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 use a 64-bit long time field here, while
17  * 32 bit architectures have a pair of unsigned long values.
18  * On big-endian systems, the lower half 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 	long			shm_atime;	/* last attach time */
30 	long			shm_dtime;	/* last detach time */
31 	long			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 */
60