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-rw-r--r--lib/sanitizer_common/sanitizer_win_weak_interception.cpp94
1 files changed, 94 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_win_weak_interception.cpp b/lib/sanitizer_common/sanitizer_win_weak_interception.cpp
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+++ b/lib/sanitizer_common/sanitizer_win_weak_interception.cpp
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+//===-- sanitizer_win_weak_interception.cpp -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// This module should be included in the sanitizer when it is implemented as a
+// shared library on Windows (dll), in order to delegate the calls of weak
+// functions to the implementation in the main executable when a strong
+// definition is provided.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_WINDOWS && SANITIZER_DYNAMIC
+#include "sanitizer_win_weak_interception.h"
+#include "sanitizer_allocator_interface.h"
+#include "sanitizer_interface_internal.h"
+#include "sanitizer_win_defs.h"
+#include "interception/interception.h"
+
+extern "C" {
+void *WINAPI GetModuleHandleA(const char *module_name);
+void abort();
+}
+
+namespace __sanitizer {
+// Try to get a pointer to real_function in the main module and override
+// dll_function with that pointer. If the function isn't found, nothing changes.
+int interceptWhenPossible(uptr dll_function, const char *real_function) {
+ uptr real = __interception::InternalGetProcAddress(
+ (void *)GetModuleHandleA(0), real_function);
+ if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0))
+ abort();
+ return 0;
+}
+} // namespace __sanitizer
+
+// Declare weak hooks.
+extern "C" {
+void __sanitizer_on_print(const char *str);
+void __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1,
+ const void *s2, uptr n, int result);
+void __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1,
+ const char *s2, int result);
+void __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1,
+ const char *s2, uptr n, int result);
+void __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1,
+ const char *s2, char *result);
+}
+
+// Include Sanitizer Common interface.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_common_interface.inc"
+
+#pragma section(".WEAK$A", read)
+#pragma section(".WEAK$Z", read)
+
+typedef void (*InterceptCB)();
+extern "C" {
+__declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list;
+__declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list;
+}
+
+static int weak_intercept_init() {
+ static bool flag = false;
+ // weak_interception_init is expected to be called by only one thread.
+ if (flag) return 0;
+ flag = true;
+
+ for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it)
+ if (*it)
+ (*it)();
+
+ // In DLLs, the callbacks are expected to return 0,
+ // otherwise CRT initialization fails.
+ return 0;
+}
+
+#pragma section(".CRT$XIB", long, read)
+__declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() =
+ weak_intercept_init;
+
+static void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason,
+ void *reserved) {
+ if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init();
+}
+
+#pragma section(".CRT$XLAB", long, read)
+__declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)(
+ void *, unsigned long, void *) = weak_intercept_thread_init;
+
+#endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC