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| author | Michael S. Tsirkin <mst@redhat.com> | 2014-12-01 17:39:39 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2014-12-09 12:05:29 +0200 |
| commit | 64f7f0510c7e6f61eab080e3f51d314849f47ac1 (patch) | |
| tree | a439f647cb9e2a8737deacdd80752b743e432d7e /drivers/vhost | |
| parent | bf995734969c3ca9de9e00138151201eab4cbb01 (diff) | |
| download | linux-64f7f0510c7e6f61eab080e3f51d314849f47ac1.tar.bz2 | |
vhost: switch to __get/__put_user exclusively
Most places in vhost can use __get/__put_user rather than
get/put_user since addresses are pre-validated.
This should be good for performance, but this also
will help make code sparse-clean: get/put_user macros
don't play well with __virtioXX bitwise tags.
Switch to get/put_user to __ variants everywhere in vhost.
There's one exception - for consistency switch that
as well, and add an explicit access_ok check.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f4374442a..6a408377598a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1038,6 +1038,7 @@ static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) int vhost_init_used(struct vhost_virtqueue *vq) { + u16 last_used_idx; int r; if (!vq->private_data) return 0; @@ -1046,7 +1047,13 @@ int vhost_init_used(struct vhost_virtqueue *vq) if (r) return r; vq->signalled_used_valid = false; - return get_user(vq->last_used_idx, &vq->used->idx); + if (!access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) + return -EFAULT; + r = __get_user(last_used_idx, &vq->used->idx); + if (r) + return r; + vq->last_used_idx = last_used_idx; + return 0; } EXPORT_SYMBOL_GPL(vhost_init_used); @@ -1404,7 +1411,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, /* Make sure buffer is written before we update index. */ smp_wmb(); - if (put_user(vq->last_used_idx, &vq->used->idx)) { + if (__put_user(vq->last_used_idx, &vq->used->idx)) { vq_err(vq, "Failed to increment used idx"); return -EFAULT; } @@ -1449,7 +1456,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) if (unlikely(!v)) return true; - if (get_user(event, vhost_used_event(vq))) { + if (__get_user(event, vhost_used_event(vq))) { vq_err(vq, "Failed to get used event idx"); return true; } |