Messages in this thread | | | Subject | Re: [PATCH 3/4] DRBG: Fix format string for debugging statements | From | Joe Perches <> | Date | Fri, 04 Jul 2014 09:57:20 -0700 |
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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; }
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