FUTEX: new PRIVATE futexes

[safe/jmp/linux-2.6] / include / linux / futex.h

diff --git a/include/linux/futex.h b/include/linux/futex.h
index f05a3f4..899fc7f 100644 (file)
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -3,6 +3,8 @@
 
 #include <linux/sched.h>
 
+union ktime;
+
 /* Second argument to futex syscall */
 
 
@@ -12,6 +14,22 @@
 #define FUTEX_REQUEUE          3
 #define FUTEX_CMP_REQUEUE      4
 #define FUTEX_WAKE_OP          5
+#define FUTEX_LOCK_PI          6
+#define FUTEX_UNLOCK_PI                7
+#define FUTEX_TRYLOCK_PI       8
+#define FUTEX_CMP_REQUEUE_PI   9
+
+#define FUTEX_PRIVATE_FLAG     128
+#define FUTEX_CMD_MASK         ~FUTEX_PRIVATE_FLAG
+
+#define FUTEX_WAIT_PRIVATE     (FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAKE_PRIVATE     (FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_REQUEUE_PRIVATE  (FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAKE_OP_PRIVATE  (FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
+#define FUTEX_LOCK_PI_PRIVATE  (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_UNLOCK_PI_PRIVATE        (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
 
 /*
  * Support for robust futexes: the kernel cleans up held futexes at
@@ -80,9 +98,14 @@ struct robust_list_head {
 #define FUTEX_OWNER_DIED       0x40000000
 
 /*
+ * Some processes have been requeued on this PI-futex
+ */
+#define FUTEX_WAITER_REQUEUED  0x20000000
+
+/*
  * The rest of the robust-futex field is for the TID:
  */
-#define FUTEX_TID_MASK         0x3fffffff
+#define FUTEX_TID_MASK         0x0fffffff
 
 /*
  * This limit protects against a deliberately circular list.
@@ -90,18 +113,66 @@ struct robust_list_head {
  */
 #define ROBUST_LIST_LIMIT      2048
 
-long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout,
+#ifdef __KERNEL__
+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);
+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 {
+       u32 __user *uaddr;
+       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, struct rw_semaphore *shared,
+                 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);
 #else
 static inline void exit_robust_list(struct task_struct *curr)
 {
 }
+static inline void exit_pi_state_list(struct task_struct *curr)
+{
+}
 #endif
+#endif /* __KERNEL__ */
 
 #define FUTEX_OP_SET           0       /* *(int *)UADDR2 = OPARG; */
 #define FUTEX_OP_ADD           1       /* *(int *)UADDR2 += OPARG; */