Re: [PATCH] IB/core: avoid 32-bit warning

From: Arnd Bergmann
Date: Wed Oct 07 2015 - 09:46:50 EST


On Wednesday 07 October 2015 16:19:27 Sagi Grimberg wrote:
> On 10/7/2015 3:29 PM, Arnd Bergmann wrote:
> > The INIT_UDATA() macro requires a pointer or unsigned long argument for
> > both input and output buffer, and all callers had a cast from when
> > the code was merged until a recent restructuring, so now we get
> >
> > core/uverbs_cmd.c: In function 'ib_uverbs_create_cq':
> > core/uverbs_cmd.c:1481:66: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> >
> > This makes the code behave as before by adding back the cast to
> > unsigned long.
> >
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Fixes: 565197dd8fb1 ("IB/core: Extend ib_uverbs_create_cq")
> >
> > diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
> > index be4cb9f04be3..88b3b78340f2 100644
> > --- a/drivers/infiniband/core/uverbs_cmd.c
> > +++ b/drivers/infiniband/core/uverbs_cmd.c
> > @@ -1478,7 +1478,7 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
> > if (copy_from_user(&cmd, buf, sizeof(cmd)))
> > return -EFAULT;
> >
> > - INIT_UDATA(&ucore, buf, cmd.response, sizeof(cmd), sizeof(resp));
> > + INIT_UDATA(&ucore, buf, (unsigned long)cmd.response, sizeof(cmd), sizeof(resp));
>
> Would it make sense to cast inside INIT_UDATA() and not have callers
> worry about it?

If we want to do this properly, INIT_UDATA should be converted into a function
call that has the right types.

My patch doesn't try to do that here, it just restores the code to how it
was for the past 10 years.

Arnd
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