Re: [PATCH v2 10/14] hv: vmbus: pin buffer pages across UIO mmap to close the reclaim race

[kernel test robot <lkp@intel.com>]

Hi Emerson,

kernel test robot noticed the following build warnings:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v7.3-rc6 next-20261008]
[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/Emerson-Busson/hv-vmbus-convert-ring-backing-through-the-chunk-allocator/20261007-160739
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/20261007190752.336426-11-emersonbusson%40gmail.com
patch subject: [PATCH v2 10/14] hv: vmbus: pin buffer pages across UIO mmap to close the reclaim race
config: i386-randconfig-1001-20261008 (https://download.01.org/0day-ci/archive/20261009/202610090058.hvXsWpoT-lkp@intel.com/config)
compiler: clang version 22.1.3 (https://github.com/llvm/llvm-project e9846648fd6183ee6d8cbdb4502213fcf902a211)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261009/202610090058.hvXsWpoT-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 <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610090058.hvXsWpoT-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/uio/uio_hv_generic.c:428:
>> drivers/uio/uio_hv_generic_mmap_test.c:36:34: warning: implicit conversion from 'u64' (aka 'unsigned long long') to 'unsigned long' changes value from 18446744073709551615 to 4294967295 [-Wconstant-conversion]
      36 |                            hv_uio_mmap_range_valid(8, U64_MAX, 1));
         |                            ~~~~~~~~~~~~~~~~~~~~~~~    ^~~~~~~
   include/linux/limits.h:25:19: note: expanded from macro 'U64_MAX'
      25 | #define U64_MAX         ((u64)~0ULL)
         |                          ^~~~~~~~~~
   include/kunit/test.h:1014:31: note: expanded from macro 'KUNIT_EXPECT_FALSE'
    1014 |         KUNIT_EXPECT_FALSE_MSG(test, condition, NULL)
         |                                      ^~~~~~~~~
   include/kunit/test.h:1019:7: note: expanded from macro 'KUNIT_EXPECT_FALSE_MSG'
    1019 |                                   condition,                                   \
         |                                   ^~~~~~~~~
   include/kunit/test.h:812:10: note: expanded from macro 'KUNIT_FALSE_MSG_ASSERTION'
     812 |                               condition,                                       \
         |                               ^~~~~~~~~
   include/kunit/test.h:788:16: note: expanded from macro 'KUNIT_UNARY_ASSERTION'
     788 |         if (likely(!!(condition_) == !!expected_true_))                        \
         |                       ^~~~~~~~~~
   include/linux/compiler.h:76:40: note: expanded from macro 'likely'
      76 | # define likely(x)      __builtin_expect(!!(x), 1)
         |                                             ^
   1 warning generated.


vim +36 drivers/uio/uio_hv_generic_mmap_test.c

    27	
    28	static void hv_uio_ring_mmap_range_test(struct kunit *test)
    29	{
    30		KUNIT_EXPECT_TRUE(test, hv_uio_mmap_range_valid(8, 0, 8));
    31		KUNIT_EXPECT_TRUE(test, hv_uio_mmap_range_valid(8, 4, 4));
    32		KUNIT_EXPECT_FALSE(test, hv_uio_mmap_range_valid(8, 8, 1));
    33		KUNIT_EXPECT_FALSE(test, hv_uio_mmap_range_valid(8, 7, 2));
    34		KUNIT_EXPECT_FALSE(test, hv_uio_mmap_range_valid(8, 0, 0));
    35		KUNIT_EXPECT_FALSE(test,
  > 36				   hv_uio_mmap_range_valid(8, U64_MAX, 1));
    37	}
    38	

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