1#ifndef _UAPI_LINUX_SHM_H_
2#define _UAPI_LINUX_SHM_H_
3
4#include <linux/ipc.h>
5#include <linux/errno.h>
6#ifndef __KERNEL__
7#include <unistd.h>
8#endif
9
10/*
11 * SHMMNI, SHMMAX and SHMALL are default upper limits which can be
12 * modified by sysctl. The SHMMAX and SHMALL values have been chosen to
13 * be as large possible without facilitating scenarios where userspace
14 * causes overflows when adjusting the limits via operations of the form
15 * "retrieve current limit; add X; update limit". It is therefore not
16 * advised to make SHMMAX and SHMALL any larger. These limits are
17 * suitable for both 32 and 64-bit systems.
18 */
19#define SHMMIN 1			 /* min shared seg size (bytes) */
20#define SHMMNI 4096			 /* max num of segs system wide */
21#define SHMMAX (ULONG_MAX - (1UL << 24)) /* max shared seg size (bytes) */
22#define SHMALL (ULONG_MAX - (1UL << 24)) /* max shm system wide (pages) */
23#define SHMSEG SHMMNI			 /* max shared segs per process */
24
25/* Obsolete, used only for backwards compatibility and libc5 compiles */
26struct shmid_ds {
27	struct ipc_perm		shm_perm;	/* operation perms */
28	int			shm_segsz;	/* size of segment (bytes) */
29	__kernel_time_t		shm_atime;	/* last attach time */
30	__kernel_time_t		shm_dtime;	/* last detach time */
31	__kernel_time_t		shm_ctime;	/* last change time */
32	__kernel_ipc_pid_t	shm_cpid;	/* pid of creator */
33	__kernel_ipc_pid_t	shm_lpid;	/* pid of last operator */
34	unsigned short		shm_nattch;	/* no. of current attaches */
35	unsigned short 		shm_unused;	/* compatibility */
36	void 			*shm_unused2;	/* ditto - used by DIPC */
37	void			*shm_unused3;	/* unused */
38};
39
40/* Include the definition of shmid64_ds and shminfo64 */
41#include <asm/shmbuf.h>
42
43/* permission flag for shmget */
44#define SHM_R		0400	/* or S_IRUGO from <linux/stat.h> */
45#define SHM_W		0200	/* or S_IWUGO from <linux/stat.h> */
46
47/* mode for attach */
48#define	SHM_RDONLY	010000	/* read-only access */
49#define	SHM_RND		020000	/* round attach address to SHMLBA boundary */
50#define	SHM_REMAP	040000	/* take-over region on attach */
51#define	SHM_EXEC	0100000	/* execution access */
52
53/* super user shmctl commands */
54#define SHM_LOCK 	11
55#define SHM_UNLOCK 	12
56
57/* ipcs ctl commands */
58#define SHM_STAT 	13
59#define SHM_INFO 	14
60
61/* Obsolete, used only for backwards compatibility */
62struct	shminfo {
63	int shmmax;
64	int shmmin;
65	int shmmni;
66	int shmseg;
67	int shmall;
68};
69
70struct shm_info {
71	int used_ids;
72	__kernel_ulong_t shm_tot;	/* total allocated shm */
73	__kernel_ulong_t shm_rss;	/* total resident shm */
74	__kernel_ulong_t shm_swp;	/* total swapped shm */
75	__kernel_ulong_t swap_attempts;
76	__kernel_ulong_t swap_successes;
77};
78
79
80#endif /* _UAPI_LINUX_SHM_H_ */
81