kernel - Fix numerous procfs/ptrace issues (3)

* Add a safety spin-lock around adjustments to p_stops so it hopefully
  interacts better with the event processing side of things.

diff --git a/sys/vfs/procfs/procfs_vnops.c b/sys/vfs/procfs/procfs_vnops.c
index f3b79bd..8974479 100644 (file)
--- a/sys/vfs/procfs/procfs_vnops.c
+++ b/sys/vfs/procfs/procfs_vnops.c
@@ -302,10 +302,14 @@ procfs_ioctl(struct vop_ioctl_args *ap)
 
        switch (ap->a_command) {
        case PIOCBIS:
+         spin_lock(&procp->p_spin);
          procp->p_stops |= *(unsigned int*)ap->a_data;
+         spin_unlock(&procp->p_spin);
          break;
        case PIOCBIC:
+         spin_lock(&procp->p_spin);
          procp->p_stops &= ~*(unsigned int*)ap->a_data;
+         spin_unlock(&procp->p_spin);
          break;
        case PIOCSFL:
          /*