this patch calls direct system calls for socket operations in the same way as power does. The system calls were introduced in kernel commit https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=977108f89c989b1eeb5c8d938e1e71913391eb5f.
There are no direct recv, send, accept syscalls available on s390. Thus
recvfrom, sendto, accept4 are called instead of the socketcall by defining __ASSUME_*_FOR_*_SYSCALL macros. See recv.c, send.c, accept.c in sysdeps/unix/sysv/linux/ folder.
The socketcalls in syscalls.list for s390-64 are removed. They were never used on s390x.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/kernel-features.h:
(__ASSUME_*_SYSCALL) Define new macros.
* sysdeps/unix/sysv/linux/s390/s390-64/syscalls.list:
Remove socketcall syscalls.
* sysdeps/unix/sysv/linux/accept.c (__libc_accept):
Use accept4 if defined __ASSUME_ACCEPT4_FOR_ACCEPT_SYSCALL.
* sysdeps/unix/sysv/linux/recv.c (__libc_recv):
Use recvfrom if defined __ASSUME_RECVFROM_FOR_RECV_SYSCALL.
* sysdeps/unix/sysv/linux/send.c (__libc_send):
Use sendto if defined __ASSUME_SENDTO_FOR_SEND_SYSCALL.
Explicit system calls for the socket operations were added in Linux kernel
in commit 86250b9d12ca for powerpc. This patch make use of those instead of
calling socketcall to save number of cycles on networking syscalls.
2015-08-25 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h: Define new macros.
* sysdeps/unix/sysv/linux/accept.c: Call direct system call.
* sysdeps/unix/sysv/linux/bind.c: Call direct system call.
* sysdeps/unix/sysv/linux/connect.c: Call direct system call.
* sysdeps/unix/sysv/linux/getpeername.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockname.c: Call direct system call.
* sysdeps/unix/sysv/linux/getsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/listen.c: Call direct system call.
* sysdeps/unix/sysv/linux/recv.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvfrom.c: Call direct system call.
* sysdeps/unix/sysv/linux/recvmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/send.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendmsg.c: Call direct system call.
* sysdeps/unix/sysv/linux/sendto.c: Call direct system call.
* sysdeps/unix/sysv/linux/setsockopt.c: Call direct system call.
* sysdeps/unix/sysv/linux/shutdown.c: Call direct system call.
* sysdeps/unix/sysv/linux/socket.c: Call direct system call.
* sysdeps/unix/sysv/linux/socketpair.c: Call direct system call.
This patch removes the socket.S implementation for all ports and replace
it by a C implementation using socketcall. For ports that implement
the syscall directly, there is no change.
The patch idea is to simplify the socket function implementation that
uses the socketcall to be based on C implemetation instead of a pseudo
assembly implementation with arch specific parts. The patch then remove
the assembly implementatation for the ports which uses socketcall
(i386, microblaze, mips, powerpc, sparc, m68k, s390 and sh).
I have cross-build GLIBC for afore-mentioned ports and tested on both
i386 and ppc32 without regressions.