[kkdwivedi:fermata 44/142] include/linux/bpf_unwind.h:260:58: warning: cast from pointer to integer of different size

[kkdwivedi:fermata 44/142] include/linux/bpf_unwind.h:260:58: warning: cast from pointer to integer of different size

[kernel test robot]

tree:   https://github.com/kkdwivedi/linux fermata
head:   4c57b609dbdca47f72c7bb3e97eb46046545dfeb
commit: 48e7cd30b23f144e3e1cda3efb64d9cf22e8614c [44/142] bpf: Let the callback of bpf_loop unwind
config: m68k-defconfig (https://download.01.org/0day-ci/archive/20261023/202610230228.Ibo7Qphi-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 16.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261023/202610230228.Ibo7Qphi-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/202610230228.Ibo7Qphi-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from kernel/bpf/bpf_iter.c:8:
   kernel/bpf/bpf_iter.c: In function '____bpf_loop':
>> include/linux/bpf_unwind.h:260:58: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     260 |         (r0) = ((bpf_callback_t)(void *)(fn))((u64)(a1), (u64)(a2), (u64)(a3),  \
         |                                                          ^
   include/linux/bpf_unwind.h:276:9: note: in expansion of macro '__bpf_call_cb'
     276 |         __bpf_call_cb(__bpf_callback_fn, fn, a1, a2, a3, a4, a5, r0, unwound)
         |         ^~~~~~~~~~~~~
   kernel/bpf/bpf_iter.c:770:17: note: in expansion of macro 'bpf_call_cb'
     770 |                 bpf_call_cb(callback, i, callback_ctx, 0, 0, 0, ret, unwound);
         |                 ^~~~~~~~~~~


vim +260 include/linux/bpf_unwind.h

e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  257  
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  258  #define __bpf_call_cb(type, fn, a1, a2, a3, a4, a5, r0, unwound)		\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  259  do {										\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20 @260  	(r0) = ((bpf_callback_t)(void *)(fn))((u64)(a1), (u64)(a2), (u64)(a3),	\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  261  					      (u64)(a4), (u64)(a5));		\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  262  	if (0)									\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  263  		goto unwound;							\
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  264  } while (0)
e56c95f1864ca19 Kumar Kartikeya Dwivedi 2026-10-20  265  

:::::: The code at line 260 was first introduced by commit
:::::: e56c95f1864ca1982840940c9f695fc2be39f039 bpf: Give a helper a way to call its callback with a pad

:::::: TO: Kumar Kartikeya Dwivedi <memxor@gmail.com>
:::::: CC: Kumar Kartikeya Dwivedi <memxor@gmail.com>

--
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https://github.com/intel/lkp-tests/wiki