1 /* Linux fcntl syscall implementation.
2 Copyright (C) 2000-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <fcntl.h>
20 #include <stdarg.h>
21 #include <errno.h>
22 #include <sysdep-cancel.h>
23
24 #ifndef __OFF_T_MATCHES_OFF64_T
25
26 # ifndef FCNTL_ADJUST_CMD
27 # define FCNTL_ADJUST_CMD(__cmd) __cmd
28 # endif
29
30 int
__libc_fcntl(int fd,int cmd,...)31 __libc_fcntl (int fd, int cmd, ...)
32 {
33 va_list ap;
34 void *arg;
35
36 va_start (ap, cmd);
37 arg = va_arg (ap, void *);
38 va_end (ap);
39
40 cmd = FCNTL_ADJUST_CMD (cmd);
41
42 switch (cmd)
43 {
44 case F_SETLKW:
45 case F_SETLKW64:
46 return SYSCALL_CANCEL (fcntl64, fd, cmd, arg);
47 case F_OFD_SETLKW:
48 {
49 struct flock *flk = (struct flock *) arg;
50 struct flock64 flk64 =
51 {
52 .l_type = flk->l_type,
53 .l_whence = flk->l_whence,
54 .l_start = flk->l_start,
55 .l_len = flk->l_len,
56 .l_pid = flk->l_pid
57 };
58 return SYSCALL_CANCEL (fcntl64, fd, cmd, &flk64);
59 }
60 case F_OFD_GETLK:
61 case F_OFD_SETLK:
62 {
63 struct flock *flk = (struct flock *) arg;
64 struct flock64 flk64 =
65 {
66 .l_type = flk->l_type,
67 .l_whence = flk->l_whence,
68 .l_start = flk->l_start,
69 .l_len = flk->l_len,
70 .l_pid = flk->l_pid
71 };
72 int ret = INLINE_SYSCALL_CALL (fcntl64, fd, cmd, &flk64);
73 if (ret == -1)
74 return -1;
75 if ((off_t) flk64.l_start != flk64.l_start
76 || (off_t) flk64.l_len != flk64.l_len)
77 {
78 __set_errno (EOVERFLOW);
79 return -1;
80 }
81 flk->l_type = flk64.l_type;
82 flk->l_whence = flk64.l_whence;
83 flk->l_start = flk64.l_start;
84 flk->l_len = flk64.l_len;
85 flk->l_pid = flk64.l_pid;
86 return ret;
87 }
88 /* Since only F_SETLKW{64}/F_OLD_SETLK are cancellation entrypoints and
89 only OFD locks require LFS handling, all others flags are handled
90 unmodified by calling __NR_fcntl64. */
91 default:
92 return __fcntl64_nocancel_adjusted (fd, cmd, arg);
93 }
94 }
95 libc_hidden_def (__libc_fcntl)
96
weak_alias(__libc_fcntl,__fcntl)97 weak_alias (__libc_fcntl, __fcntl)
98 libc_hidden_weak (__fcntl)
99
100 # include <shlib-compat.h>
101 # if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_28)
102 int
103 __old_libc_fcntl64 (int fd, int cmd, ...)
104 {
105 va_list ap;
106 void *arg;
107
108 va_start (ap, cmd);
109 arg = va_arg (ap, void *);
110 va_end (ap);
111
112 /* Previous versions called __NR_fcntl64 for fcntl (which did not handle
113 OFD locks in LFS mode). */
114 return __libc_fcntl64 (fd, cmd, arg);
115 }
116 compat_symbol (libc, __old_libc_fcntl64, fcntl, GLIBC_2_0);
117 versioned_symbol (libc, __libc_fcntl, fcntl, GLIBC_2_28);
118 # else
119 weak_alias (__libc_fcntl, fcntl)
120 # endif
121
122 #endif /* __OFF_T_MATCHES_OFF64_T */
123