increase AT_VECTOR_SIZE to terminate saved_auxv properly

include/asm-powerpc/elf.h has 6 entries in ARCH_DLINFO.  fs/binfmt_elf.c
has 14 unconditional NEW_AUX_ENT entries and 2 conditional NEW_AUX_ENT
entries.  So in the worst case, saved_auxv does not get an AT_NULL entry at
the end.

The saved_auxv array must be terminated with an AT_NULL entry.  Make the
size of mm_struct->saved_auxv arch dependend, based on the number of
ARCH_DLINFO entries.

Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 4263326..0f55b71 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -175,6 +175,7 @@
 
 	/* Create the ELF interpreter info */
 	elf_info = (elf_addr_t *)current->mm->saved_auxv;
+	/* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 #define NEW_AUX_ENT(id, val) \
 	do { \
 		elf_info[ei_index++] = id; \
@@ -185,6 +186,8 @@
 	/* 
 	 * ARCH_DLINFO must come first so PPC can do its special alignment of
 	 * AUXV.
+	 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
+	 * ARCH_DLINFO changes
 	 */
 	ARCH_DLINFO;
 #endif