[PATCH] uml: comment about cast build fix

Explain why the casting we do to silence this warning is indeed safe.

It is because the field we're casting from, though being 64-bit wide, was filled
with a pointer in first place by ourselves.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index 298d5632128b8119d06f90c1639a559b0168d20e..f6e64026f9952b90d1af98625b152ef394c454e9 100644 (file)
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -144,6 +144,7 @@ static int aio_thread(void *arg)
                                "errno = %d\n", errno);
                 }
                 else {
+                       /* This is safe as we've just a pointer here. */
                        aio = (struct aio_context *) (long) event.data;
                        if(update_aio(aio, event.res)){
                                do_aio(ctx, aio);