Messages in this thread Patch in this message |  | | | From | "Paul E. McKenney" <> | | Subject | [PATCH RFC tip/core/rcu 23/23] vhost: add __rcu annotations | | Date | Wed, 12 May 2010 14:33:42 -0700 |
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From: Arnd Bergmann <arnd@relay.de.ibm.com>
Also add rcu_dreference_protected() for code paths where locks are held.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> --- drivers/vhost/net.c | 11 ++++++++--- drivers/vhost/vhost.c | 14 ++++++++------ drivers/vhost/vhost.h | 4 ++-- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 9777583..945c5cb 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -364,7 +364,10 @@ static void vhost_net_disable_vq(struct vhost_net *n, static void vhost_net_enable_vq(struct vhost_net *n, struct vhost_virtqueue *vq) { - struct socket *sock = vq->private_data; + struct socket *sock; + + sock = rcu_dereference_protected(vq->private_data, + lockdep_is_held(&vq->mutex)); if (!sock) return; if (vq == n->vqs + VHOST_NET_VQ_TX) { @@ -380,7 +383,8 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct socket *sock; mutex_lock(&vq->mutex); - sock = vq->private_data; + sock = rcu_dereference_protected(vq->private_data, + lockdep_is_held(&vq->mutex)); vhost_net_disable_vq(n, vq); rcu_assign_pointer(vq->private_data, NULL); mutex_unlock(&vq->mutex); @@ -518,7 +522,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } /* start polling new socket */ - oldsock = vq->private_data; + oldsock = rcu_dereference_protected(vq->private_data, + lockdep_is_held(&vq->mutex)); if (sock == oldsock) goto done; diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index e69d238..fc0c077 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -180,7 +180,7 @@ 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; } @@ -212,8 +212,9 @@ 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; @@ -294,14 +295,14 @@ 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); + return memory_access_ok(dev, rcu_dereference_protected(dev->memory, lockdep_is_held(&dev->mutex)), 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, + return vq_memory_access_ok(log_base, rcu_dereference_protected(vq->dev->memory, lockdep_is_held(&dev->mutex)), vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) && (!vq->log_used || log_access_ok(log_base, vq->log_addr, sizeof *vq->used + @@ -342,7 +343,8 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) if (!memory_access_ok(d, newmem, vhost_has_feature(d, VHOST_F_LOG_ALL))) 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); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 44591ba..240396c 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -92,7 +92,7 @@ struct vhost_virtqueue { * work item execution acts instead of rcu_read_lock() and the end of * work item execution acts instead of rcu_read_lock(). * Writers use virtqueue mutex. */ - void *private_data; + void __rcu *private_data; /* Log write descriptors */ void __user *log_base; struct vhost_log log[VHOST_NET_MAX_SG]; @@ -102,7 +102,7 @@ struct vhost_dev { /* Readers use RCU to access memory table pointer * log base pointer and features. * Writers use mutex below.*/ - struct vhost_memory *memory; + struct vhost_memory __rcu *memory; struct mm_struct *mm; struct mutex mutex; unsigned acked_features; -- 1.7.0.6
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