1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/sched.h>
6 #include <linux/ktime.h>
8 #include <uapi/linux/futex.h>
14 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
15 u32 __user *uaddr2, u32 val2, u32 val3);
18 * Futexes are matched on equal values of this key.
19 * The key type depends on whether it's a shared or private mapping.
20 * Don't rearrange members without looking at hash_futex().
22 * offset is aligned to a multiple of sizeof(u32) (== 4) by definition.
23 * We use the two low order bits of offset to tell what is the kind of key :
24 * 00 : Private process futex (PTHREAD_PROCESS_PRIVATE)
25 * (no reference on an inode or mm)
26 * 01 : Shared futex (PTHREAD_PROCESS_SHARED)
27 * mapped on a file (reference on the underlying inode)
28 * 10 : Shared futex (PTHREAD_PROCESS_SHARED)
29 * (but private mapping on an mm, and reference taken on it)
32 #define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */
33 #define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */
46 unsigned long address;
56 #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } }
65 static inline void futex_init_task(struct task_struct *tsk)
67 tsk->robust_list = NULL;
69 tsk->compat_robust_list = NULL;
71 INIT_LIST_HEAD(&tsk->pi_state_list);
72 tsk->pi_state_cache = NULL;
73 tsk->futex_state = FUTEX_STATE_OK;
74 mutex_init(&tsk->futex_exit_mutex);
77 void futex_exit_recursive(struct task_struct *tsk);
78 void futex_exit_release(struct task_struct *tsk);
79 void futex_exec_release(struct task_struct *tsk);
81 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
82 u32 __user *uaddr2, u32 val2, u32 val3);
84 static inline void futex_init_task(struct task_struct *tsk) { }
85 static inline void futex_exit_recursive(struct task_struct *tsk) { }
86 static inline void futex_exit_release(struct task_struct *tsk) { }
87 static inline void futex_exec_release(struct task_struct *tsk) { }