2.6.30-rc6-git7

 kernel

diff --git a/kernel/futex.c b/kernel/futex.c
index eef8cd2..d546b2d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -193,6 +193,7 @@ static void drop_futex_key_refs(union futex_key *key)
  * @uaddr: virtual address of the futex
  * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
  * @key: address where result is stored.
+ * @rw: mapping needs to be read/write (values: VERIFY_READ, VERIFY_WRITE)
  *
  * Returns a negative error code or 0
  * The key words are stored in *key on success.
@@ -203,7 +204,8 @@ static void drop_futex_key_refs(union futex_key *key)
  *
  * lock_page() might sleep, the caller should not hold a spinlock.
  */
-static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
+static int
+get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
 {
    unsigned long address = (unsigned long)uaddr;
    struct mm_struct *mm = current->mm;
@@ -226,7 +228,7 @@ static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
     *        but access_ok() should be faster than find_vma()
     */
    if (!fshared) {
-      if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
+      if (unlikely(!access_ok(rw, uaddr, sizeof(u32))))
          return -EFAULT;
       key->private.mm = mm;
       key->private.address = address;
@@ -235,7 +237,7 @@ static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
    }
 
 again:
-   err = get_user_pages_fast(address, 1, 0, &page);
+   err = get_user_pages_fast(address, 1, rw == VERIFY_WRITE, &page);
    if (err < 0)
       return err;
 
@@ -677,7 +679,7 @@ static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
    if (!bitset)
       return -EINVAL;
 
-   ret = get_futex_key(uaddr, fshared, &key);
+   ret = get_futex_key(uaddr, fshared, &key, VERIFY_READ);
    if (unlikely(ret != 0))
       goto out;
 
@@ -723,10 +725,10 @@ futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
    int ret, op_ret;
 
 retry:
-   ret = get_futex_key(uaddr1, fshared, &key1);
+   ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
    if (unlikely(ret != 0))
       goto out;
-   ret = get_futex_key(uaddr2, fshared, &key2);
+   ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
    if (unlikely(ret != 0))
       goto out_put_key1;
 
@@ -814,10 +816,10 @@ static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
    int ret, drop_count = 0;
 
 retry:
-   ret = get_futex_key(uaddr1, fshared, &key1);
+   ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
    if (unlikely(ret != 0))
       goto out;
-   ret = get_futex_key(uaddr2, fshared, &key2);
+   ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_READ);
    if (unlikely(ret != 0))
       goto out_put_key1;
 
@@ -1140,7 +1142,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
    q.bitset = bitset;
 retry:
    q.key = FUTEX_KEY_INIT;
-   ret = get_futex_key(uaddr, fshared, &q.key);
+   ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_READ);
    if (unlikely(ret != 0))
       goto out;
 
@@ -1330,7 +1332,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
    q.pi_state = NULL;
 retry:
    q.key = FUTEX_KEY_INIT;
-   ret = get_futex_key(uaddr, fshared, &q.key);
+   ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_WRITE);
    if (unlikely(ret != 0))
       goto out;
 
@@ -1594,7 +1596,7 @@ retry:
    if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
       return -EPERM;
 
-   ret = get_futex_key(uaddr, fshared, &key);
+   ret = get_futex_key(uaddr, fshared, &key, VERIFY_WRITE);
    if (unlikely(ret != 0))
       goto out;