On Fri, Apr 29, 2016 at 08:32:19AM -0500, Josh Poimboeuf wrote:
> On Fri, Apr 29, 2016 at 04:45:43PM +1000, Stephen Rothwell wrote:
> > Hi Andrew,
> >
> > After merging the akpm-current tree, today's linux-next build (x86_64
> > allmodconfig) produced this warning:
> >
> > drivers/scsi/ipr.c: In function 'ipr_show_device_id':
> > drivers/scsi/ipr.c:4462:34: warning: format '%llx' expects argument of type
> > 'long long unsigned int', but argument 4 has type 'long unsigned int'
> > [-Wformat=]
> > len = snprintf(buf, PAGE_SIZE, "0x%llx\n", be64_to_cpu(res->dev_id));
> > ^
> >
> > Lots and lots like this :-(
> >
> > Probably introduced by commit
> >
> > eef17fb79096 ("byteswap: try to avoid __builtin_constant_p gcc bug")
> >
> > I guess __builtin_bswap64() has type "unsigned long int" :-(
>
> Hm, I suppose this is cross-compiled on a powerpc host?
>
> We probably need to add a (__u64) cast to the return value of
> __builtin_bswap64(), like:
>
> diff --git a/include/uapi/linux/swab.h b/include/uapi/linux/swab.h
> index de56fd5..d737804 100644
> --- a/include/uapi/linux/swab.h
> +++ b/include/uapi/linux/swab.h
> @@ -123,7 +123,7 @@ static inline __attribute_const__ __u32 __fswahb32(__u32
> val)
> * @x: value to byteswap
> */
> #ifdef __HAVE_BUILTIN_BSWAP64__
> -#define __swab64(x) __builtin_bswap64((__u64)(x))
> +#define __swab64(x) (__u64)__builtin_bswap64((__u64)(x))
> #else
> #define __swab64(x) \
> (__builtin_constant_p((__u64)(x)) ? \
Never mind about cross-compiling on powerpc, this has nothing to do with
that. But the above patch does seem to fix it.
--
Josh
