[msan][tsan] Refine __fxstat{,at}{,64} condition

[MaskRay]

Summary

In glibc before 2.33, include/sys/stat.h defines fstat/fstat64 to
__fxstat/__fxstat64 and provides __fxstat/__fxstat64 in libc_nonshared.a.
The symbols are glibc specific and not needed on other systems.

[MaskRay]

Change __fxstatat{,64} as well

[MaskRay]

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

1578

Note to this: FreeBSD doesn't have this libc function.

musl provides this as a glibc-compat non-API symbol. musl has #define fstat64 fstat so compiled programs won't get this symbol.

compiler-rt/lib/msan/msan_interceptors.cpp

if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT_FSTAT MSAN_INTERCEPT_FUNC(fstat)
 #else
 #define MSAN_MAYBE_INTERCEPT_FSTAT
 #endif
 
-#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, __fxstat, int magic, int fd, void *buf) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstat)(magic, fd, buf);
   if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT___FXSTAT MSAN_INTERCEPT_FUNC(__fxstat)
 #else
 #define MSAN_MAYBE_INTERCEPT___FXSTAT
 #endif
 
-#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, __fxstat64, int magic, int fd, void *buf) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstat64)(magic, fd, buf);
   if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64 MSAN_INTERCEPT_FUNC(__fxstat64)
 #else
 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64
 #endif
 
 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
 INTERCEPTOR(int, fstatat, int fd, char *pathname, void *buf, int flags) {
   ENSURE_MSAN_INITED();
   int res = REAL(fstatat)(fd, pathname, buf, flags);
   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT_FSTATAT MSAN_INTERCEPT_FUNC(fstatat)
 #else
 #  define MSAN_MAYBE_INTERCEPT_FSTATAT
 #endif
 
-#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
             int flags) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT MSAN_INTERCEPT_FUNC(__fxstatat)
 #else
 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT
 #endif
 
-#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
+#if SANITIZER_GLIBC
 INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
             int flags) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
   return res;
 }
 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64 MSAN_INTERCEPT_FUNC(__fxstatat64)

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) {
   // result in crashes due to too little stack space.
   if (guard_acquire(thr, pc, a, !SANITIZER_MAC)) {
     (*f)();
     guard_release(thr, pc, a, kGuardDone);
   }
   return 0;
 }
 
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#if SANITIZER_GLIBC
 TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) {
   SCOPED_TSAN_INTERCEPTOR(__fxstat, version, fd, buf);
   if (fd > 0)
     FdAccess(thr, pc, fd);
   return REAL(__fxstat)(version, fd, buf);
 }
 #define TSAN_MAYBE_INTERCEPT___FXSTAT TSAN_INTERCEPT(__fxstat)
 #else

 #else
   SCOPED_TSAN_INTERCEPTOR(__fxstat, 0, fd, buf);
   if (fd > 0)
     FdAccess(thr, pc, fd);
   return REAL(__fxstat)(0, fd, buf);
 #endif
 }
 
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#if SANITIZER_GLIBC
 TSAN_INTERCEPTOR(int, __fxstat64, int version, int fd, void *buf) {
   SCOPED_TSAN_INTERCEPTOR(__fxstat64, version, fd, buf);
   if (fd > 0)
     FdAccess(thr, pc, fd);
   return REAL(__fxstat64)(version, fd, buf);
 }
 #define TSAN_MAYBE_INTERCEPT___FXSTAT64 TSAN_INTERCEPT(__fxstat64)
 #else
 #define TSAN_MAYBE_INTERCEPT___FXSTAT64
 #endif
 
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#if SANITIZER_GLIBC
 TSAN_INTERCEPTOR(int, fstat64, int fd, void *buf) {
   SCOPED_TSAN_INTERCEPTOR(__fxstat64, 0, fd, buf);
   if (fd > 0)
     FdAccess(thr, pc, fd);
   return REAL(__fxstat64)(0, fd, buf);
 }
 #define TSAN_MAYBE_INTERCEPT_FSTAT64 TSAN_INTERCEPT(fstat64)
 #else
 #define TSAN_MAYBE_INTERCEPT_FSTAT64