The patch titled
dmaengine: fix broken device refcounting
has been removed from the -mm tree. Its filename was
dmaengine-fix-broken-device-refcounting.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: dmaengine: fix broken device refcounting
From: Haavard Skinnemoen <[EMAIL PROTECTED]>
When a DMA device is unregistered, its reference count is decremented twice
for each channel: Once dma_class_dev_release() and once in
dma_chan_cleanup(). This may result in the DMA device driver's remove()
function completing before all channels have been cleaned up, causing lots
of use-after-free fun.
Fix it by incrementing the device's reference count twice for each
channel during registration.
[EMAIL PROTECTED]: kill unnecessary client refcounting]
Signed-off-by: Haavard Skinnemoen <[EMAIL PROTECTED]>
Signed-off-by: Dan Williams <[EMAIL PROTECTED]>
Signed-off-by: Shannon Nelson <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
drivers/dma/dmaengine.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff -puN drivers/dma/dmaengine.c~dmaengine-fix-broken-device-refcounting
drivers/dma/dmaengine.c
--- a/drivers/dma/dmaengine.c~dmaengine-fix-broken-device-refcounting
+++ a/drivers/dma/dmaengine.c
@@ -182,10 +182,9 @@ static void dma_client_chan_alloc(struct
/* we are done once this client rejects
* an available resource
*/
- if (ack == DMA_ACK) {
+ if (ack == DMA_ACK)
dma_chan_get(chan);
- kref_get(&device->refcount);
- } else if (ack == DMA_NAK)
+ else if (ack == DMA_NAK)
return;
}
}
@@ -272,11 +271,8 @@ static void dma_clients_notify_removed(s
/* client was holding resources for this channel so
* free it
*/
- if (ack == DMA_ACK) {
+ if (ack == DMA_ACK)
dma_chan_put(chan);
- kref_put(&chan->device->refcount,
- dma_async_device_cleanup);
- }
}
mutex_unlock(&dma_list_mutex);
@@ -316,11 +312,8 @@ void dma_async_client_unregister(struct
ack = client->event_callback(client, chan,
DMA_RESOURCE_REMOVED);
- if (ack == DMA_ACK) {
+ if (ack == DMA_ACK)
dma_chan_put(chan);
- kref_put(&chan->device->refcount,
- dma_async_device_cleanup);
- }
}
list_del(&client->global_node);
@@ -397,6 +390,8 @@ int dma_async_device_register(struct dma
goto err_out;
}
+ /* One for the channel, one of the class device */
+ kref_get(&device->refcount);
kref_get(&device->refcount);
kref_init(&chan->refcount);
chan->slow_ref = 0;
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
origin.patch
git-avr32.patch
git-mtd.patch
read_current_time-cleanups.patch
generic-gpio-gpio_chip-support.patch
avr32-uses-gpio_chip.patch
mcp23s08-spi-gpio-expander.patch
mcp23s08-spi-gpio-expander-checkpatch-fixes.patch
sanitize-the-type-of-struct-useru_ar0.patch
add-cmpxchg_local-to-avr32.patch
-
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