abc7da58c4
Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values. Doing this can be harmless, but
it can also cause strings to be added to init's argument or environment
list, polluting them.
Since __setup() handling and return values are not documented, first add
documentation for that. Also add more documentation for early_param()
handling and return values.
For __setup() functions, returning 0 (not handled) has questionable
value if it is just a malformed option value, as in
rodata=junk
since returning 0 would just cause "rodata=junk" to be added to init's
environment unnecessarily:
Run /sbin/init as init process
with arguments:
/sbin/init
with environment:
HOME=/
TERM=linux
splash=native
rodata=junk
Also, there are no recommendations on whether to print a warning when an
unknown parameter value is seen. I am not addressing that here.
[1] lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220221050852.1147-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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.