include/uapi/linux/shm.h

   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_ */