include/linux/shm.h

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