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d5dba32b8f
As &card->cli_queue_lock is acquired under softirq context along the
following call chain from solos_bh(), other acquisition of the same
lock inside process context should disable at least bh to avoid double
lock.
<deadlock #1>
console_show()
--> spin_lock(&card->cli_queue_lock)
<interrupt>
--> solos_bh()
--> spin_lock(&card->cli_queue_lock)
This flaw was found by an experimental static analysis tool I am
developing for irq-related deadlock.
To prevent the potential deadlock, the patch uses spin_lock_bh()
on the card->cli_queue_lock under process context code consistently
to prevent the possible deadlock scenario.
Fixes: 9c54004ea7 ("atm: Driver for Solos PCI ADSL2+ card.")
Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>