glibc/sysdeps/unix/sysv/linux/arm/socket.S
Ulrich Drepper 95084e8a47 Socket calls could not be restarted after being interrupted by
a signal.  The parameters on the stack were corrupted by the
signal handler.
1999-04-14 13:42:04 +00:00

89 lines
2.9 KiB
ArmAsm

/* Copyright (C) 1995, 1996, 1997, 1998 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <sysdep.h>
#include <socketcall.h>
#define P(a, b) P2(a, b)
#define P2(a, b) a##b
.text
/* The socket-oriented system calls are handled unusally in Linux.
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.
The .S files for the other calls just #define socket and #include this. */
#ifndef __socket
#define __socket P(__,socket)
#endif
#define PUSHARGS_1 stmfd sp!, {a1}
#define PUSHARGS_2 stmfd sp!, {a1, a2}
#define PUSHARGS_3 stmfd sp!, {a1, a2, a3}
#define PUSHARGS_4 stmfd sp!, {a1, a2, a3, a4}
#define PUSHARGS_5 stmfd sp!, {a1, a2, a3, a4} /* Caller has already pushed arg 5 */
#define PUSHARGS_6 stmfd sp!, {a1, a2, a3, a4}
#define POPARGS_1 add sp, sp, #4
#define POPARGS_2 add sp, sp, #8
#define POPARGS_3 add sp, sp, #12
#define POPARGS_4 add sp, sp, #16
#define POPARGS_5 add sp, sp, #16
#define POPARGS_6 add sp, sp, #16
#ifndef NARGS
#define NARGS 3 /* If we were called with no wrapper, this is really socket() */
#endif
.globl __socket
ENTRY (__socket)
/* This code previously moved sp into ip and stored the args using
stmdb ip!, {a1-a4}. It did not modify sp, so the stack never had
to be restored after the syscall completed. It saved an
instruction and meant no stack cleanup work was required.
This will not work in the case of a socket call being interrupted
by a signal. If the signal handler uses any stack the arguments
to socket will be trashed. The results of a restart of any
socket call are then unpredictable. */
/* Push args onto the stack. */
P(PUSHARGS_,NARGS)
/* Do the system call trap. */
mov a1, $P(SOCKOP_,socket)
mov a2, sp
swi SYS_ify(socketcall)
/* Pop args off the stack */
P(POPARGS_,NARGS)
/* r0 is < 0 if there was an error. */
cmn r0, $124
bhs PLTJMP(syscall_error)
/* Successful; return the syscall's value. */
ret
PSEUDO_END (__socket)
weak_alias (__socket, socket)