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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>
hifive-unleashed-5.1
Dan Williams 2009-03-25 09:13:23 -07:00
parent 041b62374c
commit 257b17ca03
1 changed files with 39 additions and 12 deletions
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51
drivers/dma/dmaengine.c
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@ -602,6 +602,24 @@ void dmaengine_put(void)
}
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 @@ int dma_async_device_register(struct dma_device *device)
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 @@ int dma_async_device_register(struct dma_device *device)
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 @@ int dma_async_device_register(struct dma_device *device)
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;