/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_FUTEX_H #define _LINUX_FUTEX_H #include <linux/sched.h> #include <linux/ktime.h> #include <uapi/linux/futex.h> struct inode; struct mm_struct; struct task_struct; /* * Futexes are matched on equal values of this key. * The key type depends on whether it's a shared or private mapping. * Don't rearrange members without looking at hash_futex(). * * offset is aligned to a multiple of sizeof(u32) (== 4) by definition. * We use the two low order bits of offset to tell what is the kind of key : * 00 : Private process futex (PTHREAD_PROCESS_PRIVATE) * (no reference on an inode or mm) * 01 : Shared futex (PTHREAD_PROCESS_SHARED) * mapped on a file (reference on the underlying inode) * 10 : Shared futex (PTHREAD_PROCESS_SHARED) * (but private mapping on an mm, and reference taken on it) */ #define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */ #define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */ union futex_key { struct { u64 i_seq; unsigned long pgoff; unsigned int offset; } shared; struct { union { struct mm_struct *mm; u64 __tmp; }; unsigned long address; unsigned int offset; } private; struct { u64 ptr; unsigned long word; unsigned int offset; } both; }; #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } } #ifdef CONFIG_FUTEX enum { FUTEX_STATE_OK, FUTEX_STATE_EXITING, FUTEX_STATE_DEAD, }; static inline void futex_init_task(struct task_struct *tsk) { tsk->robust_list = NULL; #ifdef CONFIG_COMPAT tsk->compat_robust_list = NULL; #endif INIT_LIST_HEAD(&tsk->pi_state_list); tsk->pi_state_cache = NULL; tsk->futex_state = FUTEX_STATE_OK; mutex_init(&tsk->futex_exit_mutex); } void futex_exit_recursive(struct task_struct *tsk); void futex_exit_release(struct task_struct *tsk); void futex_exec_release(struct task_struct *tsk); long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3); #else static inline void futex_init_task(struct task_struct *tsk) { } static inline void futex_exit_recursive(struct task_struct *tsk) { } static inline void futex_exit_release(struct task_struct *tsk) { } static inline void futex_exec_release(struct task_struct *tsk) { } static inline long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { return -EINVAL; } #endif #endif