History log of /linux-master/usr/gen_init_cpio.c
Revision Date Author Comments
# b2441318 01-Nov-2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

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>

# c725ee54 12-Nov-2013 Michal Nazarewicz <mina86@mina86.com>

gen_init_cpio: avoid NULL pointer dereference and rework env expanding

getenv() may return NULL if given environment variable does not exist
which leads to NULL dereference when calling strncat.

Besides that, the environment variable name was copied to a temporary
env_var buffer, but this copying can be avoided by simply using the input

Lastly, the whole loop can be greatly simplified by using the snprintf
function instead of the playing with strncat.

By the way, the current implementation allows a recursive variable
expansion, as in:

$ echo 'out ${A} out ' | A='a ${B} a' B=b /tmp/a
out a b a out

I'm assuming this is just a side effect and not a conscious decision
(especially as this may lead to infinite loop), but I didn't want to
change this behaviour without consulting.

If the current behaviour is deamed incorrect, I'll be happy to send
a patch without recursive processing.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jesper Juhl <jj@codesealer.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

# 59dbaf04 26-Sep-2008 Jesper Juhl <jj@chaosbits.net>

gen_init_cpio: remove redundant empty line

Just a completely trivial patch to remove a completely redundant blank
line from usr/gen_init_cpio.c

Signed-off-by: Jesper Juhl <jj@codesealer.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

# 20f1de65 25-Oct-2012 Kees Cook <keescook@chromium.org>

gen_init_cpio: avoid stack overflow when expanding

Fix possible overflow of the buffer used for expanding environment
variables when building file list.

In the extremely unlikely case of an attacker having control over the
environment variables visible to gen_init_cpio, control over the
contents of the file gen_init_cpio parses, and gen_init_cpio was built
without compiler hardening, the attacker can gain arbitrary execution
control via a stack buffer overflow.

$ cat usr/crash.list
file foo ${BIG}${BIG}${BIG}${BIG}${BIG}${BIG} 0755 0 0
$ BIG=$(perl -e 'print "A" x 4096;') ./usr/gen_init_cpio usr/crash.list
*** buffer overflow detected ***: ./usr/gen_init_cpio terminated

This also replaces the space-indenting with tabs.

Patch based on existing fix extracted from grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: PaX Team <pageexec@freemail.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

# a8b8017c 31-Mar-2011 Michal Marek <mmarek@suse.cz>

initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries

gen_init_cpio gets the current time and uses it for each symlink,
special file, and directory. Grab the current time once and make it
possible to override it with the KBUILD_BUILD_TIMESTAMP variable for
reproducible builds.

Signed-off-by: Michal Marek <mmarek@suse.cz>

# a3c888fc 05-Jan-2011 Andrew Morton <akpm@linux-foundation.org>

gen_init_cpio: checkpatch fixes

Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

# 96aebafa 24-Dec-2010 Jesper Juhl <jj@chaosbits.net>

gen_init_cpio: Avoid race between call to stat() and call to open()

In usr/gen_init_cpio.c::cpio_mkfile() a call to stat() is made based on
pathname, subsequently the file is open()'ed and then the value of the
initial stat() call is used to allocate a buffer. This is not safe since
the file may change between the call to stat() and the call to open().
Safer to just open() the file and then do fstat() using the filedescriptor
returned by open.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

# 43f901fb 06-Oct-2010 Thomas Chou <thomas@wytron.com.tw>

gen_init_cpio: remove leading `/' from file names

When we extracted the generated cpio archive using "cpio -id" command,
it complained,

cpio: Removing leading `/' from member names
cpio: Removing leading `/' from member names
cpio: Removing leading `/' from member names

It is worse with the latest "cpio" or "pax", which tries to overwrite
the host file system with the leading '/'.

So the leading '/' of file names should be removed. This is consistent
with the initramfs come with major distributions such as Fedora or
Debian, etc.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Mike Frysinger<vapier@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

# 6d87fea4 09-Dec-2009 Mike Frysinger <vapier@gentoo.org>

gen_init_cpio: fixed fwrite warning

On compilers with security warnings enabled by default, we get:

usr/gen_init_cpio.c: In function ‘cpio_mkfile’:
usr/gen_init_cpio.c:357: warning: ignoring return value of ‘fwrite’,
declared with attribute warn_unused_result

So check the return value and handle errors accordingly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

# 5c725138 22-Sep-2009 Trevor Keith <tsrk@tsrk.net>

Fix all -Wmissing-prototypes warnings in x86 defconfig

Signed-off-by: Trevor Keith <tsrk@tsrk.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

# 3b1ec9fb 29-Oct-2008 Sally, Gene <Gene.Sally@timesys.com>

kbuild: gen_init_cpio expands shell variables in file names

Modify gen_init_cpio so that lines that specify files can contain
what looks like a shell variable that's expanded during processing.

For example:

file /sbin/kinit ${RFS_BASE}/usr/src/klibc/kinit/kinit 0755 0 0

given RFS_BASE is "/some/directory" in the environment

would be expanded to

file /sbin/kinit /some/directory/usr/src/klibc/kinit/kinit 0755 0 0

If several environment variables appear in a line, they are all expanded
with processing happening from left to right.
Undefined variables expand to a null string.
Syntax errors stop processing, letting the existing error handling
show the user offending line.

This patch helps embedded folks who frequently create several
RFS directories and then switch between them as they're tuning
an initramfs.

Signed-off-by: gene.sally@timesys.com
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

# f2434ec1 10-May-2007 Mike Frysinger <vapier@gentoo.org>

kbuild: add support for reading stdin with gen_init_cpio

Treat an argument of "-" as meaning "read stdin for cpio files" so
gen_init_cpio can be piped into.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

# 24fa5096 10-Feb-2007 Luciano Rocha <strange@nsk.no-ip.org>

[PATCH] usr/gen_init_cpio.c: support for hard links

Extend usr/gen_init_cpio.c "file" entry, adding support for hard links.

Previous format:
file <name> <location> <mode> <uid> <gid>

New format:
file <name> <location> <mode> <uid> <gid> [<hard links>]

The hard links specification is optional, keeping the previous

All hard links are defined sequentially in the resulting cpio and the
file data is present only in the last link. This is the behaviour of
GNU's cpio and is supported by the kernel initramfs extractor.

Signed-off-by: Luciano Rocha <strange@nsk.no-ip.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

# aa1e816f 18-Apr-2006 Jesper Juhl <jesper.juhl@gmail.com>

[PATCH] Fix potential NULL pointer deref in gen_init_cpio

Fix potential NULL pointer deref in gen_init_cpio.c spotted by coverity
checker. This fixes coverity bug #86

Without this patch we risk dereferencing a NULL `type' in the
"if ('\n' == *type) {" line.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

# 1da177e4 16-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org>


Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!