diff options
Diffstat (limited to 'include/linux/futex.h')
| -rw-r--r-- | include/linux/futex.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/linux/futex.h b/include/linux/futex.h index 3f153b4e156c..820125c628c1 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -100,6 +100,35 @@ long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout, extern int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi); +/* + * 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 set bit 0 to indicate if it's an inode-based key. + */ +union futex_key { + struct { + unsigned long pgoff; + struct inode *inode; + int offset; + } shared; + struct { + unsigned long address; + struct mm_struct *mm; + int offset; + } private; + struct { + unsigned long word; + void *ptr; + int offset; + } both; +}; +int get_futex_key(u32 __user *uaddr, union futex_key *key); +void get_futex_key_refs(union futex_key *key); +void drop_futex_key_refs(union futex_key *key); + #ifdef CONFIG_FUTEX extern void exit_robust_list(struct task_struct *curr); extern void exit_pi_state_list(struct task_struct *curr); |