shmbuf.h (1877B) - Raw
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef __ASM_GENERIC_SHMBUF_H 3 #define __ASM_GENERIC_SHMBUF_H 4 5 #include <asm/bitsperlong.h> 6 #include <asm/ipcbuf.h> 7 #include <asm/posix_types.h> 8 9 /* 10 * The shmid64_ds structure for x86 architecture. 11 * Note extra padding because this structure is passed back and forth 12 * between kernel and user space. 13 * 14 * shmid64_ds was originally meant to be architecture specific, but 15 * everyone just ended up making identical copies without specific 16 * optimizations, so we may just as well all use the same one. 17 * 18 * 64 bit architectures use a 64-bit long time field here, while 19 * 32 bit architectures have a pair of unsigned long values. 20 * On big-endian systems, the lower half is in the wrong place. 21 * 22 * 23 * Pad space is left for: 24 * - 2 miscellaneous 32-bit values 25 */ 26 27 struct shmid64_ds { 28 struct ipc64_perm shm_perm; /* operation perms */ 29 __kernel_size_t shm_segsz; /* size of segment (bytes) */ 30 #if __BITS_PER_LONG == 64 31 long shm_atime; /* last attach time */ 32 long shm_dtime; /* last detach time */ 33 long shm_ctime; /* last change time */ 34 #else 35 unsigned long shm_atime; /* last attach time */ 36 unsigned long shm_atime_high; 37 unsigned long shm_dtime; /* last detach time */ 38 unsigned long shm_dtime_high; 39 unsigned long shm_ctime; /* last change time */ 40 unsigned long shm_ctime_high; 41 #endif 42 __kernel_pid_t shm_cpid; /* pid of creator */ 43 __kernel_pid_t shm_lpid; /* pid of last operator */ 44 unsigned long shm_nattch; /* no. of current attaches */ 45 unsigned long __unused4; 46 unsigned long __unused5; 47 }; 48 49 struct shminfo64 { 50 unsigned long shmmax; 51 unsigned long shmmin; 52 unsigned long shmmni; 53 unsigned long shmseg; 54 unsigned long shmall; 55 unsigned long __unused1; 56 unsigned long __unused2; 57 unsigned long __unused3; 58 unsigned long __unused4; 59 }; 60 61 #endif /* __ASM_GENERIC_SHMBUF_H */