• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 */
26 struct 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 */
62 struct	shminfo {
63 	int shmmax;
64 	int shmmin;
65 	int shmmni;
66 	int shmseg;
67 	int shmall;
68 };
69 
70 struct 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