https://github.com/torvalds/linux
Revision 537d59af73d894750cff14f90fe2b6d77fbab15b authored by Dave Young on 02 June 2008, 06:50:52 UTC, committed by David S. Miller on 03 June 2008, 21:27:17 UTC
There's logic in __rfcomm_dlc_close: rfcomm_dlc_lock(d); d->state = BT_CLOSED; d->state_changed(d, err); rfcomm_dlc_unlock(d); In rfcomm_dev_state_change, it's possible that rfcomm_dev_put try to take the dlc lock, then we will deadlock. Here fixed it by unlock dlc before rfcomm_dev_get in rfcomm_dev_state_change. why not unlock just before rfcomm_dev_put? it's because there's another problem. rfcomm_dev_get/rfcomm_dev_del will take rfcomm_dev_lock, but in rfcomm_dev_add the lock order is : rfcomm_dev_lock --> dlc lock so I unlock dlc before the taken of rfcomm_dev_lock. Actually it's a regression caused by commit 1905f6c736cb618e07eca0c96e60e3c024023428 ("bluetooth : __rfcomm_dlc_close lock fix"), the dlc state_change could be two callbacks : rfcomm_sk_state_change and rfcomm_dev_state_change. I missed the rfcomm_sk_state_change that time. Thanks Arjan van de Ven <arjan@linux.intel.com> for the effort in commit 4c8411f8c115def968820a4df6658ccfd55d7f1a ("bluetooth: fix locking bug in the rfcomm socket cleanup handling") but he missed the rfcomm_dev_state_change lock issue. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Tip revision: 537d59af73d894750cff14f90fe2b6d77fbab15b authored by Dave Young on 02 June 2008, 06:50:52 UTC
bluetooth: rfcomm_dev_state_change deadlock fix
bluetooth: rfcomm_dev_state_change deadlock fix
Tip revision: 537d59a
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arch | ||
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crypto | ||
drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
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security | ||
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usr | ||
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.gitignore | -rw-r--r-- | 686 bytes |
.mailmap | -rw-r--r-- | 3.6 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 90.5 KB |
Kbuild | -rw-r--r-- | 2.4 KB |
MAINTAINERS | -rw-r--r-- | 98.3 KB |
Makefile | -rw-r--r-- | 53.8 KB |
README | -rw-r--r-- | 16.5 KB |
REPORTING-BUGS | -rw-r--r-- | 3.1 KB |
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