include/uapi/asm-generic/msgbuf.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef __ASM_GENERIC_MSGBUF_H
   3 #define __ASM_GENERIC_MSGBUF_H
   4
   5 #include <asm/bitsperlong.h>
   6 /*
   7  * generic msqid64_ds structure.
   8  *
   9  * Note extra padding because this structure is passed back and forth
  10  * between kernel and user space.
  11  *
  12  * msqid64_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 three padding words.
  18  * On big-endian systems, the padding is in the wrong place.
  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 msqid64_ds {
  26         struct ipc64_perm msg_perm;
  27         __kernel_time_t msg_stime;      /* last msgsnd time */
  28 #if __BITS_PER_LONG != 64
  29         unsigned long   __unused1;
  30 #endif
  31         __kernel_time_t msg_rtime;      /* last msgrcv time */
  32 #if __BITS_PER_LONG != 64
  33         unsigned long   __unused2;
  34 #endif
  35         __kernel_time_t msg_ctime;      /* last change time */
  36 #if __BITS_PER_LONG != 64
  37         unsigned long   __unused3;
  38 #endif
  39         __kernel_ulong_t msg_cbytes;    /* current number of bytes on queue */
  40         __kernel_ulong_t msg_qnum;      /* number of messages in queue */
  41         __kernel_ulong_t msg_qbytes;    /* max number of bytes on queue */
  42         __kernel_pid_t msg_lspid;       /* pid of last msgsnd */
  43         __kernel_pid_t msg_lrpid;       /* last receive pid */
  44         __kernel_ulong_t __unused4;
  45         __kernel_ulong_t __unused5;
  46 };
  47
  48 #endif /* __ASM_GENERIC_MSGBUF_H */