1 files changed, 70 insertions, 76 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 38cf606a2d7d..87ad28746e17 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -69,6 +69,14 @@ int __read_mostly futex_cmpxchg_enabled;
 #define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8)
 
 /*
+ * Futex flags used to encode options to functions and preserve them across
+ * restarts.
+ */
+#define FLAGS_SHARED            0x01
+#define FLAGS_CLOCKRT           0x02
+#define FLAGS_HAS_TIMEOUT       0x04
+
+/*
  * Priority Inheritance state:
  */
 struct futex_pi_state {
@@ -869,7 +877,8 @@ double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2)
 /*
  * Wake up waiters matching bitset queued on this futex (uaddr).
  */
-static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
+static int
+futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
 {
         struct futex_hash_bucket *hb;
         struct futex_q *this, *next;
@@ -880,7 +889,7 @@ 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, flags & FLAGS_SHARED, &key);
         if (unlikely(ret != 0))
                 goto out;
 
@@ -916,7 +925,7 @@ out:
  * to this virtual address:
  */
 static int
-futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
+futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
               int nr_wake, int nr_wake2, int op)
 {
         union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
@@ -926,10 +935,10 @@ 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, flags & FLAGS_SHARED, &key1);
         if (unlikely(ret != 0))
                 goto out;
-        ret = get_futex_key(uaddr2, fshared, &key2);
+        ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
         if (unlikely(ret != 0))
                 goto out_put_key1;
 
@@ -961,7 +970,7 @@ retry_private:
                 if (ret)
                         goto out_put_keys;
 
-                if (!fshared)
+                if (!(flags & FLAGS_SHARED))
                         goto retry_private;
 
                 put_futex_key(&key2);
@@ -1132,13 +1141,13 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex,
 /**
  * futex_requeue() - Requeue waiters from uaddr1 to uaddr2
  * @uaddr1:     source futex user address
- * @fshared:    0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @flags:      futex flags (FLAGS_SHARED, etc.)
  * @uaddr2:     target futex user address
  * @nr_wake:    number of waiters to wake (must be 1 for requeue_pi)
  * @nr_requeue: number of waiters to requeue (0-INT_MAX)
  * @cmpval:     @uaddr1 expected value (or %NULL)
  * @requeue_pi: if we are attempting to requeue from a non-pi futex to a
- *              pi futex (pi to pi requeue is not supported)
+ *              pi futex (pi to pi requeue is not supported)
  *
  * Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire
  * uaddr2 atomically on behalf of the top waiter.
@@ -1147,9 +1156,9 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex,
  * >=0 - on success, the number of tasks requeued or woken
  *  <0 - on error
  */
-static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
-                         int nr_wake, int nr_requeue, u32 *cmpval,
-                         int requeue_pi)
+static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
+                         u32 __user *uaddr2, int nr_wake, int nr_requeue,
+                         u32 *cmpval, int requeue_pi)
 {
         union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
         int drop_count = 0, task_count = 0, ret;
@@ -1190,10 +1199,10 @@ retry:
                 pi_state = NULL;
         }
 
-        ret = get_futex_key(uaddr1, fshared, &key1);
+        ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1);
         if (unlikely(ret != 0))
                 goto out;
-        ret = get_futex_key(uaddr2, fshared, &key2);
+        ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
         if (unlikely(ret != 0))
                 goto out_put_key1;
 
@@ -1215,7 +1224,7 @@ retry_private:
                         if (ret)
                                 goto out_put_keys;
 
-                        if (!fshared)
+                        if (!(flags & FLAGS_SHARED))
                                 goto retry_private;
 
                         put_futex_key(&key2);
@@ -1586,14 +1595,6 @@ handle_fault:
         goto retry;
 }
 
-/*
- * In case we must use restart_block to restart a futex_wait,
- * we encode in the 'flags' shared capability
- */
-#define FLAGS_SHARED            0x01
-#define FLAGS_CLOCKRT           0x02
-#define FLAGS_HAS_TIMEOUT       0x04
-
 static long futex_wait_restart(struct restart_block *restart);
 
 /**
@@ -1712,7 +1713,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
  * futex_wait_setup() - Prepare to wait on a futex
  * @uaddr:      the futex userspace address
  * @val:        the expected value
- * @fshared:    whether the futex is shared (1) or not (0)
+ * @flags:      futex flags (FLAGS_SHARED, etc.)
  * @q:          the associated futex_q
  * @hb:         storage for hash_bucket pointer to be returned to caller
  *
@@ -1725,7 +1726,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
  *  0 - uaddr contains val and hb has been locked
  * <1 - -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlcoked
  */
-static int futex_wait_setup(u32 __user *uaddr, u32 val, int fshared,
+static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
                            struct futex_q *q, struct futex_hash_bucket **hb)
 {
         u32 uval;
@@ -1750,7 +1751,7 @@ 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);
+        ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key);
         if (unlikely(ret != 0))
                 return ret;
 
@@ -1766,7 +1767,7 @@ retry_private:
                 if (ret)
                         goto out;
 
-                if (!fshared)
+                if (!(flags & FLAGS_SHARED))
                         goto retry_private;
 
                 put_futex_key(&q->key);
@@ -1784,8 +1785,8 @@ out:
         return ret;
 }
 
-static int futex_wait(u32 __user *uaddr, int fshared,
-                      u32 val, ktime_t *abs_time, u32 bitset, int clockrt)
+static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
+                      ktime_t *abs_time, u32 bitset)
 {
         struct hrtimer_sleeper timeout, *to = NULL;
         struct restart_block *restart;
@@ -1804,8 +1805,9 @@ static int futex_wait(u32 __user *uaddr, int fshared,
         if (abs_time) {
                 to = &timeout;
 
-                hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
-                                      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+                hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
+                                      CLOCK_REALTIME : CLOCK_MONOTONIC,
+                                      HRTIMER_MODE_ABS);
                 hrtimer_init_sleeper(to, current);
                 hrtimer_set_expires_range_ns(&to->timer, *abs_time,
                                              current->timer_slack_ns);
@@ -1816,7 +1818,7 @@ retry:
          * Prepare to wait on uaddr. On success, holds hb lock and increments
          * q.key refs.
          */
-        ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+        ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
         if (ret)
                 goto out;
 
@@ -1849,12 +1851,7 @@ retry:
         restart->futex.val = val;
         restart->futex.time = abs_time->tv64;
         restart->futex.bitset = bitset;
-        restart->futex.flags = FLAGS_HAS_TIMEOUT;
-
-        if (fshared)
-                restart->futex.flags |= FLAGS_SHARED;
-        if (clockrt)
-                restart->futex.flags |= FLAGS_CLOCKRT;
+        restart->futex.flags = flags;
 
         ret = -ERESTART_RESTARTBLOCK;
 
@@ -1870,7 +1867,6 @@ out:
 static long futex_wait_restart(struct restart_block *restart)
 {
         u32 __user *uaddr = restart->futex.uaddr;
-        int fshared = 0;
         ktime_t t, *tp = NULL;
 
         if (restart->futex.flags & FLAGS_HAS_TIMEOUT) {
@@ -1878,11 +1874,9 @@ static long futex_wait_restart(struct restart_block *restart)
                 tp = &t;
         }
         restart->fn = do_no_restart_syscall;
-        if (restart->futex.flags & FLAGS_SHARED)
-                fshared = 1;
-        return (long)futex_wait(uaddr, fshared, restart->futex.val, tp,
-                                restart->futex.bitset,
-                                restart->futex.flags & FLAGS_CLOCKRT);
+
+        return (long)futex_wait(uaddr, restart->futex.flags,
+                                restart->futex.val, tp, restart->futex.bitset);
 }
 
 
@@ -1892,8 +1886,8 @@ static long futex_wait_restart(struct restart_block *restart)
  * if there are waiters then it will block, it does PI, etc. (Due to
  * races the kernel might see a 0 value of the futex too.)
  */
-static int futex_lock_pi(u32 __user *uaddr, int fshared,
-                         int detect, ktime_t *time, int trylock)
+static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, int detect,
+                         ktime_t *time, int trylock)
 {
         struct hrtimer_sleeper timeout, *to = NULL;
         struct futex_hash_bucket *hb;
@@ -1916,7 +1910,7 @@ 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);
+        ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q.key);
         if (unlikely(ret != 0))
                 goto out;
 
@@ -2005,7 +1999,7 @@ uaddr_faulted:
         if (ret)
                 goto out_put_key;
 
-        if (!fshared)
+        if (!(flags & FLAGS_SHARED))
                 goto retry_private;
 
         put_futex_key(&q.key);
@@ -2017,7 +2011,7 @@ uaddr_faulted:
  * This is the in-kernel slowpath: we look up the PI state (if any),
  * and do the rt-mutex unlock.
  */
-static int futex_unlock_pi(u32 __user *uaddr, int fshared)
+static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 {
         struct futex_hash_bucket *hb;
         struct futex_q *this, *next;
@@ -2035,7 +2029,7 @@ retry:
         if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
                 return -EPERM;
 
-        ret = get_futex_key(uaddr, fshared, &key);
+        ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key);
         if (unlikely(ret != 0))
                 goto out;
 
@@ -2157,7 +2151,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
 /**
  * futex_wait_requeue_pi() - Wait on uaddr and take uaddr2
  * @uaddr:      the futex we initially wait on (non-pi)
- * @fshared:    whether the futexes are shared (1) or not (0).  They must be
+ * @flags:      futex flags (FLAGS_SHARED, FLAGS_CLOCKRT, etc.), they must be
  *              the same type, no requeueing from private to shared, etc.
  * @val:        the expected value of uaddr
  * @abs_time:   absolute timeout
@@ -2195,9 +2189,9 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
  *  0 - On success
  * <0 - On error
  */
-static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
+static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
                                  u32 val, ktime_t *abs_time, u32 bitset,
-                                 int clockrt, u32 __user *uaddr2)
+                                 u32 __user *uaddr2)
 {
         struct hrtimer_sleeper timeout, *to = NULL;
         struct rt_mutex_waiter rt_waiter;
@@ -2212,8 +2206,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
 
         if (abs_time) {
                 to = &timeout;
-                hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
-                                      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+                hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
+                                      CLOCK_REALTIME : CLOCK_MONOTONIC,
+                                      HRTIMER_MODE_ABS);
                 hrtimer_init_sleeper(to, current);
                 hrtimer_set_expires_range_ns(&to->timer, *abs_time,
                                              current->timer_slack_ns);
@@ -2227,7 +2222,7 @@ 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);
+        ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
         if (unlikely(ret != 0))
                 goto out;
 
@@ -2240,7 +2235,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
          * Prepare to wait on uaddr. On success, increments q.key (key1) ref
          * count.
          */
-        ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+        ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
         if (ret)
                 goto out_key2;
 
@@ -2547,58 +2542,57 @@ void exit_robust_list(struct task_struct *curr)
 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
                 u32 __user *uaddr2, u32 val2, u32 val3)
 {
-        int clockrt, ret = -ENOSYS;
-        int cmd = op & FUTEX_CMD_MASK;
-        int fshared = 0;
+        int ret = -ENOSYS, cmd = op & FUTEX_CMD_MASK;
+        unsigned int flags = 0;
 
         if (!(op & FUTEX_PRIVATE_FLAG))
-                fshared = 1;
+                flags |= FLAGS_SHARED;
 
-        clockrt = op & FUTEX_CLOCK_REALTIME;
-        if (clockrt && cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI)
-                return -ENOSYS;
+        if (op & FUTEX_CLOCK_REALTIME) {
+                flags |= FLAGS_CLOCKRT;
+                if (cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI)
+                        return -ENOSYS;
+        }
 
         switch (cmd) {
         case FUTEX_WAIT:
                 val3 = FUTEX_BITSET_MATCH_ANY;
         case FUTEX_WAIT_BITSET:
-                ret = futex_wait(uaddr, fshared, val, timeout, val3, clockrt);
+                ret = futex_wait(uaddr, flags, val, timeout, val3);
                 break;
         case FUTEX_WAKE:
                 val3 = FUTEX_BITSET_MATCH_ANY;
         case FUTEX_WAKE_BITSET:
-                ret = futex_wake(uaddr, fshared, val, val3);
+                ret = futex_wake(uaddr, flags, val, val3);
                 break;
         case FUTEX_REQUEUE:
-                ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, NULL, 0);
+                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
                 break;
         case FUTEX_CMP_REQUEUE:
-                ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
-                                    0);
+                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
                 break;
         case FUTEX_WAKE_OP:
-                ret = futex_wake_op(uaddr, fshared, uaddr2, val, val2, val3);
+                ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
                 break;
         case FUTEX_LOCK_PI:
                 if (futex_cmpxchg_enabled)
-                        ret = futex_lock_pi(uaddr, fshared, val, timeout, 0);
+                        ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
                 break;
         case FUTEX_UNLOCK_PI:
                 if (futex_cmpxchg_enabled)
-                        ret = futex_unlock_pi(uaddr, fshared);
+                        ret = futex_unlock_pi(uaddr, flags);
                 break;
         case FUTEX_TRYLOCK_PI:
                 if (futex_cmpxchg_enabled)
-                        ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1);
+                        ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
                 break;
         case FUTEX_WAIT_REQUEUE_PI:
                 val3 = FUTEX_BITSET_MATCH_ANY;
-                ret = futex_wait_requeue_pi(uaddr, fshared, val, timeout, val3,
-                                            clockrt, uaddr2);
+                ret = futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
+                                            uaddr2);
                 break;
         case FUTEX_CMP_REQUEUE_PI:
-                ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
-                                    1);
+                ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
                 break;
         default:
                 ret = -ENOSYS;