mainline build failure due to 6c77676645ad ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()")

[Sudip Mukherjee]

Hi All,

The latest mainline kernel branch fails to build for "arm allmodconfig",
"xtensa allmodconfig" and "csky allmodconfig" with the error:

In file included from ./include/linux/kernel.h:26,
                 from ./include/linux/crypto.h:16,
                 from ./include/crypto/hash.h:11,
                 from lib/iov_iter.c:2:
lib/iov_iter.c: In function 'iter_xarray_get_pages':
./include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
   20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
      |                                   ^~
./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck'
   26 |                 (__typecheck(x, y) && __no_side_effects(x, y))
      |                  ^~~~~~~~~~~
./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp'
   36 |         __builtin_choose_expr(__safe_cmp(x, y), \
      |                               ^~~~~~~~~~
./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp'
   45 | #define min(x, y)       __careful_cmp(x, y, <)
      |                         ^~~~~~~~~~~~~
lib/iov_iter.c:1464:16: note: in expansion of macro 'min'
 1464 |         return min(nr * PAGE_SIZE - offset, maxsize);
      |                ^~~
lib/iov_iter.c: In function 'iter_xarray_get_pages_alloc':
./include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
   20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
      |                                   ^~
./include/linux/minmax.h:26:18: note: in expansion of macro '__typecheck'
   26 |                 (__typecheck(x, y) && __no_side_effects(x, y))
      |                  ^~~~~~~~~~~
./include/linux/minmax.h:36:31: note: in expansion of macro '__safe_cmp'
   36 |         __builtin_choose_expr(__safe_cmp(x, y), \
      |                               ^~~~~~~~~~
./include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp'
   45 | #define min(x, y)       __careful_cmp(x, y, <)
      |                         ^~~~~~~~~~~~~
lib/iov_iter.c:1628:16: note: in expansion of macro 'min'
 1628 |         return min(nr * PAGE_SIZE - offset, maxsize);


git bisect pointed to 6c77676645ad ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()")

And, reverting it on top of mainline branch has fixed the build failure.

--
Regards
Sudip