1 #ifndef _LINUX_FUTEX_H 2 #define _LINUX_FUTEX_H 3 4 #include <uapi/linux/futex.h> 5 6 struct inode; 7 struct mm_struct; 8 struct task_struct; 9 union ktime; 10 11 long do_futex(u32 __user *uaddr, int op, u32 val, union ktime *timeout, 12 u32 __user *uaddr2, u32 val2, u32 val3); 13 14 extern int 15 handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi); 16 17 /* 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(). 21 * 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) 30 */ 31 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 */ 34 35 union futex_key { 36 struct { 37 unsigned long pgoff; 38 struct inode *inode; 39 int offset; 40 } shared; 41 struct { 42 unsigned long address; 43 struct mm_struct *mm; 44 int offset; 45 } private; 46 struct { 47 unsigned long word; 48 void *ptr; 49 int offset; 50 } both; 51 }; 52 53 #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } } 54 55 #ifdef CONFIG_FUTEX 56 extern void exit_robust_list(struct task_struct *curr); 57 extern void exit_pi_state_list(struct task_struct *curr); 58 #ifdef CONFIG_HAVE_FUTEX_CMPXCHG 59 #define futex_cmpxchg_enabled 1 60 #else 61 extern int futex_cmpxchg_enabled; 62 #endif 63 #else exit_robust_list(struct task_struct * curr)64 static inline void exit_robust_list(struct task_struct *curr) 65 { 66 } exit_pi_state_list(struct task_struct * curr)67 static inline void exit_pi_state_list(struct task_struct *curr) 68 { 69 } 70 #endif 71 #endif 72