1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <stdarg.h>
30 #include <fcntl.h>
31 
32 #include "private/bionic_fdtrack.h"
33 
34 #if defined(__LP64__)
35 
36 extern "C" int __fcntl(int fd, int cmd, ...);
37 
fcntl(int fd,int cmd,...)38 int fcntl(int fd, int cmd, ...) {
39   va_list args;
40   va_start(args, cmd);
41 
42   // This is a bit sketchy, especially because arg can be an int, but all of our
43   // supported 64-bit ABIs pass arg in a register.
44   void* arg = va_arg(args, void*);
45   va_end(args);
46 
47   int rc = __fcntl(fd, cmd, arg);
48   if (cmd == F_DUPFD) {
49     return FDTRACK_CREATE_NAME("F_DUPFD", rc);
50   } else if (cmd == F_DUPFD_CLOEXEC) {
51     return FDTRACK_CREATE_NAME("F_DUPFD_CLOEXEC", rc);
52   }
53   return rc;
54 }
55 
56 #else
57 
58 extern "C" int __fcntl64(int, int, ...);
59 
60 // For fcntl we use the fcntl64 system call to signal that we're using struct flock64.
fcntl(int fd,int cmd,...)61 int fcntl(int fd, int cmd, ...) {
62   va_list ap;
63 
64   va_start(ap, cmd);
65   void* arg = va_arg(ap, void*);
66   va_end(ap);
67 
68   if (cmd == F_DUPFD) {
69     return FDTRACK_CREATE_NAME("F_DUPFD", __fcntl64(fd, cmd, arg));
70   } else if (cmd == F_DUPFD_CLOEXEC) {
71     return FDTRACK_CREATE_NAME("F_DUPFD_CLOEXEC", __fcntl64(fd, cmd, arg));
72   }
73   return __fcntl64(fd, cmd, arg);
74 }
75 
76 #endif
77