6aa210d27b
When ioctl debugging is turned on, the v4l_printk_ioctl() is used to log the ioctl that is called. It uses an array of ioctl information to log the ioctl name and it correctly checks for out-of-bound indexing of that array. However, the array may have holes since not all ioctl numbers are used. In that case the name of the ioctl is NULL. It is harmless (printk handles NULL pointers), but not intended. Instead use the v4l2_is_known_ioctl() function to determine if the ioctl information is available or not. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@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.