y2038: Remove newstat family from default syscall set

We have four generations of stat() syscalls:
- the oldstat syscalls that are only used on the older architectures
- the newstat family that is used on all 64-bit architectures but
  lacked support for large files on 32-bit architectures.
- the stat64 family that is used mostly on 32-bit architectures to
  replace newstat
- statx() to replace all of the above, adding 64-bit timestamps among
  other things.

We already compile stat64 only on those architectures that need it,
but newstat is always built, including on those that don't reference
it. This adds a new __ARCH_WANT_NEW_STAT symbol along the lines of
__ARCH_WANT_OLD_STAT and __ARCH_WANT_STAT64 to control compilation of
newstat. All architectures that need it use an explict define, the
others now get a little bit smaller, and future architecture (including
64-bit targets) won't ever see it.
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/alpha/include/asm/unistd.h

@@ -6,6 +6,7 @@
 
 #define NR_SYSCALLS			523
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME

arch/arm/include/asm/unistd.h

@@ -16,6 +16,7 @@
 #include <uapi/asm/unistd.h>
 #include <asm/unistd-nr.h>
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME
 #define __ARCH_WANT_SYS_PAUSE

arch/arm64/include/uapi/asm/unistd.h

@@ -16,5 +16,6 @@
  */
 
 #define __ARCH_WANT_RENAMEAT
+#define __ARCH_WANT_NEW_STAT
 
 #include <asm-generic/unistd.h>

arch/ia64/include/asm/unistd.h

@@ -28,6 +28,8 @@
 #define __IGNORE_vfork		/* clone() */
 #define __IGNORE_umount2	/* umount() */
 
+#define __ARCH_WANT_NEW_STAT
+
 #if !defined(__ASSEMBLY__) && !defined(ASSEMBLER)
 
 #include <linux/types.h>

arch/m68k/include/asm/unistd.h

@@ -7,6 +7,7 @@
 
 #define NR_syscalls		380
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_OLD_STAT
 #define __ARCH_WANT_STAT64

arch/microblaze/include/asm/unistd.h

@@ -15,6 +15,7 @@
 
 /* #define __ARCH_WANT_OLD_READDIR */
 /* #define __ARCH_WANT_OLD_STAT */
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_ALARM
 #define __ARCH_WANT_SYS_GETHOSTNAME

arch/mips/include/asm/unistd.h

@@ -24,6 +24,7 @@
 
 #ifndef __ASSEMBLY__
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_SYS_ALARM
 #define __ARCH_WANT_SYS_GETHOSTNAME

arch/parisc/include/asm/unistd.h

@@ -141,6 +141,7 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5)	\
     return K_INLINE_SYSCALL(name, 5, arg1, arg2, arg3, arg4, arg5);	\
 }
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_ALARM

arch/powerpc/include/asm/unistd.h

@@ -22,6 +22,7 @@
 #include <linux/compiler.h>
 #include <linux/linkage.h>
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_ALARM

arch/s390/include/asm/unistd.h

@@ -15,6 +15,7 @@
 #define __IGNORE_pkey_alloc
 #define __IGNORE_pkey_free
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_SYS_ALARM
 #define __ARCH_WANT_SYS_GETHOSTNAME

arch/sh/include/asm/unistd.h

@@ -5,6 +5,7 @@
 #  include <asm/unistd_64.h>
 # endif
 
+# define __ARCH_WANT_NEW_STAT
 # define __ARCH_WANT_OLD_READDIR
 # define __ARCH_WANT_OLD_STAT
 # define __ARCH_WANT_STAT64

arch/sparc/include/asm/unistd.h

@@ -21,6 +21,7 @@
 #else
 #define __NR_time		231 /* Linux sparc32                               */
 #endif
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_ALARM

arch/x86/include/asm/unistd.h

@@ -31,6 +31,7 @@
 
 # endif
 
+# define __ARCH_WANT_NEW_STAT
 # define __ARCH_WANT_OLD_READDIR
 # define __ARCH_WANT_OLD_STAT
 # define __ARCH_WANT_SYS_ALARM

arch/xtensa/include/asm/unistd.h

@@ -5,6 +5,7 @@
 #define __ARCH_WANT_SYS_CLONE
 #include <uapi/asm/unistd.h>
 
+#define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_STAT64
 #define __ARCH_WANT_SYS_UTIME
 #define __ARCH_WANT_SYS_LLSEEK

fs/stat.c

@@ -280,6 +280,8 @@ SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, stat
 
 #endif /* __ARCH_WANT_OLD_STAT */
 
+#ifdef __ARCH_WANT_NEW_STAT
+
 #if BITS_PER_LONG == 32
 #  define choose_32_64(a,b) a
 #else
@@ -378,6 +380,7 @@ SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
 
 	return error;
 }
+#endif
 
 static int do_readlinkat(int dfd, const char __user *pathname,
 			 char __user *buf, int bufsiz)