CentOS 7 build warning, chacha20_avx512vl

[Vbook A1]

Hello,

this is the build log of the latest "stable" WireGuard on the latest CentOS 7:

> -bash-4.2# make
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/main.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/noise.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/device.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/peer.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/timers.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/queueing.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/send.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/receive.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/socket.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/hashtables.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/allowedips.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/ratelimiter.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/cookie.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/netlink.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/curve25519.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/chacha20poly1305.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/blake2s.o
>  AS [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/chacha20-x86_64.o
> /dev/shm/WireGuard-0.0.20180304/src/crypto/chacha20-x86_64.o: warning: objtool: chacha20_avx512vl()+0x3f: can't find jump dest instruction at .text+0x2669
>  AS [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/poly1305-x86_64.o
>  AS [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/blake2s-x86_64.o
>  AS [M]  /dev/shm/WireGuard-0.0.20180304/src/crypto/curve25519-x86_64.o
>  CC [M]  /dev/shm/WireGuard-0.0.20180304/src/compat/siphash/siphash.o
>  LD [M]  /dev/shm/WireGuard-0.0.20180304/src/wireguard.o
>  Building modules, stage 2.
>  MODPOST 1 modules
>  CC      /dev/shm/WireGuard-0.0.20180304/src/wireguard.mod.o
>  LD [M]  /dev/shm/WireGuard-0.0.20180304/src/wireguard.ko
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/wg.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/config.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/show.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/terminal.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/ipc.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/mnlg.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/encoding.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/curve25519.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/setconf.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/genkey.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/showconf.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/pubkey.o
>  CC      /dev/shm/WireGuard-0.0.20180304/src/tools/set.o
>  LD      /dev/shm/WireGuard-0.0.20180304/src/tools/wg


git "unstable" version gives the same warning:

>   AS [M]  /dev/shm/WireGuard/src/crypto/chacha20-x86_64.o
> /dev/shm/WireGuard/src/crypto/chacha20-x86_64.o: warning: objtool: chacha20_avx512vl()+0x3f: can't find jump dest instruction at .text+0x2669


However Wireguard [seemingly] works well despite this warning, tested
with three CentOS 7 servers. Is it OK?


System info:
CentOS 7.4.1708 64bit
Kernel 3.10.0-693.21.1.el7.x86_64
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-16)
Make 3.82
elfutils 0.168-8.el7
libmnl 1.0.3-7.el7


BTW many thanks for such a great software, I fell in love with
Wireguard for its simplicity after working for several years with
OpenVPN.