diff options
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c579dcc9200c..8b5a1b33d0fe 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -320,7 +320,7 @@ long vhost_dev_reset_owner(struct vhost_dev *dev) vhost_dev_cleanup(dev); memory->nregions = 0; - dev->memory = memory; + RCU_INIT_POINTER(dev->memory, memory); return 0; } @@ -352,8 +352,9 @@ void vhost_dev_cleanup(struct vhost_dev *dev) fput(dev->log_file); dev->log_file = NULL; /* No one will access memory at this point */ - kfree(dev->memory); - dev->memory = NULL; + kfree(rcu_dereference_protected(dev->memory, + lockdep_is_held(&dev->mutex))); + RCU_INIT_POINTER(dev->memory, NULL); if (dev->mm) mmput(dev->mm); dev->mm = NULL; @@ -440,14 +441,22 @@ static int vq_access_ok(unsigned int num, /* Caller should have device mutex but not vq mutex */ int vhost_log_access_ok(struct vhost_dev *dev) { - return memory_access_ok(dev, dev->memory, 1); + struct vhost_memory *mp; + + mp = rcu_dereference_protected(dev->memory, + lockdep_is_held(&dev->mutex)); + return memory_access_ok(dev, mp, 1); } /* Verify access for write logging. */ /* Caller should have vq mutex and device mutex */ static int vq_log_access_ok(struct vhost_virtqueue *vq, void __user *log_base) { - return vq_memory_access_ok(log_base, vq->dev->memory, + struct vhost_memory *mp; + + mp = rcu_dereference_protected(vq->dev->memory, + lockdep_is_held(&vq->mutex)); + return vq_memory_access_ok(log_base, mp, vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) && (!vq->log_used || log_access_ok(log_base, vq->log_addr, sizeof *vq->used + @@ -487,7 +496,8 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) kfree(newmem); return -EFAULT; } - oldmem = d->memory; + oldmem = rcu_dereference_protected(d->memory, + lockdep_is_held(&d->mutex)); rcu_assign_pointer(d->memory, newmem); synchronize_rcu(); kfree(oldmem); @@ -858,11 +868,12 @@ int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, if (r < 0) return r; len -= l; - if (!len) + if (!len) { + if (vq->log_ctx) + eventfd_signal(vq->log_ctx, 1); return 0; + } } - if (vq->log_ctx) - eventfd_signal(vq->log_ctx, 1); /* Length written exceeds what we have stored. This is a bug. */ BUG(); return 0; |