include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small

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

Hi Kees,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   5619b098e2fbf3a23bf13d91897056a1fe238c6d
commit: 808aac63e2bdf9bae08485e072bf3d317a18acbf uaccess: Introduce ucopysize.h
date:   1 year, 1 month ago
config: um-randconfig-001-20260403 (https://download.01.org/0day-ci/archive/20260403/202604030531.O6FveVgn-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260403/202604030531.O6FveVgn-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
| Fixes: 808aac63e2bd ("uaccess: Introduce ucopysize.h")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604030531.O6FveVgn-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from net/sctp/socket.c:45:
   In file included from include/linux/sched/signal.h:9:
   In file included from include/linux/sched/task.h:13:
   In file included from include/linux/uaccess.h:10:
>> include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
      45 |                         __bad_copy_from();
         |                         ^
   1 error generated.


vim +45 include/linux/ucopysize.h

    36	
    37	static __always_inline __must_check bool
    38	check_copy_size(const void *addr, size_t bytes, bool is_source)
    39	{
    40		int sz = __builtin_object_size(addr, 0);
    41		if (unlikely(sz >= 0 && sz < bytes)) {
    42			if (!__builtin_constant_p(bytes))
    43				copy_overflow(sz, bytes);
    44			else if (is_source)
  > 45				__bad_copy_from();
    46			else
    47				__bad_copy_to();
    48			return false;
    49		}
    50		if (WARN_ON_ONCE(bytes > INT_MAX))
    51			return false;
    52		check_object_size(addr, bytes, is_source);
    53		return true;
    54	}
    55	

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