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| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2011-05-16 13:09:08 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-06-03 10:34:26 +0900 |
| commit | a66ccccb5525a5606a2000066889a71e0c8a9867 (patch) | |
| tree | 700d578d287983c739de0beb2df746ebccc5d3ca | |
| parent | b8f653f794ec459132a903c7b7d6aa40bbe5c2a1 (diff) | |
| download | lwn-a66ccccb5525a5606a2000066889a71e0c8a9867.tar.gz lwn-a66ccccb5525a5606a2000066889a71e0c8a9867.zip | |
xhci: Fix memory leak in ring cache deallocation.
commit 30f89ca021c3e584b61bc5a14eede89f74b2e826 upstream.
When an endpoint ring is freed, it is either cached in a per-device ring
cache, or simply freed if the ring cache is full. If the ring was added
to the cache, then virt_dev->num_rings_cached is incremented. The cache
is designed to hold up to 31 endpoint rings, in array indexes 0 to 30.
When the device is freed (when the slot was disabled),
xhci_free_virt_device() is called, it would free the cached rings in
array indexes 0 to virt_dev->num_rings_cached.
Unfortunately, the original code in xhci_free_or_cache_endpoint_ring()
would put the first entry into the ring cache in array index 1, instead of
array index 0. This was caused by the second assignment to rings_cached:
rings_cached = virt_dev->num_rings_cached;
if (rings_cached < XHCI_MAX_RINGS_CACHED) {
virt_dev->num_rings_cached++;
rings_cached = virt_dev->num_rings_cached;
virt_dev->ring_cache[rings_cached] =
virt_dev->eps[ep_index].ring;
This meant that when the device was freed, cached rings with indexes 0 to
N would be freed, and the last cached ring in index N+1 would not be
freed. When the driver was unloaded, this caused interesting messages
like:
xhci_hcd 0000:06:00.0: dma_pool_destroy xHCI ring segments, ffff880063040000 busy
This should be queued to stable kernels back to 2.6.33.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/host/xhci-mem.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 217299869887..175434ddc216 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -207,14 +207,13 @@ void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci, rings_cached = virt_dev->num_rings_cached; if (rings_cached < XHCI_MAX_RINGS_CACHED) { - virt_dev->num_rings_cached++; - rings_cached = virt_dev->num_rings_cached; virt_dev->ring_cache[rings_cached] = virt_dev->eps[ep_index].ring; + virt_dev->num_rings_cached++; xhci_dbg(xhci, "Cached old ring, " "%d ring%s cached\n", - rings_cached, - (rings_cached > 1) ? "s" : ""); + virt_dev->num_rings_cached, + (virt_dev->num_rings_cached > 1) ? "s" : ""); } else { xhci_ring_free(xhci, virt_dev->eps[ep_index].ring); xhci_dbg(xhci, "Ring cache full (%d rings), " |