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#include <asm/ipcbuf.h>
7
8/*
9 * generic msqid64_ds structure.
10 *
11 * Note extra padding because this structure is passed back and forth
12 * between kernel and user space.
13 *
14 * msqid64_ds was originally meant to be architecture specific, but
15 * everyone just ended up making identical copies without specific
16 * optimizations, so we may just as well all use the same one.
17 *
18 * 64 bit architectures use a 64-bit long time field here, while
19 * 32 bit architectures have a pair of unsigned long values.
20 * On big-endian systems, the lower half is in the wrong place.
21 *
22 * Pad space is left for:
23 * - 2 miscellaneous 32-bit values
24 */
25
26struct msqid64_ds {
27 struct ipc64_perm msg_perm;
28#if __BITS_PER_LONG == 64
29 long msg_stime; /* last msgsnd time */
30 long msg_rtime; /* last msgrcv time */
31 long msg_ctime; /* last change time */
32#else
33 unsigned long msg_stime; /* last msgsnd time */
34 unsigned long msg_stime_high;
35 unsigned long msg_rtime; /* last msgrcv time */
36 unsigned long msg_rtime_high;
37 unsigned long msg_ctime; /* last change time */
38 unsigned long msg_ctime_high;
39#endif
40 unsigned long msg_cbytes; /* current number of bytes on queue */
41 unsigned long msg_qnum; /* number of messages in queue */
42 unsigned long msg_qbytes; /* max number of bytes on queue */
43 __kernel_pid_t msg_lspid; /* pid of last msgsnd */
44 __kernel_pid_t msg_lrpid; /* last receive pid */
45 unsigned long __unused4;
46 unsigned long __unused5;
47};
48
49#endif /* __ASM_GENERIC_MSGBUF_H */
50

source code of linux/include/uapi/asm-generic/msgbuf.h