Hi "Björn,

I love your patch! Yet something to improve:

[auto build test ERROR on bpf-next/master]
[also build test ERROR on next-20191122]
[cannot apply to v5.4-rc8]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Bj-rn-T-pel/Introduce-the-BPF-dispatcher-and-xdp_call-h/20191125-033931
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: x86_64-randconfig-a001-20191124 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.2-10+deb8u1) 4.9.2
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   kernel/bpf/dispatcher.c: In function 'bpf_dispatcher_update':
>> kernel/bpf/dispatcher.c:144:31: error: 'BPF_MOD_JUMP_TO_NOP' undeclared (first use in this function)
      bpf_arch_text_poke(d->func, BPF_MOD_JUMP_TO_NOP,
                                  ^
   kernel/bpf/dispatcher.c:144:31: note: each undeclared identifier is reported only once for each function it appears in
>> kernel/bpf/dispatcher.c:159:37: error: 'BPF_MOD_JUMP_TO_JUMP' undeclared (first use in this function)
      err = bpf_arch_text_poke(d->func, BPF_MOD_JUMP_TO_JUMP,
                                        ^
>> kernel/bpf/dispatcher.c:163:37: error: 'BPF_MOD_NOP_TO_JUMP' undeclared (first use in this function)
      err = bpf_arch_text_poke(d->func, BPF_MOD_NOP_TO_JUMP,
                                        ^

vim +/BPF_MOD_JUMP_TO_NOP +144 kernel/bpf/dispatcher.c

   135	
   136	static void bpf_dispatcher_update(struct bpf_dispatcher *d)
   137	{
   138		void *old_image = d->image + ((d->selector + 1) & 1) * PAGE_SIZE / 2;
   139		void *new_image = d->image + (d->selector & 1) * PAGE_SIZE / 2;
   140		s64 ips[BPF_DISPATCHER_MAX] = {}, *ipsp = &ips[0];
   141		int i, err;
   142	
   143		if (!d->num_progs) {
 > 144			bpf_arch_text_poke(d->func, BPF_MOD_JUMP_TO_NOP,
   145					   old_image, NULL);
   146			return;
   147		}
   148	
   149		for (i = 0; i < BPF_DISPATCHER_MAX; i++) {
   150			if (d->progs[i])
   151				*ipsp++ = (s64)(uintptr_t)d->progs[i]->bpf_func;
   152		}
   153		err = arch_prepare_bpf_dispatcher(new_image, &ips[0], d->num_progs);
   154		if (err)
   155			return;
   156	
   157		if (d->selector) {
   158			/* progs already running at this address */
 > 159			err = bpf_arch_text_poke(d->func, BPF_MOD_JUMP_TO_JUMP,
   160						 old_image, new_image);
   161		} else {
   162			/* first time registering */
 > 163			err = bpf_arch_text_poke(d->func, BPF_MOD_NOP_TO_JUMP,
   164						 NULL, new_image);
   165		}
   166		if (err)
   167			return;
   168		d->selector++;
   169	}
   170	

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0-DAY kernel test infrastructure                 Open Source Technology Center
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