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author | Frederic Weisbecker <fweisbec@gmail.com> | 2010-02-27 16:18:46 +0100 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-02-27 16:18:46 +0100 |
commit | 018cbffe6819f6f8db20a0a3acd9bab9bfd667e4 (patch) | |
tree | fadde2521591998dc653fa094c636e8a547e620d /kernel/futex.c | |
parent | 1dd2980d990068e20045b90c424518cc7f3657ff (diff) | |
parent | 60b341b778cc2929df16c0a504c91621b3c6a4ad (diff) | |
download | op-kernel-dev-018cbffe6819f6f8db20a0a3acd9bab9bfd667e4.zip op-kernel-dev-018cbffe6819f6f8db20a0a3acd9bab9bfd667e4.tar.gz |
Merge commit 'v2.6.33' into perf/core
Merge reason:
__percpu annotations need the corresponding sparse address
space definition upstream.
Conflicts:
tools/perf/util/probe-event.c (trivial)
Diffstat (limited to 'kernel/futex.c')
-rw-r--r-- | kernel/futex.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index d9b3a22..e7a35f10 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -530,8 +530,25 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb, return -EINVAL; WARN_ON(!atomic_read(&pi_state->refcount)); - WARN_ON(pid && pi_state->owner && - pi_state->owner->pid != pid); + + /* + * When pi_state->owner is NULL then the owner died + * and another waiter is on the fly. pi_state->owner + * is fixed up by the task which acquires + * pi_state->rt_mutex. + * + * We do not check for pid == 0 which can happen when + * the owner died and robust_list_exit() cleared the + * TID. + */ + if (pid && pi_state->owner) { + /* + * Bail out if user space manipulated the + * futex value. + */ + if (pid != task_pid_vnr(pi_state->owner)) + return -EINVAL; + } atomic_inc(&pi_state->refcount); *ps = pi_state; @@ -758,6 +775,13 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) if (!pi_state) return -EINVAL; + /* + * If current does not own the pi_state then the futex is + * inconsistent and user space fiddled with the futex value. + */ + if (pi_state->owner != current) + return -EINVAL; + raw_spin_lock(&pi_state->pi_mutex.wait_lock); new_owner = rt_mutex_next_owner(&pi_state->pi_mutex); @@ -1971,7 +1995,7 @@ retry_private: /* Unqueue and drop the lock */ unqueue_me_pi(&q); - goto out; + goto out_put_key; out_unlock_put_key: queue_unlock(&q, hb); |