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>

include/asm-sh/elf.h

@@ -133,6 +133,7 @@ extern void __kernel_vsyscall;
 #define VDSO_BASE		((unsigned long)current->mm->context.vdso)
 #define VDSO_SYM(x)		(VDSO_BASE + (unsigned long)(x))
 
+/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
 #define ARCH_DLINFO						\
 do {								\
 	if (vdso_enabled)					\

include/asm-sh/system.h

@@ -15,6 +15,7 @@
 struct task_struct *__switch_to(struct task_struct *prev,
 				struct task_struct *next);
 
+#define AT_VECTOR_SIZE_ARCH 1 /* entries in ARCH_DLINFO */
 /*
  *	switch_to() should switch tasks to task nr n, first
  */