Skip to main content

Browse the archive

Revision 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 authored by Fabio M. De Francesco on 23 February 2022, 10:02:52 UTC, committed by Jakub Kicinski on 24 February 2022, 17:09:33 UTC 
net/smc: Use a mutex for locking "struct smc_pnettable"
 
smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib()
which, in turn, calls mutex_lock(&smc_ib_devices.mutex).

read_lock() disables preemption. Therefore, the code acquires a mutex while in
atomic context and it leads to a SAC bug.

Fix this bug by replacing the rwlock with a mutex.

Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support")
Confirmed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent e13ad14
Raw File
vexpress.rst 
Kernel driver vexpress
======================

Supported systems:

  * ARM Ltd. Versatile Express platform

    Prefix: 'vexpress'

    Datasheets:

      * "Hardware Description" sections of the Technical Reference Manuals
	for the Versatile Express boards:

	- http://infocenter.arm.com/help/topic/com.arm.doc.subset.boards.express/index.html

      * Section "4.4.14. System Configuration registers" of the V2M-P1 TRM:

	- http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0447-/index.html

Author: Pawel Moll

Description
-----------

Versatile Express platform (http://www.arm.com/versatileexpress/) is a
reference & prototyping system for ARM Ltd. processors. It can be set up
from a wide range of boards, each of them containing (apart of the main
chip/FPGA) a number of microcontrollers responsible for platform
configuration and control. Theses microcontrollers can also monitor the
board and its environment by a number of internal and external sensors,
providing information about power lines voltages and currents, board
temperature and power usage. Some of them also calculate consumed energy
and provide a cumulative use counter.

The configuration devices are _not_ memory mapped and must be accessed
via a custom interface, abstracted by the "vexpress_config" API.

As these devices are non-discoverable, they must be described in a Device
Tree passed to the kernel. Details of the DT binding for them can be found
in Documentation/devicetree/bindings/hwmon/vexpress.txt.
back to top