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Re: [PATCH] Assume that accept4 is available
On 18/04/2017 16:37, Florian Weimer wrote:
> On 04/17/2017 05:01 PM, Adhemerval Zanella wrote:
>>> + {
>>> + socklen_t sa_len = sizeof (server_address);
>>> + xgetsockname (server_socket, (struct sockaddr *) &server_address,
>>> + &sa_len);
>>> + TEST_VERIFY (sa_len == sizeof (server_address));
>>> + }
>
>> Why the brackets? I usually seems this unnecessary.
>
> I prefer to restrict the scope of local variables if possible.
Ok.
>
>> Now that we are assuming accept4 support regardless, I think
>> we can simplify it even more and just have either
>> __ASSUME_ACCEPT4_SYSCALL or __ASSUME_SOCKETCALL
>> (which would imply __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL).
>
> We currently need all those because some override headers include sysdeps/unix/sysv/linux/kernel-features.h before their own definitions, others after. Rectifying that is a bit involved, and I don't want to do it with this change.
>
All right, I think we can cleanup this in another patch (I will prob work on
it when you patch lands).
> I believe I have addressed your other suggestions with the attached patch.
Yes, I think it is all covered, thanks.
>
> Thanks,
> Florian
>
> accept4.patch
>
>
> Assume that accept4 is always available and works
>
> Simplify the Linux accept4 implementation based on the assumption
> that it is available in some way. __ASSUME_ACCEPT4_SOCKETCALL was
> previously unused, so remove it.
>
> For ia64, the accept4 system call (and socket call) were backported
> in kernel version 3.2.18. Reflect this in the installation
> instructions.
>
> 2017-04-18 Florian Weimer <fweimer@redhat.com>
>
> * nscd/connections.c (have_accept4): Removed definition.
> (nscd_run_worker, main_loop_poll, main_loop_epolll): Assume that
> accept4 works.
> * manual/install.texi (Linux): Require at least kernel 3.2.18 for
> ia64 because that was the first version with accept4 support.
> * support/Makefile (libsupport-routines): Add xaccept4.
> * support/xsocket.h (xaccept4): Declare.
> * support/xaccept4.c: New file.
> * socket/tst-accept4.c: New file.
> * socket/Makefile (tests): Add tst-accept4.
> * sysdeps/mach/hurd/kernel-features.h (__ASSUME_ACCEPT4): Remove
> definition.
> * sysdeps/nacl/kernel-features.h (__ASSUME_ACCEPT4): Remove
> comment.
> * sysdeps/unix/sysv/linux/accept4.c: Assume that an accept4
> implementation is available.
> (accept4): Use the system call if available, otherwise use the
> socket call.
> * sysdeps/unix/sysv/linux/ia64/configure.ac (arch_minimum_kernel):
> Set to 3.2.18.
> * sysdeps/unix/sysv/linux/ia64/kernel-features.h
> (__ASSUME_ACCEPT4_SYSCALL, __ASSUME_ACCEPT4): Do not undefine.
> accept4 is unconditionally available in later 3.2 stable kernels.
> (__ASSUME_ACCEPT4_SYSCALL): Define.
> * sysdeps/unix/sysv/linux/kernel-features.h
> (__ASSUME_ACCEPT4_SOCKETCALL, __ASSUME_ACCEPT4): Remove
> definitions.
> * sysdeps/unix/sysv/linux/i386/kernel-features.h
> (__ASSUME_ACCEPT4_SYSCALL): Define for Linux 4.3 or later.
>
> diff --git a/INSTALL b/INSTALL
> index 60f714e..920c4df 100644
> --- a/INSTALL
> +++ b/INSTALL
> @@ -501,13 +501,15 @@ Specific advice for GNU/Linux systems
>
> If you are installing the GNU C Library on GNU/Linux systems, you need
> to have the header files from a 3.2 or newer kernel around for
> -reference. These headers must be installed using 'make
> -headers_install'; the headers present in the kernel source directory are
> -not suitable for direct use by the GNU C Library. You do not need to
> -use that kernel, just have its headers installed where the GNU C Library
> -can access them, referred to here as INSTALL-DIRECTORY. The easiest way
> -to do this is to unpack it in a directory such as
> -'/usr/src/linux-VERSION'. In that directory, run 'make headers_install
> +reference. (For the ia64 architecture, you need version 3.2.18 or newer
> +because this is the first version with support for the 'accept4' system
> +call.) These headers must be installed using 'make headers_install';
> +the headers present in the kernel source directory are not suitable for
> +direct use by the GNU C Library. You do not need to use that kernel,
> +just have its headers installed where the GNU C Library can access them,
> +referred to here as INSTALL-DIRECTORY. The easiest way to do this is to
> +unpack it in a directory such as '/usr/src/linux-VERSION'. In that
> +directory, run 'make headers_install
> INSTALL_HDR_PATH=INSTALL-DIRECTORY'. Finally, configure the GNU C
> Library with the option '--with-headers=INSTALL-DIRECTORY/include'. Use
> the most recent kernel you can get your hands on. (If you are
> diff --git a/manual/install.texi b/manual/install.texi
> index 99397c2..d39d2da 100644
> --- a/manual/install.texi
> +++ b/manual/install.texi
> @@ -566,6 +566,8 @@ patches, although we try to avoid this.
>
> If you are installing @theglibc{} on @gnulinuxsystems{}, you need to have
> the header files from a 3.2 or newer kernel around for reference.
> +(For the ia64 architecture, you need version 3.2.18 or newer because this
> +is the first version with support for the @code{accept4} system call.)
> These headers must be installed using @samp{make headers_install}; the
> headers present in the kernel source directory are not suitable for
> direct use by @theglibc{}. You do not need to use that kernel, just have
> diff --git a/nscd/connections.c b/nscd/connections.c
> index a5ca57a..cc1ed72 100644
> --- a/nscd/connections.c
> +++ b/nscd/connections.c
> @@ -257,10 +257,6 @@ int inotify_fd = -1;
> static int nl_status_fd = -1;
> #endif
>
> -#ifndef __ASSUME_ACCEPT4
> -static int have_accept4;
> -#endif
> -
> /* Number of times clients had to wait. */
> unsigned long int client_queued;
>
> @@ -1650,16 +1646,6 @@ nscd_run_worker (void *p)
> /* We are done with the list. */
> pthread_mutex_unlock (&readylist_lock);
>
> -#ifndef __ASSUME_ACCEPT4
> - if (have_accept4 < 0)
> - {
> - /* We do not want to block on a short read or so. */
> - int fl = fcntl (fd, F_GETFL);
> - if (fl == -1 || fcntl (fd, F_SETFL, fl | O_NONBLOCK) == -1)
> - goto close_and_out;
> - }
> -#endif
> -
> /* Now read the request. */
> request_header req;
> if (__builtin_expect (TEMP_FAILURE_RETRY (read (fd, &req, sizeof (req)))
> @@ -2099,24 +2085,8 @@ main_loop_poll (void)
> if (conns[0].revents != 0)
> {
> /* We have a new incoming connection. Accept the connection. */
> - int fd;
> -
> -#ifndef __ASSUME_ACCEPT4
> - fd = -1;
> - if (have_accept4 >= 0)
> -#endif
> - {
> - fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
> + int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
> SOCK_NONBLOCK));
> -#ifndef __ASSUME_ACCEPT4
> - if (have_accept4 == 0)
> - have_accept4 = fd != -1 || errno != ENOSYS ? 1 : -1;
> -#endif
> - }
> -#ifndef __ASSUME_ACCEPT4
> - if (have_accept4 < 0)
> - fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL));
> -#endif
>
> /* Use the descriptor if we have not reached the limit. */
> if (fd >= 0)
> @@ -2284,24 +2254,8 @@ main_loop_epoll (int efd)
> if (revs[cnt].data.fd == sock)
> {
> /* A new connection. */
> - int fd;
> -
> -# ifndef __ASSUME_ACCEPT4
> - fd = -1;
> - if (have_accept4 >= 0)
> -# endif
> - {
> - fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
> + int fd = TEMP_FAILURE_RETRY (accept4 (sock, NULL, NULL,
> SOCK_NONBLOCK));
> -# ifndef __ASSUME_ACCEPT4
> - if (have_accept4 == 0)
> - have_accept4 = fd != -1 || errno != ENOSYS ? 1 : -1;
> -# endif
> - }
> -# ifndef __ASSUME_ACCEPT4
> - if (have_accept4 < 0)
> - fd = TEMP_FAILURE_RETRY (accept (sock, NULL, NULL));
> -# endif
>
> /* Use the descriptor if we have not reached the limit. */
> if (fd >= 0)
> diff --git a/socket/Makefile b/socket/Makefile
> index 25d4f68..1e2555d 100644
> --- a/socket/Makefile
> +++ b/socket/Makefile
> @@ -31,6 +31,8 @@ routines := accept bind connect getpeername getsockname getsockopt \
> setsockopt shutdown socket socketpair isfdtype opensock \
> sockatmark accept4 recvmmsg sendmmsg
>
> +tests := tst-accept4
> +
> aux := sa_len
>
> include ../Rules
> diff --git a/socket/tst-accept4.c b/socket/tst-accept4.c
> new file mode 100644
> index 0000000..a5cf3a2
> --- /dev/null
> +++ b/socket/tst-accept4.c
> @@ -0,0 +1,131 @@
> +/* Test the accept4 function with differing flags arguments.
> + Copyright (C) 2017 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <http://www.gnu.org/licenses/>. */
> +
> +#include <arpa/inet.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <stdbool.h>
> +#include <support/check.h>
> +#include <support/xsocket.h>
> +#include <support/xunistd.h>
> +#include <sys/socket.h>
> +
> +static bool
> +is_nonblocking (int fd)
> +{
> + int status = fcntl (fd, F_GETFL);
> + if (status < 0)
> + FAIL_EXIT1 ("fcntl (F_GETFL): %m");
> + return status & O_NONBLOCK;
> +}
> +
> +static bool
> +is_cloexec (int fd)
> +{
> + int status = fcntl (fd, F_GETFD);
> + if (status < 0)
> + FAIL_EXIT1 ("fcntl (F_GETFD): %m");
> + return status & FD_CLOEXEC;
> +}
> +
> +struct client
> +{
> + int socket;
> + struct sockaddr_in address;
> +};
> +
> +/* Perform a non-blocking connect to *SERVER_ADDRESS. */
> +static struct client
> +client_connect (const struct sockaddr_in *server_address)
> +{
> + struct client result;
> + result.socket = xsocket (AF_INET,
> + SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
> + TEST_VERIFY (is_nonblocking (result.socket));
> + TEST_VERIFY (is_cloexec (result.socket));
> + int ret = connect (result.socket, (const struct sockaddr *) server_address,
> + sizeof (*server_address));
> + if (ret < 0 && errno != EINPROGRESS)
> + FAIL_EXIT1 ("client connect: %m");
> + socklen_t sa_len = sizeof (result.address);
> + xgetsockname (result.socket, (struct sockaddr *) &result.address,
> + &sa_len);
> + TEST_VERIFY (sa_len == sizeof (result.address));
> + return result;
> +}
> +
> +static void
> +check_same_address (const struct sockaddr_in *left,
> + const struct sockaddr_in *right)
> +{
> + TEST_VERIFY (left->sin_family == AF_INET);
> + TEST_VERIFY (right->sin_family == AF_INET);
> + TEST_VERIFY (left->sin_addr.s_addr == right->sin_addr.s_addr);
> + TEST_VERIFY (left->sin_port == right->sin_port);
> +}
> +
> +static int
> +do_test (void)
> +{
> + /* Create server socket. */
> + int server_socket = xsocket (AF_INET, SOCK_STREAM, 0);
> + TEST_VERIFY (!is_nonblocking (server_socket));
> + TEST_VERIFY (!is_cloexec (server_socket));
> + struct sockaddr_in server_address =
> + {
> + .sin_family = AF_INET,
> + .sin_addr = {.s_addr = htonl (INADDR_LOOPBACK) },
> + };
> + xbind (server_socket,
> + (struct sockaddr *) &server_address, sizeof (server_address));
> + {
> + socklen_t sa_len = sizeof (server_address);
> + xgetsockname (server_socket, (struct sockaddr *) &server_address,
> + &sa_len);
> + TEST_VERIFY (sa_len == sizeof (server_address));
> + }
> + xlisten (server_socket, 5);
> +
> + for (int do_nonblock = 0; do_nonblock < 2; ++do_nonblock)
> + for (int do_cloexec = 0; do_cloexec < 2; ++do_cloexec)
> + {
> + int sockflags = 0;
> + if (do_nonblock)
> + sockflags |= SOCK_NONBLOCK;
> + if (do_cloexec)
> + sockflags |= SOCK_CLOEXEC;
> +
> + struct client client = client_connect (&server_address);
> + struct sockaddr_in client_address;
> + socklen_t sa_len = sizeof (client_address);
> + int client_socket = xaccept4 (server_socket,
> + (struct sockaddr *) &client_address,
> + &sa_len, sockflags);
> + TEST_VERIFY (sa_len == sizeof (client_address));
> + TEST_VERIFY (is_nonblocking (client_socket) == do_nonblock);
> + TEST_VERIFY (is_cloexec (client_socket) == do_cloexec);
> + check_same_address (&client.address, &client_address);
> + xclose (client_socket);
> + xclose (client.socket);
> + }
> +
> + xclose (server_socket);
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/support/Makefile b/support/Makefile
> index 1f33fa0..38dbd83 100644
> --- a/support/Makefile
> +++ b/support/Makefile
> @@ -50,6 +50,7 @@ libsupport-routines = \
> temp_file \
> write_message \
> xaccept \
> + xaccept4 \
> xasprintf \
> xbind \
> xcalloc \
> diff --git a/support/xaccept4.c b/support/xaccept4.c
> new file mode 100644
> index 0000000..67dd95e
> --- /dev/null
> +++ b/support/xaccept4.c
> @@ -0,0 +1,32 @@
> +/* accept4 with error checking.
> + Copyright (C) 2017 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <http://www.gnu.org/licenses/>. */
> +
> +#include <support/xsocket.h>
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <support/check.h>
> +
> +int
> +xaccept4 (int fd, struct sockaddr *sa, socklen_t *salen, int flags)
> +{
> + int clientfd = accept4 (fd, sa, salen, flags);
> + if (clientfd < 0)
> + FAIL_EXIT1 ("accept4 (%d, 0x%x): %m", fd, flags);
> + return clientfd;
> +}
> diff --git a/support/xsocket.h b/support/xsocket.h
> index 0dbf13a..d672494 100644
> --- a/support/xsocket.h
> +++ b/support/xsocket.h
> @@ -30,6 +30,7 @@ void xconnect (int, const struct sockaddr *, socklen_t);
> void xbind (int, const struct sockaddr *, socklen_t);
> void xlisten (int, int);
> int xaccept (int, struct sockaddr *, socklen_t *);
> +int xaccept4 (int, struct sockaddr *, socklen_t *, int);
> void xsendto (int, const void *, size_t, int,
> const struct sockaddr *, socklen_t);
> size_t xrecvfrom (int, void *, size_t, int, struct sockaddr *, socklen_t *);
> diff --git a/sysdeps/mach/hurd/kernel-features.h b/sysdeps/mach/hurd/kernel-features.h
> index 20cb3ba..1966388 100644
> --- a/sysdeps/mach/hurd/kernel-features.h
> +++ b/sysdeps/mach/hurd/kernel-features.h
> @@ -19,5 +19,3 @@
> /* This file can define __ASSUME_* macros checked by certain source files.
> Almost none of these are used outside of sysdeps/unix/sysv/linux code.
> But those referring to POSIX-level features like O_* flags can be. */
> -
> -#define __ASSUME_ACCEPT4 1
> diff --git a/sysdeps/nacl/kernel-features.h b/sysdeps/nacl/kernel-features.h
> index 32834fd..ba315b6 100644
> --- a/sysdeps/nacl/kernel-features.h
> +++ b/sysdeps/nacl/kernel-features.h
> @@ -19,7 +19,3 @@
> /* This file can define __ASSUME_* macros checked by certain source files.
> Almost none of these are used outside of sysdeps/unix/sysv/linux code.
> But those referring to POSIX-level features like O_* flags can be. */
> -
> -/*
> -#define __ASSUME_ACCEPT4 1
> -*/
> diff --git a/sysdeps/unix/sysv/linux/accept4.c b/sysdeps/unix/sysv/linux/accept4.c
> index 53afd7a..0592f43 100644
> --- a/sysdeps/unix/sysv/linux/accept4.c
> +++ b/sysdeps/unix/sysv/linux/accept4.c
> @@ -22,75 +22,20 @@
>
> #include <sysdep-cancel.h>
> #include <sys/syscall.h>
> +#include <socketcall.h>
> #include <kernel-features.h>
>
> +int
> +accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
> +{
> /* Do not use the accept4 syscall on socketcall architectures unless
> it was added at the same time as the socketcall support or can be
> assumed to be present. */
> #if defined __ASSUME_SOCKETCALL \
> && !defined __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL \
> && !defined __ASSUME_ACCEPT4_SYSCALL
> -# undef __NR_accept4
> -#endif
> -
> -#ifdef __NR_accept4
> -int
> -accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
> -{
> - return SYSCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags);
> -}
> -#elif defined __NR_socketcall
> -# include <socketcall.h>
> -# ifdef __ASSUME_ACCEPT4_SOCKETCALL
> -int
> -accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
> -{
> return SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags);
> -}
> -# else
> -static int have_accept4;
> -
> -int
> -accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
> -{
> - if (__glibc_likely (have_accept4 >= 0))
> - {
> - int ret = SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len,
> - flags);
> - /* The kernel returns -EINVAL for unknown socket operations.
> - We need to convert that error to an ENOSYS error. */
> - if (__builtin_expect (ret < 0, 0)
> - && have_accept4 == 0
> - && errno == EINVAL)
> - {
> - /* Try another call, this time with the FLAGS parameter
> - cleared and an invalid file descriptor. This call will not
> - cause any harm and it will return immediately. */
> - ret = SOCKETCALL_CANCEL (invalid, -1);
> - if (errno == EINVAL)
> - {
> - have_accept4 = -1;
> - __set_errno (ENOSYS);
> - }
> - else
> - {
> - have_accept4 = 1;
> - __set_errno (EINVAL);
> - }
> - return -1;
> - }
> - return ret;
> - }
> - __set_errno (ENOSYS);
> - return -1;
> -}
> -# endif /* __ASSUME_ACCEPT4_SOCKETCALL */
> -#else /* __NR_socketcall */
> -int
> -accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags)
> -{
> - __set_errno (ENOSYS);
> - return -1;
> -}
> -stub_warning (accept4)
> +#else
> + return SYSCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags);
> #endif
> +}
> diff --git a/sysdeps/unix/sysv/linux/ia64/configure b/sysdeps/unix/sysv/linux/ia64/configure
> index 1d4e5d1..3cf7237 100644
> --- a/sysdeps/unix/sysv/linux/ia64/configure
> +++ b/sysdeps/unix/sysv/linux/ia64/configure
> @@ -2,3 +2,7 @@
> # Local configure fragment for sysdeps/unix/sysv/linux/ia64
>
> ldd_rewrite_script=$dir/ldd-rewrite.sed
> +
> +# First version with support for the accept4 system call.
> +# Linux 3.3 includes it as well.
> +arch_minimum_kernel=3.2.18
> diff --git a/sysdeps/unix/sysv/linux/ia64/configure.ac b/sysdeps/unix/sysv/linux/ia64/configure.ac
> index 4fb5647..94a578c 100644
> --- a/sysdeps/unix/sysv/linux/ia64/configure.ac
> +++ b/sysdeps/unix/sysv/linux/ia64/configure.ac
> @@ -2,3 +2,7 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
> # Local configure fragment for sysdeps/unix/sysv/linux/ia64
>
> ldd_rewrite_script=$dir/ldd-rewrite.sed
> +
> +# First version with support for the accept4 system call.
> +# Linux 3.3 includes it as well.
> +arch_minimum_kernel=3.2.18
> diff --git a/sysdeps/unix/sysv/linux/ia64/kernel-features.h b/sysdeps/unix/sysv/linux/ia64/kernel-features.h
> index ac9403e..cda0ad6 100644
> --- a/sysdeps/unix/sysv/linux/ia64/kernel-features.h
> +++ b/sysdeps/unix/sysv/linux/ia64/kernel-features.h
> @@ -22,13 +22,8 @@
>
> #include_next <kernel-features.h>
>
> -/* Support for the accept4 syscall was added in 3.3. */
> -#if __LINUX_KERNEL_VERSION < 0x030300
> -# undef __ASSUME_ACCEPT4_SYSCALL
> -# undef __ASSUME_ACCEPT4
> -#endif
> -
> #define __ASSUME_RECV_SYSCALL 1
> #define __ASSUME_SEND_SYSCALL 1
> +#define __ASSUME_ACCEPT4_SYSCALL 1
>
> #endif /* _KERNEL_FEATURES_H */
> diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
> index fd936c5..b981466 100644
> --- a/sysdeps/unix/sysv/linux/kernel-features.h
> +++ b/sysdeps/unix/sysv/linux/kernel-features.h
> @@ -75,18 +75,11 @@
> architectures using a separate syscall rather than socketcall that
> syscall was only added later, and some architectures first had
> socketcall support then a separate syscall. Define
> - __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
> - architecture and accept4 is available through socketcall,
> __ASSUME_ACCEPT4_SYSCALL if it is available through a separate
> - syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
> + syscall, and __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
> available through a separate syscall at the same time as through
> - socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
> - to work. */
> -#ifdef __ASSUME_SOCKETCALL
> -# define __ASSUME_ACCEPT4_SOCKETCALL 1
> -#endif
> + socketcall. */
> #define __ASSUME_ACCEPT4_SYSCALL 1
> -#define __ASSUME_ACCEPT4 1
>
> /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29. */
> #define __ASSUME_FUTEX_CLOCK_REALTIME 1
>