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.

3 files changed, 7 insertions, 20 deletions

diff --git a/ChangeLog b/ChangeLog
index 4d4905b0e1..13634d7401 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-03-02  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	[BZ #19682]
+	* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list:
+	Remove socketcall syscalls.
+
 2016-02-25  Carlos O'Donell  <carlos@redhat.com>
 
 	[BZ #18665]
diff --git a/NEWS b/NEWS
index 53cf5a4d85..4aed159d64 100644
--- a/NEWS
+++ b/NEWS
@@ -10,7 +10,7 @@ Version 2.20.1
 * The following bugs are resolved with this release:
 
   16009, 16617, 16618, 17266, 17269, 17370, 17371, 17460, 17485, 17555,
-  17625, 17630, 17801, 18032, 18665, 18694, 18928, 19018.
+  17625, 17630, 17801, 18032, 18665, 18694, 18928, 19018, 19682.
 
 * A stack-based buffer overflow was found in libresolv when invoked from
   libnss_dns, allowing specially crafted DNS responses to seize control
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list b/sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list
index 5b8c1024ac..9f03d26fea 100644
--- 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