diff options
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 7cd55e07879..49fa953aaf6 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -22,6 +22,7 @@ #include <linux/poll.h> #include <linux/file.h> #include <linux/highmem.h> +#include <linux/slab.h> #include <linux/net.h> #include <linux/if_packet.h> @@ -235,6 +236,10 @@ static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem, int log_all) { int i; + + if (!mem) + return 0; + for (i = 0; i < mem->nregions; ++i) { struct vhost_memory_region *m = mem->regions + i; unsigned long a = m->userspace_addr; @@ -476,8 +481,10 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) if (r < 0) break; eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); - if (IS_ERR(eventfp)) - return PTR_ERR(eventfp); + if (IS_ERR(eventfp)) { + r = PTR_ERR(eventfp); + break; + } if (eventfp != vq->kick) { pollstop = filep = vq->kick; pollstart = vq->kick = eventfp; @@ -489,8 +496,10 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) if (r < 0) break; eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); - if (IS_ERR(eventfp)) - return PTR_ERR(eventfp); + if (IS_ERR(eventfp)) { + r = PTR_ERR(eventfp); + break; + } if (eventfp != vq->call) { filep = vq->call; ctx = vq->call_ctx; @@ -505,8 +514,10 @@ static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp) if (r < 0) break; eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); - if (IS_ERR(eventfp)) - return PTR_ERR(eventfp); + if (IS_ERR(eventfp)) { + r = PTR_ERR(eventfp); + break; + } if (eventfp != vq->error) { filep = vq->error; vq->error = eventfp; @@ -1024,7 +1035,12 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) /* This actually signals the guest, using eventfd. */ void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) { - __u16 flags = 0; + __u16 flags; + /* Flush out used index updates. This is paired + * with the barrier that the Guest executes when enabling + * interrupts. */ + smp_mb(); + if (get_user(flags, &vq->avail->flags)) { vq_err(vq, "Failed to get flags"); return; |