1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2#ifndef _UAPI_LINUX_SHM_H_ 3#define _UAPI_LINUX_SHM_H_ 4 5#include <linux/ipc.h> 6#include <linux/errno.h> 7#include <asm-generic/hugetlb_encode.h> 8#ifndef __KERNEL__ 9#include <unistd.h> 10#endif 11 12/* 13 * SHMMNI, SHMMAX and SHMALL are default upper limits which can be 14 * modified by sysctl. The SHMMAX and SHMALL values have been chosen to 15 * be as large possible without facilitating scenarios where userspace 16 * causes overflows when adjusting the limits via operations of the form 17 * "retrieve current limit; add X; update limit". It is therefore not 18 * advised to make SHMMAX and SHMALL any larger. These limits are 19 * suitable for both 32 and 64-bit systems. 20 */ 21#define SHMMIN 1 /* min shared seg size (bytes) */ 22#define SHMMNI 4096 /* max num of segs system wide */ 23#define SHMMAX (ULONG_MAX - (1UL << 24)) /* max shared seg size (bytes) */ 24#define SHMALL (ULONG_MAX - (1UL << 24)) /* max shm system wide (pages) */ 25#define SHMSEG SHMMNI /* max shared segs per process */ 26 27/* Obsolete, used only for backwards compatibility and libc5 compiles */ 28struct shmid_ds { 29 struct ipc_perm shm_perm; /* operation perms */ 30 int shm_segsz; /* size of segment (bytes) */ 31 __kernel_old_time_t shm_atime; /* last attach time */ 32 __kernel_old_time_t shm_dtime; /* last detach time */ 33 __kernel_old_time_t shm_ctime; /* last change time */ 34 __kernel_ipc_pid_t shm_cpid; /* pid of creator */ 35 __kernel_ipc_pid_t shm_lpid; /* pid of last operator */ 36 unsigned short shm_nattch; /* no. of current attaches */ 37 unsigned short shm_unused; /* compatibility */ 38 void *shm_unused2; /* ditto - used by DIPC */ 39 void *shm_unused3; /* unused */ 40}; 41 42/* Include the definition of shmid64_ds and shminfo64 */ 43#include <asm/shmbuf.h> 44 45/* 46 * shmget() shmflg values. 47 */ 48/* The bottom nine bits are the same as open(2) mode flags */ 49#define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */ 50#define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */ 51/* Bits 9 & 10 are IPC_CREAT and IPC_EXCL */ 52#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */ 53#define SHM_NORESERVE 010000 /* don't check for reservations */ 54 55/* 56 * Huge page size encoding when SHM_HUGETLB is specified, and a huge page 57 * size other than the default is desired. See hugetlb_encode.h 58 */ 59#define SHM_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT 60#define SHM_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK 61 62#define SHM_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB 63#define SHM_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB 64#define SHM_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB 65#define SHM_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB 66#define SHM_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB 67#define SHM_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB 68#define SHM_HUGE_32MB HUGETLB_FLAG_ENCODE_32MB 69#define SHM_HUGE_256MB HUGETLB_FLAG_ENCODE_256MB 70#define SHM_HUGE_512MB HUGETLB_FLAG_ENCODE_512MB 71#define SHM_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB 72#define SHM_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB 73#define SHM_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB 74 75/* 76 * shmat() shmflg values 77 */ 78#define SHM_RDONLY 010000 /* read-only access */ 79#define SHM_RND 020000 /* round attach address to SHMLBA boundary */ 80#define SHM_REMAP 040000 /* take-over region on attach */ 81#define SHM_EXEC 0100000 /* execution access */ 82 83/* super user shmctl commands */ 84#define SHM_LOCK 11 85#define SHM_UNLOCK 12 86 87/* ipcs ctl commands */ 88#define SHM_STAT 13 89#define SHM_INFO 14 90#define SHM_STAT_ANY 15 91 92/* Obsolete, used only for backwards compatibility */ 93struct shminfo { 94 int shmmax; 95 int shmmin; 96 int shmmni; 97 int shmseg; 98 int shmall; 99}; 100 101struct shm_info { 102 int used_ids; 103 __kernel_ulong_t shm_tot; /* total allocated shm */ 104 __kernel_ulong_t shm_rss; /* total resident shm */ 105 __kernel_ulong_t shm_swp; /* total swapped shm */ 106 __kernel_ulong_t swap_attempts; 107 __kernel_ulong_t swap_successes; 108}; 109 110 111#endif /* _UAPI_LINUX_SHM_H_ */ 112