I tried to compile linux-2.6.32.53 with grsecurity-2.2.2-2.6.32.53-201201062206 and found that it fails to build with:
fs/binfmt_elf.c: In function 'pax_parse_pax_flags':
fs/binfmt_elf.c:896:6: error: 'found_flags' undeclared (first use in this function)
fs/binfmt_elf.c:896:6: note: each undeclared identifier is reported only once for each function it appears in
fs/binfmt_elf.c:905:4: error: implicit declaration of function 'pax_parse_hardmode' [-Werror=implicit-function-declaration]
fs/binfmt_elf.c: At top level:
fs/binfmt_elf.c:561:22: warning: 'pax_parse_pt_pax_softmode' defined but not used [-Wunused-function]
fs/binfmt_elf.c:746:22: warning: 'pax_parse_xattr_pax_softmode' defined but not used [-Wunused-function]
fs/binfmt_elf.c:787:22: warning: 'pax_parse_xattr_pax_hardmode' defined but not used [-Wunused-function]
cc1: some warnings being treated as errors
make[1]: *** [fs/binfmt_elf.o] Error 1
make: *** [fs] Error 2