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1/* Copyright (C) 1995-2025 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#ifndef _SYS_SHM_H
19# error "Never include <bits/shm.h> directly; use <sys/shm.h> instead."
20#endif
21
22#include <bits/types.h>
23#include <bits/wordsize.h>
24#include <bits/shmlba.h>
25
26/* Permission flag for shmget. */
27#define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */
28#define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */
29
30/* Flags for `shmat'. */
31#define SHM_RDONLY 010000 /* attach read-only else read-write */
32#define SHM_RND 020000 /* round attach address to SHMLBA */
33#define SHM_REMAP 040000 /* take-over region on attach */
34#define SHM_EXEC 0100000 /* execution access */
35
36/* Commands for `shmctl'. */
37#define SHM_LOCK 11 /* lock segment (root only) */
38#define SHM_UNLOCK 12 /* unlock segment (root only) */
39
40__BEGIN_DECLS
41
42/* Type to count number of attaches. */
43typedef __syscall_ulong_t shmatt_t;
44
45#include <bits/types/struct_shmid_ds.h>
46#include <bits/types/struct_shmid64_ds.h>
47
48#ifdef __USE_MISC
49
50/* ipcs ctl commands */
51# define SHM_STAT 13
52# define SHM_INFO 14
53# define SHM_STAT_ANY 15
54
55/* shm_mode upper byte flags */
56# define SHM_DEST 01000 /* segment will be destroyed on last detach */
57# define SHM_LOCKED 02000 /* segment will not be swapped */
58# define SHM_HUGETLB 04000 /* segment is mapped via hugetlb */
59# define SHM_NORESERVE 010000 /* don't check for reservations */
60
61/* When SHM_HUGETLB is set, bits [26:31] encode the log2 of the huge page size.
62 The following definitions are associated with this huge page size encoding.
63 It is responsibility of the application to know which sizes are supported on
64 the running system. See shmget(2) man page for details. */
65
66#define SHM_HUGE_SHIFT 26
67#define SHM_HUGE_MASK 0x3f
68
69#define SHM_HUGE_16KB (14 << SHM_HUGE_SHIFT)
70#define SHM_HUGE_64KB (16 << SHM_HUGE_SHIFT)
71#define SHM_HUGE_512KB (19 << SHM_HUGE_SHIFT)
72#define SHM_HUGE_1MB (20 << SHM_HUGE_SHIFT)
73#define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
74#define SHM_HUGE_8MB (23 << SHM_HUGE_SHIFT)
75#define SHM_HUGE_16MB (24 << SHM_HUGE_SHIFT)
76#define SHM_HUGE_32MB (25 << SHM_HUGE_SHIFT)
77#define SHM_HUGE_256MB (28 << SHM_HUGE_SHIFT)
78#define SHM_HUGE_512MB (29 << SHM_HUGE_SHIFT)
79#define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
80#define SHM_HUGE_2GB (31 << SHM_HUGE_SHIFT)
81#define SHM_HUGE_16GB (34U << SHM_HUGE_SHIFT)
82
83struct shminfo
84 {
85 __syscall_ulong_t shmmax;
86 __syscall_ulong_t shmmin;
87 __syscall_ulong_t shmmni;
88 __syscall_ulong_t shmseg;
89 __syscall_ulong_t shmall;
90 __syscall_ulong_t __glibc_reserved1;
91 __syscall_ulong_t __glibc_reserved2;
92 __syscall_ulong_t __glibc_reserved3;
93 __syscall_ulong_t __glibc_reserved4;
94 };
95
96struct shm_info
97 {
98 int used_ids;
99 __syscall_ulong_t shm_tot; /* total allocated shm */
100 __syscall_ulong_t shm_rss; /* total resident shm */
101 __syscall_ulong_t shm_swp; /* total swapped shm */
102 __syscall_ulong_t swap_attempts;
103 __syscall_ulong_t swap_successes;
104 };
105
106#endif /* __USE_MISC */
107
108__END_DECLS