include/asm-generic/shmbuf.h

   1 #ifndef __ASM_GENERIC_SHMBUF_H
   2 #define __ASM_GENERIC_SHMBUF_H
   3
   4 #include <asm/bitsperlong.h>
   5
   6 /*
   7  * The shmid64_ds structure for x86 architecture.
   8  * Note extra padding because this structure is passed back and forth
   9  * between kernel and user space.
  10  *
  11  * shmid64_ds was originally meant to be architecture specific, but
  12  * everyone just ended up making identical copies without specific
  13  * optimizations, so we may just as well all use the same one.
  14  *
  15  * 64 bit architectures typically define a 64 bit __kernel_time_t,
  16  * so they do not need the first two padding words.
  17  * On big-endian systems, the padding is in the wrong place.
  18  *
  19  *
  20  * Pad space is left for:
  21  * - 64-bit time_t to solve y2038 problem
  22  * - 2 miscellaneous 32-bit values
  23  */
  24
  25 struct shmid64_ds {
  26         struct ipc64_perm       shm_perm;       /* operation perms */
  27         size_t                  shm_segsz;      /* size of segment (bytes) */
  28         __kernel_time_t         shm_atime;      /* last attach time */
  29 #if __BITS_PER_LONG != 64
  30         unsigned long           __unused1;
  31 #endif
  32         __kernel_time_t         shm_dtime;      /* last detach time */
  33 #if __BITS_PER_LONG != 64
  34         unsigned long           __unused2;
  35 #endif
  36         __kernel_time_t         shm_ctime;      /* last change time */
  37 #if __BITS_PER_LONG != 64
  38         unsigned long           __unused3;
  39 #endif
  40         __kernel_pid_t          shm_cpid;       /* pid of creator */
  41         __kernel_pid_t          shm_lpid;       /* pid of last operator */
  42         unsigned long           shm_nattch;     /* no. of current attaches */
  43         unsigned long           __unused4;
  44         unsigned long           __unused5;
  45 };
  46
  47 struct shminfo64 {
  48         unsigned long   shmmax;
  49         unsigned long   shmmin;
  50         unsigned long   shmmni;
  51         unsigned long   shmseg;
  52         unsigned long   shmall;
  53         unsigned long   __unused1;
  54         unsigned long   __unused2;
  55         unsigned long   __unused3;
  56         unsigned long   __unused4;
  57 };
  58
  59 #endif /* __ASM_GENERIC_SHMBUF_H */