diff -up mozilla/security/coreconf/Linux.mk.relro mozilla/security/coreconf/Linux.mk
--- mozilla/security/coreconf/Linux.mk.relro	2010-08-12 18:32:29.000000000 -0700
+++ mozilla/security/coreconf/Linux.mk	2011-09-27 16:12:22.234743170 -0700
@@ -179,6 +179,12 @@ FREEBL_NO_DEPEND = 1
 endif
 endif
 
+# harden DSOs/executables a bit against exploits
+ifeq (2.6,$(firstword $(sort 2.6 $(OS_RELEASE))))
+DSO_LDOPTS+=-Wl,-z,relro
+LDFLAGS	+= -Wl,-z,relro
+endif
+
 USE_SYSTEM_ZLIB = 1
 ZLIB_LIBS = -lz