Re: [PATCH v2 03/25] io_uring/kbuf: add support for kernel-managed buffer rings

[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/20251218083319.3485503-4-joannelkoong%40gmail.com
patch subject: [PATCH v2 03/25] io_uring/kbuf: add support for kernel-managed buffer rings
config: nios2-allnoconfig (https://download.01.org/0day-ci/archive/20251221/202512212016.Nbc4ikuj-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/20251221/202512212016.Nbc4ikuj-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/202512212016.Nbc4ikuj-lkp@intel.com/

All warnings (new ones prefixed by >>):

   io_uring/kbuf.c: In function 'io_setup_kmbuf_ring':
>> io_uring/kbuf.c:810:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     810 |                 buf->addr = (u64)buf_region;
         |                             ^


vim +810 io_uring/kbuf.c

   781	
   782	static int io_setup_kmbuf_ring(struct io_ring_ctx *ctx,
   783				       struct io_buffer_list *bl,
   784				       struct io_uring_buf_reg *reg)
   785	{
   786		struct io_uring_buf_ring *ring;
   787		unsigned long ring_size;
   788		void *buf_region;
   789		unsigned int i;
   790		int ret;
   791	
   792		/* allocate pages for the ring structure */
   793		ring_size = flex_array_size(ring, bufs, bl->nr_entries);
   794		ring = kzalloc(ring_size, GFP_KERNEL_ACCOUNT);
   795		if (!ring)
   796			return -ENOMEM;
   797	
   798		ret = io_create_region_multi_buf(ctx, &bl->region, bl->nr_entries,
   799						 reg->buf_size);
   800		if (ret) {
   801			kfree(ring);
   802			return ret;
   803		}
   804	
   805		/* initialize ring buf entries to point to the buffers */
   806		buf_region = bl->region.ptr;
   807		for (i = 0; i < bl->nr_entries; i++) {
   808			struct io_uring_buf *buf = &ring->bufs[i];
   809	
 > 810			buf->addr = (u64)buf_region;
   811			buf->len = reg->buf_size;
   812			buf->bid = i;
   813	
   814			buf_region += reg->buf_size;
   815		}
   816		ring->tail = bl->nr_entries;
   817	
   818		bl->buf_ring = ring;
   819	
   820		return 0;
   821	}
   822	

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