From: davidriley@chromium.org To: dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Cc: David Airlie <airlied@linux.ie>, Gerd Hoffmann <kraxel@redhat.com>, Daniel Vetter <daniel@ffwll.ch>, linux-kernel@vger.kernel.org, David Riley <davidriley@chromium.org> Subject: [PATCH 4/4] drm/virtio: Add memory barriers for capset cache. Date: Wed, 5 Jun 2019 16:44:23 -0700 [thread overview] Message-ID: <20190605234423.11348-4-davidriley@chromium.org> (raw) In-Reply-To: <20190605234423.11348-1-davidriley@chromium.org> From: David Riley <davidriley@chromium.org> After data is copied to the cache entry, atomic_set is used indicate that the data is the entry is valid without appropriate memory barriers. Similarly the read side was missing the same memory barries. Signed-off-by: David Riley <davidriley@chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +++ drivers/gpu/drm/virtio/virtgpu_vq.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 88c1ed57a3c5..502f5f7c2298 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -542,6 +542,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, if (!ret) return -EBUSY; + /* is_valid check must proceed before copy of the cache entry. */ + virt_rmb(); + ptr = cache_ent->caps_cache; if (copy_to_user((void __user *)(unsigned long)args->addr, ptr, size)) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index dd5ead2541c2..b974eba4fe7d 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -583,6 +583,8 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev, cache_ent->id == le32_to_cpu(cmd->capset_id)) { memcpy(cache_ent->caps_cache, resp->capset_data, cache_ent->size); + /* Copy must occur before is_valid is signalled. */ + virt_wmb(); atomic_set(&cache_ent->is_valid, 1); break; } -- 2.22.0.rc1.311.g5d7573a151-goog
WARNING: multiple messages have this Message-ID (diff)
From: davidriley@chromium.org To: dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Cc: David Airlie <airlied@linux.ie>, Gerd Hoffmann <kraxel@redhat.com>, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] drm/virtio: Add memory barriers for capset cache. Date: Wed, 5 Jun 2019 16:44:23 -0700 [thread overview] Message-ID: <20190605234423.11348-4-davidriley@chromium.org> (raw) In-Reply-To: <20190605234423.11348-1-davidriley@chromium.org> From: David Riley <davidriley@chromium.org> After data is copied to the cache entry, atomic_set is used indicate that the data is the entry is valid without appropriate memory barriers. Similarly the read side was missing the same memory barries. Signed-off-by: David Riley <davidriley@chromium.org> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 +++ drivers/gpu/drm/virtio/virtgpu_vq.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 88c1ed57a3c5..502f5f7c2298 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -542,6 +542,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, if (!ret) return -EBUSY; + /* is_valid check must proceed before copy of the cache entry. */ + virt_rmb(); + ptr = cache_ent->caps_cache; if (copy_to_user((void __user *)(unsigned long)args->addr, ptr, size)) diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index dd5ead2541c2..b974eba4fe7d 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -583,6 +583,8 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev, cache_ent->id == le32_to_cpu(cmd->capset_id)) { memcpy(cache_ent->caps_cache, resp->capset_data, cache_ent->size); + /* Copy must occur before is_valid is signalled. */ + virt_wmb(); atomic_set(&cache_ent->is_valid, 1); break; } -- 2.22.0.rc1.311.g5d7573a151-goog _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2019-06-05 23:44 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-05 23:44 [PATCH 1/4] drm/virtio: Ensure cached capset entries are valid before copying davidriley 2019-06-05 23:44 ` davidriley 2019-06-05 23:44 ` [PATCH 2/4] drm/virtio: Wake up all waiters when capset response comes in davidriley 2019-06-05 23:44 ` davidriley 2019-06-05 23:44 ` [PATCH 3/4] drm/virtio: Fix cache entry creation race davidriley 2019-06-05 23:44 ` davidriley 2019-06-05 23:44 ` davidriley [this message] 2019-06-05 23:44 ` [PATCH 4/4] drm/virtio: Add memory barriers for capset cache davidriley 2019-06-06 7:41 ` Gerd Hoffmann 2019-06-06 7:41 ` Gerd Hoffmann 2019-06-05 23:44 ` davidriley 2019-06-10 21:18 ` [PATCH v2 0/4] drm/virtio: Ensure cached capset entries are valid before copying davidriley 2019-06-10 21:18 ` davidriley 2019-06-10 21:18 ` [PATCH v2 1/4] " davidriley 2019-06-10 21:18 ` davidriley 2019-06-10 21:18 ` [PATCH v2 2/4] drm/virtio: Wake up all waiters when capset response comes in davidriley 2019-06-10 21:18 ` davidriley 2019-06-10 21:18 ` [PATCH v2 3/4] drm/virtio: Fix cache entry creation race davidriley 2019-06-10 21:18 ` davidriley 2019-06-10 21:18 ` [PATCH v2 4/4] drm/virtio: Add memory barriers for capset cache davidriley 2019-06-13 6:59 ` Gerd Hoffmann 2019-06-13 6:59 ` Gerd Hoffmann 2019-06-13 6:59 ` Gerd Hoffmann 2019-06-10 21:18 ` davidriley
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