| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 | |
| 7 | /* |
| 8 | * The semid64_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 | * semid64_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 | * |
| 19 | * On big-endian systems, the padding is in the wrong place for |
| 20 | * historic reasons, so user space has to reconstruct a time_t |
| 21 | * value using |
| 22 | * |
| 23 | * user_semid_ds.sem_otime = kernel_semid64_ds.sem_otime + |
| 24 | * ((long long)kernel_semid64_ds.sem_otime_high << 32) |
| 25 | * |
| 26 | * Pad space is left for 2 miscellaneous 32-bit values |
| 27 | */ |
| 28 | struct semid64_ds { |
| 29 | struct ipc64_perm sem_perm; /* permissions .. see ipc.h */ |
| 30 | #if __BITS_PER_LONG == 64 |
| 31 | long sem_otime; /* last semop time */ |
| 32 | long sem_ctime; /* last change time */ |
| 33 | #else |
| 34 | unsigned long sem_otime; /* last semop time */ |
| 35 | unsigned long sem_otime_high; |
| 36 | unsigned long sem_ctime; /* last change time */ |
| 37 | unsigned long sem_ctime_high; |
| 38 | #endif |
| 39 | unsigned long sem_nsems; /* no. of semaphores in array */ |
| 40 | unsigned long __unused3; |
| 41 | unsigned long __unused4; |
| 42 | }; |
| 43 | |
| 44 | #endif /* __ASM_GENERIC_SEMBUF_H */ |