Chengfeng Ye 15319a4e8e atm: solos-pci: Fix potential deadlock on &tx_queue_lock
As &card->tx_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 #2>
pclose()
--> spin_lock(&card->tx_queue_lock)
<interrupt>
   --> solos_bh()
   --> fpga_tx()
   --> spin_lock(&card->tx_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 &card->tx_queue_lock under process context code consistently to
prevent the possible deadlock scenario.

Fixes: 213e85d38912 ("solos-pci: clean up pclose() function")
Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-09 21:17:45 +00:00
..
2022-03-15 11:01:52 +00:00
2015-01-18 00:28:41 -05:00
2021-03-15 12:43:10 -07:00
2021-05-21 13:55:32 -07:00