From: kernel test robot

Sent: 27 February 2024 01:34

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linux/master mkl-can-next/testing kdave/for-next akpm-mm/mm-nonmm-unstable
axboe-block/for-next linus/master v6.8-rc6 next-20240226]
[cannot apply to next-20240223 dtor-input/next dtor-input/for-linus horms-ipvs/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/David-Laight/minmax-Put-all-the-clamp-
definitions-together/20240226-005902
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/8657dd5c2264456f8a005520a3b90e2b%40AcuMS.aculab.com
patch subject: [PATCH next v2 03/11] minmax: Simplify signedness check
config: alpha-defconfig (https://download.01.org/0day-ci/archive/20240227/202402270937.9kmO5PFt-
lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-
ci/archive/20240227/202402270937.9kmO5PFt-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202402270937.9kmO5PFt-lkp@intel.com/ (local)

All warnings (new ones prefixed by >>):

   In file included from include/linux/kernel.h:28,
                    from include/linux/cpumask.h:10,
                    from include/linux/smp.h:13,
                    from include/linux/lockdep.h:14,
                    from include/linux/spinlock.h:63,
                    from include/linux/swait.h:7,
                    from include/linux/completion.h:12,
                    from include/linux/crypto.h:15,
                    from include/crypto/aead.h:13,
                    from include/crypto/internal/aead.h:11,
                    from crypto/skcipher.c:12:
   crypto/skcipher.c: In function 'skcipher_get_spot':

quoted

quoted

include/linux/minmax.h:31:70: warning: ordered comparison of pointer with integer zero [-Wextra]

      31 |         (is_unsigned_type(typeof(x)) || (__is_constexpr(x) ? (x) + 0 >= 0 : 0))

Hmmm -Wextra isn't normally set.
But I do wish the compiler would do dead code elimination before
these warnings.

Apart from stopping code using min()/max() for pointer types
(all the type checking is pointless) I think that __is_constextr()
can be implemented using _Generic (instead of sizeof(type)) and then the
true/false return values can be specified and need not be the same types.
That test can then be:
	(__if_constexpr(x, x, -1) >= 0)
(The '+ 0' is there to convert bool to int and won't be needed
for non-constant bool.)

I may drop the last few patches until MIN/MAX have been removed
from everywhere else to free up the names.

	David

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