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| author | Matt Evans <matt@ozlabs.org> | 2011-03-29 13:40:56 +1100 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2011-05-02 16:42:50 -0700 |
| commit | 7ed603ecf8b68ab81f4c83097d3063d43ec73bb8 (patch) | |
| tree | 3eed33c09dda5e98e79692e69a1270d48a6f8299 /drivers | |
| parent | 92a3da410aac6e14daaefe13c60368ca28e85830 (diff) | |
| download | kernel_samsung_smdk4412-7ed603ecf8b68ab81f4c83097d3063d43ec73bb8.zip kernel_samsung_smdk4412-7ed603ecf8b68ab81f4c83097d3063d43ec73bb8.tar.gz kernel_samsung_smdk4412-7ed603ecf8b68ab81f4c83097d3063d43ec73bb8.tar.bz2 | |
xhci: Add an assertion to check for virt_dev=0 bug.
During a "plug-unplug" stress test on an NEC xHCI card, a null pointer
dereference was observed. xhci_address_device() dereferenced a null
virt_dev (possibly an erroneous udev->slot_id?); this patch adds a WARN_ON &
message to aid debug if it can be recreated.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/xhci.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index e8ab189..5c0ae90 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -2546,6 +2546,17 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev) virt_dev = xhci->devs[udev->slot_id]; + if (WARN_ON(!virt_dev)) { + /* + * In plug/unplug torture test with an NEC controller, + * a zero-dereference was observed once due to virt_dev = 0. + * Print useful debug rather than crash if it is observed again! + */ + xhci_warn(xhci, "Virt dev invalid for slot_id 0x%x!\n", + udev->slot_id); + return -EINVAL; + } + slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx); /* * If this is the first Set Address since device plug-in or |