1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef __ASM_GENERIC_SHMBUF_H
3 #define __ASM_GENERIC_SHMBUF_H
5 #include <asm/bitsperlong.h>
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.
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.
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.
21 * Pad space is left for:
22 * - 2 miscellaneous 32-bit values
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 */
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;
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;
53 unsigned long __unused1;
54 unsigned long __unused2;
55 unsigned long __unused3;
56 unsigned long __unused4;
59 #endif /* __ASM_GENERIC_SHMBUF_H */