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/* fcntl.cc: fcntl syscall
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2005, 2008, 2009,
2010, 2011, 2012 Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <unistd.h>
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "cygtls.h"
extern "C" int
fcntl64 (int fd, int cmd, ...)
{
int res = -1;
intptr_t arg = 0;
va_list args;
pthread_testcancel ();
debug_printf ("fcntl(%d, %d, ...)", fd, cmd);
myfault efault;
if (efault.faulted (EFAULT))
return -1;
cygheap_fdget cfd (fd, true);
if (cfd < 0)
goto done;
/* FIXME? All numerical args to fcntl are defined as long on Linux.
This relies on a really dirty trick on x86_64: A 32 bit mov to
a register (e.g. mov $1, %edx) always sets the high 32 bit to 0.
We're following the Linux lead here since the third arg to any
function is in a register anyway (%r8 in MS ABI). That's the easy
case which is covered here by always reading the arg with
sizeof (intptr_t) == sizeof (long) == sizeof (void*) which matches
all targets.
However, the POSIX standard defines all numerical args as type int.
If we take that literally, we had a (small) problem on 64 bit, since
sizeof (void*) != sizeof (int). If we would like to follow POSIX
more closely than Linux, we'd have to call va_arg on a per cmd basis. */
va_start (args, cmd);
arg = va_arg (args, intptr_t);
va_end (args);
switch (cmd)
{
case F_DUPFD:
case F_DUPFD_CLOEXEC:
if (arg >= 0 && arg < OPEN_MAX_MAX)
{
int flags = cmd == F_DUPFD_CLOEXEC ? O_CLOEXEC : 0;
res = cygheap->fdtab.dup3 (fd, cygheap_fdnew ((arg) - 1), flags);
}
else
{
set_errno (EINVAL);
res = -1;
}
break;
case F_GETLK:
case F_SETLK:
case F_SETLKW:
{
struct flock *fl = (struct flock *) arg;
fl->l_type &= F_RDLCK | F_WRLCK | F_UNLCK;
res = cfd->lock (cmd, fl);
}
break;
default:
res = cfd->fcntl (cmd, arg);
break;
}
done:
syscall_printf ("%R = fcntl(%d, %d, %ly)", res, fd, cmd, arg);
return res;
}
#ifdef __x86_64__
EXPORT_ALIAS (fcntl64, _fcntl)
#else
extern "C" int
_fcntl (int fd, int cmd, ...)
{
intptr_t arg = 0;
va_list args;
struct __flock32 *src = NULL;
struct flock dst;
myfault efault;
if (efault.faulted (EFAULT))
return -1;
va_start (args, cmd);
arg = va_arg (args, intptr_t);
va_end (args);
if (cmd == F_GETLK || cmd == F_SETLK || cmd == F_SETLKW)
{
src = (struct __flock32 *) arg;
dst.l_type = src->l_type;
dst.l_whence = src->l_whence;
dst.l_start = src->l_start;
dst.l_len = src->l_len;
dst.l_pid = src->l_pid;
arg = (intptr_t) &dst;
}
int res = fcntl64 (fd, cmd, arg);
if (cmd == F_GETLK)
{
src->l_type = dst.l_type;
src->l_whence = dst.l_whence;
src->l_start = dst.l_start;
src->l_len = dst.l_len;
src->l_pid = (short) dst.l_pid;
}
return res;
}
#endif
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