Index: b/usr/src/head/unistd.h
===================================================================
--- a/usr/src/head/unistd.h
+++ b/usr/src/head/unistd.h
@@ -714,6 +714,19 @@ extern char *ttyname_r(int, char *, int)
 extern int getentropy(void *, size_t);
 #endif	/* !_STRICT_SYMBOLS */
 
+#if defined(_GNU_SOURCE) || defined(__EXTENSIONS__)
+#ifdef __GNUC__
+# define TEMP_FAILURE_RETRY(exp) \
+(__extension__ ( \
+{ long int ____res____; \
+   do ____res____ = (long int) (exp); \
+   while (____res____ == -1L && errno == EINTR); \
+   ____res____; } \
+))
+#endif /* __GNUC__ */
+#endif
+
+
 #ifdef	__cplusplus
 }
 #endif