2.6.32.8

 kernel

diff --git a/kernel/futex.c b/kernel/futex.c
index fb65e82..3b74909 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -203,8 +203,6 @@ 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.
@@ -216,7 +214,7 @@ 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, int rw)
+get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
 {
    unsigned long address = (unsigned long)uaddr;
    struct mm_struct *mm = current->mm;
@@ -239,7 +237,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
     *        but access_ok() should be faster than find_vma()
     */
    if (!fshared) {
-      if (unlikely(!access_ok(rw, uaddr, sizeof(u32))))
+      if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
          return -EFAULT;
       key->private.mm = mm;
       key->private.address = address;
@@ -248,7 +246,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
    }
 
 again:
-   err = get_user_pages_fast(address, 1, rw == VERIFY_WRITE, &page);
+   err = get_user_pages_fast(address, 1, 1, &page);
    if (err < 0)
       return err;
 
@@ -304,8 +302,14 @@ void put_futex_key(int fshared, union futex_key *key)
  */
 static int fault_in_user_writeable(u32 __user *uaddr)
 {
-   int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,
-             1, 1, 0, NULL, NULL);
+   struct mm_struct *mm = current->mm;
+   int ret;
+
+   down_read(&mm->mmap_sem);
+   ret = get_user_pages(current, mm, (unsigned long)uaddr,
+              1, 1, 0, NULL, NULL);
+   up_read(&mm->mmap_sem);
+
    return ret < 0 ? ret : 0;
 }
 
@@ -861,7 +865,7 @@ 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, VERIFY_READ);
+   ret = get_futex_key(uaddr, fshared, &key);
    if (unlikely(ret != 0))
       goto out;
 
@@ -907,10 +911,10 @@ futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
    int ret, op_ret;
 
 retry:
-   ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
+   ret = get_futex_key(uaddr1, fshared, &key1);
    if (unlikely(ret != 0))
       goto out;
-   ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
+   ret = get_futex_key(uaddr2, fshared, &key2);
    if (unlikely(ret != 0))
       goto out_put_key1;
 
@@ -1169,11 +1173,10 @@ retry:
       pi_state = NULL;
    }
 
-   ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
+   ret = get_futex_key(uaddr1, fshared, &key1);
    if (unlikely(ret != 0))
       goto out;
-   ret = get_futex_key(uaddr2, fshared, &key2,
-             requeue_pi ? VERIFY_WRITE : VERIFY_READ);
+   ret = get_futex_key(uaddr2, fshared, &key2);
    if (unlikely(ret != 0))
       goto out_put_key1;
 
@@ -1732,7 +1735,7 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, int fshared,
     */
 retry:
    q->key = FUTEX_KEY_INIT;
-   ret = get_futex_key(uaddr, fshared, &q->key, VERIFY_READ);
+   ret = get_futex_key(uaddr, fshared, &q->key);
    if (unlikely(ret != 0))
       return ret;
 
@@ -1898,7 +1901,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
    q.requeue_pi_key = NULL;
 retry:
    q.key = FUTEX_KEY_INIT;
-   ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_WRITE);
+   ret = get_futex_key(uaddr, fshared, &q.key);
    if (unlikely(ret != 0))
       goto out;
 
@@ -2017,7 +2020,7 @@ retry:
    if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
       return -EPERM;
 
-   ret = get_futex_key(uaddr, fshared, &key, VERIFY_WRITE);
+   ret = get_futex_key(uaddr, fshared, &key);
    if (unlikely(ret != 0))
       goto out;
 
@@ -2209,7 +2212,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
    rt_waiter.task = NULL;
 
    key2 = FUTEX_KEY_INIT;
-   ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
+   ret = get_futex_key(uaddr2, fshared, &key2);
    if (unlikely(ret != 0))
       goto out;