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-rw-r--r--lib/interception/interception_linux.cpp83
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diff --git a/lib/interception/interception_linux.cpp b/lib/interception/interception_linux.cpp
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+//===-- interception_linux.cpp ----------------------------------*- C++ -*-===//
+//
+// 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 file is a part of AddressSanitizer, an address sanity checker.
+//
+// Linux-specific interception methods.
+//===----------------------------------------------------------------------===//
+
+#include "interception.h"
+
+#if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD || \
+ SANITIZER_OPENBSD || SANITIZER_SOLARIS
+
+#include <dlfcn.h> // for dlsym() and dlvsym()
+
+namespace __interception {
+
+#if SANITIZER_NETBSD
+static int StrCmp(const char *s1, const char *s2) {
+ while (true) {
+ if (*s1 != *s2)
+ return false;
+ if (*s1 == 0)
+ return true;
+ s1++;
+ s2++;
+ }
+}
+#endif
+
+static void *GetFuncAddr(const char *name, uptr wrapper_addr) {
+#if SANITIZER_NETBSD
+ // FIXME: Find a better way to handle renames
+ if (StrCmp(name, "sigaction"))
+ name = "__sigaction14";
+#endif
+ void *addr = dlsym(RTLD_NEXT, name);
+ if (!addr) {
+ // If the lookup using RTLD_NEXT failed, the sanitizer runtime library is
+ // later in the library search order than the DSO that we are trying to
+ // intercept, which means that we cannot intercept this function. We still
+ // want the address of the real definition, though, so look it up using
+ // RTLD_DEFAULT.
+ addr = dlsym(RTLD_DEFAULT, name);
+
+ // In case `name' is not loaded, dlsym ends up finding the actual wrapper.
+ // We don't want to intercept the wrapper and have it point to itself.
+ if ((uptr)addr == wrapper_addr)
+ addr = nullptr;
+ }
+ return addr;
+}
+
+bool InterceptFunction(const char *name, uptr *ptr_to_real, uptr func,
+ uptr wrapper) {
+ void *addr = GetFuncAddr(name, wrapper);
+ *ptr_to_real = (uptr)addr;
+ return addr && (func == wrapper);
+}
+
+// Android and Solaris do not have dlvsym
+#if !SANITIZER_ANDROID && !SANITIZER_SOLARIS && !SANITIZER_OPENBSD
+static void *GetFuncAddr(const char *name, const char *ver) {
+ return dlvsym(RTLD_NEXT, name, ver);
+}
+
+bool InterceptFunction(const char *name, const char *ver, uptr *ptr_to_real,
+ uptr func, uptr wrapper) {
+ void *addr = GetFuncAddr(name, ver);
+ *ptr_to_real = (uptr)addr;
+ return addr && (func == wrapper);
+}
+#endif // !SANITIZER_ANDROID
+
+} // namespace __interception
+
+#endif // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD ||
+ // SANITIZER_OPENBSD || SANITIZER_SOLARIS