tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef _UAPI_LINUX_SHM_H_
2#define _UAPI_LINUX_SHM_H_
3
4#include <linux/ipc.h>
5#include <linux/errno.h>
6#include <asm-generic/hugetlb_encode.h>
7#ifndef __KERNEL__
8#include <unistd.h>
9#endif
10
11/*
12 * SHMMNI, SHMMAX and SHMALL are default upper limits which can be
13 * modified by sysctl. The SHMMAX and SHMALL values have been chosen to
14 * be as large possible without facilitating scenarios where userspace
15 * causes overflows when adjusting the limits via operations of the form
16 * "retrieve current limit; add X; update limit". It is therefore not
17 * advised to make SHMMAX and SHMALL any larger. These limits are
18 * suitable for both 32 and 64-bit systems.
19 */
20#define SHMMIN 1 /* min shared seg size (bytes) */
21#define SHMMNI 4096 /* max num of segs system wide */
22#define SHMMAX (ULONG_MAX - (1UL << 24)) /* max shared seg size (bytes) */
23#define SHMALL (ULONG_MAX - (1UL << 24)) /* max shm system wide (pages) */
24#define SHMSEG SHMMNI /* max shared segs per process */
25
26/* Obsolete, used only for backwards compatibility and libc5 compiles */
27struct shmid_ds {
28 struct ipc_perm shm_perm; /* operation perms */
29 int shm_segsz; /* size of segment (bytes) */
30 __kernel_time_t shm_atime; /* last attach time */
31 __kernel_time_t shm_dtime; /* last detach time */
32 __kernel_time_t shm_ctime; /* last change time */
33 __kernel_ipc_pid_t shm_cpid; /* pid of creator */
34 __kernel_ipc_pid_t shm_lpid; /* pid of last operator */
35 unsigned short shm_nattch; /* no. of current attaches */
36 unsigned short shm_unused; /* compatibility */
37 void *shm_unused2; /* ditto - used by DIPC */
38 void *shm_unused3; /* unused */
39};
40
41/* Include the definition of shmid64_ds and shminfo64 */
42#include <asm/shmbuf.h>
43
44/*
45 * shmget() shmflg values.
46 */
47/* The bottom nine bits are the same as open(2) mode flags */
48#define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */
49#define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */
50/* Bits 9 & 10 are IPC_CREAT and IPC_EXCL */
51#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
52#define SHM_NORESERVE 010000 /* don't check for reservations */
53
54/*
55 * Huge page size encoding when SHM_HUGETLB is specified, and a huge page
56 * size other than the default is desired. See hugetlb_encode.h
57 */
58#define SHM_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT
59#define SHM_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK
60
61#define SHM_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB
62#define SHM_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB
63#define SHM_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB
64#define SHM_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB
65#define SHM_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB
66#define SHM_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB
67#define SHM_HUGE_256MB HUGETLB_FLAG_ENCODE_256MB
68#define SHM_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB
69#define SHM_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB
70#define SHM_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB
71
72/*
73 * shmat() shmflg values
74 */
75#define SHM_RDONLY 010000 /* read-only access */
76#define SHM_RND 020000 /* round attach address to SHMLBA boundary */
77#define SHM_REMAP 040000 /* take-over region on attach */
78#define SHM_EXEC 0100000 /* execution access */
79
80/* super user shmctl commands */
81#define SHM_LOCK 11
82#define SHM_UNLOCK 12
83
84/* ipcs ctl commands */
85#define SHM_STAT 13
86#define SHM_INFO 14
87
88/* Obsolete, used only for backwards compatibility */
89struct shminfo {
90 int shmmax;
91 int shmmin;
92 int shmmni;
93 int shmseg;
94 int shmall;
95};
96
97struct shm_info {
98 int used_ids;
99 __kernel_ulong_t shm_tot; /* total allocated shm */
100 __kernel_ulong_t shm_rss; /* total resident shm */
101 __kernel_ulong_t shm_swp; /* total swapped shm */
102 __kernel_ulong_t swap_attempts;
103 __kernel_ulong_t swap_successes;
104};
105
106
107#endif /* _UAPI_LINUX_SHM_H_ */