y2038: utimes: Rework #ifdef guards for compat syscalls

After changing over to 64-bit time_t syscalls, many architectures will
want compat_sys_utimensat() but not respective handlers for utime(),
utimes() and futimesat(). This adds a new __ARCH_WANT_SYS_UTIME32 to
complement __ARCH_WANT_SYS_UTIME. For now, all 64-bit architectures that
support CONFIG_COMPAT set it, but future 64-bit architectures will not
(tile would not have needed it either, but got removed).

As older 32-bit architectures get converted to using CONFIG_64BIT_TIME,
they will have to use __ARCH_WANT_SYS_UTIME32 instead of
__ARCH_WANT_SYS_UTIME. Architectures using the generic syscall ABI don't
need either of them as they never had a utime syscall.

Since the compat_utimbuf structure is now required outside of
CONFIG_COMPAT, I'm moving it into compat_time.h.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
changed from last version:
- renamed __ARCH_WANT_COMPAT_SYS_UTIME to __ARCH_WANT_SYS_UTIME32

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/utimes.c b/fs/utimes.c
index 2f6f08061a26..bdcf2daf39c1 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -218,13 +218,14 @@ SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
 }
 #endif
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_32BIT_TIME
 /*
  * Not all architectures have sys_utime, so implement this in terms
  * of sys_utimes.
  */
+#ifdef __ARCH_WANT_SYS_UTIME32
 COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
-		       struct compat_utimbuf __user *, t)
+		       struct old_utimbuf32 __user *, t)
 {
 	struct timespec64 tv[2];
 
@@ -237,6 +238,7 @@ COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
 	}
 	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
 }
+#endif
 
 COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
 {
@@ -253,6 +255,7 @@ COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filena
 	return do_utimes(dfd, filename, t ? tv : NULL, flags);
 }
 
+#ifdef __ARCH_WANT_SYS_UTIME32
 static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
 				struct old_timeval32 __user *t)
 {
@@ -285,3 +288,4 @@ COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct old_timeval
 	return do_compat_futimesat(AT_FDCWD, filename, t);
 }
 #endif
+#endif