linux/arch/um/Kconfig.char
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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# SPDX-License-Identifier: GPL-2.0
menu "UML Character Devices"
config STDERR_CONSOLE
bool "stderr console"
default y
help
console driver which dumps all printk messages to stderr.
config SSL
bool "Virtual serial line"
help
The User-Mode Linux environment allows you to create virtual serial
lines on the UML that are usually made to show up on the host as
ttys or ptys.
See <http://user-mode-linux.sourceforge.net/old/input.html> for more
information and command line examples of how to use this facility.
Unless you have a specific reason for disabling this, say Y.
config NULL_CHAN
bool "null channel support"
help
This option enables support for attaching UML consoles and serial
lines to a device similar to /dev/null. Data written to it disappears
and there is never any data to be read.
config PORT_CHAN
bool "port channel support"
help
This option enables support for attaching UML consoles and serial
lines to host portals. They may be accessed with 'telnet <host>
<port number>'. Any number of consoles and serial lines may be
attached to a single portal, although what UML device you get when
you telnet to that portal will be unpredictable.
It is safe to say 'Y' here.
config PTY_CHAN
bool "pty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host pseudo-terminals. Access to both traditional
pseudo-terminals (/dev/pty*) and pts pseudo-terminals are controlled
with this option. The assignment of UML devices to host devices
will be announced in the kernel message log.
It is safe to say 'Y' here.
config TTY_CHAN
bool "tty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host terminals. Access to both virtual consoles
(/dev/tty*) and the slave side of pseudo-terminals (/dev/ttyp* and
/dev/pts/*) are controlled by this option.
It is safe to say 'Y' here.
config XTERM_CHAN
bool "xterm channel support"
help
This option enables support for attaching UML consoles and serial
lines to xterms. Each UML device so assigned will be brought up in
its own xterm.
It is safe to say 'Y' here.
config NOCONFIG_CHAN
bool
default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN)
config CON_ZERO_CHAN
string "Default main console channel initialization"
default "fd:0,fd:1"
help
This is the string describing the channel to which the main console
will be attached by default. This value can be overridden from the
command line. The default value is "fd:0,fd:1", which attaches the
main console to stdin and stdout.
It is safe to leave this unchanged.
config CON_CHAN
string "Default console channel initialization"
default "xterm"
help
This is the string describing the channel to which all consoles
except the main console will be attached by default. This value can
be overridden from the command line. The default value is "xterm",
which brings them up in xterms.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have X or xterm available.
config SSL_CHAN
string "Default serial line channel initialization"
default "pty"
help
This is the string describing the channel to which the serial lines
will be attached by default. This value can be overridden from the
command line. The default value is "pty", which attaches them to
traditional pseudo-terminals.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have a set of /dev/pty* devices.
config UML_SOUND
tristate "Sound support"
help
This option enables UML sound support. If enabled, it will pull in
soundcore and the UML hostaudio relay, which acts as a intermediary
between the host's dsp and mixer devices and the UML sound system.
It is safe to say 'Y' here.
config SOUND
tristate
default UML_SOUND
config SOUND_OSS_CORE
bool
default UML_SOUND
config HOSTAUDIO
tristate
default UML_SOUND
endmenu