1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2#ifndef __ASM_GENERIC_SEMBUF_H 3#define __ASM_GENERIC_SEMBUF_H 4 5#include <asm/bitsperlong.h> 6#include <asm/ipcbuf.h> 7 8/* 9 * The semid64_ds structure for most architectures (though it came from x86_32 10 * originally). Note extra padding because this structure is passed back and 11 * forth between kernel and user space. 12 * 13 * semid64_ds was originally meant to be architecture specific, but 14 * everyone just ended up making identical copies without specific 15 * optimizations, so we may just as well all use the same one. 16 * 17 * 64 bit architectures use a 64-bit long time field here, while 18 * 32 bit architectures have a pair of unsigned long values. 19 * 20 * On big-endian systems, the padding is in the wrong place for 21 * historic reasons, so user space has to reconstruct a time_t 22 * value using 23 * 24 * user_semid_ds.sem_otime = kernel_semid64_ds.sem_otime + 25 * ((long long)kernel_semid64_ds.sem_otime_high << 32) 26 * 27 * Pad space is left for 2 miscellaneous 32-bit values 28 */ 29struct semid64_ds { 30 struct ipc64_perm sem_perm; /* permissions .. see ipc.h */ 31#if __BITS_PER_LONG == 64 32 long sem_otime; /* last semop time */ 33 long sem_ctime; /* last change time */ 34#else 35 unsigned long sem_otime; /* last semop time */ 36 unsigned long sem_otime_high; 37 unsigned long sem_ctime; /* last change time */ 38 unsigned long sem_ctime_high; 39#endif 40 unsigned long sem_nsems; /* no. of semaphores in array */ 41 unsigned long __unused3; 42 unsigned long __unused4; 43}; 44 45#endif /* __ASM_GENERIC_SEMBUF_H */ 46