46 lines · c
1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */2#ifndef __ASM_GENERIC_SEMBUF_H3#define __ASM_GENERIC_SEMBUF_H4 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_3210 * originally). Note extra padding because this structure is passed back and11 * forth between kernel and user space.12 *13 * semid64_ds was originally meant to be architecture specific, but14 * everyone just ended up making identical copies without specific15 * 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, while18 * 32 bit architectures have a pair of unsigned long values.19 *20 * On big-endian systems, the padding is in the wrong place for21 * historic reasons, so user space has to reconstruct a time_t22 * value using23 *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 values28 */29struct semid64_ds {30 struct ipc64_perm sem_perm; /* permissions .. see ipc.h */31#if __BITS_PER_LONG == 6432 long sem_otime; /* last semop time */33 long sem_ctime; /* last change time */34#else35 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#endif40 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