1bdc85550a
The sysfs `state` attribute is not protected against race conditions.
If multiple processes perform a device state transition on the same
device in parallel, unexpected behaviors might occur.
For transitioning the device state, adf_sysfs.c calls the functions
adf_dev_init(), adf_dev_start(), adf_dev_stop() and adf_dev_shutdown()
which are unprotected and interdependent on each other. To perform a
state transition, these functions needs to be called in a specific
order:
* device up: adf_dev_init() -> adf_dev_start()
* device down: adf_dev_stop() -> adf_dev_shutdown()
This change introduces the functions adf_dev_up() and adf_dev_down()
which wrap the state machine functions and protect them with a
per-device lock. These are then used in adf_sysfs.c instead of the
individual state transition functions.
Fixes: 5ee52118ac14 ("crypto: qat - expose device state through sysfs for 4xxx")
Signed-off-by: Shashank Gupta <shashank.gupta@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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.