futex.h
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#ifndef _LINUX_FUTEX_H
#define _LINUX_FUTEX_H
#include <uapi/linux/futex.h>
struct inode;
struct mm_struct;
struct task_struct;
union ktime;
long do_futex(u32 __user *uaddr, int op, u32 val, union ktime *timeout,
u32 __user *uaddr2, u32 val2, u32 val3);
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 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 {
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;
};
#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } }
#ifdef CONFIG_FUTEX
extern void exit_robust_list(struct task_struct *curr);
extern void exit_pi_state_list(struct task_struct *curr);
#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
#define futex_cmpxchg_enabled 1
#else
extern int futex_cmpxchg_enabled;
#endif
#else
static inline void exit_robust_list(struct task_struct *curr)
{
}
static inline void exit_pi_state_list(struct task_struct *curr)
{
}
#endif
#endif