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 * - 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 #if __BITS_PER_LONG == 64
29 __kernel_time_t shm_atime; /* last attach time */
30 __kernel_time_t shm_dtime; /* last detach time */
31 __kernel_time_t shm_ctime; /* last change time */
32 #else
33 unsigned long shm_atime; /* last attach time */
34 unsigned long shm_atime_high;
35 unsigned long shm_dtime; /* last detach time */
36 unsigned long shm_dtime_high;
37 unsigned long shm_ctime; /* last change time */
38 unsigned long shm_ctime_high;
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 */