LXR linux/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 */
  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