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 #include <asm/ipcbuf.h>
7 #include <asm/posix_types.h>
8 
9 /*
10  * The shmid64_ds structure for x86 architecture.
11  * Note extra padding because this structure is passed back and forth
12  * between kernel and user space.
13  *
14  * shmid64_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  *
23  * Pad space is left for:
24  * - 2 miscellaneous 32-bit values
25  */
26 
27 struct shmid64_ds {
28 	struct ipc64_perm	shm_perm;	/* operation perms */
29 	__kernel_size_t		shm_segsz;	/* size of segment (bytes) */
30 #if __BITS_PER_LONG == 64
31 	long			shm_atime;	/* last attach time */
32 	long			shm_dtime;	/* last detach time */
33 	long			shm_ctime;	/* last change time */
34 #else
35 	unsigned long		shm_atime;	/* last attach time */
36 	unsigned long		shm_atime_high;
37 	unsigned long		shm_dtime;	/* last detach time */
38 	unsigned long		shm_dtime_high;
39 	unsigned long		shm_ctime;	/* last change time */
40 	unsigned long		shm_ctime_high;
41 #endif
42 	__kernel_pid_t		shm_cpid;	/* pid of creator */
43 	__kernel_pid_t		shm_lpid;	/* pid of last operator */
44 	unsigned long		shm_nattch;	/* no. of current attaches */
45 	unsigned long		__unused4;
46 	unsigned long		__unused5;
47 };
48 
49 struct shminfo64 {
50 	unsigned long		shmmax;
51 	unsigned long		shmmin;
52 	unsigned long		shmmni;
53 	unsigned long		shmseg;
54 	unsigned long		shmall;
55 	unsigned long		__unused1;
56 	unsigned long		__unused2;
57 	unsigned long		__unused3;
58 	unsigned long		__unused4;
59 };
60 
61 #endif /* __ASM_GENERIC_SHMBUF_H */
62