#include <linux/signal.h>
#include <linux/module.h>
#include <linux/magic.h>
+#include <linux/pid.h>
+#include <linux/nsproxy.h>
+
#include <asm/futex.h>
#include "rtmutex_common.h"
* For other futexes, it points to ¤t->mm->mmap_sem and
* caller must have taken the reader lock. but NOT any spinlocks.
*/
-int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
- union futex_key *key)
+static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
+ union futex_key *key)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
}
return err;
}
-EXPORT_SYMBOL_GPL(get_futex_key);
/*
* Take a reference to the resource addressed by a key.
* Can be called while holding spinlocks.
*
*/
-inline void get_futex_key_refs(union futex_key *key)
+static void get_futex_key_refs(union futex_key *key)
{
if (key->both.ptr == 0)
return;
break;
}
}
-EXPORT_SYMBOL_GPL(get_futex_key_refs);
/*
* Drop a reference to the resource addressed by a key.
* The hash bucket spinlock must not be held.
*/
-void drop_futex_key_refs(union futex_key *key)
+static void drop_futex_key_refs(union futex_key *key)
{
if (!key->both.ptr)
return;
break;
}
}
-EXPORT_SYMBOL_GPL(drop_futex_key_refs);
static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
{
struct task_struct *p;
rcu_read_lock();
- p = find_task_by_pid(pid);
-
+ p = find_task_by_vpid(pid);
if (!p || ((current->euid != p->euid) && (current->euid != p->uid)))
p = ERR_PTR(-ESRCH);
else
if (!(uval & FUTEX_OWNER_DIED)) {
int ret = 0;
- newval = FUTEX_WAITERS | new_owner->pid;
+ newval = FUTEX_WAITERS | task_pid_vnr(new_owner);
curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
if (curval == -EFAULT)
ret = -EFAULT;
- if (curval != uval)
+ else if (curval != uval)
ret = -EINVAL;
if (ret) {
spin_unlock(&pi_state->pi_mutex.wait_lock);
}
/*
- * Fixup the pi_state owner with current.
+ * Fixup the pi_state owner with the new owner.
*
* Must be called with hash bucket lock held and mm->sem held for non
* private futexes.
*/
static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *curr)
+ struct task_struct *newowner)
{
- u32 newtid = curr->pid | FUTEX_WAITERS;
+ u32 newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
struct futex_pi_state *pi_state = q->pi_state;
u32 uval, curval, newval;
int ret;
} else
newtid |= FUTEX_OWNER_DIED;
- pi_state->owner = curr;
+ pi_state->owner = newowner;
- spin_lock_irq(&curr->pi_lock);
+ spin_lock_irq(&newowner->pi_lock);
WARN_ON(!list_empty(&pi_state->list));
- list_add(&pi_state->list, &curr->pi_state_list);
- spin_unlock_irq(&curr->pi_lock);
+ list_add(&pi_state->list, &newowner->pi_state_list);
+ spin_unlock_irq(&newowner->pi_lock);
/*
* We own it, so we have to replace the pending owner
/*
* In case we must use restart_block to restart a futex_wait,
- * we encode in the 'arg3' shared capability
+ * we encode in the 'flags' shared capability
*/
-#define ARG3_SHARED 1
+#define FLAGS_SHARED 1
static long futex_wait_restart(struct restart_block *restart);
struct restart_block *restart;
restart = ¤t_thread_info()->restart_block;
restart->fn = futex_wait_restart;
- restart->arg0 = (unsigned long)uaddr;
- restart->arg1 = (unsigned long)val;
- restart->arg2 = (unsigned long)abs_time;
- restart->arg3 = 0;
+ restart->futex.uaddr = (u32 *)uaddr;
+ restart->futex.val = val;
+ restart->futex.time = abs_time->tv64;
+ restart->futex.flags = 0;
+
if (fshared)
- restart->arg3 |= ARG3_SHARED;
+ restart->futex.flags |= FLAGS_SHARED;
return -ERESTART_RESTARTBLOCK;
}
static long futex_wait_restart(struct restart_block *restart)
{
- u32 __user *uaddr = (u32 __user *)restart->arg0;
- u32 val = (u32)restart->arg1;
- ktime_t *abs_time = (ktime_t *)restart->arg2;
+ u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
struct rw_semaphore *fshared = NULL;
+ ktime_t t;
+ t.tv64 = restart->futex.time;
restart->fn = do_no_restart_syscall;
- if (restart->arg3 & ARG3_SHARED)
+ if (restart->futex.flags & FLAGS_SHARED)
fshared = ¤t->mm->mmap_sem;
- return (long)futex_wait(uaddr, fshared, val, abs_time);
+ return (long)futex_wait(uaddr, fshared, restart->futex.val, &t);
}
* (by doing a 0 -> TID atomic cmpxchg), while holding all
* the locks. It will most likely not succeed.
*/
- newval = current->pid;
+ newval = task_pid_vnr(current);
curval = cmpxchg_futex_value_locked(uaddr, 0, newval);
* Detect deadlocks. In case of REQUEUE_PI this is a valid
* situation and we return success to user space.
*/
- if (unlikely((curval & FUTEX_TID_MASK) == current->pid)) {
+ if (unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(current))) {
ret = -EDEADLK;
goto out_unlock_release_sem;
}
*/
if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
/* Keep the OWNER_DIED bit */
- newval = (curval & ~FUTEX_TID_MASK) | current->pid;
+ newval = (curval & ~FUTEX_TID_MASK) | task_pid_vnr(current);
ownerdied = 0;
lock_taken = 1;
}
* when we were on the way back before we locked the
* hash bucket.
*/
- if (q.pi_state->owner == curr &&
- rt_mutex_trylock(&q.pi_state->pi_mutex)) {
- ret = 0;
+ if (q.pi_state->owner == curr) {
+ /*
+ * Try to get the rt_mutex now. This might
+ * fail as some other task acquired the
+ * rt_mutex after we removed ourself from the
+ * rt_mutex waiters list.
+ */
+ if (rt_mutex_trylock(&q.pi_state->pi_mutex))
+ ret = 0;
+ else {
+ /*
+ * pi_state is incorrect, some other
+ * task did a lock steal and we
+ * returned due to timeout or signal
+ * without taking the rt_mutex. Too
+ * late. We can access the
+ * rt_mutex_owner without locking, as
+ * the other task is now blocked on
+ * the hash bucket lock. Fix the state
+ * up.
+ */
+ struct task_struct *owner;
+ int res;
+
+ owner = rt_mutex_owner(&q.pi_state->pi_mutex);
+ res = fixup_pi_state_owner(uaddr, &q, owner);
+
+ WARN_ON(rt_mutex_owner(&q.pi_state->pi_mutex) !=
+ owner);
+
+ /* propagate -EFAULT, if the fixup failed */
+ if (res)
+ ret = res;
+ }
} else {
/*
* Paranoia check. If we did not take the lock
/*
* We release only a lock we actually own:
*/
- if ((uval & FUTEX_TID_MASK) != current->pid)
+ if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
return -EPERM;
/*
* First take all the futex related locks:
* anyone else up:
*/
if (!(uval & FUTEX_OWNER_DIED))
- uval = cmpxchg_futex_value_locked(uaddr, current->pid, 0);
+ uval = cmpxchg_futex_value_locked(uaddr, task_pid_vnr(current), 0);
if (unlikely(uval == -EFAULT))
* Rare case: we managed to release the lock atomically,
* no need to wake anyone else up:
*/
- if (unlikely(uval == current->pid))
+ if (unlikely(uval == task_pid_vnr(current)))
goto out_unlock;
/*
ret = -ESRCH;
rcu_read_lock();
- p = find_task_by_pid(pid);
+ p = find_task_by_vpid(pid);
if (!p)
goto err_unlock;
ret = -EPERM;
if (get_user(uval, uaddr))
return -1;
- if ((uval & FUTEX_TID_MASK) == curr->pid) {
+ if ((uval & FUTEX_TID_MASK) == task_pid_vnr(curr)) {
/*
* Ok, this dying thread is truly holding a futex
* of interest. Set the OWNER_DIED bit atomically
projects / cascardo / linux.git / blobdiff