1 //===-- sanitizer_win_weak_interception.cc --------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
9 // This module should be included in the sanitizer when it is implemented as a
10 // shared library on Windows (dll), in order to delegate the calls of weak
11 // functions to the implementation in the main executable when a strong
12 // definition is provided.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_common/sanitizer_platform.h"
16 #if SANITIZER_WINDOWS && SANITIZER_DYNAMIC
17 #include "sanitizer_win_weak_interception.h"
18 #include "sanitizer_allocator_interface.h"
19 #include "sanitizer_interface_internal.h"
20 #include "sanitizer_win_defs.h"
21 #include "interception/interception.h"
24 void *WINAPI GetModuleHandleA(const char *module_name);
28 namespace __sanitizer {
29 // Try to get a pointer to real_function in the main module and override
30 // dll_function with that pointer. If the function isn't found, nothing changes.
31 int interceptWhenPossible(uptr dll_function, const char *real_function) {
32 uptr real = __interception::InternalGetProcAddress(
33 (void *)GetModuleHandleA(0), real_function);
34 if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0))
38 } // namespace __sanitizer
40 // Declare weak hooks.
42 void __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1,
43 const void *s2, uptr n, int result);
44 void __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1,
45 const char *s2, int result);
46 void __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1,
47 const char *s2, uptr n, int result);
48 void __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1,
49 const char *s2, char *result);
52 // Include Sanitizer Common interface.
53 #define INTERFACE_FUNCTION(Name)
54 #define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
55 #include "sanitizer_common_interface.inc"
57 #pragma section(".WEAK$A", read) // NOLINT
58 #pragma section(".WEAK$Z", read) // NOLINT
60 typedef void (*InterceptCB)();
62 __declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list;
63 __declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list;
66 static int weak_intercept_init() {
67 static bool flag = false;
68 // weak_interception_init is expected to be called by only one thread.
72 for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it)
76 // In DLLs, the callbacks are expected to return 0,
77 // otherwise CRT initialization fails.
81 #pragma section(".CRT$XIB", long, read) // NOLINT
82 __declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() =
85 static void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason,
87 if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init();
90 #pragma section(".CRT$XLAB", long, read) // NOLINT
91 __declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)(
92 void *, unsigned long, void *) = weak_intercept_thread_init;
94 #endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC