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