Found in the SVN valgrind code
svn diff -c 13504 configure.in 

Upstream-Status: Backport

Signed-off-by: Saul Wold <sgw@linux.intel.com>

Index: valgrind-3.8.1/configure.in
===================================================================
--- valgrind-3.8.1.orig/configure.in
+++ valgrind-3.8.1/configure.in
@@ -924,6 +924,13 @@ case "${GLIBC_VERSION}" in
 	DEFAULT_SUPP="$srcdir/glibc-2.34567-NPTL-helgrind.supp ${DEFAULT_SUPP}"
 	DEFAULT_SUPP="$srcdir/glibc-2.X-drd.supp ${DEFAULT_SUPP}"
 	;;
+     2.18)
+	AC_MSG_RESULT(2.18 family)
+	AC_DEFINE([GLIBC_2_18], 1, [Define to 1 if you're using glibc 2.18.x])
+	DEFAULT_SUPP="glibc-2.X.supp ${DEFAULT_SUPP}"
+	DEFAULT_SUPP="$srcdir/glibc-2.34567-NPTL-helgrind.supp ${DEFAULT_SUPP}"
+	DEFAULT_SUPP="$srcdir/glibc-2.X-drd.supp ${DEFAULT_SUPP}"
+	;;
      darwin)
 	AC_MSG_RESULT(Darwin)
 	AC_DEFINE([DARWIN_LIBC], 1, [Define to 1 if you're using Darwin])