x86/vdso: Change time() prototype to match __vdso_time()

gcc-8 warns that time() is an alias for __vdso_time() but the two
have different prototypes:

  arch/x86/entry/vdso/vclock_gettime.c:327:5: error: 'time' alias between functions of incompatible types 'int(time_t *)' {aka 'int(long int *)'} and 'time_t(time_t *)' {aka 'long int(long int *)'} [-Werror=attribute-alias]
   int time(time_t *t)
       ^~~~
  arch/x86/entry/vdso/vclock_gettime.c:318:16: note: aliased declaration here

I could not figure out whether this is intentional, but I see that
changing it to return time_t avoids the warning.

Returning 'int' from time() is also a bit questionable, as it causes an
overflow in y2038 even on 64-bit architectures that use a 64-bit time_t
type. On 32-bit architecture with 64-bit time_t, time() should always
be implement by the C library by calling a (to be added) clock_gettime()
variant that takes a sufficiently wide argument.

Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 11b13c4b43d5..f19856d95c60 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -324,5 +324,5 @@ notrace time_t __vdso_time(time_t *t)
 		*t = result;
 	return result;
 }
-int time(time_t *t)
+time_t time(time_t *t)
 	__attribute__((weak, alias("__vdso_time")));