include/asm-generic/msgbuf.h

   1 #ifndef __ASM_GENERIC_MSGBUF_H
   2 #define __ASM_GENERIC_MSGBUF_H
   3
   4 #include <asm/bitsperlong.h>
   5 /*
   6  * generic msqid64_ds structure.
   7  *
   8  * Note extra padding because this structure is passed back and forth
   9  * between kernel and user space.
  10  *
  11  * msqid64_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 three padding words.
  17  * On big-endian systems, the padding is in the wrong place.
  18  *
  19  * Pad space is left for:
  20  * - 64-bit time_t to solve y2038 problem
  21  * - 2 miscellaneous 32-bit values
  22  */
  23
  24 struct msqid64_ds {
  25         struct ipc64_perm msg_perm;
  26         __kernel_time_t msg_stime;      /* last msgsnd time */
  27 #if __BITS_PER_LONG != 64
  28         unsigned long   __unused1;
  29 #endif
  30         __kernel_time_t msg_rtime;      /* last msgrcv time */
  31 #if __BITS_PER_LONG != 64
  32         unsigned long   __unused2;
  33 #endif
  34         __kernel_time_t msg_ctime;      /* last change time */
  35 #if __BITS_PER_LONG != 64
  36         unsigned long   __unused3;
  37 #endif
  38         unsigned long  msg_cbytes;      /* current number of bytes on queue */
  39         unsigned long  msg_qnum;        /* number of messages in queue */
  40         unsigned long  msg_qbytes;      /* max number of bytes on queue */
  41         __kernel_pid_t msg_lspid;       /* pid of last msgsnd */
  42         __kernel_pid_t msg_lrpid;       /* last receive pid */
  43         unsigned long  __unused4;
  44         unsigned long  __unused5;
  45 };
  46
  47 #endif /* __ASM_GENERIC_MSGBUF_H */