1 files changed, 26 insertions, 3 deletions

diff --git a/include/linux/futex.h b/include/linux/futex.h
index 1bd8dfcb037b..899fc7f20edd 100644
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -19,6 +19,18 @@ union ktime;
 #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
  * thread exit time.
@@ -114,8 +126,18 @@ handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);
  * 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.
- */
+ * 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 {
@@ -134,7 +156,8 @@ union futex_key {
                 int offset;
         } both;
 };
-int get_futex_key(u32 __user *uaddr, union futex_key *key);
+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);