| /* 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) |
| |
| #pragma warning(push, 3) |
| #include <windows.h> |
| #pragma warning(pop) |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <openssl/mem.h> |
| |
| |
| void CRYPTO_once(CRYPTO_once_t *in_once, void (*init)(void)) { |
| volatile LONG *once = (LONG*) in_once; |
| |
| assert(sizeof(LONG) == sizeof(CRYPTO_once_t)); |
| /* 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(); |
| /* 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 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 */ |