1/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
2 Copyright (C) 2001-2023 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 <errno.h>
20#include <fcntl.h>
21#include <not-cancel.h>
22#include <pthread.h>
23#include <shlib-compat.h>
24#include <shm-directory.h>
25#include <unistd.h>
26#include <sys/mman.h>
27
28/* Open shared memory object. */
29int
30__shm_open (const char *name, int oflag, mode_t mode)
31{
32 struct shmdir_name dirname;
33 int ret =__shm_get_name (&dirname, name, false);
34 if (ret != 0)
35 {
36 __set_errno (ret);
37 return -1;
38 }
39
40 oflag |= O_NOFOLLOW | O_CLOEXEC;
41#if defined (SHM_ANON) && defined (O_TMPFILE)
42 if (name == SHM_ANON)
43 oflag |= O_TMPFILE;
44#endif
45
46 int fd = __open64_nocancel (dirname.name, oflag, mode);
47 if (fd == -1 && __glibc_unlikely (errno == EISDIR))
48 /* It might be better to fold this error with EINVAL since
49 directory names are just another example for unsuitable shared
50 object names and the standard does not mention EISDIR. */
51 __set_errno (EINVAL);
52
53 return fd;
54}
55versioned_symbol (libc, __shm_open, shm_open, GLIBC_2_34);
56
57#if OTHER_SHLIB_COMPAT (librt, GLIBC_2_2, GLIBC_2_34)
58compat_symbol (libc, __shm_open, shm_open, GLIBC_2_2);
59#endif
60