Hi Christian,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.20-rc5]
[cannot apply to next-20181207]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Christian-Brauner/signal-add-taskfd_send_signal-syscall/20181209-044342
config: ia64-allnoconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 8.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=8.1.0 make.cross ARCH=ia64 

All warnings (new ones prefixed by >>):

   <stdin>:1185:2: warning: #warning syscall perf_event_open not implemented [-Wcpp]
   <stdin>:1239:2: warning: #warning syscall seccomp not implemented [-Wcpp]
   <stdin>:1317:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp]
   <stdin>:1320:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp]
   <stdin>:1323:2: warning: #warning syscall pkey_free not implemented [-Wcpp]
   <stdin>:1326:2: warning: #warning syscall statx not implemented [-Wcpp]
   <stdin>:1332:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp]
   <stdin>:1335:2: warning: #warning syscall rseq not implemented [-Wcpp]
>> <stdin>:1338:2: warning: #warning syscall taskfd_send_signal not implemented [-Wcpp]

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