include/uapi/asm-generic/shmbuf.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef __ASM_GENERIC_SHMBUF_H
   3 #define __ASM_GENERIC_SHMBUF_H
   4
   5 #include <asm/bitsperlong.h>
   6
   7 /*
   8  * The shmid64_ds structure for x86 architecture.
   9  * Note extra padding because this structure is passed back and forth
  10  * between kernel and user space.
  11  *
  12  * shmid64_ds was originally meant to be architecture specific, but
  13  * everyone just ended up making identical copies without specific
  14  * optimizations, so we may just as well all use the same one.
  15  *
  16  * 64 bit architectures typically define a 64 bit __kernel_time_t,
  17  * so they do not need the first two padding words.
  18  * On big-endian systems, the padding is in the wrong place.
  19  *
  20  *
  21  * Pad space is left for:
  22  * - 64-bit time_t to solve y2038 problem
  23  * - 2 miscellaneous 32-bit values
  24  */
  25
  26 struct shmid64_ds {
  27         struct ipc64_perm       shm_perm;       /* operation perms */
  28         size_t                  shm_segsz;      /* size of segment (bytes) */
  29         __kernel_time_t         shm_atime;      /* last attach time */
  30 #if __BITS_PER_LONG != 64
  31         unsigned long           __unused1;
  32 #endif
  33         __kernel_time_t         shm_dtime;      /* last detach time */
  34 #if __BITS_PER_LONG != 64
  35         unsigned long           __unused2;
  36 #endif
  37         __kernel_time_t         shm_ctime;      /* last change time */
  38 #if __BITS_PER_LONG != 64
  39         unsigned long           __unused3;
  40 #endif
  41         __kernel_pid_t          shm_cpid;       /* pid of creator */
  42         __kernel_pid_t          shm_lpid;       /* pid of last operator */
  43         __kernel_ulong_t        shm_nattch;     /* no. of current attaches */
  44         __kernel_ulong_t        __unused4;
  45         __kernel_ulong_t        __unused5;
  46 };
  47
  48 struct shminfo64 {
  49         __kernel_ulong_t        shmmax;
  50         __kernel_ulong_t        shmmin;
  51         __kernel_ulong_t        shmmni;
  52         __kernel_ulong_t        shmseg;
  53         __kernel_ulong_t        shmall;
  54         __kernel_ulong_t        __unused1;
  55         __kernel_ulong_t        __unused2;
  56         __kernel_ulong_t        __unused3;
  57         __kernel_ulong_t        __unused4;
  58 };
  59
  60 #endif /* __ASM_GENERIC_SHMBUF_H */