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.
This patch splits s390 out of the main Linux kernel-features.h.
Not tested.
* sysdeps/unix/sysv/linux/s390/kernel-features.h: New file.
* sysdeps/unix/sysv/linux/kernel-features.h [__s390__]
(__ASSUME_SOCKETCALL): Do not define.
