[tsan] Fix build failure with _FORTIFY_SOURCE

[tstellar]

Summary

When _FORTIFY_SOURCE is defined, the glibc headers define realpath which
clashes with the definition in compiler-rt. In order to fix this for
realpath and also to protect us from future failues, when _FORTIFY_SOURCE
is defined, define our interceptor function with the __interceptor_ prefix.

[serge-sans-paille]

compiler-rt/lib/interception/interception.h

140

maybe call them `__fortified_interceptor` to make their purpose more explicit?

compiler-rt/lib/interception/interception_linux.h

35

I don't find DECLARED_FUNC as explicit as REAL and WRAP. ALIAS ? EXTERNAL ?

[vitalybuka]

Can you add a test probably in sanitizer_common which reproduces the issue?

[tstellar]

In D92521#2434366, @vitalybuka wrote:

Can you add a test probably in sanitizer_common which reproduces the issue?

The build failure is when building compiler-rt itself, and not in the application trying to use compiler-rt. Should I just create a test mini-sanitizer with one interceptor to demonstrate the problem?

[vitalybuka]

In D92521#2434442, @tstellar wrote:

In D92521#2434366, @vitalybuka wrote:

Can you add a test probably in sanitizer_common which reproduces the issue?

The build failure is when building compiler-rt itself, and not in the application trying to use compiler-rt. Should I just create a test mini-sanitizer with one interceptor to demonstrate the problem?

How exactly do you call cmake to reproduce this?

[vitalybuka]

I was able to reproduce.

We don't want interceptors depend on set of include files like with DECLARED_FUNC

I guess simple solution is to remove #include <stdlib.h> from dd_interceptors.cpp and
extern "C" void *malloc(size_t size);
extern "C" void free(void *ptr);
or move code which needs stdlib into a separate cpp file

[vitalybuka]

I assume it's not needed after D93877

compiler-rt/lib/interception/interception.h

 //===-- interception.h ------------------------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 //
const interpose_substitution substitution_##func_name[] \
     { reinterpret_cast<const uptr>(wrapper_name), \
       reinterpret_cast<const uptr>(func_name) } \
 }
 
 # define WRAP(x) wrap_##x
 # define WRAPPER_NAME(x) "wrap_"#x
 # define INTERCEPTOR_ATTRIBUTE
 # define DECLARE_WRAPPER(ret_type, func, ...)
+# define DECLARED_FUNC(func) func
 
 #elif SANITIZER_WINDOWS
 # define WRAP(x) __asan_wrap_##x
 # define WRAPPER_NAME(x) "__asan_wrap_"#x
 # define INTERCEPTOR_ATTRIBUTE __declspec(dllexport)
 # define DECLARE_WRAPPER(ret_type, func, ...) \
     extern "C" ret_type func(__VA_ARGS__);
 # define DECLARE_WRAPPER_WINAPI(ret_type, func, ...) \
     extern "C" __declspec(dllimport) ret_type __stdcall func(__VA_ARGS__);
 #elif SANITIZER_RTEMS
 # define WRAP(x) x
 # define WRAPPER_NAME(x) #x
 # define INTERCEPTOR_ATTRIBUTE
 # define DECLARE_WRAPPER(ret_type, func, ...)
+#elif defined(_FORTIFY_SOURCE) && (SANITIZER_FREEBSD || SANITIZER_NETBSD || !SANITIZER_FUCHSIA)
+# define WRAP(x) __interceptor_ ## x
+# define WRAPPER_NAME(x) "__interceptor_" #x
+# define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
+# define DECLARED_FUNC(func) WRAP(func)
+# define DECLARE_WRAPPER(ret_type, func, ...) \
+    extern "C" ret_type __interceptor_ ## func(__VA_ARGS__) \
+    __attribute__((visibility("default")));
 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD
 # define WRAP(x) __interceptor_ ## x
 # define WRAPPER_NAME(x) "__interceptor_" #x
 # define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
 // FreeBSD's dynamic linker (incompliantly) gives non-weak symbols higher
 // priority than weak ones so weak aliases won't work for indirect calls
 // in position-independent (-fPIC / -fPIE) mode.
 # define DECLARE_WRAPPER(ret_type, func, ...) \

compiler-rt/lib/interception/interception_linux.h

 //===-- interception_linux.h ------------------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 //

 
 namespace __interception {
 bool InterceptFunction(const char *name, uptr *ptr_to_real, uptr func,
                        uptr wrapper);
 bool InterceptFunction(const char *name, const char *ver, uptr *ptr_to_real,
                        uptr func, uptr wrapper);
 }  // namespace __interception
 
 #define INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func) \
   ::__interception::InterceptFunction(            \
       #func,                                      \
       (::__interception::uptr *) & REAL(func),    \
-      (::__interception::uptr) & (func),          \
+      (::__interception::uptr) & (DECLARED_FUNC(func)),       \
       (::__interception::uptr) & WRAP(func))
 
 // Android and Solaris do not have dlvsym
 #if !SANITIZER_ANDROID && !SANITIZER_SOLARIS
 #define INTERCEPT_FUNCTION_VER_LINUX_OR_FREEBSD(func, symver) \
   ::__interception::InterceptFunction(                        \
       #func, symver,                                          \
       (::__interception::uptr *) & REAL(func),                \
-      (::__interception::uptr) & (func),                      \
+      (::__interception::uptr) & (DECLARED_FUNC(func)),       \
       (::__interception::uptr) & WRAP(func))
 #else
 #define INTERCEPT_FUNCTION_VER_LINUX_OR_FREEBSD(func, symver) \
   INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func)
 #endif  // !SANITIZER_ANDROID && !SANITIZER_SOLARIS
 
 #endif  // INTERCEPTION_LINUX_H
 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD ||
         // SANITIZER_SOLARIS