Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_FUTEX_H |
3 | #define _LINUX_FUTEX_H | |
4 | ||
ba31c1a4 | 5 | #include <linux/sched.h> |
2456e855 | 6 | #include <linux/ktime.h> |
ba31c1a4 | 7 | |
607ca46e | 8 | #include <uapi/linux/futex.h> |
0771dfef | 9 | |
9064a678 MF |
10 | struct inode; |
11 | struct mm_struct; | |
12 | struct task_struct; | |
9064a678 | 13 | |
9adef58b RR |
14 | /* |
15 | * Futexes are matched on equal values of this key. | |
16 | * The key type depends on whether it's a shared or private mapping. | |
17 | * Don't rearrange members without looking at hash_futex(). | |
18 | * | |
19 | * offset is aligned to a multiple of sizeof(u32) (== 4) by definition. | |
34f01cc1 ED |
20 | * We use the two low order bits of offset to tell what is the kind of key : |
21 | * 00 : Private process futex (PTHREAD_PROCESS_PRIVATE) | |
22 | * (no reference on an inode or mm) | |
23 | * 01 : Shared futex (PTHREAD_PROCESS_SHARED) | |
24 | * mapped on a file (reference on the underlying inode) | |
25 | * 10 : Shared futex (PTHREAD_PROCESS_SHARED) | |
26 | * (but private mapping on an mm, and reference taken on it) | |
27 | */ | |
28 | ||
29 | #define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */ | |
30 | #define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */ | |
31 | ||
9adef58b RR |
32 | union futex_key { |
33 | struct { | |
8019ad13 | 34 | u64 i_seq; |
9adef58b | 35 | unsigned long pgoff; |
8019ad13 | 36 | unsigned int offset; |
9adef58b RR |
37 | } shared; |
38 | struct { | |
8019ad13 PZ |
39 | union { |
40 | struct mm_struct *mm; | |
41 | u64 __tmp; | |
42 | }; | |
9adef58b | 43 | unsigned long address; |
8019ad13 | 44 | unsigned int offset; |
9adef58b RR |
45 | } private; |
46 | struct { | |
8019ad13 | 47 | u64 ptr; |
9adef58b | 48 | unsigned long word; |
8019ad13 | 49 | unsigned int offset; |
9adef58b RR |
50 | } both; |
51 | }; | |
9adef58b | 52 | |
8019ad13 | 53 | #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } } |
38d47c1b | 54 | |
0771dfef | 55 | #ifdef CONFIG_FUTEX |
3d4775df TG |
56 | enum { |
57 | FUTEX_STATE_OK, | |
18f69438 | 58 | FUTEX_STATE_EXITING, |
3d4775df TG |
59 | FUTEX_STATE_DEAD, |
60 | }; | |
2de0db99 | 61 | |
ba31c1a4 | 62 | static inline void futex_init_task(struct task_struct *tsk) |
0771dfef | 63 | { |
ba31c1a4 TG |
64 | tsk->robust_list = NULL; |
65 | #ifdef CONFIG_COMPAT | |
66 | tsk->compat_robust_list = NULL; | |
67 | #endif | |
68 | INIT_LIST_HEAD(&tsk->pi_state_list); | |
69 | tsk->pi_state_cache = NULL; | |
3d4775df | 70 | tsk->futex_state = FUTEX_STATE_OK; |
3f186d97 | 71 | mutex_init(&tsk->futex_exit_mutex); |
3d4775df TG |
72 | } |
73 | ||
18f69438 | 74 | void futex_exit_recursive(struct task_struct *tsk); |
150d7158 TG |
75 | void futex_exit_release(struct task_struct *tsk); |
76 | void futex_exec_release(struct task_struct *tsk); | |
ba31c1a4 TG |
77 | |
78 | long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, | |
79 | u32 __user *uaddr2, u32 val2, u32 val3); | |
80 | #else | |
81 | static inline void futex_init_task(struct task_struct *tsk) { } | |
18f69438 | 82 | static inline void futex_exit_recursive(struct task_struct *tsk) { } |
150d7158 TG |
83 | static inline void futex_exit_release(struct task_struct *tsk) { } |
84 | static inline void futex_exec_release(struct task_struct *tsk) { } | |
2de0db99 DB |
85 | static inline long do_futex(u32 __user *uaddr, int op, u32 val, |
86 | ktime_t *timeout, u32 __user *uaddr2, | |
87 | u32 val2, u32 val3) | |
88 | { | |
89 | return -EINVAL; | |
90 | } | |
bc2eecd7 NP |
91 | #endif |
92 | ||
1da177e4 | 93 | #endif |