Re: [PATCH v2 05/25] io_uring/kbuf: support kernel-managed buffer rings in buffer selection

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

Hi Joanne,

kernel test robot noticed the following build warnings:

[auto build test WARNING on axboe/for-next]
[also build test WARNING on linus/master v6.19-rc1 next-20251219]
[cannot apply to mszeredi-fuse/for-next]
[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/Joanne-Koong/io_uring-kbuf-refactor-io_buf_pbuf_register-logic-into-generic-helpers/20251218-165107
base:   https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git for-next
patch link:    https://lore.kernel.org/r/20251218083319.3485503-6-joannelkoong%40gmail.com
patch subject: [PATCH v2 05/25] io_uring/kbuf: support kernel-managed buffer rings in buffer selection
config: nios2-allnoconfig (https://download.01.org/0day-ci/archive/20251221/202512212111.RWRN4N7A-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251221/202512212111.RWRN4N7A-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/202512212111.RWRN4N7A-lkp@intel.com/

All warnings (new ones prefixed by >>):

   io_uring/kbuf.c: In function 'io_ring_buffer_select':
>> io_uring/kbuf.c:210:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     210 |                 sel.kaddr = (void *)buf->addr;
         |                             ^
   io_uring/kbuf.c: In function 'io_setup_kmbuf_ring':
   io_uring/kbuf.c:826:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     826 |                 buf->addr = (u64)buf_region;
         |                             ^


vim +210 io_uring/kbuf.c

   183	
   184	static struct io_br_sel io_ring_buffer_select(struct io_kiocb *req, size_t *len,
   185						      struct io_buffer_list *bl,
   186						      unsigned int issue_flags)
   187	{
   188		struct io_uring_buf_ring *br = bl->buf_ring;
   189		__u16 tail, head = bl->head;
   190		struct io_br_sel sel = { };
   191		struct io_uring_buf *buf;
   192		u32 buf_len;
   193	
   194		tail = smp_load_acquire(&br->tail);
   195		if (unlikely(tail == head))
   196			return sel;
   197	
   198		if (head + 1 == tail)
   199			req->flags |= REQ_F_BL_EMPTY;
   200	
   201		buf = io_ring_head_to_buf(br, head, bl->mask);
   202		buf_len = READ_ONCE(buf->len);
   203		if (*len == 0 || *len > buf_len)
   204			*len = buf_len;
   205		req->flags |= REQ_F_BUFFER_RING | REQ_F_BUFFERS_COMMIT;
   206		req->buf_index = READ_ONCE(buf->bid);
   207		sel.buf_list = bl;
   208		sel.addr = u64_to_user_ptr(READ_ONCE(buf->addr));
   209		if (bl->flags & IOBL_KERNEL_MANAGED)
 > 210			sel.kaddr = (void *)buf->addr;
   211		else
   212			sel.addr = u64_to_user_ptr(READ_ONCE(buf->addr));
   213	
   214		if (io_should_commit(req, bl, issue_flags)) {
   215			io_kbuf_commit(req, sel.buf_list, *len, 1);
   216			sel.buf_list = NULL;
   217		}
   218		return sel;
   219	}
   220	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki