }
+ *options = nullptr;
+ return true;
+}
+
+static bool CheckLoadMallocDebug(char** options) {
+ // If DEBUG_MALLOC_ENV_OPTIONS is set then it overrides the system properties.
+ char* env = getenv(DEBUG_ENV_OPTIONS);
+ if (env == nullptr || env[0] == '\0') {
+ if (__system_property_get(DEBUG_PROPERTY_OPTIONS, *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(DEBUG_PROPERTY_PROGRAM, 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++) {
+ g_functions[i] = nullptr;
+ }
+}
+
+static 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;
+ }
+
+ static constexpr const char* names[] = {
+ "initialize",
+ "finalize",
+ "get_malloc_leak_info",
+ "free_malloc_leak_info",
+ "malloc_backtrace",
+ };
+ for (size_t i = 0; i < FUNC_LAST; i++) {
+ char symbol[128];
+ snprintf(symbol, sizeof(symbol), "%s_%s", prefix, names[i]);
+ g_functions[i] = dlsym(impl_handle, symbol);
+ if (g_functions[i] == nullptr) {
+ error_log("%s: %s routine not found in %s", getprogname(), symbol, shared_lib);
+ dlclose(impl_handle);
+ ClearGlobalFunctions();
+ return nullptr;
+ }
+ }
+
+ if (!InitMallocFunctions(impl_handle, dispatch_table, prefix)) {
+ dlclose(impl_handle);
+ ClearGlobalFunctions();
+ return nullptr;
+ }
+
+ return impl_handle;
}
// Initializes memory allocation framework once per process.
static void malloc_init_impl(libc_globals* globals) {
- char value[PROP_VALUE_MAX];
-
- // If DEBUG_MALLOC_ENV_OPTIONS is set then it overrides the system properties.
- const char* options = getenv(DEBUG_MALLOC_ENV_OPTIONS);
- if (options == nullptr || options[0] == '\0') {
- if (__system_property_get(DEBUG_MALLOC_PROPERTY_OPTIONS, value) == 0 || value[0] == '\0') {
- return;
- }
- options = value;
-
- // Check to see if only a specific program should have debug malloc enabled.
- char program[PROP_VALUE_MAX];
- if (__system_property_get(DEBUG_MALLOC_PROPERTY_PROGRAM, program) != 0 &&
- strstr(getprogname(), program) == nullptr) {
- return;
- }
- }
-
- // Load the debug malloc shared library.
- void* malloc_impl_handle = dlopen(DEBUG_SHARED_LIB, RTLD_NOW | RTLD_LOCAL);
- if (malloc_impl_handle == nullptr) {
- error_log("%s: Unable to open debug malloc shared library %s: %s",
- getprogname(), DEBUG_SHARED_LIB, dlerror());
+ const char* prefix;
+ const char* shared_lib;
+ 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)) {
+ prefix = "debug";
+ shared_lib = DEBUG_SHARED_LIB;
+ } else if (CheckLoadMallocHooks(&options)) {
+ prefix = "hooks";
+ shared_lib = HOOKS_SHARED_LIB;
+ } else {
return;
}
- // Initialize malloc debugging in the loaded module.
- auto init_func = reinterpret_cast<bool (*)(const MallocDispatch*, int*, const char*)>(
- dlsym(malloc_impl_handle, "debug_initialize"));
- if (init_func == nullptr) {
- error_log("%s: debug_initialize routine not found in %s", getprogname(), DEBUG_SHARED_LIB);
- dlclose(malloc_impl_handle);
+ MallocDispatch dispatch_table;
+ void* impl_handle = LoadSharedLibrary(shared_lib, prefix, &dispatch_table);
+ if (impl_handle == nullptr) {
return;
}
- // Get the syms for the external functions.
- void* finalize_sym = dlsym(malloc_impl_handle, "debug_finalize");
- if (finalize_sym == nullptr) {
- error_log("%s: debug_finalize routine not found in %s", getprogname(), DEBUG_SHARED_LIB);
- dlclose(malloc_impl_handle);
- return;
- }
-
- void* get_leak_info_sym = dlsym(malloc_impl_handle, "debug_get_malloc_leak_info");
- if (get_leak_info_sym == nullptr) {
- error_log("%s: debug_get_malloc_leak_info routine not found in %s", getprogname(),
- DEBUG_SHARED_LIB);
- dlclose(malloc_impl_handle);
- return;
- }
-
- void* free_leak_info_sym = dlsym(malloc_impl_handle, "debug_free_malloc_leak_info");
- if (free_leak_info_sym == nullptr) {
- error_log("%s: debug_free_malloc_leak_info routine not found in %s", getprogname(),
- DEBUG_SHARED_LIB);
- dlclose(malloc_impl_handle);
- return;
- }
-
- void* malloc_backtrace_sym = dlsym(malloc_impl_handle, "debug_malloc_backtrace");
- if (malloc_backtrace_sym == nullptr) {
- error_log("%s: debug_malloc_backtrace routine not found in %s", getprogname(),
- DEBUG_SHARED_LIB);
- dlclose(malloc_impl_handle);
- return;
- }
-
+ init_func_t init_func = reinterpret_cast<init_func_t>(g_functions[FUNC_INITIALIZE]);
if (!init_func(&__libc_malloc_default_dispatch, &gMallocLeakZygoteChild, options)) {
- dlclose(malloc_impl_handle);
+ dlclose(impl_handle);
+ ClearGlobalFunctions();
return;
}
- MallocDispatch malloc_dispatch_table;
- if (!InitMalloc(malloc_impl_handle, &malloc_dispatch_table, "debug")) {
- auto finalize_func = reinterpret_cast<void (*)()>(finalize_sym);
- finalize_func();
- dlclose(malloc_impl_handle);
- return;
- }
+ globals->malloc_dispatch = dispatch_table;
- g_debug_finalize_func = reinterpret_cast<void (*)()>(finalize_sym);
- g_debug_get_malloc_leak_info_func = reinterpret_cast<void (*)(
- uint8_t**, size_t*, size_t*, size_t*, size_t*)>(get_leak_info_sym);
- g_debug_free_malloc_leak_info_func = reinterpret_cast<void (*)(uint8_t*)>(free_leak_info_sym);
- g_debug_malloc_backtrace_func = reinterpret_cast<ssize_t (*)(
- void*, uintptr_t*, size_t)>(malloc_backtrace_sym);
-
- globals->malloc_dispatch = malloc_dispatch_table;
- libc_malloc_impl_handle = malloc_impl_handle;
-
- info_log("%s: malloc debug enabled", getprogname());
+ 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,
@@ -478,10 +502,11 @@
#ifndef LIBC_STATIC
extern "C" ssize_t malloc_backtrace(void* pointer, uintptr_t* frames, size_t frame_count) {
- if (g_debug_malloc_backtrace_func == nullptr) {
+ void* func = g_functions[FUNC_MALLOC_BACKTRACE];
+ if (func == nullptr) {
return 0;
}
- return g_debug_malloc_backtrace_func(pointer, frames, frame_count);
+ return reinterpret_cast<malloc_backtrace_func_t>(func)(pointer, frames, frame_count);
}
#else
extern "C" ssize_t malloc_backtrace(void*, uintptr_t*, size_t) {