1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/* fcntl.cc: fcntl syscall
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 ();
__try
{
debug_printf ("fcntl(%d, %d, ...)", fd, cmd);
/* Don't lock the fd table when performing locking calls. */
cygheap_fdget cfd (fd, cmd < F_GETLK || cmd > F_SETLKW);
if (cfd < 0)
__leave;
/* 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;
default:
res = cfd->fcntl (cmd, arg);
break;
}
}
__except (EFAULT) {}
__endtry
syscall_printf ("%R = fcntl(%d, %d, %ly)", res, fd, cmd, arg);
return res;
}
#ifdef __x86_64__
EXPORT_ALIAS (fcntl64, fcntl)
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;
__try
{
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;
}
__except (EFAULT)
__endtry
return -1;
}
#endif
|
