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- /* Copyright (c) 2015, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #include "internal.h"
-
- #if defined(OPENSSL_WINDOWS) && !defined(OPENSSL_NO_THREADS)
-
- #pragma warning(push, 3)
- #include <windows.h>
- #pragma warning(pop)
-
- #include <assert.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include <openssl/mem.h>
- #include <openssl/type_check.h>
-
-
- OPENSSL_COMPILE_ASSERT(sizeof(CRYPTO_MUTEX) >= sizeof(CRITICAL_SECTION),
- CRYPTO_MUTEX_too_small);
-
- static void run_once(CRYPTO_once_t *in_once, void (*init)(void *), void *arg) {
- volatile LONG *once = in_once;
-
- /* Values must be aligned. */
- assert((((uintptr_t) once) & 3) == 0);
-
- /* This assumes that reading *once has acquire semantics. This should be true
- * on x86 and x86-64, where we expect Windows to run. */
- #if !defined(OPENSSL_X86) && !defined(OPENSSL_X86_64)
- #error "Windows once code may not work on other platforms." \
- "You can use InitOnceBeginInitialize on >=Vista"
- #endif
- if (*once == 1) {
- return;
- }
-
- for (;;) {
- switch (InterlockedCompareExchange(once, 2, 0)) {
- case 0:
- /* The value was zero so we are the first thread to call |CRYPTO_once|
- * on it. */
- init(arg);
- /* Write one to indicate that initialisation is complete. */
- InterlockedExchange(once, 1);
- return;
-
- case 1:
- /* Another thread completed initialisation between our fast-path check
- * and |InterlockedCompareExchange|. */
- return;
-
- case 2:
- /* Another thread is running the initialisation. Switch to it then try
- * again. */
- SwitchToThread();
- break;
-
- default:
- abort();
- }
- }
- }
-
- static void call_once_init(void *arg) {
- void (*init_func)(void);
- /* MSVC does not like casting between data and function pointers. */
- memcpy(&init_func, &arg, sizeof(void *));
- init_func();
- }
-
- void CRYPTO_once(CRYPTO_once_t *in_once, void (*init)(void)) {
- void *arg;
- /* MSVC does not like casting between data and function pointers. */
- memcpy(&arg, &init, sizeof(void *));
- run_once(in_once, call_once_init, arg);
- }
-
- void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
- if (!InitializeCriticalSectionAndSpinCount((CRITICAL_SECTION *) lock, 0x400)) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
- /* Since we have to support Windows XP, read locks are actually exclusive. */
- EnterCriticalSection((CRITICAL_SECTION *) lock);
- }
-
- void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
- EnterCriticalSection((CRITICAL_SECTION *) lock);
- }
-
- void CRYPTO_MUTEX_unlock(CRYPTO_MUTEX *lock) {
- LeaveCriticalSection((CRITICAL_SECTION *) lock);
- }
-
- void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
- DeleteCriticalSection((CRITICAL_SECTION *) lock);
- }
-
- static void static_lock_init(void *arg) {
- struct CRYPTO_STATIC_MUTEX *lock = arg;
- if (!InitializeCriticalSectionAndSpinCount(&lock->lock, 0x400)) {
- abort();
- }
- }
-
- void CRYPTO_STATIC_MUTEX_lock_read(struct CRYPTO_STATIC_MUTEX *lock) {
- /* Since we have to support Windows XP, read locks are actually exclusive. */
- run_once(&lock->once, static_lock_init, lock);
- EnterCriticalSection(&lock->lock);
- }
-
- void CRYPTO_STATIC_MUTEX_lock_write(struct CRYPTO_STATIC_MUTEX *lock) {
- CRYPTO_STATIC_MUTEX_lock_read(lock);
- }
-
- void CRYPTO_STATIC_MUTEX_unlock(struct CRYPTO_STATIC_MUTEX *lock) {
- LeaveCriticalSection(&lock->lock);
- }
-
- static CRITICAL_SECTION g_destructors_lock;
- static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
-
- static CRYPTO_once_t g_thread_local_init_once = CRYPTO_ONCE_INIT;
- static DWORD g_thread_local_key;
- static int g_thread_local_failed;
-
- static void thread_local_init(void) {
- if (!InitializeCriticalSectionAndSpinCount(&g_destructors_lock, 0x400)) {
- g_thread_local_failed = 1;
- return;
- }
- g_thread_local_key = TlsAlloc();
- g_thread_local_failed = (g_thread_local_key == TLS_OUT_OF_INDEXES);
- }
-
- static void NTAPI thread_local_destructor(PVOID module,
- DWORD reason, PVOID reserved) {
- if (DLL_THREAD_DETACH != reason && DLL_PROCESS_DETACH != reason) {
- return;
- }
-
- CRYPTO_once(&g_thread_local_init_once, thread_local_init);
- if (g_thread_local_failed) {
- return;
- }
-
- void **pointers = (void**) TlsGetValue(g_thread_local_key);
- if (pointers == NULL) {
- return;
- }
-
- thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
-
- EnterCriticalSection(&g_destructors_lock);
- memcpy(destructors, g_destructors, sizeof(destructors));
- LeaveCriticalSection(&g_destructors_lock);
-
- unsigned i;
- for (i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
- if (destructors[i] != NULL) {
- destructors[i](pointers[i]);
- }
- }
-
- OPENSSL_free(pointers);
- }
-
- /* Thread Termination Callbacks.
- *
- * Windows doesn't support a per-thread destructor with its TLS primitives.
- * So, we build it manually by inserting a function to be called on each
- * thread's exit. This magic is from http://www.codeproject.com/threads/tls.asp
- * and it works for VC++ 7.0 and later.
- *
- * Force a reference to _tls_used to make the linker create the TLS directory
- * if it's not already there. (E.g. if __declspec(thread) is not used). Force
- * a reference to p_thread_callback_boringssl to prevent whole program
- * optimization from discarding the variable. */
- #ifdef _WIN64
- #pragma comment(linker, "/INCLUDE:_tls_used")
- #pragma comment(linker, "/INCLUDE:p_thread_callback_boringssl")
- #else
- #pragma comment(linker, "/INCLUDE:__tls_used")
- #pragma comment(linker, "/INCLUDE:_p_thread_callback_boringssl")
- #endif
-
- /* .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
- * called automatically by the OS loader code (not the CRT) when the module is
- * loaded and on thread creation. They are NOT called if the module has been
- * loaded by a LoadLibrary() call. It must have implicitly been loaded at
- * process startup.
- *
- * By implicitly loaded, I mean that it is directly referenced by the main EXE
- * or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
- * implicitly loaded.
- *
- * See VC\crt\src\tlssup.c for reference. */
-
- /* The linker must not discard p_thread_callback_boringssl. (We force a reference
- * to this variable with a linker /INCLUDE:symbol pragma to ensure that.) If
- * this variable is discarded, the OnThreadExit function will never be
- * called. */
- #ifdef _WIN64
-
- /* .CRT section is merged with .rdata on x64 so it must be constant data. */
- #pragma const_seg(".CRT$XLC")
- /* When defining a const variable, it must have external linkage to be sure the
- * linker doesn't discard it. */
- extern const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl;
- const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
- /* Reset the default section. */
- #pragma const_seg()
-
- #else
-
- #pragma data_seg(".CRT$XLC")
- PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
- /* Reset the default section. */
- #pragma data_seg()
-
- #endif /* _WIN64 */
-
- void *CRYPTO_get_thread_local(thread_local_data_t index) {
- CRYPTO_once(&g_thread_local_init_once, thread_local_init);
- if (g_thread_local_failed) {
- return NULL;
- }
-
- void **pointers = TlsGetValue(g_thread_local_key);
- if (pointers == NULL) {
- return NULL;
- }
- return pointers[index];
- }
-
- int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
- thread_local_destructor_t destructor) {
- CRYPTO_once(&g_thread_local_init_once, thread_local_init);
- if (g_thread_local_failed) {
- destructor(value);
- return 0;
- }
-
- void **pointers = TlsGetValue(g_thread_local_key);
- if (pointers == NULL) {
- pointers = OPENSSL_malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
- if (pointers == NULL) {
- destructor(value);
- return 0;
- }
- memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
- if (TlsSetValue(g_thread_local_key, pointers) == 0) {
- OPENSSL_free(pointers);
- destructor(value);
- return 0;
- }
- }
-
- EnterCriticalSection(&g_destructors_lock);
- g_destructors[index] = destructor;
- LeaveCriticalSection(&g_destructors_lock);
-
- pointers[index] = value;
- return 1;
- }
-
- #endif /* OPENSSL_WINDOWS && !OPENSSL_NO_THREADS */
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