[kkdwivedi:fermata 51/53] net/core/bpf_xdp_xmit.c:50:17: sparse: sparse: symbol 'bpf_xdp_xmit' was not declared. Should it be static?

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

tree:   https://github.com/kkdwivedi/linux fermata
head:   00ca9ce5685ac6da21cec48b9b0a8a0d6c11af32
commit: 1b42184dd7689f6237a0f659b39ea8d56198fd35 [51/53] bpf: Add bpf_xdp_xmit() to transmit arena bytes as an XDP frame
config: openrisc-randconfig-r2301-20261006 (https://download.01.org/0day-ci/archive/20261006/202610060937.Tdp8i48Q-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 12.5.0
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261006/202610060937.Tdp8i48Q-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/202610060937.Tdp8i48Q-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> net/core/bpf_xdp_xmit.c:50:17: sparse: sparse: symbol 'bpf_xdp_xmit' was not declared. Should it be static?
>> net/core/bpf_xdp_xmit.c:110:17: sparse: sparse: symbol 'bpf_xdp_xmit_flush' was not declared. Should it be static?

vim +/bpf_xdp_xmit +50 net/core/bpf_xdp_xmit.c

    38	
    39	/**
    40	 * bpf_xdp_xmit - transmit bytes from arena memory as an XDP frame
    41	 * @ifindex: the device, in the initial network namespace
    42	 * @buf__arena: the frame, from its Ethernet header on, in arena memory
    43	 * @len: its length in bytes, at most BPF_XDP_XMIT_MAX
    44	 * @flags: BPF_XDP_XMIT_F_NO_FLUSH to queue without ringing the doorbell
    45	 * @aux: the calling program (implicit)
    46	 *
    47	 * Returns 0 once the frame is queued on the device, -ENOSPC when the
    48	 * device's queue is full, or another -errno.
    49	 */
  > 50	__bpf_kfunc int bpf_xdp_xmit(u32 ifindex, void *buf__arena, u32 len, u64 flags,
    51				     struct bpf_prog_aux *aux)
    52	{
    53		u64 start = bpf_arena_get_kern_vm_start(aux->arena), addr = (u64)(long)buf__arena;
    54		unsigned int size = SKB_DATA_ALIGN(sizeof(struct xdp_frame) + BPF_XDP_XMIT_HEADROOM + len) +
    55				    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
    56		struct net_device *dev;
    57		struct xdp_frame *xdpf;
    58		void *p, *data;
    59		int ret;
    60	
    61		if (flags & ~BPF_XDP_XMIT_F_NO_FLUSH)
    62			return -EINVAL;
    63		if (len < ETH_HLEN || len > BPF_XDP_XMIT_MAX)
    64			return -EINVAL;
    65		if (!aux->arena || addr < start || addr + len > start + SZ_4G)
    66			return -EFAULT;
    67		for (p = buf__arena; p < buf__arena + len; p += PAGE_SIZE - offset_in_page(p))
    68			if (!vmalloc_to_page(p))
    69				return -EFAULT;
    70	
    71		local_bh_disable();
    72		rcu_read_lock();
    73		dev = dev_get_by_index_rcu(&init_net, ifindex);
    74		if (!dev || !dev->netdev_ops->ndo_xdp_xmit) {
    75			ret = -ENODEV;
    76			goto out;
    77		}
    78		xdpf = netdev_alloc_frag(size);
    79		if (!xdpf) {
    80			ret = -ENOMEM;
    81			goto out;
    82		}
    83		memset(xdpf, 0, sizeof(*xdpf));
    84		data = (void *)xdpf + sizeof(*xdpf) + BPF_XDP_XMIT_HEADROOM;
    85		memcpy(data, buf__arena, len);
    86		xdpf->data = data;
    87		xdpf->len = len;
    88		xdpf->headroom = BPF_XDP_XMIT_HEADROOM;
    89		xdpf->frame_sz = size;
    90		xdpf->mem_type = MEM_TYPE_PAGE_SHARED;
    91		ret = dev->netdev_ops->ndo_xdp_xmit(dev, 1, &xdpf,
    92						    flags & BPF_XDP_XMIT_F_NO_FLUSH ? 0 : XDP_XMIT_FLUSH);
    93		if (ret == 1) {
    94			ret = 0;
    95		} else {
    96			xdp_return_frame(xdpf);
    97			if (ret >= 0)
    98				ret = -ENOSPC;
    99		}
   100	out:
   101		rcu_read_unlock();
   102		local_bh_enable();
   103		return ret;
   104	}
   105	
   106	/**
   107	 * bpf_xdp_xmit_flush - ring the doorbell for frames queued without a flush
   108	 * @ifindex: the device, in the initial network namespace
   109	 */
 > 110	__bpf_kfunc int bpf_xdp_xmit_flush(u32 ifindex)
   111	{
   112		struct net_device *dev;
   113		int ret;
   114	
   115		local_bh_disable();
   116		rcu_read_lock();
   117		dev = dev_get_by_index_rcu(&init_net, ifindex);
   118		if (!dev || !dev->netdev_ops->ndo_xdp_xmit) {
   119			ret = -ENODEV;
   120			goto out;
   121		}
   122		ret = dev->netdev_ops->ndo_xdp_xmit(dev, 0, NULL, XDP_XMIT_FLUSH);
   123		if (ret > 0)
   124			ret = 0;
   125	out:
   126		rcu_read_unlock();
   127		local_bh_enable();
   128		return ret;
   129	}
   130	

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