fe779dbb42
[ Upstream commit 15319a4e8ee4b098118591c6ccbd17237f841613 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.