[android-common:android15-6.6-2026-01 1/1] kernel/bpf/dmabuf_iter.c:117:17: warning: no previous prototype for function 'bpf_iter_dmabuf_new'

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

Hi Mercier,

FYI, the error/warning still remains.

tree:   https://android.googlesource.com/kernel/common android15-6.6-2026-01
head:   438a142b9dc1da06a555c9853456f23e76cfb744
commit: 755db8b11c512ff80570c0a57821350f2ba67937 [1/1] BACKPORT: bpf: Add open coded dmabuf iterator
config: i386-buildonly-randconfig-001-20260708 (https://download.01.org/0day-ci/archive/20260709/202607090141.RMFcN5KQ-lkp@intel.com/config)
compiler: clang version 22.1.3 (https://github.com/llvm/llvm-project e9846648fd6183ee6d8cbdb4502213fcf902a211)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260709/202607090141.RMFcN5KQ-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/202607090141.RMFcN5KQ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/bpf/dmabuf_iter.c:117:17: warning: no previous prototype for function 'bpf_iter_dmabuf_new' [-Wmissing-prototypes]
     117 | __bpf_kfunc int bpf_iter_dmabuf_new(struct bpf_iter_dmabuf *it)
         |                 ^
   kernel/bpf/dmabuf_iter.c:117:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
     117 | __bpf_kfunc int bpf_iter_dmabuf_new(struct bpf_iter_dmabuf *it)
         |             ^
         |             static 
>> kernel/bpf/dmabuf_iter.c:128:29: warning: no previous prototype for function 'bpf_iter_dmabuf_next' [-Wmissing-prototypes]
     128 | __bpf_kfunc struct dma_buf *bpf_iter_dmabuf_next(struct bpf_iter_dmabuf *it)
         |                             ^
   kernel/bpf/dmabuf_iter.c:128:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
     128 | __bpf_kfunc struct dma_buf *bpf_iter_dmabuf_next(struct bpf_iter_dmabuf *it)
         |             ^
         |             static 
>> kernel/bpf/dmabuf_iter.c:140:18: warning: no previous prototype for function 'bpf_iter_dmabuf_destroy' [-Wmissing-prototypes]
     140 | __bpf_kfunc void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it)
         |                  ^
   kernel/bpf/dmabuf_iter.c:140:13: note: declare 'static' if the function is not intended to be used outside of this translation unit
     140 | __bpf_kfunc void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it)
         |             ^
         |             static 
   3 warnings generated.


vim +/bpf_iter_dmabuf_new +117 kernel/bpf/dmabuf_iter.c

   116	
 > 117	__bpf_kfunc int bpf_iter_dmabuf_new(struct bpf_iter_dmabuf *it)
   118	{
   119		struct bpf_iter_dmabuf_kern *kit = (void *)it;
   120	
   121		BUILD_BUG_ON(sizeof(*kit) > sizeof(*it));
   122		BUILD_BUG_ON(__alignof__(*kit) != __alignof__(*it));
   123	
   124		kit->dmabuf = NULL;
   125		return 0;
   126	}
   127	
 > 128	__bpf_kfunc struct dma_buf *bpf_iter_dmabuf_next(struct bpf_iter_dmabuf *it)
   129	{
   130		struct bpf_iter_dmabuf_kern *kit = (void *)it;
   131	
   132		if (kit->dmabuf)
   133			kit->dmabuf = dma_buf_iter_next(kit->dmabuf);
   134		else
   135			kit->dmabuf = dma_buf_iter_begin();
   136	
   137		return kit->dmabuf;
   138	}
   139	
 > 140	__bpf_kfunc void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it)

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