aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-05-19 18:42:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-05-19 18:42:45 -0700
commit007a93a1bac9a7c8a936204d0c063faa824942f3 (patch)
tree3b1c84a8bfcac99897e70ef1fb7302cf7445129a
parent33252572e727ccdcc54efdb67157e7ab3d6942db (diff)
parent64d1304a64477629cb16b75491a77bafe6f86963 (diff)
Merge branch 'core/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: setup writeable mapping for futex ops which modify user space data
-rw-r--r--kernel/futex.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index eef8cd26b5e5..d546b2d53a62 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;

Privacy Policy