1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SHM_H_ 3 #define _LINUX_SHM_H_ 4 5 #include <linux/list.h> 6 #include <asm/page.h> 7 #include <uapi/linux/shm.h> 8 #include <asm/shmparam.h> 9 10 struct shmid_kernel /* private to the kernel */ 11 { 12 struct kern_ipc_perm shm_perm; 13 struct file *shm_file; 14 unsigned long shm_nattch; 15 unsigned long shm_segsz; 16 time64_t shm_atim; 17 time64_t shm_dtim; 18 time64_t shm_ctim; 19 pid_t shm_cprid; 20 pid_t shm_lprid; 21 struct user_struct *mlock_user; 22 23 /* The task created the shm object. NULL if the task is dead. */ 24 struct task_struct *shm_creator; 25 struct list_head shm_clist; /* list by creator */ 26 } __randomize_layout; 27 28 /* shm_mode upper byte flags */ 29 #define SHM_DEST 01000 /* segment will be destroyed on last detach */ 30 #define SHM_LOCKED 02000 /* segment will not be swapped */ 31 32 #ifdef CONFIG_SYSVIPC 33 struct sysv_shm { 34 struct list_head shm_clist; 35 }; 36 37 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr, 38 unsigned long shmlba); 39 bool is_file_shm_hugepages(struct file *file); 40 void exit_shm(struct task_struct *task); 41 #define shm_init_task(task) INIT_LIST_HEAD(&(task)->sysvshm.shm_clist) 42 #else 43 struct sysv_shm { 44 /* empty */ 45 }; 46 47 static inline long do_shmat(int shmid, char __user *shmaddr, 48 int shmflg, unsigned long *addr, 49 unsigned long shmlba) 50 { 51 return -ENOSYS; 52 } 53 static inline bool is_file_shm_hugepages(struct file *file) 54 { 55 return false; 56 } 57 static inline void exit_shm(struct task_struct *task) 58 { 59 } 60 static inline void shm_init_task(struct task_struct *task) 61 { 62 } 63 #endif 64 65 #endif /* _LINUX_SHM_H_ */ 66