1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux 1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef __ASM_GENERIC_SEMBUF_H 2 #ifndef __ASM_GENERIC_SEMBUF_H
3 #define __ASM_GENERIC_SEMBUF_H 3 #define __ASM_GENERIC_SEMBUF_H
4 4
5 #include <asm/bitsperlong.h> 5 #include <asm/bitsperlong.h>
6 #include <asm/ipcbuf.h> 6 #include <asm/ipcbuf.h>
7 7
8 /* 8 /*
9 * The semid64_ds structure for most architect !! 9 * The semid64_ds structure for x86 architecture.
10 * originally). Note extra padding because thi !! 10 * Note extra padding because this structure is passed back and forth
11 * forth between kernel and user space. !! 11 * between kernel and user space.
12 * 12 *
13 * semid64_ds was originally meant to be archi 13 * semid64_ds was originally meant to be architecture specific, but
14 * everyone just ended up making identical cop 14 * everyone just ended up making identical copies without specific
15 * optimizations, so we may just as well all u 15 * optimizations, so we may just as well all use the same one.
16 * 16 *
17 * 64 bit architectures use a 64-bit long time 17 * 64 bit architectures use a 64-bit long time field here, while
18 * 32 bit architectures have a pair of unsigne 18 * 32 bit architectures have a pair of unsigned long values.
19 * 19 *
20 * On big-endian systems, the padding is in th 20 * On big-endian systems, the padding is in the wrong place for
21 * historic reasons, so user space has to reco 21 * historic reasons, so user space has to reconstruct a time_t
22 * value using 22 * value using
23 * 23 *
24 * user_semid_ds.sem_otime = kernel_semid64_ds 24 * user_semid_ds.sem_otime = kernel_semid64_ds.sem_otime +
25 * ((long long)kernel_semid64_ds. 25 * ((long long)kernel_semid64_ds.sem_otime_high << 32)
26 * 26 *
27 * Pad space is left for 2 miscellaneous 32-bi 27 * Pad space is left for 2 miscellaneous 32-bit values
28 */ 28 */
29 struct semid64_ds { 29 struct semid64_ds {
30 struct ipc64_perm sem_perm; /* per 30 struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
31 #if __BITS_PER_LONG == 64 31 #if __BITS_PER_LONG == 64
32 long sem_otime; /* las 32 long sem_otime; /* last semop time */
33 long sem_ctime; /* las 33 long sem_ctime; /* last change time */
34 #else 34 #else
35 unsigned long sem_otime; /* las 35 unsigned long sem_otime; /* last semop time */
36 unsigned long sem_otime_high; 36 unsigned long sem_otime_high;
37 unsigned long sem_ctime; /* las 37 unsigned long sem_ctime; /* last change time */
38 unsigned long sem_ctime_high; 38 unsigned long sem_ctime_high;
39 #endif 39 #endif
40 unsigned long sem_nsems; /* no. 40 unsigned long sem_nsems; /* no. of semaphores in array */
41 unsigned long __unused3; 41 unsigned long __unused3;
42 unsigned long __unused4; 42 unsigned long __unused4;
43 }; 43 };
44 44
45 #endif /* __ASM_GENERIC_SEMBUF_H */ 45 #endif /* __ASM_GENERIC_SEMBUF_H */
46 46
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