diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/futex.c | 541 | ||||
| -rw-r--r-- | kernel/futex_compat.c | 3 | ||||
| -rw-r--r-- | kernel/rtmutex.c | 41 | ||||
| -rw-r--r-- | kernel/rtmutex_common.h | 34 |
4 files changed, 532 insertions, 87 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index e1246ccbf89a..4a60ef55dab4 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -53,6 +53,12 @@ #include "rtmutex_common.h" +#ifdef CONFIG_DEBUG_RT_MUTEXES +# include "rtmutex-debug.h" +#else +# include "rtmutex.h" +#endif + #define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8) /* @@ -102,6 +108,12 @@ struct futex_q { /* Optional priority inheritance state: */ struct futex_pi_state *pi_state; struct task_struct *task; + + /* + * This waiter is used in case of requeue from a + * normal futex to a PI-futex + */ + struct rt_mutex_waiter waiter; }; /* @@ -180,6 +192,9 @@ int get_futex_key(u32 __user *uaddr, union futex_key *key) if (unlikely((vma->vm_flags & (VM_IO|VM_READ)) != VM_READ)) return (vma->vm_flags & VM_IO) ? -EPERM : -EACCES; + /* Save the user address in the ley */ + key->uaddr = uaddr; + /* * Private mappings are handled in a simple way. * @@ -439,7 +454,8 @@ void exit_pi_state_list(struct task_struct *curr) } static int -lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, struct futex_q *me) +lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, + union futex_key *key, struct futex_pi_state **ps) { struct futex_pi_state *pi_state = NULL; struct futex_q *this, *next; @@ -450,7 +466,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, struct futex_q *me) head = &hb->chain; plist_for_each_entry_safe(this, next, head, list) { - if (match_futex(&this->key, &me->key)) { + if (match_futex(&this->key, key)) { /* * Another waiter already exists - bump up * the refcount and return its pi_state: @@ -465,7 +481,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, struct futex_q *me) WARN_ON(!atomic_read(&pi_state->refcount)); atomic_inc(&pi_state->refcount); - me->pi_state = pi_state; + *ps = pi_state; return 0; } @@ -492,7 +508,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, struct futex_q *me) rt_mutex_init_proxy_locked(&pi_state->pi_mutex, p); /* Store the key for possible exit cleanups: */ - pi_state->key = me->key; + pi_state->key = *key; spin_lock_irq(&p->pi_lock); WARN_ON(!list_empty(&pi_state->list)); @@ -502,7 +518,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, struct futex_q *me) put_task_struct(p); - me->pi_state = pi_state; + *ps = pi_state; return 0; } @@ -562,6 +578,8 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) */ if (!(uval & FUTEX_OWNER_DIED)) { newval = FUTEX_WAITERS | new_owner->pid; + /* Keep the FUTEX_WAITER_REQUEUED flag if it was set */ + newval |= (uval & FUTEX_WAITER_REQUEUED); pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); @@ -666,6 +684,254 @@ out: } /* + * Called from futex_requeue_pi. + * Set FUTEX_WAITERS and FUTEX_WAITER_REQUEUED flags on the + * PI-futex value; search its associated pi_state if an owner exist + * or create a new one without owner. + */ +static inline int +lookup_pi_state_for_requeue(u32 __user *uaddr, struct futex_hash_bucket *hb, + union futex_key *key, + struct futex_pi_state **pi_state) +{ + u32 curval, uval, newval; + +retry: + /* + * We can't handle a fault cleanly because we can't + * release the locks here. Simply return the fault. + */ + if (get_futex_value_locked(&curval, uaddr)) + return -EFAULT; + + /* set the flags FUTEX_WAITERS and FUTEX_WAITER_REQUEUED */ + if ((curval & (FUTEX_WAITERS | FUTEX_WAITER_REQUEUED)) + != (FUTEX_WAITERS | FUTEX_WAITER_REQUEUED)) { + /* + * No waiters yet, we prepare the futex to have some waiters. + */ + + uval = curval; + newval = uval | FUTEX_WAITERS | FUTEX_WAITER_REQUEUED; + + pagefault_disable(); + curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); + pagefault_enable(); + + if (unlikely(curval == -EFAULT)) + return -EFAULT; + if (unlikely(curval != uval)) + goto retry; + } + + if (!(curval & FUTEX_TID_MASK) + || lookup_pi_state(curval, hb, key, pi_state)) { + /* the futex has no owner (yet) or the lookup failed: + allocate one pi_state without owner */ + + *pi_state = alloc_pi_state(); + + /* Already stores the key: */ + (*pi_state)->key = *key; + + /* init the mutex without owner */ + __rt_mutex_init(&(*pi_state)->pi_mutex, NULL); + } + + return 0; +} + +/* + * Keep the first nr_wake waiter from futex1, wake up one, + * and requeue the next nr_requeue waiters following hashed on + * one physical page to another physical page (PI-futex uaddr2) + */ +static int futex_requeue_pi(u32 __user *uaddr1, u32 __user *uaddr2, + int nr_wake, int nr_requeue, u32 *cmpval) +{ + union futex_key key1, key2; + struct futex_hash_bucket *hb1, *hb2; + struct plist_head *head1; + struct futex_q *this, *next; + struct futex_pi_state *pi_state2 = NULL; + struct rt_mutex_waiter *waiter, *top_waiter = NULL; + struct rt_mutex *lock2 = NULL; + int ret, drop_count = 0; + + if (refill_pi_state_cache()) + return -ENOMEM; + +retry: + /* + * First take all the futex related locks: + */ + down_read(¤t->mm->mmap_sem); + + ret = get_futex_key(uaddr1, &key1); + if (unlikely(ret != 0)) + goto out; + ret = get_futex_key(uaddr2, &key2); + if (unlikely(ret != 0)) + goto out; + + hb1 = hash_futex(&key1); + hb2 = hash_futex(&key2); + + double_lock_hb(hb1, hb2); + + if (likely(cmpval != NULL)) { + u32 curval; + + ret = get_futex_value_locked(&curval, uaddr1); + + if (unlikely(ret)) { + spin_unlock(&hb1->lock); + if (hb1 != hb2) + spin_unlock(&hb2->lock); + + /* + * If we would have faulted, release mmap_sem, fault + * it in and start all over again. + */ + up_read(¤t->mm->mmap_sem); + + ret = get_user(curval, uaddr1); + + if (!ret) + goto retry; + + return ret; + } + if (curval != *cmpval) { + ret = -EAGAIN; + goto out_unlock; + } + } + + head1 = &hb1->chain; + plist_for_each_entry_safe(this, next, head1, list) { + if (!match_futex (&this->key, &key1)) + continue; + if (++ret <= nr_wake) { + wake_futex(this); + } else { + /* + * FIRST: get and set the pi_state + */ + if (!pi_state2) { + int s; + /* do this only the first time we requeue someone */ + s = lookup_pi_state_for_requeue(uaddr2, hb2, + &key2, &pi_state2); + if (s) { + ret = s; + goto out_unlock; + } + + lock2 = &pi_state2->pi_mutex; + spin_lock(&lock2->wait_lock); + + /* Save the top waiter of the wait_list */ + if (rt_mutex_has_waiters(lock2)) + top_waiter = rt_mutex_top_waiter(lock2); + } else + atomic_inc(&pi_state2->refcount); + + + this->pi_state = pi_state2; + + /* + * SECOND: requeue futex_q to the correct hashbucket + */ + + /* + * If key1 and key2 hash to the same bucket, no need to + * requeue. + */ + if (likely(head1 != &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_futex_key_refs(&key2); + drop_count++; + + + /* + * THIRD: queue it to lock2 + */ + spin_lock_irq(&this->task->pi_lock); + waiter = &this->waiter; + waiter->task = this->task; + waiter->lock = lock2; + plist_node_init(&waiter->list_entry, this->task->prio); + plist_node_init(&waiter->pi_list_entry, this->task->prio); + plist_add(&waiter->list_entry, &lock2->wait_list); + this->task->pi_blocked_on = waiter; + spin_unlock_irq(&this->task->pi_lock); + + if (ret - nr_wake >= nr_requeue) + break; + } + } + + /* If we've requeued some tasks and the top_waiter of the rt_mutex + has changed, we must adjust the priority of the owner, if any */ + if (drop_count) { + struct task_struct *owner = rt_mutex_owner(lock2); + if (owner && + (top_waiter != (waiter = rt_mutex_top_waiter(lock2)))) { + int chain_walk = 0; + + spin_lock_irq(&owner->pi_lock); + if (top_waiter) + plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters); + else + /* + * There was no waiters before the requeue, + * the flag must be updated + */ + mark_rt_mutex_waiters(lock2); + + plist_add(&waiter->pi_list_entry, &owner->pi_waiters); + __rt_mutex_adjust_prio(owner); + if (owner->pi_blocked_on) { + chain_walk = 1; + get_task_struct(owner); + } + + spin_unlock_irq(&owner->pi_lock); + spin_unlock(&lock2->wait_lock); + + if (chain_walk) + rt_mutex_adjust_prio_chain(owner, 0, lock2, NULL, + current); + } else { + /* No owner or the top_waiter does not change */ + mark_rt_mutex_waiters(lock2); + spin_unlock(&lock2->wait_lock); + } + } + +out_unlock: + spin_unlock(&hb1->lock); + if (hb1 != hb2) + spin_unlock(&hb2->lock); + + /* drop_futex_key_refs() must be called outside the spinlocks. */ + while (--drop_count >= 0) + drop_futex_key_refs(&key1); + +out: + up_read(¤t->mm->mmap_sem); + return ret; +} + +/* * Wake up all waiters hashed on the physical page that is mapped * to this virtual address: */ @@ -984,9 +1250,10 @@ static int unqueue_me(struct futex_q *q) /* * PI futexes can not be requeued and must remove themself from the - * hash bucket. The hash bucket lock is held on entry and dropped here. + * hash bucket. The hash bucket lock (i.e. lock_ptr) is held on entry + * and dropped here. */ -static void unqueue_me_pi(struct futex_q *q, struct futex_hash_bucket *hb) +static void unqueue_me_pi(struct futex_q *q) { WARN_ON(plist_node_empty(&q->list)); plist_del(&q->list, &q->list.plist); @@ -995,11 +1262,65 @@ static void unqueue_me_pi(struct futex_q *q, struct futex_hash_bucket *hb) free_pi_state(q->pi_state); q->pi_state = NULL; - spin_unlock(&hb->lock); + spin_unlock(q->lock_ptr); drop_futex_key_refs(&q->key); } +/* + * Fixup the pi_state owner with current. + * + * The cur->mm semaphore must be held, it is released at return of this + * function. + */ +static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, + struct futex_hash_bucket *hb, + struct task_struct *curr) +{ + u32 newtid = curr->pid | FUTEX_WAITERS; + struct futex_pi_state *pi_state = q->pi_state; + u32 uval, curval, newval; + int ret; + + /* Owner died? */ + if (pi_state->owner != NULL) { + spin_lock_irq(&pi_state->owner->pi_lock); + WARN_ON(list_empty(&pi_state->list)); + list_del_init(&pi_state->list); + spin_unlock_irq(&pi_state->owner->pi_lock); + } else + newtid |= FUTEX_OWNER_DIED; + + pi_state->owner = curr; + + spin_lock_irq(&curr->pi_lock); + WARN_ON(!list_empty(&pi_state->list)); + list_add(&pi_state->list, &curr->pi_state_list); + spin_unlock_irq(&curr->pi_lock); + + /* Unqueue and drop the lock */ + unqueue_me_pi(q); + up_read(&curr->mm->mmap_sem); + /* + * We own it, so we have to replace the pending owner + * TID. This must be atomic as we have preserve the + * owner died bit here. + */ + ret = get_user(uval, uaddr); + while (!ret) { + newval = (uval & FUTEX_OWNER_DIED) | newtid; + newval |= (uval & FUTEX_WAITER_REQUEUED); + curval = futex_atomic_cmpxchg_inatomic(uaddr, + uval, newval); + if (curval == -EFAULT) + ret = -EFAULT; + if (curval == uval) + break; + uval = curval; + } + return ret; +} + static long futex_wait_restart(struct restart_block *restart); static int futex_wait(u32 __user *uaddr, u32 val, ktime_t *abs_time) { @@ -1009,7 +1330,7 @@ static int futex_wait(u32 __user *uaddr, u32 val, ktime_t *abs_time) struct futex_q q; u32 uval; int ret; - struct hrtimer_sleeper t; + struct hrtimer_sleeper t, *to = NULL; int rem = 0; q.pi_state = NULL; @@ -1063,6 +1384,14 @@ static int futex_wait(u32 __user *uaddr, u32 val, ktime_t *abs_time) if (uval != val) goto out_unlock_release_sem; + /* + * This rt_mutex_waiter structure is prepared here and will + * be used only if this task is requeued from a normal futex to + * a PI-futex with futex_requeue_pi. + */ + debug_rt_mutex_init_waiter(&q.waiter); + q.waiter.task = NULL; + /* Only actually queue if *uaddr contained val. */ __queue_me(&q, hb); @@ -1092,6 +1421,7 @@ static int futex_wait(u32 __user *uaddr, u32 val, ktime_t *abs_time) if (!abs_time) schedule(); else { + to = &t; hrtimer_init(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); hrtimer_init_sleeper(&t, current); t.timer.expires = *abs_time; @@ -1119,6 +1449,66 @@ static int futex_wait(u32 __user *uaddr, u32 val, ktime_t *abs_time) * we are the only user of it. */ + if (q.pi_state) { + /* + * We were woken but have been requeued on a PI-futex. + * We have to complete the lock acquisition by taking + * the rtmutex. + */ + + struct rt_mutex *lock = &q.pi_state->pi_mutex; + + spin_lock(&lock->wait_lock); + if (unlikely(q.waiter.task)) { + remove_waiter(lock, &q.waiter); + } + spin_unlock(&lock->wait_lock); + + if (rem) + ret = -ETIMEDOUT; + else + ret = rt_mutex_timed_lock(lock, to, 1); + + down_read(&curr->mm->mmap_sem); + spin_lock(q.lock_ptr); + + /* + * Got the lock. We might not be the anticipated owner if we + * did a lock-steal - fix up the PI-state in that case. + */ + if (!ret && q.pi_state->owner != curr) { + /* + * We MUST play with the futex we were requeued on, + * NOT the current futex. + * We can retrieve it from the key of the pi_state + */ + uaddr = q.pi_state->key.uaddr; + + /* mmap_sem and hash_bucket lock are unlocked at + return of this function */ + ret = fixup_pi_state_owner(uaddr, &q, hb, curr); + } else { + /* + * Catch the rare case, where the lock was released + * when we were on the way back before we locked + * the hash bucket. + */ + if (ret && q.pi_state->owner == curr) { + if (rt_mutex_trylock(&q.pi_state->pi_mutex)) + ret = 0; + } + /* Unqueue and drop the lock */ + unqueue_me_pi(&q); + up_read(&curr->mm->mmap_sem); + } + + debug_rt_mutex_free_waiter(&q.waiter); + + return ret; + } + + debug_rt_mutex_free_waiter(&q.waiter); + /* If we were woken (and unqueued), we succeeded, whatever. */ if (!unqueue_me(&q)) return 0; @@ -1161,6 +1551,51 @@ static long futex_wait_restart(struct restart_block *restart) } +static void set_pi_futex_owner(struct futex_hash_bucket *hb, + union futex_key *key, struct task_struct *p) +{ + struct plist_head *head; + struct futex_q *this, *next; + struct futex_pi_state *pi_state = NULL; + struct rt_mutex *lock; + + /* Search a waiter that should already exists */ + + head = &hb->chain; + + plist_for_each_entry_safe(this, next, head, list) { + if (match_futex (&this->key, key)) { + pi_state = this->pi_state; + break; + } + } + + BUG_ON(!pi_state); + + /* set p as pi_state's owner */ + lock = &pi_state->pi_mutex; + + spin_lock(&lock->wait_lock); + spin_lock_irq(&p->pi_lock); + + list_add(&pi_state->list, &p->pi_state_list); + pi_state->owner = p; + + + /* set p as pi_mutex's owner */ + debug_rt_mutex_proxy_lock(lock, p); + WARN_ON(rt_mutex_owner(lock)); + rt_mutex_set_owner(lock, p, 0); + rt_mutex_deadlock_account_lock(lock, p); + + plist_add(&rt_mutex_top_waiter(lock)->pi_list_entry, + &p->pi_waiters); + __rt_mutex_adjust_prio(p); + + spin_unlock_irq(&p->pi_lock); + spin_unlock(&lock->wait_lock); +} + /* * Userspace tried a 0 -> TID atomic transition of the futex value * and failed. The kernel side here does the whole locking operation: @@ -1175,7 +1610,7 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, struct futex_hash_bucket *hb; u32 uval, newval, curval; struct futex_q q; - int ret, attempt = 0; + int ret, lock_held, attempt = 0; if (refill_pi_state_cache()) return -ENOMEM; @@ -1198,6 +1633,8 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, hb = queue_lock(&q, -1, NULL); retry_locked: + lock_held = 0; + /* * To avoid races, we attempt to take the lock here again * (by doing a 0 -> TID atomic cmpxchg), while holding all @@ -1216,7 +1653,16 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, if (unlikely((curval & FUTEX_TID_MASK) == current->pid)) { if (!detect && 0) force_sig(SIGKILL, current); - ret = -EDEADLK; + /* + * Normally, this check is done in user space. + * In case of requeue, the owner may attempt to lock this futex, + * even if the ownership has already been given by the previous + * waker. + * In the usual case, this is a case of deadlock, but not in case + * of REQUEUE_PI. + */ + if (!(curval & FUTEX_WAITER_REQUEUED)) + ret = -EDEADLK; goto out_unlock_release_sem; } @@ -1228,7 +1674,18 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, goto out_unlock_release_sem; uval = curval; - newval = uval | FUTEX_WAITERS; + /* + * In case of a requeue, check if there already is an owner + * If not, just take the futex. + */ + if ((curval & FUTEX_WAITER_REQUEUED) && !(curval & FUTEX_TID_MASK)) { + /* set current as futex owner */ + newval = curval | current->pid; + lock_held = 1; + } else + /* Set the WAITERS flag, so the owner will know it has someone + to wake at next unlock */ + newval = curval | FUTEX_WAITERS; pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); @@ -1239,11 +1696,16 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, if (unlikely(curval != uval)) goto retry_locked; + if (lock_held) { + set_pi_futex_owner(hb, &q.key, curr); + goto out_unlock_release_sem; + } + /* * We dont have the lock. Look up the PI state (or create it if * we are the first waiter): */ - ret = lookup_pi_state(uval, hb, &q); + ret = lookup_pi_state(uval, hb, &q.key, &q.pi_state); if (unlikely(ret)) { /* @@ -1306,45 +1768,10 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, * Got the lock. We might not be the anticipated owner if we * did a lock-steal - fix up the PI-state in that case. */ - if (!ret && q.pi_state->owner != curr) { - u32 newtid = current->pid | FUTEX_WAITERS; - - /* Owner died? */ - if (q.pi_state->owner != NULL) { - spin_lock_irq(&q.pi_state->owner->pi_lock); - WARN_ON(list_empty(&q.pi_state->list)); - list_del_init(&q.pi_state->list); - spin_unlock_irq(&q.pi_state->owner->pi_lock); - } else - newtid |= FUTEX_OWNER_DIED; - - q.pi_state->owner = current; - - spin_lock_irq(¤t->pi_lock); - WARN_ON(!list_empty(&q.pi_state->list)); - list_add(&q.pi_state->list, ¤t->pi_state_list); - spin_unlock_irq(¤t->pi_lock); - - /* Unqueue and drop the lock */ - unqueue_me_pi(&q, hb); - up_read(&curr->mm->mmap_sem); - /* - * We own it, so we have to replace the pending owner - * TID. This must be atomic as we have preserve the - * owner died bit here. - */ - ret = get_user(uval, uaddr); - while (!ret) { - newval = (uval & FUTEX_OWNER_DIED) | newtid; - curval = futex_atomic_cmpxchg_inatomic(uaddr, - uval, newval); - if (curval == -EFAULT) - ret = -EFAULT; - if (curval == uval) - break; - uval = curval; - } - } else { + if (!ret && q.pi_state->owner != curr) + /* mmap_sem is unlocked at return of this function */ + ret = fixup_pi_state_owner(uaddr, &q, hb, curr); + else { /* * Catch the rare case, where the lock was released * when we were on the way back before we locked @@ -1355,7 +1782,7 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, ktime_t *time, ret = 0; } /* Unqueue and drop the lock */ - unqueue_me_pi(&q, hb); + unqueue_me_pi(&q); up_read(&curr->mm->mmap_sem); } @@ -1724,6 +2151,8 @@ retry: * userspace. */ mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED; + /* Also keep the FUTEX_WAITER_REQUEUED flag if set */ + mval |= (uval & FUTEX_WAITER_REQUEUED); nval = futex_atomic_cmpxchg_inatomic(uaddr, uval, mval); if (nval == -EFAULT) @@ -1854,6 +2283,9 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, case FUTEX_TRYLOCK_PI: ret = futex_lock_pi(uaddr, 0, timeout, 1); break; + case FUTEX_CMP_REQUEUE_PI: + ret = futex_requeue_pi(uaddr, uaddr2, val, val2, &val3); + break; default: ret = -ENOSYS; } @@ -1883,7 +2315,8 @@ asmlinkage long sys_futex(u32 __user *uaddr, int op, u32 val, /* * requeue parameter in 'utime' if op == FUTEX_REQUEUE. */ - if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE) + if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE + || op == FUTEX_CMP_REQUEUE_PI) val2 = (u32) (unsigned long) utime; return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index dff27c471ea6..338a9b489fbc 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -156,7 +156,8 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val, t = ktime_add(ktime_get(), t); tp = &t; } - 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, tp, uaddr2, val2, val3); diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 180978cb2f75..12879f6c1ec3 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -56,7 +56,7 @@ * state. */ -static void +void rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner, unsigned long mask) { @@ -81,29 +81,6 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) } /* - * 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 - -/* * Calculate task priority from the waiter list priority * * Return task->normal_prio when the waiter list is empty or when @@ -123,7 +100,7 @@ int rt_mutex_getprio(struct task_struct *task) * * This can be both boosting and unboosting. task->pi_lock must be held. */ -static void __rt_mutex_adjust_prio(struct task_struct *task) +void __rt_mutex_adjust_prio(struct task_struct *task) { int prio = rt_mutex_getprio(task); @@ -159,11 +136,11 @@ int max_lock_depth = 1024; * Decreases task's usage by one - may thus free the task. * Returns 0 or -EDEADLK. */ -static 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) +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) { struct rt_mutex *lock; struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter; @@ -524,8 +501,8 @@ static void wakeup_next_waiter(struct rt_mutex *lock) * * Must be called with lock->wait_lock held */ -static void remove_waiter(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter) +void remove_waiter(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter) { int first = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h index 9c75856e791e..242ec7ee740b 100644 --- a/kernel/rtmutex_common.h +++ b/kernel/rtmutex_common.h @@ -113,6 +113,29 @@ static inline unsigned long rt_mutex_owner_pending(struct rt_mutex *lock) } /* + * 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(struct rt_mutex *lock, 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 |