From: Joe Perches <joe@perches•com>
To: Dan Carpenter <dan.carpenter@oracle•com>
Cc: Stephan Mueller <smueller@chronox•de>,
Stephen Rothwell <sfr@canb•auug.org.au>,
Herbert Xu <herbert@gondor•apana.org.au>,
kbuild test robot <fengguang.wu@intel•com>,
kbuild@01•org, linux-crypto@vger•kernel.org,
Randy Dunlap <rdunlap@infradead•org>,
linux-next@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: [PATCH 3/4] DRBG: Fix format string for debugging statements
Date: Fri, 04 Jul 2014 09:57:20 -0700 [thread overview]
Message-ID: <1404493040.6384.21.camel@joe-AO725> (raw)
In-Reply-To: <20140704112116.GC25934@mwanda>
On Fri, 2014-07-04 at 14:21 +0300, Dan Carpenter wrote:
> On Sat, Jun 28, 2014 at 08:53:19PM -0700, Joe Perches wrote:
> > On Sun, 2014-06-29 at 05:46 +0200, Stephan Mueller wrote:
> > > Am Sonntag, 29. Juni 2014, 12:24:02 schrieb Stephen Rothwell:
> > >
> > > Hi Stephen,
> > >
> > > > Hi Stephan,
> > > >
> > > > On Sat, 28 Jun 2014 22:01:46 +0200 Stephan Mueller <smueller@chronox•de>
> > > wrote:
> > > > > @@ -1987,8 +1987,9 @@ static int __init drbg_init(void)
> > > > >
> > > > > if (ARRAY_SIZE(drbg_cores) * 2 > ARRAY_SIZE(drbg_algs)) {
> > > > >
> > > > > pr_info("DRBG: Cannot register all DRBG types"
> > > > >
> > > > > - "(slots needed: %lu, slots available: %lu)\n",
> > > > > - ARRAY_SIZE(drbg_cores) * 2, ARRAY_SIZE(drbg_algs));
> > > > > + "(slots needed: %u, slots available: %u)\n",
> > > > > + (unsigned int)ARRAY_SIZE(drbg_cores) * 2,
> > > > > + (unsigned int)ARRAY_SIZE(drbg_algs));
> > > >
> > > > Doesn't ARRAY_SIZE() always return a size_t? In which case surely we
> > > > need no casts, but need to us %zu in the format string.
> > >
> > > Unfortunately not at all. On my x86_64, I get the compiler warning that
> > > ARRAY_SIZE is a long unsigned int without the cast.
It doesn't seem to for 4.8.
Is there some specific gcc version where this occurs?
> > diff --git a/include/linux/kernel.h b/include/linux/kernel.h
[]
> > -#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
> > +#define ARRAY_SIZE(arr) \
> > + (sizeof(arr) / sizeof((arr)[0]) + (size_t)__must_be_array(arr))
>
>
> This change is a no-op isn't it?
Yes, it is. Dumb idea.
Assuming there's some odd promotion, size_t should have been around the
whole thing
#define ARRAY_SIZE(arr) \
((size_t)((sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)))
> I think Stephen Rothwell's suggestion
> is correct. In linux-next this was changed to %lu which also works...
>
> Are there arches %zu and %lu are different?
I get the same output types and error warnings compiling this
either -m32 or -m64
#include <stdio.h>
#include <stdlib.h>
#define typecheck(type, x) \
({ \
type __dummy; \
typeof(x) __dummy2; \
(void)(&__dummy == &__dummy2); \
1; \
})
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
int main(int argc, char **argv)
{
char foo[100];
size_t array = sizeof(foo);
typeof (ARRAY_SIZE(foo)) member = ARRAY_SIZE(foo);
int member1 = ARRAY_SIZE(foo);
size_t member2 = ARRAY_SIZE(foo);
typecheck(size_t, member);
typecheck(int, member);
typecheck(size_t, member1);
typecheck(int, member1);
typecheck(size_t, member2);
typecheck(int, member2);
printf("array: %zu, member: %zu\n", array, (int)member);
return 0;
}
next prev parent reply other threads:[~2014-07-04 16:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-28 19:57 [PATCH 0/4] DRBG: Fixes for sparse tool reports Stephan Mueller
2014-06-28 19:58 ` [PATCH 1/4] DRBG: use of kernel linked list Stephan Mueller
2014-07-04 14:11 ` Herbert Xu
2014-06-28 20:00 ` [PATCH 2/4] DRBG: cleanup of preprocessor macros Stephan Mueller
2014-06-29 2:20 ` Stephen Rothwell
2014-06-29 5:07 ` Stephan Mueller
2014-06-29 7:41 ` Randy Dunlap
2014-06-29 11:37 ` Stephan Mueller
2014-07-04 14:15 ` Herbert Xu
2014-07-05 0:03 ` Stephan Mueller
2014-06-28 20:01 ` [PATCH 3/4] DRBG: Fix format string for debugging statements Stephan Mueller
2014-06-29 2:24 ` Stephen Rothwell
2014-06-29 3:46 ` Stephan Mueller
2014-06-29 3:53 ` Joe Perches
2014-06-29 4:54 ` Stephan Mueller
2014-07-04 11:21 ` Dan Carpenter
2014-07-04 16:57 ` Joe Perches [this message]
2014-07-04 23:57 ` Stephan Mueller
2014-07-05 0:09 ` Joe Perches
2014-07-05 0:15 ` Stephan Mueller
2014-07-05 0:24 ` Joe Perches
2014-07-05 0:27 ` Stephan Mueller
2014-06-28 20:04 ` [PATCH 4/4] DRBG: Call CTR DRBG DF function only once Stephan Mueller
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