mm: compaction: add /proc trigger for memory compaction
[linux-2.6.git] / kernel / futex_compat.c
index cc098e1..d49afb2 100644 (file)
@@ -30,6 +30,15 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
        return 0;
 }
 
+static void __user *futex_uaddr(struct robust_list __user *entry,
+                               compat_long_t futex_offset)
+{
+       compat_uptr_t base = ptr_to_compat(entry);
+       void __user *uaddr = compat_ptr(base + futex_offset);
+
+       return uaddr;
+}
+
 /*
  * Walk curr->robust_list (very carefully, it's a userspace list!)
  * and mark any locks found there dead, and notify any waiters.
@@ -45,6 +54,9 @@ void compat_exit_robust_list(struct task_struct *curr)
        compat_long_t futex_offset;
        int rc;
 
+       if (!futex_cmpxchg_enabled)
+               return;
+
        /*
         * Fetch the list head (which was registered earlier, via
         * sys_set_robust_list()):
@@ -76,11 +88,12 @@ void compat_exit_robust_list(struct task_struct *curr)
                 * A pending lock might already be on the list, so
                 * dont process it twice:
                 */
-               if (entry != pending)
-                       if (handle_futex_death((void __user *)entry + futex_offset,
-                                               curr, pi))
-                               return;
+               if (entry != pending) {
+                       void __user *uaddr = futex_uaddr(entry, futex_offset);
 
+                       if (handle_futex_death(uaddr, curr, pi))
+                               return;
+               }
                if (rc)
                        return;
                uentry = next_uentry;
@@ -94,15 +107,20 @@ void compat_exit_robust_list(struct task_struct *curr)
 
                cond_resched();
        }
-       if (pending)
-               handle_futex_death((void __user *)pending + futex_offset,
-                                  curr, pip);
+       if (pending) {
+               void __user *uaddr = futex_uaddr(pending, futex_offset);
+
+               handle_futex_death(uaddr, curr, pip);
+       }
 }
 
 asmlinkage long
 compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
                           compat_size_t len)
 {
+       if (!futex_cmpxchg_enabled)
+               return -ENOSYS;
+
        if (unlikely(len != sizeof(*head)))
                return -EINVAL;
 
@@ -117,6 +135,10 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 {
        struct compat_robust_list_head __user *head;
        unsigned long ret;
+       const struct cred *cred = current_cred(), *pcred;
+
+       if (!futex_cmpxchg_enabled)
+               return -ENOSYS;
 
        if (!pid)
                head = current->compat_robust_list;
@@ -124,17 +146,18 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
                struct task_struct *p;
 
                ret = -ESRCH;
-               read_lock(&tasklist_lock);
-               p = find_task_by_pid_ns(pid,
-                               current->nsproxy->pid_ns);
+               rcu_read_lock();
+               p = find_task_by_vpid(pid);
                if (!p)
                        goto err_unlock;
                ret = -EPERM;
-               if ((current->euid != p->euid) && (current->euid != p->uid) &&
-                               !capable(CAP_SYS_PTRACE))
+               pcred = __task_cred(p);
+               if (cred->euid != pcred->euid &&
+                   cred->euid != pcred->uid &&
+                   !capable(CAP_SYS_PTRACE))
                        goto err_unlock;
                head = p->compat_robust_list;
-               read_unlock(&tasklist_lock);
+               rcu_read_unlock();
        }
 
        if (put_user(sizeof(*head), len_ptr))
@@ -142,7 +165,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
        return put_user(ptr_to_compat(head), head_ptr);
 
 err_unlock:
-       read_unlock(&tasklist_lock);
+       rcu_read_unlock();
 
        return ret;
 }
@@ -156,7 +179,9 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
        int val2 = 0;
        int cmd = op & FUTEX_CMD_MASK;
 
-       if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) {
+       if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
+                     cmd == FUTEX_WAIT_BITSET ||
+                     cmd == FUTEX_WAIT_REQUEUE_PI)) {
                if (get_compat_timespec(&ts, utime))
                        return -EFAULT;
                if (!timespec_valid(&ts))
@@ -164,10 +189,11 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 
                t = timespec_to_ktime(ts);
                if (cmd == FUTEX_WAIT)
-                       t = ktime_add(ktime_get(), t);
+                       t = ktime_add_safe(ktime_get(), t);
                tp = &t;
        }
-       if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE)
+       if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
+           cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
                val2 = (int) (unsigned long) utime;
 
        return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);