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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#endif11 12/*13 * SHMMNI, SHMMAX and SHMALL are default upper limits which can be14 * modified by sysctl. The SHMMAX and SHMALL values have been chosen to15 * be as large possible without facilitating scenarios where userspace16 * causes overflows when adjusting the limits via operations of the form17 * "retrieve current limit; add X; update limit". It is therefore not18 * advised to make SHMMAX and SHMALL any larger. These limits are19 * 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 page57 * size other than the default is desired. See hugetlb_encode.h58 */59#define SHM_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT60#define SHM_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK61 62#define SHM_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB63#define SHM_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB64#define SHM_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB65#define SHM_HUGE_2MB HUGETLB_FLAG_ENCODE_2MB66#define SHM_HUGE_8MB HUGETLB_FLAG_ENCODE_8MB67#define SHM_HUGE_16MB HUGETLB_FLAG_ENCODE_16MB68#define SHM_HUGE_32MB HUGETLB_FLAG_ENCODE_32MB69#define SHM_HUGE_256MB HUGETLB_FLAG_ENCODE_256MB70#define SHM_HUGE_512MB HUGETLB_FLAG_ENCODE_512MB71#define SHM_HUGE_1GB HUGETLB_FLAG_ENCODE_1GB72#define SHM_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB73#define SHM_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB74 75/*76 * shmat() shmflg values77 */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 1185#define SHM_UNLOCK 1286 87/* ipcs ctl commands */88#define SHM_STAT 1389#define SHM_INFO 1490#define SHM_STAT_ANY 1591 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