futex priority based wakeup

Index: linux-2.6/kernel/futex.c
===================================================================
@@ -106,12 +106,12 @@ struct futex_pi_state {
  * we can wake only the relevant ones (hashed queues may be shared).
  *
  * A futex_q has a woken state, just like tasks have TASK_RUNNING.
- * It is considered woken when list_empty(&q->list) || q->lock_ptr == 0.
+ * It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
  * The order of wakup is always to make the first condition true, then
  * wake up q->waiters, then make the second condition true.
  */
 struct futex_q {
-	struct list_head list;
+	struct plist_node list;
 	wait_queue_head_t waiters;
 
 	/* Which hash list lock to use: */

@@ -133,8 +133,8 @@ struct futex_q {
  * Split the global futex_lock into every hash list lock.
  */
 struct futex_hash_bucket {
-       spinlock_t              lock;
-       struct list_head       chain;
+	spinlock_t lock;
+	struct plist_head chain;
 };
 
 static struct futex_hash_bucket futex_queues[1<<FUTEX_HASHBITS];

@@ -465,13 +465,13 @@ lookup_pi_state(u32 uval, struct futex_h
 {
 	struct futex_pi_state *pi_state = NULL;
 	struct futex_q *this, *next;
-	struct list_head *head;
+	struct plist_head *head;
 	struct task_struct *p;
 	pid_t pid;
 
 	head = &hb->chain;
 
-	list_for_each_entry_safe(this, next, head, list) {
+	plist_for_each_entry_safe(this, next, head, list) {
 		if (match_futex(&this->key, &me->key)) {
 			/*
 			 * Another waiter already exists - bump up

@@ -535,12 +535,12 @@ lookup_pi_state(u32 uval, struct futex_h
  */
 static void wake_futex(struct futex_q *q)
 {
-	list_del_init(&q->list);
+	plist_del(&q->list, &q->list.plist);
 	if (q->filp)
 		send_sigio(&q->filp->f_owner, q->fd, POLL_IN);
 	/*
 	 * The lock in wake_up_all() is a crucial memory barrier after the
-	 * list_del_init() and also before assigning to q->lock_ptr.
+	 * plist_del() and also before assigning to q->lock_ptr.
 	 */
 	wake_up_all(&q->waiters);
 	/*

@@ -653,7 +653,7 @@ static int futex_wake(u32 __user *uaddr,
 {
 	struct futex_hash_bucket *hb;
 	struct futex_q *this, *next;
-	struct list_head *head;
+	struct plist_head *head;
 	union futex_key key;
 	int ret;
 

@@ -667,7 +667,7 @@ static int futex_wake(u32 __user *uaddr,
 	spin_lock(&hb->lock);
 	head = &hb->chain;
 
-	list_for_each_entry_safe(this, next, head, list) {
+	plist_for_each_entry_safe(this, next, head, list) {
 		if (match_futex (&this->key, &key)) {
 			if (this->pi_state) {
 				ret = -EINVAL;

@@ -695,7 +695,7 @@ futex_wake_op(u32 __user *uaddr1, u32 __
 {
 	union futex_key key1, key2;
 	struct futex_hash_bucket *hb1, *hb2;
-	struct list_head *head;
+	struct plist_head *head;
 	struct futex_q *this, *next;
 	int ret, op_ret, attempt = 0;
 

@@ -768,7 +768,7 @@ retry:
 
 	head = &hb1->chain;
 
-	list_for_each_entry_safe(this, next, head, list) {
+	plist_for_each_entry_safe(this, next, head, list) {
 		if (match_futex (&this->key, &key1)) {
 			wake_futex(this);
 			if (++ret >= nr_wake)

@@ -780,7 +780,7 @@ retry:
 		head = &hb2->chain;
 
 		op_ret = 0;
-		list_for_each_entry_safe(this, next, head, list) {
+		plist_for_each_entry_safe(this, next, head, list) {
 			if (match_futex (&this->key, &key2)) {
 				wake_futex(this);
 				if (++op_ret >= nr_wake2)

@@ -807,7 +807,7 @@ static int futex_requeue(u32 __user *uad
 {
 	union futex_key key1, key2;
 	struct futex_hash_bucket *hb1, *hb2;
-	struct list_head *head1;
+	struct plist_head *head1;
 	struct futex_q *this, *next;
 	int ret, drop_count = 0;
 

@@ -856,7 +856,7 @@ static int futex_requeue(u32 __user *uad
 	}
 
 	head1 = &hb1->chain;
-	list_for_each_entry_safe(this, next, head1, list) {
+	plist_for_each_entry_safe(this, next, head1, list) {
 		if (!match_futex (&this->key, &key1))
 			continue;
 		if (++ret <= nr_wake) {

@@ -867,9 +867,13 @@ static int futex_requeue(u32 __user *uad
 			 * requeue.
 			 */
 			if (likely(head1 != &hb2->chain)) {
-				list_move_tail(&this->list, &hb2->chain);
+				plist_del(&this->list, &hb1->chain);
+				plist_add(&this->list, &hb2->chain);
 				this->lock_ptr = &hb2->lock;
-			}
+#ifdef CONFIG_DEBUG_PI_LIST
+				this->list.plist.lock = &hb2->lock;
+#endif
+ 			}
 			this->key = key2;
 			get_key_refs(&key2);
 			drop_count++;

@@ -914,7 +918,23 @@ queue_lock(struct futex_q *q, int fd, st
 
 static inline void __queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
 {
-	list_add_tail(&q->list, &hb->chain);
+	int prio;
+
+	/*
+	 * The priority used to register this element is
+	 * - either the real thread-priority for the real-time threads
+	 * (i.e. threads with a priority lower than MAX_RT_PRIO)
+	 * - or MAX_RT_PRIO for non-RT threads.
+	 * Thus, all RT-threads are woken first in priority order, and
+	 * the others are woken last, in FIFO order.
+	 */
+	prio = min(current->normal_prio, MAX_RT_PRIO);
+
+	plist_node_init(&q->list, prio);
+#ifdef CONFIG_DEBUG_PI_LIST
+	q->list.plist.lock = &hb->lock;
+#endif
+	plist_add(&q->list, &hb->chain);
 	q->task = current;
 	spin_unlock(&hb->lock);
 }

@@ -969,8 +989,8 @@ static int unqueue_me(struct futex_q *q)
 			spin_unlock(lock_ptr);
 			goto retry;
 		}
-		WARN_ON(list_empty(&q->list));
-		list_del(&q->list);
+		WARN_ON(plist_node_empty(&q->list));
+		plist_del(&q->list, &q->list.plist);
 
 		BUG_ON(q->pi_state);
 

@@ -988,8 +1008,8 @@ static int unqueue_me(struct futex_q *q)
  */
 static void unqueue_me_pi(struct futex_q *q, struct futex_hash_bucket *hb)
 {
-	WARN_ON(list_empty(&q->list));
-	list_del(&q->list);
+	WARN_ON(plist_node_empty(&q->list));
+	plist_del(&q->list, &q->list.plist);
 
 	BUG_ON(!q->pi_state);
 	free_pi_state(q->pi_state);

@@ -1082,10 +1102,10 @@ static int futex_wait(u32 __user *uaddr,
 	__set_current_state(TASK_INTERRUPTIBLE);
 	add_wait_queue(&q.waiters, &wait);
 	/*
-	 * !list_empty() is safe here without any lock.
+	 * !plist_node_empty() is safe here without any lock.
 	 * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
 	 */
-	if (likely(!list_empty(&q.list)))
+	if (likely(!plist_node_empty(&q.list)))
 		time = schedule_timeout(time);
 	__set_current_state(TASK_RUNNING);
 

@@ -1358,7 +1378,7 @@ static int futex_unlock_pi(u32 __user *u
 	struct futex_hash_bucket *hb;
 	struct futex_q *this, *next;
 	u32 uval;
-	struct list_head *head;
+	struct plist_head *head;
 	union futex_key key;
 	int ret, attempt = 0;
 

@@ -1409,7 +1429,7 @@ retry_locked:
 	 */
 	head = &hb->chain;
 
-	list_for_each_entry_safe(this, next, head, list) {
+	plist_for_each_entry_safe(this, next, head, list) {
 		if (!match_futex (&this->key, &key))
 			continue;
 		ret = wake_futex_pi(uaddr, uval, this);

@@ -1483,10 +1503,10 @@ static unsigned int futex_poll(struct fi
 	poll_wait(filp, &q->waiters, wait);
 
 	/*
-	 * list_empty() is safe here without any lock.
+	 * plist_node_empty() is safe here without any lock.
 	 * q->lock_ptr != 0 is not safe, because of ordering against wakeup.
 	 */
-	if (list_empty(&q->list))
+	if (plist_node_empty(&q->list))
 		ret = POLLIN | POLLRDNORM;
 
 	return ret;

@@ -1869,7 +1889,7 @@ static int __init init(void)
 	}
 
 	for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {
-		INIT_LIST_HEAD(&futex_queues[i].chain);
+		plist_head_init(&futex_queues[i].chain, &futex_queues[i].lock);
 		spin_lock_init(&futex_queues[i].lock);
 	}
 	return 0;

Index: linux-2.6/kernel/futex.c
===================================================================
@@ -1020,7 +1020,7 @@ static void unqueue_me_pi(struct futex_q
 	drop_key_refs(&q->key);
 }
 
-static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
+static int futex_wait(u32 __user *uaddr, u32 val, struct timespec *time)
 {
 	struct task_struct *curr = current;
 	DECLARE_WAITQUEUE(wait, curr);

@@ -1028,6 +1028,8 @@ static int futex_wait(u32 __user *uaddr,
 	struct futex_q q;
 	u32 uval;
 	int ret;
+	struct hrtimer_sleeper t;
+	int rem = 0;
 
 	q.pi_state = NULL;
  retry:

@@ -1105,8 +1107,31 @@ static int futex_wait(u32 __user *uaddr,
 	 * !plist_node_empty() is safe here without any lock.
 	 * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
 	 */
-	if (likely(!plist_node_empty(&q.list)))
-		time = schedule_timeout(time);
+	if (likely(!plist_node_empty(&q.list))) {
+		if (time->tv_sec == 0 && time->tv_nsec == 0)
+			schedule();
+		else {
+			hrtimer_init(&t.timer, CLOCK_MONOTONIC, HRTIMER_REL);
+			hrtimer_init_sleeper(&t, current);
+			t.timer.expires = timespec_to_ktime(*time);
+
+			hrtimer_start(&t.timer, t.timer.expires, HRTIMER_REL);
+
+			/*
+			 * the timer could have already expired, in which
+			 * case current would be flagged for rescheduling.
+			 * Don't bother calling schedule.
+			 */
+			if (likely(t.task))
+				schedule();
+
+			hrtimer_cancel(&t.timer);
+
+			/* Flag if a timeout occured */
+			rem = (t.task == NULL);
+		}
+	}
+
 	__set_current_state(TASK_RUNNING);
 
 	/*

@@ -1117,7 +1142,7 @@ static int futex_wait(u32 __user *uaddr,
 	/* If we were woken (and unqueued), we succeeded, whatever. */
 	if (!unqueue_me(&q))
 		return 0;
-	if (time == 0)
+	if (rem)
 		return -ETIMEDOUT;
 	/*
 	 * We expect signal_pending(current), but another thread may

@@ -1139,8 +1164,8 @@ static int futex_wait(u32 __user *uaddr,
  * 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 detect, unsigned long sec,
-			 long nsec, int trylock)
+static int futex_lock_pi(u32 __user *uaddr, int detect, struct timespec *time,
+			 int trylock)
 {
 	struct hrtimer_sleeper timeout, *to = NULL;
 	struct task_struct *curr = current;

@@ -1152,11 +1177,11 @@ static int futex_lock_pi(u32 __user *uad
 	if (refill_pi_state_cache())
 		return -ENOMEM;
 
-	if (sec != MAX_SCHEDULE_TIMEOUT) {
+	if (time->tv_sec || time->tv_nsec) {
 		to = &timeout;
 		hrtimer_init(&to->timer, CLOCK_REALTIME, HRTIMER_ABS);
 		hrtimer_init_sleeper(to, current);
-		to->timer.expires = ktime_set(sec, nsec);
+		to->timer.expires = timespec_to_ktime(*time);
 	}
 
 	q.pi_state = NULL;

@@ -1792,7 +1817,7 @@ void exit_robust_list(struct task_struct
 	}
 }
 
-long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout,
+long do_futex(u32 __user *uaddr, int op, u32 val, struct timespec *timeout,
 		u32 __user *uaddr2, u32 val2, u32 val3)
 {
 	int ret;

@@ -1818,13 +1843,13 @@ long do_futex(u32 __user *uaddr, int op,
 		ret = futex_wake_op(uaddr, uaddr2, val, val2, val3);
 		break;
 	case FUTEX_LOCK_PI:
-		ret = futex_lock_pi(uaddr, val, timeout, val2, 0);
+		ret = futex_lock_pi(uaddr, val, timeout, 0);
 		break;
 	case FUTEX_UNLOCK_PI:
 		ret = futex_unlock_pi(uaddr);
 		break;
 	case FUTEX_TRYLOCK_PI:
-		ret = futex_lock_pi(uaddr, 0, timeout, val2, 1);
+		ret = futex_lock_pi(uaddr, 0, timeout, 1);
 		break;
 	default:
 		ret = -ENOSYS;

@@ -1837,8 +1862,7 @@ asmlinkage long sys_futex(u32 __user *ua
 			  struct timespec __user *utime, u32 __user *uaddr2,
 			  u32 val3)
 {
-	struct timespec t;
-	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
+	struct timespec t = {.tv_sec = 0, .tv_nsec = 0};
 	u32 val2 = 0;
 
 	if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) {

@@ -1846,12 +1870,6 @@ asmlinkage long sys_futex(u32 __user *ua
 			return -EFAULT;
 		if (!timespec_valid(&t))
 			return -EINVAL;
-		if (op == FUTEX_WAIT)
-			timeout = timespec_to_jiffies(&t) + 1;
-		else {
-			timeout = t.tv_sec;
-			val2 = t.tv_nsec;
-		}
 	}
 	/*
 	 * requeue parameter in 'utime' if op == FUTEX_REQUEUE.

@@ -1859,7 +1877,7 @@ asmlinkage long sys_futex(u32 __user *ua
 	if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE)
 		val2 = (u32) (unsigned long) utime;
 
-	return do_futex(uaddr, op, val, timeout, uaddr2, val2, val3);
+	return do_futex(uaddr, op, val, &t, uaddr2, val2, val3);
 }
 
 static int futexfs_get_sb(struct file_system_type *fs_type,

Index: linux-2.6/kernel/futex_compat.c
===================================================================
@@ -141,8 +141,7 @@ asmlinkage long compat_sys_futex(u32 __u
 		struct compat_timespec __user *utime, u32 __user *uaddr2,
 		u32 val3)
 {
-	struct timespec t;
-	unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
+	struct timespec t = {.tv_sec = 0, .tv_nsec = 0};
 	int val2 = 0;
 
 	if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) {

@@ -150,15 +149,9 @@ asmlinkage long compat_sys_futex(u32 __u
 			return -EFAULT;
 		if (!timespec_valid(&t))
 			return -EINVAL;
-		if (op == FUTEX_WAIT)
-			timeout = timespec_to_jiffies(&t) + 1;
-		else {
-			timeout = t.tv_sec;
-			val2 = t.tv_nsec;
-		}
 	}
 	if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE)
 		val2 = (int) (unsigned long) utime;
 
-	return do_futex(uaddr, op, val, timeout, uaddr2, val2, val3);
+	return do_futex(uaddr, op, val, &t, uaddr2, val2, val3);
 }

Index: linux-2.6/include/linux/futex.h
===================================================================
@@ -94,7 +94,7 @@ struct robust_list_head {
 #define ROBUST_LIST_LIMIT	2048
 
 #ifdef __KERNEL__
-long do_futex(u32 __user *uaddr, int op, u32 val, unsigned long timeout,
+long do_futex(u32 __user *uaddr, int op, u32 val, struct timespec *timeout,
 	      u32 __user *uaddr2, u32 val2, u32 val3);
 
 extern int

Index: linux-2.6/include/linux/futex.h
===================================================================
@@ -15,6 +15,7 @@
 #define FUTEX_LOCK_PI		6
 #define FUTEX_UNLOCK_PI		7
 #define FUTEX_TRYLOCK_PI	8
+#define FUTEX_CMP_REQUEUE_PI	9
 
 /*
  * Support for robust futexes: the kernel cleans up held futexes at

@@ -83,9 +84,14 @@ struct robust_list_head {
 #define FUTEX_OWNER_DIED	0x40000000
 
 /*
+ * Some processes have been requeued on this PI-futex
+ */
+#define FUTEX_WAITER_REQUEUED	0x20000000
+
+/*
  * The rest of the robust-futex field is for the TID:
  */
-#define FUTEX_TID_MASK		0x3fffffff
+#define FUTEX_TID_MASK		0x0fffffff
 
 /*
  * This limit protects against a deliberately circular list.

728 lines not on this page · raw message

71 lines not on this page · raw message

Index: linux-2.6/kernel/rtmutex_common.h
===================================================================
@@ -113,6 +113,29 @@ static inline unsigned long rt_mutex_own
 }
 
 /*
+ * We can speed up the acquire/release, if the architecture
+ * supports cmpxchg and if there's no debugging state to be set up
+ */
+#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES)
+# define rt_mutex_cmpxchg(l,c,n)	(cmpxchg(&l->owner, c, n) == c)
+static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+{
+	unsigned long owner, *p = (unsigned long *) &lock->owner;
+
+	do {
+		owner = *p;
+	} while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner);
+}
+#else
+# define rt_mutex_cmpxchg(l,c,n)	(0)
+static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+{
+	lock->owner = (struct task_struct *)
+			((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);
+}
+#endif
+
+/*
  * PI-futex support (proxy locking functions, etc.):
  */
 extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);

@@ -120,4 +143,15 @@ extern void rt_mutex_init_proxy_locked(s
 				       struct task_struct *proxy_owner);
 extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
 				  struct task_struct *proxy_owner);
+
+extern void rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner,
+			       unsigned long mask);
+extern void __rt_mutex_adjust_prio(struct task_struct *task);
+extern int rt_mutex_adjust_prio_chain(struct task_struct *task,
+				      int deadlock_detect,
+				      struct rt_mutex *orig_lock,
+				      struct rt_mutex_waiter *orig_waiter,
+				      struct task_struct *top_task);
+extern void remove_waiter(struct rt_mutex *lock,
+			  struct rt_mutex_waiter *waiter);
 #endif

Index: linux-2.6/kernel/futex_compat.c
===================================================================
@@ -150,7 +150,8 @@ asmlinkage long compat_sys_futex(u32 __u
 		if (!timespec_valid(&t))
 			return -EINVAL;
 	}
-	if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE)
+	if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE
+	    || op == FUTEX_CMP_REQUEUE_PI)
 		val2 = (int) (unsigned long) utime;
 
 	return do_futex(uaddr, op, val, &t, uaddr2, val2, val3);

Index: linux-2.6/include/asm-x86_64/futex.h
===================================================================
@@ -41,6 +41,39 @@
 	  "=&r" (tem)						\
 	: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
 
+#define __futex_atomic_op1_64(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile (						\
+"1:	" insn "\n"						\
+"2:	.section .fixup,\"ax\"\n\
+3:	movq	%3, %1\n\
+	jmp	2b\n\
+	.previous\n\
+	.section __ex_table,\"a\"\n\
+	.align	8\n\
+	.quad	1b,3b\n\
+	.previous"						\
+	: "=r" (oldval), "=r" (ret), "=m" (*uaddr)		\
+	: "i" (-EFAULT), "m" (*uaddr), "0" (oparg), "1" (0))
+
+#define __futex_atomic_op2_64(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile (						\
+"1:	movq	%2, %0\n\
+	movq	%0, %3\n"					\
+	insn "\n"						\
+"2:	" LOCK_PREFIX "cmpxchgq %3, %2\n\
+	jnz	1b\n\
+3:	.section .fixup,\"ax\"\n\
+4:	movq	%5, %1\n\
+	jmp	3b\n\
+	.previous\n\
+	.section __ex_table,\"a\"\n\
+	.align	8\n\
+	.quad	1b,4b,2b,4b\n\
+	.previous"						\
+	: "=&a" (oldval), "=&r" (ret), "=m" (*uaddr),		\
+	  "=&r" (tem)						\
+	: "r" (oparg), "i" (-EFAULT), "m" (*uaddr), "1" (0))
+
 static inline int
 futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 {

@@ -95,6 +128,60 @@ futex_atomic_op_inuser (int encoded_op,
 }
 
 static inline int
+futex_atomic_op_inuser64 (int encoded_op, u64 __user *uaddr)
+{
+	int op = (encoded_op >> 28) & 7;
+	int cmp = (encoded_op >> 24) & 15;
+	u64 oparg = (encoded_op << 8) >> 20;
+	u64 cmparg = (encoded_op << 20) >> 20;
+	u64 oldval = 0, ret, tem;
+
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u64)))
+		return -EFAULT;
+
+	inc_preempt_count();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op1_64("xchgq %0, %2", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op1_64(LOCK_PREFIX "xaddq %0, %2", ret, oldval,
+				   uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op2_64("orq %4, %3", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op2_64("andq %4, %3", ret, oldval, uaddr, ~oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op2_64("xorq %4, %3", ret, oldval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	dec_preempt_count();
+
+	if (!ret) {
+		switch (cmp) {
+		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+		default: ret = -ENOSYS;
+		}
+	}
+	return ret;
+}
+
+static inline int
 futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 {
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))

@@ -121,5 +208,31 @@ futex_atomic_cmpxchg_inatomic(int __user
 	return oldval;
 }
 
+static inline u64
+futex_atomic_cmpxchg_inatomic64(u64 __user *uaddr, u64 oldval, u64 newval)
+{
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u64)))
+		return -EFAULT;
+
+	__asm__ __volatile__(
+		"1:	" LOCK_PREFIX "cmpxchgq %3, %1		\n"
+
+		"2:	.section .fixup, \"ax\"			\n"
+		"3:	mov     %2, %0				\n"
+		"	jmp     2b				\n"
+		"	.previous				\n"
+
+		"	.section __ex_table, \"a\"		\n"
+		"	.align  8				\n"
+		"	.quad   1b,3b				\n"
+		"	.previous				\n"
+
+		: "=a" (oldval), "=m" (*uaddr)
+		: "i" (-EFAULT), "r" (newval), "0" (oldval)
+		: "memory"
+	);
+
+	return oldval;
+}
 #endif
 #endif

Index: linux-2.6/include/asm-x86_64/unistd.h
===================================================================
@@ -619,8 +619,10 @@ __SYSCALL(__NR_sync_file_range, sys_sync
 __SYSCALL(__NR_vmsplice, sys_vmsplice)
 #define __NR_move_pages		279
 __SYSCALL(__NR_move_pages, sys_move_pages)
+#define __NR_futex64		280
+__SYSCALL(__NR_futex64, sys_futex64)
 
-#define __NR_syscall_max __NR_move_pages
+#define __NR_syscall_max __NR_futex64
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR

Index: linux-2.6/include/linux/syscalls.h
===================================================================
@@ -178,6 +178,9 @@ asmlinkage long sys_set_tid_address(int
 asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val,
 			struct timespec __user *utime, u32 __user *uaddr2,
 			u32 val3);
+asmlinkage long sys_futex64(u64 __user *uaddr, int op, u64 val,
+			struct timespec __user *utime, u64 __user *uaddr2,
+			u64 val3);
 
 asmlinkage long sys_init_module(void __user *umod, unsigned long len,
 				const char __user *uargs);

567 lines not on this page · raw message

Index: linux-2.6/kernel/sys_ni.c
===================================================================
@@ -41,6 +41,7 @@ cond_syscall(sys_sendmsg);
 cond_syscall(sys_recvmsg);
 cond_syscall(sys_socketcall);
 cond_syscall(sys_futex);
+cond_syscall(sys_futex64);
 cond_syscall(compat_sys_futex);
 cond_syscall(sys_set_robust_list);
 cond_syscall(compat_sys_set_robust_list);

Index: linux-2.6/include/linux/futex.h
===================================================================
@@ -100,8 +100,9 @@ struct robust_list_head {
 #define ROBUST_LIST_LIMIT	2048
 
 #ifdef __KERNEL__
-long do_futex(u32 __user *uaddr, int op, u32 val, struct timespec *timeout,
-	      u32 __user *uaddr2, u32 val2, u32 val3);
+long do_futex(unsigned long __user *uaddr, int op, unsigned long val,
+	      struct timespec *timeout, unsigned long __user *uaddr2,
+	      unsigned long val2, unsigned long val3, int futex64);
 
 extern int
 handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi);

Index: linux-2.6/kernel/futex_compat.c
===================================================================
@@ -154,5 +154,6 @@ asmlinkage long compat_sys_futex(u32 __u
 	    || op == FUTEX_CMP_REQUEUE_PI)
 		val2 = (int) (unsigned long) utime;
 
-	return do_futex(uaddr, op, val, &t, uaddr2, val2, val3);
+	return do_futex((unsigned long __user*)uaddr, op, val, &t,
+			(unsigned long __user*)uaddr2, val2, val3, 0);
 }