dmaengine: fail device registration if channel registration fails
Atsushi points out:
"If alloc_percpu or kzalloc failed, chan_id does not match with its
position in device->channels list.
And above "continue" looks buggy anyway. Keeping incomplete channels
in device->channels list looks very dangerous..."
Also, fix up leakage of idr_ref in the idr_pre_get() and channel init
fail cases.
Reported-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 280a9d2..49243d1 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -602,6 +602,24 @@
}
EXPORT_SYMBOL(dmaengine_put);
+static int get_dma_id(struct dma_device *device)
+{
+ int rc;
+
+ idr_retry:
+ if (!idr_pre_get(&dma_idr, GFP_KERNEL))
+ return -ENOMEM;
+ mutex_lock(&dma_list_mutex);
+ rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
+ mutex_unlock(&dma_list_mutex);
+ if (rc == -EAGAIN)
+ goto idr_retry;
+ else if (rc != 0)
+ return rc;
+
+ return 0;
+}
+
/**
* dma_async_device_register - registers DMA devices found
* @device: &dma_device
@@ -640,27 +658,25 @@
idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
if (!idr_ref)
return -ENOMEM;
- atomic_set(idr_ref, 0);
- idr_retry:
- if (!idr_pre_get(&dma_idr, GFP_KERNEL))
- return -ENOMEM;
- mutex_lock(&dma_list_mutex);
- rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
- mutex_unlock(&dma_list_mutex);
- if (rc == -EAGAIN)
- goto idr_retry;
- else if (rc != 0)
+ rc = get_dma_id(device);
+ if (rc != 0) {
+ kfree(idr_ref);
return rc;
+ }
+
+ atomic_set(idr_ref, 0);
/* represent channels in sysfs. Probably want devs too */
list_for_each_entry(chan, &device->channels, device_node) {
+ rc = -ENOMEM;
chan->local = alloc_percpu(typeof(*chan->local));
if (chan->local == NULL)
- continue;
+ goto err_out;
chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
if (chan->dev == NULL) {
free_percpu(chan->local);
- continue;
+ chan->local = NULL;
+ goto err_out;
}
chan->chan_id = chancnt++;
@@ -677,6 +693,8 @@
if (rc) {
free_percpu(chan->local);
chan->local = NULL;
+ kfree(chan->dev);
+ atomic_dec(idr_ref);
goto err_out;
}
chan->client_count = 0;
@@ -707,6 +725,15 @@
return 0;
err_out:
+ /* if we never registered a channel just release the idr */
+ if (atomic_read(idr_ref) == 0) {
+ mutex_lock(&dma_list_mutex);
+ idr_remove(&dma_idr, device->dev_id);
+ mutex_unlock(&dma_list_mutex);
+ kfree(idr_ref);
+ return rc;
+ }
+
list_for_each_entry(chan, &device->channels, device_node) {
if (chan->local == NULL)
continue;