Re: [axboe-block:for-6.10/io_uring 42/42] io_uring/register.c:175:24: warning: arithmetic between different enumeration types ('enum io_uring_register_restriction_op' and 'enum io_uring_register_op')

[Gabriel Krisman Bertazi <krisman@suse.de>]

kernel test robot <lkp@intel.com> writes:

[+ io_uring list ]

>>> io_uring/register.c:175:24: warning: arithmetic between different
> enumeration types ('enum io_uring_register_restriction_op' and 'enum
> io_uring_register_op') [-Wenum-enum-conversion]
>      175 |         if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
>          |                               ^~~~~~~~~~~~~~~~~~~~~~~
>    io_uring/register.c:31:58: note: expanded from macro 'IORING_MAX_RESTRICTIONS'
>       31 | #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
>          |                                  ~~~~~~~~~~~~~~~~~~~~~~~ ^
>       32 |                                  IORING_REGISTER_LAST + IORING_OP_LAST)
>          |                                  ~~~~~~~~~~~~~~~~~~~~
>    14 warnings generated.

hm.

Do we want to fix?  The arithmetic is safe here.  I actually tried
triggering the warning with gcc, but even with -Wenum-conversion in
gcc-12 (which is in -Wextra and we don't use in the kernel build), I
couldn't do it.  only llvm catches this.

can we explicit cast to int to silent it?

-- 
Gabriel Krisman Bertazi