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/* Copyright (C) 1995-2015 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 <sysdep-cancel.h>
#include <socketcall.h>
#include <tls.h>
#include <kernel-features.h>
#define EINVAL 22
#define ENOSYS 38
#ifdef __ASSUME_ACCEPT4_SOCKETCALL
# define errlabel SYSCALL_ERROR_LABEL
#else
# define errlabel .Lerr
.data
have_accept4:
.long 0
#endif
.text
/* The socket-oriented system calls are handled unusally in Linux/i386.
They are all gated through the single `socketcall' system call number.
`socketcall' takes two arguments: the first is the subcode, specifying
which socket function is being called; and the second is a pointer to
the arguments to the specific function. */
.globl __libc_accept4
ENTRY (__libc_accept4)
#ifdef CENABLE
SINGLE_THREAD_P
jne 1f
#endif
/* Save registers. */
movl %ebx, %edx
cfi_register (3, 2)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 4(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
/* Restore registers. */
movl %edx, %ebx
cfi_restore (3)
/* %eax is < 0 if there was an error. */
cmpl $-125, %eax
jae errlabel
/* Successful; return the syscall's value. */
ret
#ifdef CENABLE
/* We need one more register. */
1: pushl %esi
cfi_adjust_cfa_offset(4)
/* Enable asynchronous cancellation. */
CENABLE
movl %eax, %esi
cfi_offset(6, -8) /* %esi */
/* Save registers. */
movl %ebx, %edx
cfi_register (3, 2)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 8(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
/* Restore registers. */
movl %edx, %ebx
cfi_restore (3)
/* Restore the cancellation. */
xchgl %esi, %eax
CDISABLE
/* Restore registers. */
movl %esi, %eax
popl %esi
cfi_restore (6)
cfi_adjust_cfa_offset(-4)
/* %eax is < 0 if there was an error. */
cmpl $-125, %eax
jae errlabel
/* Successful; return the syscall's value. */
ret
#endif
#ifndef __ASSUME_ACCEPT4_SOCKETCALL
/* The kernel returns -EINVAL for unknown socket operations.
We need to convert that error to an ENOSYS error. */
.Lerr: cmpl $-EINVAL, %eax
jne SYSCALL_ERROR_LABEL
/* Save registers. */
pushl %ebx
cfi_adjust_cfa_offset(4)
cfi_offset(ebx, -8)
# ifdef PIC
SETUP_PIC_REG (dx)
addl $_GLOBAL_OFFSET_TABLE_, %edx
movl have_accept4@GOTOFF(%edx), %eax
# else
movl have_accept4, %eax
# endif
testl %eax, %eax
jne 1f
/* 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. */
movl $-1, 8(%esp)
movl $0, 20(%esp)
movl $SYS_ify(socketcall), %eax /* System call number in %eax. */
movl $SOCKOP_accept4, %ebx /* Subcode is first arg to syscall. */
lea 8(%esp), %ecx /* Address of args is 2nd arg. */
/* Do the system call trap. */
ENTER_KERNEL
cmpl $-EINVAL, %eax
movl $-1, %eax
je 3f
movl $1, %eax
3:
# ifdef PIC
movl %eax, have_accept4@GOTOFF(%edx)
# else
movl %eax, have_accept4
# endif
testl %eax, %eax
1: movl $-EINVAL, %eax
jns 2f
movl $-ENOSYS, %eax
/* Restore registers. */
2: popl %ebx
cfi_restore (ebx)
jmp SYSCALL_ERROR_LABEL
#endif
PSEUDO_END (__libc_accept4)
weak_alias (__libc_accept4, accept4)
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