S390: Do not use direct socket syscalls if build on kernels >= 4.3. [BZ #19682]

Beginning with Linux 4.3, the kernel headers contain direct
system call numbers __NR_socket etc. on s390x. On older kernels,
the socket-multiplexer syscall __NR_socketcall was used.

To enable these new syscalls, the patch
"S390: Call direct system calls for socket operations."
(https://sourceware.org/git/?p=glibc.git;a=commit;h=016495b818cb61df7d0d10e6db54074271b3e3a5)
was applied upstream.

If glibc 2.23 is configured with --enable-kernel=4.3 and newer,
the direct socket syscalls are used.
For older kernels, the socket-multiplexer syscall is used instead.

In glibc 2.22 and earlier, this patch is not applied.
If you build glibc on a kernel < 4.3, the socket-multiplexer
syscall is used. But if you build glibc on kernel >= 4.3, the
direct socket-syscalls are used. If you install this glibc on a
kernel < 4.3, all socket operations will fail.
See "Bug 19682 - s390x: Incorrect syscall definitions cause
breakage with Linux 4.3 headers"
(https://sourceware.org/bugzilla/show_bug.cgi?id=19682)
The configure switch --enable-kernel does not influence this
behaviour on older glibc-releases.

The solution is to remove the direct socket-syscalls in
sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list
(this patch) on older glibc-releases as it was done by the
upstream patch, too. These entries were never used on s390x,
but the c-files in sysdeps/unix/sysv/linux/.
After this removal, the behaviour of the socket functions are
not changed compared to the original glibc release version
and the socket-multiplexer-syscall is always used.

(cherry picked from commit 425c48c217ef93c2c4f81f9f3bb2fdba096877a2)

diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list b/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list
index 5b8c1024ac73bf8ec3a2807643eff86cc2a6c127..9f03d26feadc7608c4737eedb8f0fef1327a44eb 100644 (file)
--- a/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list
@@ -12,22 +12,3 @@ shmget               -       shmget          i:iii   __shmget        shmget
 semop          -       semop           i:ipi   __semop         semop
 semget         -       semget          i:iii   __semget        semget
 semctl         -       semctl          i:iiii  __semctl        semctl
-
-# proper socket implementations:
-accept         -       accept          Ci:iBN  __libc_accept   __accept accept
-bind           -       bind            i:ipi   __bind          bind
-connect                -       connect         Ci:ipi  __libc_connect  __connect connect
-getpeername    -       getpeername     i:ipp   __getpeername   getpeername
-getsockname    -       getsockname     i:ipp   __getsockname   getsockname
-getsockopt     -       getsockopt      i:iiiBN __getsockopt    getsockopt
-listen         -       listen          i:ii    __listen        listen
-recv           -       recv            Ci:ibni __libc_recv     __recv recv
-recvfrom       -       recvfrom        Ci:ibniBN       __libc_recvfrom __recvfrom recvfrom
-recvmsg                -       recvmsg         Ci:ipi  __libc_recvmsg  __recvmsg recvmsg
-send           -       send            Ci:ibni __libc_send     __send send
-sendmsg                -       sendmsg         Ci:ipi  __libc_sendmsg  __sendmsg sendmsg
-sendto         -       sendto          Ci:ibnibn       __libc_sendto   __sendto sendto
-setsockopt     -       setsockopt      i:iiibn __setsockopt    setsockopt
-shutdown       -       shutdown        i:ii    __shutdown      shutdown
-socket         -       socket          i:iii   __socket        socket
-socketpair     -       socketpair      i:iiif  __socketpair    socketpair